ARTICLES ON TEXTILE FIBER, YARN, FABRIC, DYEING AND GARMENTS PRODUCTION

Procedure For Management Review in Garments

2013-06-07T23:27:00.002+06:00

Objective

To ensure that all relevant information regarding the operation of the quality management system is conveyed to executive management, so that appropriate decisions can be made concerning the effectiveness and suitability of the system.

Scope

This procedure applies to the review conducted by the top management of Muazuddin Textile to check effectiveness of the quality system.

Responsibility

The Management Representative is responsible for directing the organizational aspects of this procedure. Other responsibilities are as indicated.

Procedure

4.1 Management review meetings are held quarterly till certification after that twice a year.

4.2 The following personnel participate in the meeting:

• Managing Director

• Factory Manager

• Management Representative

• Production Manager

• QC Manager

• Any other people requested by committee members

4.3 Meetings are chaired by the Managing Director or Factory Manager.

4.4 The meeting agenda includes:

• Business arising from the last meeting

• Review of Quality Policy & Quality objectives

• Customer feedback & Customer Complaint

• Process performance & product conformity

• Corrective & preventive action requests

• Results of internal audits

• Resource requirements

• Any other matter relating to the quality management system

4.5 The meeting agenda is distributed to all participants, at least two days prior to the meeting date, via Notification of Management Review (MR/3/05).

4.6 Minutes of the meeting are recorded and distributed to participants within five days of the meeting – Management Review Minutes (MR/3/06).

4.7 The progress of actions arising from the review is monitored to ensure effective implementation.

5.0 Related Documents

Notification Management Review MR/3/05

Management Review MR/3/06

Internal Quality Audit of Garments

2013-06-07T23:21:00.002+06:00

Objective

To ensure that each department works according to the Quality Management System.

Scope

This procedure applies to all internal audit activities within the departments participating in the quality system.
Responsibility

The MR of Muazzuddin Texttile Limited is responsible for the preparation of audit schedules and selecting independent auditors for all departments. The Auditor is responsible for audit and follow up procedures.
Procedure

4.1.1 All departments will be audited at least once in a year. Audits of any or all departments may be carried out more frequently on the advice of Chief Executive /Management Representative or as a result of previous audits.

4.1.2 MR of the organization with his coordinator prepares the Internal Quality Audit Schedule on yearly basis which contains the audit dates and name of the auditors. The schedule is presented to all department Heads.

4.1.3 In case of any change Internal Quality Audit Schedule MR/3/09 may be revised and reissued.

4.1 Audit

4.2.1 Auditor/audit team perform audit, conducts opening meeting with auditee/ departmental head and note down audit results.

4.2.2 Detail of persons interviewed, documents checked and other audit activities are recorded on Audit Activity Log, MR/3/10.

4.2.3 Any nonconformity found during the audit is reported on Nonconformity Report, MR/3/11. Department heads will decide on corrective action and target dated.

4.2.4 For each audit, an Audit Summary Report, MR/3/12 is prepared.

4.2.5 The non conformities are discussed with the auditee in a closing session after conducting the audit and copy of the non-conformity reports are also presented to the auditee on the same day. The auditor prompts the auditee for review of the non conformities raised and agrees on the corrective action and target date suggested by the auditee.

4.2.6 In case of disagreement over a non conformity between Auditors and Auditee, the issue is finally resolved by the Management Representative.

4.2.7 Copy of Audit Summary Report may be provided to the Auditee while original is retained by MR.

4.2.8 In case of second party audit the same procedure is adapted and same reports are used.

4.3 Follow up:

4.3.1 Follow up audit is conducted either by the auditor who conducted the first audit or by other independent auditor assigned by MR, thereby closing NC forms by target dates as stated in.

4.3.2 If in the follow up audit it is observed that action taken on any nonconformity is not effective or not taken then a Corrective & Preventative Action Form, MR/3/07 is raised.

4.3.3 For statistical purposes as an aid to improvement, the Audit Statistics Report, MR/3/13 is completed for each audit.

4.4 Second Party Audit

4.4.1 The second party audits are done by the consultant or any approved source, which is independent of the activities of the organization. The records are maintained as per this procedure.

4.4.2 The Management Representative is responsible for the follow up.

5.0 Related Documents

Internal Quality Audit Schedule (MR/3/09)

Audit Activity Log (MR/3/10)

Non Conformity Report (MR/3/11)

Audit Summary Report (MR/3/12)

Audit Statistics Report (MR/3/13)

CPA Request Form (MR/3/07)

Corrective and Preventive Actions for garments

2013-06-03T03:10:00.001+06:00

1.0 Objective

This procedure outlines the requirements of taking appropriate Corrective and Preventive Actions against non-conformance or the potential non conformance in order to avoid or prevent the reoccurrence of non-conformity.

2.0 Scope

This procedure is applicable to all functions in the company who can suggest and implement corrective and preventive actions for continual improvement in the quality management system.

3.0 Responsibilities

◊ The Management Representative has responsibility for directing the activities of this procedure.

◊ All company personnel are encouraged to identify and bring into the notice of their supervisor an area for improvement in the quality management system.

◊ The section in-charge or departmental head can initiate the corrective and preventive action by filling in the Corrective / Preventive Action Request (CPAR) describing the unsatisfactory condition or the improvement suggestion.

4.0 Procedure

4.1 Improvement

All company personnel are encouraged to identify opportunities for improvement in the quality management system related to his work function. The improvements may be identified in the following manner:

a) Progressive up-grading the quality objectives on routine basis

b) Performance improvements

c) Initiating corrective actions on recurrent problems

d) Initiating preventive actions on potential non-conformities

e) Giving suggestions for improvement

f) Quality Circles

4.2 Initiating Corrective Actions

Corrective actions are taken to eliminate the causes of non-conformities to prevent their recurrence. Corrective Actions may be initiated in the following cases:

: Identification of major product non-conformity or recurrent problems

: Any non-compliance identified during follow up internal quality audit

: Customer feedback including customer complaints

: Non-conforming deliveries from suppliers

4.3 Requesting and Processing CAR’s

Corrective actions can be initiated by any person in the company by reporting it to his section in-charge or departmental head. The concerned section in-charge or departmental head fills in the Corrective / Preventive Action Request (CPAR). The request contains a description of the unsatisfactory condition that needs to be corrected and are addressed to the manager who is responsible for the area where condition occurred.

The CPAR is sent to MR, who reviews the corrective action with concerned departmental head. After approval by departmental head, the responsible person and target date for implementing the corrective actions are assigned then the corrective action listed into Corrective Action Log.

The responsible person investigates the causes of the problem that initiated the request. The investigation process includes:

: Interviewing the concerned persons and gathering their views about the possible causes of non-conformities.

: Observing and examining the concerned processes and related records.

: Examining the supplier and his supplies, where required.

: If appropriate, make use of statistical techniques (cause and effect diagram) to determine root causes.

He then proposes a corrective action to be taken and indicates the date by which the corrective action will be fully implemented.

4.4 Implementation of Corrective Action

When a corrective and preventive action is decided upon, it is implemented on trial basis and the results are closely monitored. Further measures or changes in the measures may have to be made during the trial period until satisfactory results are attained. The magnitude of corrective action depends on the nature of non-conformity and its effect on the quality of product.

4.5 Verification of Corrective Action

On, or immediately after, the due date of implementation of a corrective action, concern person follows up to determine if the corrective action has been implemented and if it is effective. When there is objective evidence that the corrective action is effective, the CAR can be closed out. If more work is needed to fully implement the action, a new follow up date is agreed upon.

When the corrective and preventive measures are found to be effective, they are incorporated in the quality system by making suitable changes in the relevant documents such as drawings, specifications, operating procedures, work instructions and quality system procedures.

4.6 Preventive Actions

Preventive actions are taken to eliminate any potential causes of non-conformity. The objective is to provide a mean for detecting any deterioration in processes, work standards and systems and thus to prevent the occurrence of a non-conformity.

The need for preventive action is brought out by analysis of the following information:

: Data on product and process trends

: Customer feedback

: Inspection and test records

: Performance reviews of suppliers

A preventive action can also be initiated by any person by reporting it to his/her (Employee) section in-charge or departmental head who fills in the CPAR and sends it to MR. The procedure for processing, implementation and follow-up of preventive actions is the same as described in subsections 4.3, 4.4, and 4.5 above.

4.7 Management Review meetings

Status of corrective and preventive actions is presented in management review meetings as input. MR compiles the status of corrective and preventive actions and submits it in the management review.

5.0 Records Related to Improvement Procedure

Corrective / Preventive Action Request (MR/3/07)

Corrective & Preventive Action Log (MR/3/08)

Procedure for Administration in garments industry

2013-06-03T03:02:00.001+06:00

1. Purpose & Scope:

To develop an effective system this identifies and evaluates the health and the working environment of the company. Production unit comes with in the scope of this work Instruction.

2. Responsibilities:

The Administration Manager & MR is responsible for directing the activities relating to this work instruction.

3. Procedure:

3.1 Medical History:

When ever any employee will be hired for Muazuddin Textile Limited the doctor will check the

Worker and will prepare the Medical History Card of the worker.

3.1.2 Doctor will examine the worker weather he / she has any history of such a disease, which is transferable like hepatitis T.B etc, or not if any of the person carries such a diseases Doctor will inform the Admin dept.

3.1.3 No such person will be employed in Muazuddin Textile Limited who carries such a disease, which is transferable.

3.1.4 Every three months doctor will examine all employees and will keep the history of the worker in the Medical History Card (ADM/3/01).

3.1.5 Medical History Card will be kept in every employees file.

3.1.6 If the Medical History Card is not properly maintained Admin Manager should raise a CPA to inform & take necessary initiative by the higher management.

3.2 Working Environment:

3.2.1 On monthly bases Admin Dept. or MR will check the working condition and the environment of

The factory.

3.2.2 During the visit Admin Manager will prepare the working Environment Check list (ADM/3/02).

3.2.3 Admin Manager can raise CPA if he founds working environment unsatisfactory.

4. Related Documents:

Medical History Card ADM/3/01

Working Environment Check List ADM/3/02

Procedure For Human Resources (HR) & Training for Garments industry

2013-06-03T02:57:00.001+06:00

1. PURPOSE
To identify, provide and track employee-training requirement, for all employees in the organization.

2. SCOPE
This procedure is applicable for all the employees of the organization

3. RESPONSIBILITIES & AUTHORITIES
The administrative manager is responsible to follow this procedure & MR monitors the update status of the activities.
4. PROCEDURE
4.1Hiring of Personnel
The job requirements and specifications for a position (e.g., minimum qualification, experience and other requirements related to the job position) are defined in the concerned Job Description.

The requirement for any hiring is identified by Factory Manager / concerned departmental head. The request for new hiring is communicated to Factory Manager through Personnel Requisition form.

Factory Manager reviews and assesses the legitimacy and validity of the new hiring and makes recommendations for the new hiring. The requisition is then forwarded to Managing Director for approval of new hiring.

After approval, the position is advertised in the notice board or local newspapers. In addition, personnel having any reference may be directly contacted. The candidates are asked to submit their CVs/bio-data.

The bio-data are scrutinized and short-listed by Administration Department basis on the requirements of the job position. Short-listed candidates are issued call for interview.

A panel of interviewer is formed to interview and assess the candidates. The interview panel consists of following members:

n Managing Director / Executive Director / Director
n Factory Manager
n Admin Manager
n Concerned Departmental Head

The candidate is initially hired on temporary basis for a 3 (three) month’s probationary period after which his/her performance is reviewed and assessed by his departmental head. In case of satisfactory performance, he is hired on permanent basis. This rule may not be applicable for hiring operators / helpers /workers.

Administration Department maintains the personal files (including operators and inspectors) of personnel which includes their bio-data, credentials and training records.

4.2 Training and Skill Development
4.2.1 Orientation to New Employees
· Orientation of new employees includes:
· Orientation on administrative policies (e.g., working hours, leaves, medical, disciplinary policies)
· Understanding of Quality Policy
· Understanding of job responsibilities and authorities
· On-job training

After the joining of the new employee, Administrative Manager/ Concern Departmental Head initiate the orientation of employee by filling in the Training Record. The employee is first given orientation on administrative policies and quality policy by MR. The training is recorded on Training Record form.

4.1.1. Continual Identification of Training Needs
Training needs of employees are continually identified by their departmental heads/in-charges as a result of following developments:
n Changes in services or operations;
n New or revised procedures, or changes in the quality policy;
n Inadequate performance of individuals or groups of personnel.
n Results of internal quality audits;
n Corrective/Preventive Actions

Based on these identified training needs, Admin Manager Plans and arranges internal training sessions of employees. Training records of concerned persons are updated.

4.1.2.External Training
Admin Manager contacts various external training courses, if they feel that this training will be helpful for the employee.

After completion of course, the concerned person submits a copy of course certificate to Administration department. These certificates are filed in the personal record and the training records of concerned employees are updated.

4.2. Performance Evaluation
At the end of each year, employee initiates the performance evaluation of company’s personnel. Accordingly, Performance Evaluation forms of personnel are sent to the concerned departmental heads.

Performance results for the previous year are assessed based on the following criteria:
n Company’s objectives
n Achievement of specific tasks
n Completion of assignments
n Management’s expectations

In addition, the improvement areas and the corresponding training requirements for next year are also identified. The evaluation forms duly filled are sent back to Admin department.

Employee compiles the training requirements identified in the evaluation forms and prepares a tentative annual Training Plan. The training plan is thoroughly reviewed by concerned departmental heads and approved by MR.

5.0 Related Documents:

Training Need Assessment MR/2/14
Employee Training Record MR/2/15
Performance Evaluation form MR/2/16

Work Instructions for Trial Samples of garments

2013-05-31T23:57:00.001+06:00

Sample is very important part of garments manufacturing technology. All of the instruction and requirement are practically get from a garments sample. Most of the sample is made very carefully with a multi skill operator. It must be approved by buyer.

1.0 Purpose & scope:
2 Pieces of the trial samples of every style are made to get the technical know how of the constructions of the style and to show the same to the middle management in the sewing section.
To identify critical & new operations for further training.

2.0 Responsibilities:
It is the Sewing In Charge responsibility to maintain all the trial samples & to provide the necessary training to the Line QC, supervisors, and workers.

3.0 Procedure
3.1 Before the pre-production meeting starts the Sewing In Charge gets the fabric cut panels from the cutting department.

3.2 Sewing In Charge will assign 2 trial samples to the respective Line QCs for sewing as per customer-approved sample. The Manager – Quality Control will verify the samples (for construction only) against the customer-approved samples.
3.3 If training required for vital operations associated with the style, to commence training immediately.

4.0 Related Resources
1. Customer approved sample.
2. Cut panels

Procedure for Garments Store according to ISO

2013-05-31T23:35:00.001+06:00

1.0 Purpose & Scope

To maintain a simplified, organized system of monitoring goods received, proper handling & safe storage of the same in the store and maintaining accurate records of all related documents needed in performing those duties.

2.0 Responsibilities

The Store In-Charge is responsible for directing all the activities relating to this instruction.

3.0 Procedure
3.1 Demand of Goods

3.1.1 After receiving the Store Requisition (STR/3/01) form the Departments, Store In-Charge will check the stocks if the required items are there they will be issued.

3.1.2 Incase the goods are not available; Store In-Charge will prepare Store Purchase Requisition (STR/3/03) and will forward to the accounts department for purchase.

3.2 Receiving Goods

3.2.1 Order wise goods (Fabrics & Accessories) are received against the work order copy send by the Merchandising Department. Spare parts & other stationery items are received against the Store Purchase Requisition (STR/3/03).

3.2.2 Upon receipt of the Fabrics, Spare parts and Accessories items Store In-Charge prepares Inventory Report (STR/3/02). Then he informs the concerned department head regarding goods arrival.

3.2.3 Fabrics are received by the Store In-Charge and kept in the receiving area or identified as “Under Inspection”. QC department is informed to carry out the inspection and checks the fabrics against their requirement. After inspections are carried out QC personnel prepare Good Receiving Note (STR/3/04) and send a copy to the merchandiser if the fabrics are OK or NOT. After receiving Goods Receiving Note (STR/3/04), Store In-Charge will keep the fabrics in a designated place using identification tags (Order No. & Buyer Name) and he also updates the Stock Ledger (STR/3/05) for Fabrics.

3.2.4 Upon receipt of the Spare parts and Accessories items, concerned department will come & check weather the items are as per requirement or not and they will prepare Goods Receiving Note (STR/3/04) for those items and give the final acceptance for storing the goods. Store In-Charge keep the items in a designated place using identification tags and also updates the Stock Ledger (STR/3/06 & STR/3/07) for Spare Parts & Accessories separately.

3.2.5 The Store In-Charge will check stationary items against their quantity & physical conditions by himself. No Good Receiving Note will be maintained for stationery items. If he founds the stationery items in good shape and in right quantity, he will update the items in the Stock Ledger (STR/3/08) and will keep those items in their designated place.

3.2.6 If any items found defective or not as per quantity, defective items should be segregated and identified as “Rejected” and merchandiser or purchase department will be informed immediately for necessary action.

3.2.7 Copy of all Goods Receiving Note (STR/3/04) is forwarded to merchandising and accounts department for necessary action.

3.3 Issue

3.3.1 Goods are issued against Store Requisition (STR/3/01) duly approved by the Factory Manager or Production Manager. After every issue the Stock Ledgers are updated.

3.3.2 Store In-Charge issues machine Spare parts after he receives the old parts.

3.4 Handling and Storage Instruction

3.4.1 Stationary items are kept on suitable storage racks.

3.4.2 All Fabrics are segregated and identified by Order No. or Buyer Name And kept in pre-determined areas for easy reference and quick supply.

3.4.3 All the fabrics are covered to protect the same from dust or flying insects.

3.5 Stock Condition Assessment

3.5.1 Condition of stock in store is assessed on yearly basis.

3.5.2 Any item found damaged or deteriorated is segregated and disposed off accordingly.

3.5.3 Concerned Departmental Heads are consulted to assess if the goods can be used or not.

3.5.4 List of obsolete / unusable items is prepared and submitted to the Managing Director for disposal.

4.0 Related Documents

Store Requisition STR/3/01

Store Inventory Sheet STR/3/02

Store Purchase Requisition STR/3/03

Goods Receiving Note STR/3/04

Stock Ledger (Fabrics) STR/3/05

Stock Ledger (Spare Parts) STR/3/06

Stock Ledger (Accessories) STR/3/07

Stock Ledger (Stationery) STR/3/08

Garments Working Environment check list according to Compliance Based on ISO

2013-05-31T23:23:00.001+06:00

COMPLIANCE ISSUES
01. The Facility Floor, Storage area is clean and well maintained?
02. Has white wash or color wash taken place at least in the last 18 months?
03. Is the facility well lit and well ventilated. Are there windows and sufficient fans in all working areas for adequate circulation, ventilation & temperature control?
04. Are there exhaust fans in the production floor to prevent accumulation of fumes and dust?
05. Is there sufficient work surface lighting in production areas-such as cutting, sewing and pressing?
06. Is there sufficient work drinking water available on the work floor and are there means for cooling the water in summer?
07. Are their sufficient toilets available to the workers (at least 1: 25)?
08. Are the toilets functioning and clean?
09. Are exhaust fans provided in the toilets?
10. Exits are visibly marked and exit doors are working properly?
11. Exit doors and aisles are not blocked even temporarily?
12. Emergency lights are installed above exits and staircase and are properly charged?
13. Staircases are unobstructed and free of carton and boxes?
14. Doors which are not to be used as an exit are posted with a “NOT AN EXIT” sign (i.e. in the language to be understood by all workers)?
15. Exit lead directly to open space and safe access to a public way?
16. Exit floors are not tripping hazard and potential tripping hazard is posted with “Watch your step” sign?
17. Fire extinguishers are visibly marked, properly labeled, mounted and charged and also show the date of their last inspection?
18. Fire alarms are working and found on all floors?
19. There is battery back up alarm system, manual alarm system or electric alarm system?
20. Electrical boxes, circuit breakers and outlets are:
a. Covered
b. Posted with “DANGER” sign?
21. Circuit breakers are properly labeled to identify equipment it disconnects?
22. Electrical boxes and circuit breakers:
a. Are kept free of obstruction
b. Covers are closed?
23. Flammables are stored in a separate storage area?
24. Electrical equipment are:
In an enclosed area or approved cabinet
Has sufficient space around it for safe operation / maintenance?
25. Electrical equipment area / enclosure is not used as a storage area?
26. Generator room not used as a storage area (old machinery, discarded boxes etc.)?
27. Personal protective equipment available e.g. hand gloves for cutting section, mask for sand brushing, goggles for buttoning section etc.?
28. Well-stocked first aid kit available on each floor and staff trained in basic first aid.
29. Is a notice affixed in every floor naming the person in charge of the first aid box?
30. Evacuation Plan posted and clearly marked?
31. There is no form of physical abuse, including threats of violence, sexual harassment, screaming at workers or other verbal abuse?
32. Sufficient sand and reserved water available for fire fighting?
33. Is there a canteen for the employees?
34. Is there a prayer room for the employees?
35. Are there any broken needles, metal pieces lying on the floor and is the same removed?
Are needle logbook maintained?

Garment Machine Maintenance Procedure according to ISO

2013-05-29T23:13:00.000+06:00

1.0 Purpose & scope
Get the optimum performance & results from the machines with regard to quality & productivity. To be corrective & preventive where determining the root concerns all activities causes and take effective actions.

2.0 Responsibilities:
It is the Maintenance In-charge responsibility for the overall activity of the section & he has mechanics to assist him in all functions related to corrective & preventive maintenance

3.0 Procedure:
3.1 Installation of new Machinery
3.1.1 To read the assembly instructions manual provided by the supplier which contains, Kit identification, Table assembly instructions, belt installation, electrical wiring diagrams etc.
3.1.2 Check for damaged parts and if found inform supplier immediately
3.1.3 Verify all the function of the machines such as trimming, tacking sensors etc. are in order
3.1.4 Number the machines according to brand, type, and serial for easy reference.
3.1.5 Maintain record of machine brand, machine Installation date & machine no. the Machine History Register (MNT/3/01)

3.2 Preventive Maintenance
3.2.1 The Maintenance In-charge prepares a Preventive Maintenance Schedule (MNT/3/02) once a year, which contains the maintenance checklist and the frequency
3.2.2 The frequency of the maintenance is decided based on the machine manufacturer’s recommendations and on past experience.
3.2.3 The Preventive Maintenance Schedule (MNT/3/02) is approved by the Factory Manager / Production Manager and is circulated to all Department Heads.
3.2.4 Preventive maintenance of every machine is carried out according to the preventive maintenance schedule.
3.2.5 Services of Machines are recorded on Machine History Register (MNT/3/01) and also in Maintenance Register (MNT/3/03). Maintenance of machine at correct times is closely monitored & assured by the Production Manager.

3.3 Machine Break Down
3.3.1 During the production process, if the machine performance fails to comply with the required standard in regard to puckering, thread breakage, skipping etc. immediately the helper informs the line supervisor and supervisor informs the maintenance personnel immediately.
3.3.2 If the mechanic needs time to repair it, he should replace it with another machine to avoid production failures.
3.3.3 If spare parts are required, a requisition should be raised and approval should be obtained from the Factory Manager / Production Manager prior to replacement.
3.3.4 After Machine adjustments are completed, the mechanic must check a few pieces and depending on the result may or may not go for further machine adjustment.
3.3.5 The Mechanic has to record the particulars & job details in the Machine History Register (MNT/3/01) and Maintenance Register (MNT/3/03).
3.3.6 The duration of the interruption is recorded on the Maintenance Register (MNT/3/03) and the Mechanics also signs on the operator’s production control sheet.
3.3.7 Parts replaced are also recorded on Maintenance Register (MNT/3/01).

3.4. Receipt and Issue of Spare Parts
3.4.1 The parts are received from the store by raising a Store Requisition Slip (STR/3/01) duly signed by the Factory Manager/Production Manager.
3.4.2. While issuing new parts, the maintenance In-charge first checks the damaged old part. If the old part cannot be repaired only then a new part is issued, provided it does not effect production.

4.0 Related Documents
Machine History Register MNT/3/01
Preventive Maintenance Schedule MNT/3/02
Daily Maintenance Register MNT/3/03
Store Requisition Slip STR/3/01

Wish You Good Luck..................................
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Document Control in Garments Industry, ISO requirment

2013-05-29T22:29:00.000+06:00

1.0 Objective
To ensure that all documents forming the Quality Management System (QMS) are controlled and distributed so that only latest documents issued are in use by those employees requiring them.

2.0 Scope
This procedure covers all document control activities regarding the quality management system.

3.0 Responsibility
The Management Representative (MR) is responsible for directing activities relating to this procedure. Where other functions have responsibility, they are so indicated.

4.0 Procedure
4.1 Document Hierarchy

Level 1:   Quality Manual
Level 2:   Procedures, Matrix, Work Instructions, Quality Plan & External origin
Level 3:   Quality Records & Formats

4.2 Document Identification
4.2.1 The documents are identified by their titles, codes or by the ISO 9001:2000 standard clause reference

4.3 Document Coding
4.3.1 The corner of pages contains:
Document Code example: PRD/2/012
Issue Number Issue 1
Page Number Page 1 of 4

4.3.2 The document code is of the form AAA/B/CCC, where:

• AAA is the department (see list below). Can be 2 to 4 letters.
• B is the document level, 2, or 3.
• CCC is the individual document number, starting from 01.
The exception is the quality manual, which is coded simply as QM/1.

4.3 Procedures Structure
The format of the documents is not standardized with respect to design and layout, however, level 1, level 2 (except the External origins) and Level 3 documents contain at least the following information:

-Related Documents (If any)
-Written and Reviewed by

-Approved by
-Issue Date & No.

4.4 Document Initiation/Review/Approval
4.4.1 Documents are written by or with the help of the appropriate personnel involved with the activity.
4.4.2 Reviewed by the author of the documents or the person indicated.
4.4.3 Approvals:
Departmental Procedures – Managing Director/ Factory Manager/ Management Representative
MR Procedures – Managing Director/Factory Manager
Quality Manual – Managing Director

4.5 Issuing Documents
4.5.1 The original document, signed, unstamped and dated, is retained in the Central Quality File. This file comprises separate folders for each department, containing all the quality system documents for that department.
4.5.2 Copies of all Level 1 & 2 documents are made and issued to a department are stamped “Controlled Copy” and are recorded on a Document Master List (MR/3/01) for each department.
4.5.3 A Circulation Record, MR/3/002, accompanies each original document.
4.5.4 Copies of documents are distributed to the appropriate personnel who sign the Circulation Record.
4.5.5 Uncontrolled photocopies are only allowed for use by external parties, e.g. customers, auditors, etc. These are stamped on the front page as “Uncontrolled Copy”. Distribution records are not maintained for these copies.
4.5.6 The preparation and updating the work instructions (if required) is the responsibility of the departmental heads. If the work instructions are to be displayed on the board, the departmental head will ensure that the latest version of the work instruction is displayed. The original, approved text of the work instruction will be retained in the Central Quality File, along with a Circulation Form.
4.5.7 Job Descriptions, Quality Plans, Quality Policy and Objectives are circulated in the same way.
4.5.8 Some level 3 documents are maintained on electronic media (soft copies). These documents are controlled through custom made software security system. These documents are identified by their name/title. These documents are backed up on weekly basis.

4.6 Amending Documents
4.6.1 Changes required are raised on a Change Request Form, and submitted to the Management Representative.
4.6.2 Management Representative in consultation with the personnel who initially wrote and approved the document gives approval of proposed change.
4.6.3 If the changes are approved a new issue is published. The issue number advances, that is, Issue 1 becomes Issue 2, etc.
4.6.4 The change(s)/new addition(s) are identified by underline / highlighting the amended section.

4.7 Withdrawal of Obsolete Documents
4.7.1 The amended document is issued and distributed according to procedure (see section 4.6).
4.7.2 The Document Master List (MR/3/01) is updated.
4.7.3 All obsolete copies are withdrawn and signed for according to the Circulation Record.
4.7.4 The original copy of the obsolete document, along with its Circulation Record and Change Proposal, is kept for reference purposes, in an Obsolete Document File, MR/3/04. The front page is red stamped as “Obsolete”.
4.7.5 Old documents are stamped in red as “Obsolete”. They are retained, if required for reference, or destroyed on the authority of the concerned department head. All remaining copies are destroyed

4.8 Issuing & Amending Level 3 Formats
4.8.1 Preparation of formats is the responsibility of department heads.
4.8.2 A blank (for sample) copy is attached to the relevant procedure or work instruction in Central Quality File for reference. If the same format is used for more than one document, then it need not be attached with every procedure.
4.8.3 They are printed on white paper and include a code number and issue number.
4.8.4 Copies are allowed for working activities.
4.8.5 Changes are made according to sections 4.6.1 and 4.6.2 and the issue number advanced and the previous copy is replaced in central Quality File.
4.8.6 Amended issues are sent to the Management Representative for inclusion in controlled copies of the relevant document. The Change Proposal and a copy of the obsolete document is kept in the Obsolete Document File.
4.8.7 Department heads are responsible for withdrawal and destruction of old issues and distribution of new issues to the concerned work areas

4.9 Control of External Origin Documents
External Documents are controlled in the same way like internal documents except the copy of the external document may not be retained in the central quality file.

4.10 Document Maintained
A Master List of Documents (MR/3/01) is maintained in central quality file to identify the latest issue of the document in circulation the revision status is incorporated in the individual documents.

4.11 Computer Back-up
All the documents of the Quality Management System are stored in the computer and for safety purpose a back up in the form of floppy disks and are kept by the Management Representative.

5.0 Related Documents
Document Master List MR/3/01
Circulation Record MR/3/02
Change Proposal MR/3/03

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Procedure for Garments Measuring And Monitoring Devices based on ISO

2013-05-28T23:57:00.003+06:00

1.0 Objective
This procedure ensures that appropriate Inspection, Measuring and Test Equipment are identified, calibrated, preserved, controlled and maintained.

2.0 Scope
Applies to all Inspection, Measuring and Test equipment (IM&T) used in Muazuddin Textile Limited

3.0 Responsibility
Manager Quality control shall ensure appropriate control, calibration and maintenance of inspection, Measuring and Test equipment.

4.0 Procedure
4.1 Identification:
4.1.1 All the measuring and monitoring devices which are used in Swan Garments Limited Will be identified with unique identification number.

4.1.2 Location of measuring equipments is done by the following codes:
- QC Quality Control department
- PR Production department

4.1.3 The identification number will be indicated on all measuring equipment by affixing of sticker, permanent ink pen or any other suitable indicator.

4.1.4 All those equipment that do not require calibration will be identified with a sticker showing ‘CNR’ (Calibration Not Required).

4.2 Master List of All Inspection Measuring & Test (IMT) Equipment

4.2.1 A master list of Measuring and Monitoring Devices shall be maintained by the QC Manager.

4.2.2 The Master List shall include Equipment Name, Equipment ID, Location, Model (If available), Range / Capacity, Calibration Frequency & Calibration done by.

4.3 Calibration Type
4.3.1 External Calibration
4.3.1.1 Out-side calibration services agencies will be approved by the top management. Before approval, top management will ensure that calibration agency has appropriate accredited standards, which are traceable to any national/international standards.

4.3.1.2 Person responsible for calibration will send the equipment to calibration agency in proper packages or he will inform the concerned agency to send their engineers to our premises for calibration/maintenance what so ever is required.

4.3.1.3 Upon receiving the equipment from calibration agency, he will make sure that “Calibration Status Sticker” is pasted on equipment. This sticker shows the date of calibration and next due date.

4.3.1.4 He will also ensure that the calibration agency has sent a calibration certificate along with each equipment.

4.3.1.5 He will maintain records of these certificates.

4.3.2 In House Calibration
4.3.2.1 The person responsible will perform the in-house calibration in a controlled environment, if required.

4.3.2.2 All the in-house calibration will be performed according to appropriate calibration procedures.

4.3.2.3 After performing calibration, he will affix the calibration status sticker, indicating the date of calibration, next due date and the signature of the person who performs the calibration as shown below:

Calibration Sticker

Equipment ID _______________ Sig. ____________________

Calibration Date_____________ Next Due Date_____________

4.3.2.4 He will also maintain the record in calibration data card.

4.4 Calibration Interval
4.4.1 The person responsible for calibration with co-ordination of concerned department head will decide the interval of different equipment on the basis of their sensitivity / usage or on advice of manufacturer (if any).

4.4.2 He will increase or decrease the calibration interval of equipment on the basis of calibration results.

4.5 Action Taken when Calibration Results are not satisfactory.
4.5.1 If calibration results are found out of tolerance (Accuracy required), the user/person who has performed the calibration will immediately inform the concerned department about the results.

4.5.2 Concern department head will take actions to validate the previous inspection made from this equipment, if possible.

4.5.3 He will also consider the effects of these not satisfactory results on the quality of the final product.

5.0 Related Documents
Master List of Measuring and Monitoring Devices
External Calibration Certificates
Calibration Data Card (In-house Calibration)

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Control of Non-conforming product in garments manufacturing

2013-05-28T23:38:00.001+06:00

1. PURPOSE
- To provided a system for evaluating defective products
- Evaluating the cause of defects and eliminate the nonconformity.
- Creating a permanent solution that prevents recurrence of problems.

2. SCOPE
All non-conforming fabrics, accessories, packing materials are purchased and garments are made by Muazuddin Textile Limited.

3. RESPONSIBILITIES & AUTHORITIES
Merchandising Manager, Factory Manager, Production Manager, Quality Control Manager, Cutting In-charge, Finishing In-charge, Store In-charge, Quality Inspectors & Maintenance In-charge are responsible for following this procedure.

4. PROCEDURE
4.1 In-coming product

4.1.1 If products (fabrics, accessories, washing, packaging materials & spare parts) do not meet the specification are stored separately from the conforming products and identified as “Non-conforming Product”

4.1.2 Store In charge prepares Non-conforming Report and submits it to the Production Manager/Quality Control Manager.

4.1.3 Production Manager /QC Manager review the non-conformity product and give disposition decision after discussing with the respective merchandiser & Factory Manager.

4.1.4 Store-In charge disposes the material as per decision taken by the Factory Manager or by the respective Merchandiser.

4.2 In Process Non-conforming material /products (Cutting)
4.2.1 If any discrepancy identified during marker inspection then marker is segregated and recorded in Spreading Quality Report. Identified Non-conforming marker is rectified as per the specification and cutting quality inspector re-checks the marker.

4.2.2 Identified non-conforming items are segregated during Cutting Quality Inspection and Panel check. The acceptable components are stored for making another size. The components which are not acceptable will be treated as rejected or destroyed or stored as stock lot. Cutting QC Inspector / Quality Control Manager is responsible to give disposition decision on identified non-conforming items.

4.3 In-process Non-conforming material/product (Sewing)
4.3.1 Non-conforming garments identified by Quality Inspector during the complete garments checking (100% garments).

4.3.2 The defective items sent back to line for re-work. Garments which are not re-workable shall be rejected and segregated. Disposition record of such is maintained in the same form in the comments column

4.3.3 Operators will correct the non-conformity. Record of disposition shall be maintained in respective checking record form. The corrected garments will be re-inspected in normal routine process.

4.4 Finished Garments

4.4.1 Non-conforming finished garments are identified during inspection in finishing area and recorded in the inspection report.

4.4.2 Non-conforming finished garments may be disposed as per decision of the Quality Control Manager /Production Manager. The decision may be as follows:

• Repaired, inspected and shipped to original buyer
• Repaired and sold to another buyer as stock lot in concession
• Destroy which are not repairable

4.5 Non-conformity identified after shipment
If any non-conformity is identified after shipment of the garments by Muazuddin Textile Limited. The Factory Manager or Merchandiser will immediately notify the buyer via e-mail, Fax or Telephone.

4.6 Records
Non-Conforming Report

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Case Study of Y Knitting Mills Ltd.

2013-05-22T22:35:00.005+06:00

Survey of Bangladesh Textile industry to Up-date Database/MIS and to Assess the Requirement of Textile Technologists at Different Levels

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Prepared by

Green University of Bangladesh

Introduction:

The case study of Y Knitting Mills Ltd. is situated at Valuka, Mymensing. In respect of technical point of views (machines, raw materials, production planning, sequence and operation, maintenance, utility service, store and inventory control, cost analysis), it is a very good graded Knit Dyeing Mill and a strong base of financial aspect and marketing activities, this Mill is 100% export oriented and running up to now with profit.

A brief description of X1 Weaving Mills Ltd:

1. Name of the Mill : Y Knitting Mills Ltd

2. Nature of the Ownership : Private Limited Company

3. Year of Establishment : 2005

4. Authorized Capital : Tk: 39.07

5. Paid-up Capital : Tk: ?

6. Land Area : 5 Bighas

7. Physical Structure : Pucca + Pre-Fabricated

8. Type or Nature of Mill : Knitting

9. Machine and Equipments, Capacity and Capacity Utilization:

SlNo.	Name of the Machine	Origin and Year of Purchase	No. of Machine	Installed Capacity Kg/Day	Target Production Kg/Day	Capacity Utilization (%)
1	Circular Knitting	Mayer &Cie Germany	24	10368	9331	90
2	Dyeing Machine	Origio, Itally	20	8400	7560	90

10. Stock Position and Volume of Shortfall (July 2007-December 2007)

Types of Stock	Stock (Kg)	Value of Stock (Tk)
Yarn	45000	5,40,0000

There was no shortage of raw material in the mill during July 2007 to December 2007.

11. Last Three Years Production (in Kg)

Sl. No.	Product	2005-06	2006-07	2007 (July07-Dec 07)
1	Cotton Fabric	85,00,000 yds	95,00,000 yds	51,00,000 yds
2	Total	85,00,000 yds	95,00,000 yds	51,00,000 yds

Production history of last two years.

12. Production and Shortfall During July 2007-December 2007

SlNo.	Name of the Machine	No. of Machine	Installed Capacity Yds/Day	Target Production Yds/Day	CapacityUtilizatio Yds/Day	Shortfall
1	Ball Warping	3	72000	65000	33000	49%
2	Dyeing Machine	1	72000	65000	33000	49%
3	Long Chain Beamer	8	72000	65000	33000	49%
4	Loom	100	65000	60000	33000	45%
5	Sizing	1	60000	58000	33000	43%

13. Calculation of Sale Price During July 2007-December 2007

Products	Cost of Production	Sale Price	Total Revenue (Tk)	Profit (Tk)
Woven Fabric	127.65 Tk/Yd	140.42 Tk/Yd	65,10,15,000	6,40,05,000

14. Reason of Production Shortfall During July 2007-December 2007

Sl. No.	Reason of Production	Shortfall During The Quarter
1	Electricity Failure	X
2	Shortage of Raw Material	X
3	Shortage of Working Capital	X
4	Lack of Proper Planning	X
5	Misleading Lead Time/Procurement Time	X
6	Lack f Spare and Accessories	X
7	Strike/Unrest	X
8	Natural Disaster	X
9	Shortage of Skilled Manpower	√

From the above table it is clear that shortfall of production is only for shortage of skilled manpower. It is assumed that huge 50% production shortfall occurs due to shortage of Textile Technologists.

15. Cost of Good Sold

CHART OF COST OF THE FACTORY

16. Number of Shifts, Working Hours and Days During July 2007-December 2007

No. of Shifts/Day	Total No. of Shifts During July 2007-December 2007	Total No. of Days During July 2007-December 2007	Total No. of Working Hours During the Quarter
2	312	156	2496

17. Raw Material/Input Used During July 2007-December 2007

2808000 Kg

18. Wastages in terms of % (During the Quarter Ended Decmber 2007)

Yarn	Fabric	Total
0.5%	0.5%	1%

19. Investment:

Fixed Assets in Tk		Working Capital in Tk
Original Value	Present Depreciated Value	In Cost Price as on 31^stDecember 2007
39.01 Cores		2.5 Cores

20. Wages and Salaries (Tk) as in December 2007

Period	Officers and Staffs	Labour
December 2007	13,50,000.00	16,50,000.00

21. Manpower as on 31^st December 2007:

Level of Skill ness	Education	Requirement	Existing	Shortfall	Shortage (%)
Managerial Level	B. Sc/M.Sc./MBA in Textile Engg.	1	0	0	100%
High Skill/Expertise Level	B. Sc in Textile Engineering	6	5	1	17%
Moderate Skill Level	Diploma in Textile Engineering	15	10	5	33%
Specialized Skill Level	Trade Course	25	15	10	40%
Skilled /Unskilled Labour	Skilled by Experience	390	410	20	(+5)%

From the above table we have a clear idea about the present condition of overall situation of different mills and we can simulate this case in real/practical fields forenginners and technicians in the following ways.

Figure: Requirement of Textile Engineers and Technologists at Different Level.

22. Product Diversification Matching with the Need of RMG Sector and Quality

Improvement

Sub-Sector	Existing Supply/Yr of Products to RMG Sector		Scope of Additional Production and Supply to RMG Sector		Scope for Improvement of the Product
Sub-Sector	Products	Quantity	Yes/No	How?	Yes/No	How?
Weaving	Fabric	99,00,000Yds	Yes	By Increasing Skilled Manpower	Yes	By Increasing Skilled Manpower

23. Conclusion:

From the above study, it is clear that the reason of shortfall of product is only due to shortage of Textile Technologists/Engineers. We have seen that there is about 40% shortage of Textile Technologists/Engineers at different levels. It is possible to achieve 100% target production and also quality by recruiting Textile Technologists/Engineers. So it is essential to appoint Textile Technologists/Engineers at different levels in all the textile mills within short time to face the challenge of 21^st century.

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Most common Textile Inspection System

2013-05-05T02:18:00.000+06:00

Piece goods inspection system:

In 1955 ten points piece goods evaluation was approved by the textile distribution & national federation of textiles. This system assigns penalty points to each defect.

Ten points system:- Filling defects penalty
Warp defects Penalty Full width 10 points

10-30 ̎ 10 points 5 ̎ ½ the width: 5 ″

5-10 ̎ 5 ″ 1-5 ̎ :- 3 ″

1-5 ̎ 3 ″ up to 1 ̎ :- 1 ″

Up to 1 ̎ 1 ″

Under the ten point system, a piece is graded a fixed if the total penalty point do not exceed the total yardage of the piece. A piece is graded a ‘second” if the total penalty points exceed the total yardage of the piece.

Four points system:

It is widely used in textiles. It is simple & easy to under stand. Inspection is done about 10% of the product in the shipment. This system has been applied by AAMA (American Apparel manufacturing association).

The four points system classifies classified defects as follow:

Size of defects Penalty

3 ̎ or less 1 point

Over 3 ̎not over 6 ̎ 2 ″

Over 6 ̎but not over 9 ̎ 3 ″

Over 9 ̎ 4 ″

A maximum 4 points is changed for one leniaroooo yard

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Fabric faults produced during weaving & knitting production

2013-05-05T02:10:00.000+06:00

Weaving fault:
Warp way defect:
I. Warp stitching : Occurred due to want of interlacement between warp & weft yarn which happen:
Ø If the warp threads of one shed goes to another.
Ø Faulty dobby or jacquard mechanism.
Ø Warp yarn if loose.
Ø Height of the harness card if not equal.
Ø Warp is not properly sized.

a) Long float: causes due to
Ø If the warp yarn does not take part in interlacement.
Ø Tappet is not properly tied.
Ø Peg if dobby displaced.
Ø Jacquard harness or cord cutting if defective.
Ø Worn out Reed if used.

b) Wrong warp threads: due to drafting & lifting.
Missing warp: causes due to:
Ø Wrong denting.
Ø Broken warp yarn in the beam.
Ø Out of order warp stop motion.

d) Double warp: warp way marks on the fabric due to:
Ø Wrong reed count used.
Ø Wrong denting in the reed.

e) Loose warp: Causes due to
Ø Loose warp exist on the beam in loop form.
Ø Yarn tension in the dropper.
Ø Size picks up unequal.

f) Knot in the warp yarn: If there are any knots in warp yarns.

g) Selvedge effect: Causes due to :
Ø If the body and selvedge warp yarns tension is unequal.
Ø If the reed space is greater but the width of the fabric is les.
Ø Sharp temple ring spikes.

h) Weft cut at the selvedge: due to
Ø Absent of weft yarn in the selvedge
Ø Defective ring temple.
Ø If the temple not properly set.

i) Temple mark: Mark on the selvedge of the fabric due to: light fabric if course temple is used.

Weft way fault:
1. Miss pick or broken pick:- Causes Due to
Ø Broken pick.
Ø Yarn of pirnoooo is finish.
Ø If weft yarn breaks at the middle.
Ø Picking much uniform occurred by empty shuttle.

2. Broken design: If the lifting mechanism is defective.

3. Thick & thin place which is called bar on the fabric.

4. Shuttle mark:
Ø Shuttle flies.
Ø Shuttle box is not properly set.

Defective of knitted goods to be unspected:

1. Broken ends: If the yarn breaks, holes create in the fabric.
Ø During loop formation if the yarn previously broken in the needle.

2. Drop stitch:
Ø Due to defective needle.
Ø Yarn feeder not properly set.
Ø Wrong take up mechanism.
Ø Stitching tension if not proper.

3. Slugging.
Ø Only occurs in continuous filament yarn.
Ø Occurs due to mechanical strain in the next process stages.

4. Tuck & doable stitch: Occurs due to badly oooo or knitted loop. It results the formation small brads or thick & thin places in large ascoooo.

5. Bunching up: Visible knots in the fabric eyes known as beads.

6. Vertical stripe: Vertically shown streaks on the Wales which causes due to:
Ø Gauge is not done according to count.
Ø Stitch size.
Ø Course density.

7. Horizontal stripe: unevenness along the course direction.
Ø Yarn feeder if not properly set.
Ø Tension if not uniform.

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AQL | Acceptable Quality Limits or Level

2013-05-05T01:58:00.000+06:00

Major concept of Acceptable Quality Limit or Level:
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It is the allowable percent defective in a lot. This is introduced according to American military Standard of product inspection rules. There are generally 6 AQL used in textile which are as follows:- 1%,1.5%,2.5%,4%,6.5%,and 10%. Among them 2.5%,4%,6.5% and 10% are widely used and accepted according to price and type of garments.

Uses of AQL: In this system, sample is selected statistical method by using random sampling technique from a lot. After proper inspection along with the test results, the decision is taken, whether the lot will be accepted or rejected. Now a days this system is widely used in garments sector before the delivery. Although it is used from raw material to finished product also.

Acceptable sampling system consists of five parts:
1. Lot size
2. Sample size
3. AQL
4. Acceptable number
5. Reject number

Quality Inspection of factories:
According to JIS, Inspection is defined as “ to measure goods by some methods and by comparison with the results obtained against the criteria to judge whether the individual goods are defective or not

In textile factories the fabrics are inspected at the grey state, after pretreatment, coloration and finishing. After inspection the fabrics are classified according to their quality. Therefore fabrics are inspected to meet the requirements of the customers.

The fabrics are categorized in the following way depending upon the faults:

I. Fresh or First quality: Fabrics, hemming major, minor faults according to buyer specification and requirements.
II. Short length or two parts: It is a piece of cloth having a shorter length( More then 50 cm ). Jar parts become equal to fresh quality. Generally buyers gives (3-5)% discount value for the short length.
III. Seconds: Fabrics containing much objectionable minor defects and (8-15)% discount is allowed.
IV. Fents: Cut pieces of fabric measuring 90 cm or more but less than 150 cm lengths. For fents trade discount is (15-30) %.
V. Rags: Cut pieces of fabric measuring 25 c or more but less than 90 cm. This categories are sold by weight and realization is only about 50% of fresh fabric.
VI. Chilly: These are pieces of 25 cm length fabric less than this. These fabrics are bought & sold and trade discount generally given is ( 50-80).

Quality Parameters of Woven Fabrics to be inspected are as follows:

(1) Dimensional characteristics:
a) Length b) Width c) Thickness

(2) Weight of fabric:
a) Weight/unit area b) Weight/unit length

(3) Fabric strength & Elongation
a) Tensile strength b) Tearing c) Bursting

(4) Threads/inch:
a) Ends/inch
b) Picks/inch

(5) Yarn count
a) Warp count
b) Weft count

(6) Crimp
a) Warp count
b) Weft count

(7) Handle

a) Stiffness
b) Drape

(8) Crease resistance & crease recovery

(9) Air permeability

(10) Abrasion resistance and pilling.

(11) Shrinkages/Dimensional stability

(12) Different fastness properties:-
a) Washing fastness
b) Light fastness
c) Perspiration fastness
d) Rubbing

(13) Flameability

(14) Water resistance or absorption power

(15) Design of fabric

(16) Appearance of fabric

Quality parameters for knitted fabric to be inspected:

1. Strength & elongation
2. Course density
3. Wales density
4. Loop length
5. Deformation
6. GSM
7. Yarn count
8. Design

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Bonded Fabric

2013-04-25T01:09:00.000+06:00

Bonded fabric is a combined structure of fabric that is being created by joining two set of fabric. This attachment of two fabrics can be made with adhesive or thin bonding fabric with low melting point without any major changes of finished fabric thickness. Here a face or shell fabric is joined with backing fabric. Artificial leather products can be a good example of this type of fabric. Bonded fabric also used in design purposes and fabric stabilization.

An aqueous acrylic adhesive is used for joining bonded fabric. A latex adhesive such as, acrylate, a vinyl chloride or vinyl acetate or thermosetting resin also being used for this purpose. This bonding strength between these two layer fabrics is the main thing where the end uses of the finished product depends on.

Fabric Bonding Procedure:
There are two common methods for attaching fabric to fabric.
1. Wet adhesive method
2. Flame foam method

Wet adhesive method:
· An adhesive liquid is applied to the back of the face fabric.
· Face fabric is set on backing fabric and passed together between the heated rollers.
· Thus, the heat fixes the adhesive between two fabrics and makes the bonded fabric.

Flame foam method:
· Here, a thin layer of polyurethane foam is used to attach two set of fabrics
· First, polyurethane foam is melted a little by passing it over a fire/heat.
· Then this melted foam is set between two layers of fabric just like a sandwich.
· After that, when the foam got dries, it attach the two layers of fabric.

Actually the foam in the bonded fabric is so thin (around 0.010 inch). That why, It doesn’t make any significant changes on the thickness of the finished fabric. By this method fabric may got stiffer than the wet-adhesive method. Sometime foam may appear of the surface of the fabric. That’s why it is not better not to use this method with open-weave fabrics.

Advantages
· This bonded fabric is much cheaper in price
· This fabric is machine washable
· Fabric doesn’t crease easily

Crimp based on warp and weft yarn on fabric

2013-03-14T23:02:00.001+06:00

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CRIMP
When warp and weft yarns are interlaced in a fabric they follow a WAVE or CORRUGATED configuration, the plane of the weave being substantially perpendicular to that of the fabric. This WAVINESS OF YARN is called CRIMP of yarn and is expressed quantitatively either as a fraction, c or as a percentage, c per cent:

c = (Ly - Lf)/Lf; and, c per cent = (Ly – Lf) x 100/Lf

Where Ly = the un crimped length of the yarn, and, Lf = its extent in the fabric.

The expression c = (Ly – Lf) / Lf may be written as:

c = Ly / (Lf - 1), from which

(1 + c) = Ly / Lf;

where (1 + c) is called the crimp ratio. It is useful in fabric calculations.

MATH: Calculate the length of warp required to weave 160 yds. of cloth if the warp crimp is 12 percent.

We know,
Lf = 160 yd. and c1 percent = 12; so c1 = 0.12, where c1 is fractional warp crimp, and

Ly = Lf (1 + c) = 160 x 1.12 = 179.2 yd.

So, to prepare 160 yds of fabric 179.2 yds of warp is required.

MATH: What length of cloth can be woven from 800 yds of warp if the crimp is 8 percent?

We know
Ly = 800 Yd., and c1 percent = 8, so c1 = 0.08; where c1 is fractional warp crimp, and

Lf =Ly/(1+c) = 800/1.08 = 740.8 yds.

So, 800 yds. of warp will weave 740.8 yd of cloth.

When the shuttle inserts the weft in the open shed, the weft is un crimped, and each pick has a length Ly, which is equal to the width occupied by the warp in the reed. This is called the reed width. When it is beaten up by the reed and incorporated into the cloth at the cloth fell, the weft attempts to crimp under the scissors-like pressure exerted by the warp threads. At this stage, it is prevented from crimping freely by the temples, whose function is to hold out the cloth near the fell to reed width, so as to prevent excessive abrasion of the warp threads near each selvedge by the reed. As the cloth moves forward towards the breast beam, it leaves the temples and is free to contract to a length Lf, called loom-state width. The weft is now crimped. We have three variables, i) reed width, ii) the width of the loom-state cloth, and iii) the weft crimp in the loom-state cloth. If we know two of these variables, the third can be calculated as illustrated by the following examples.

MATH: Calculate the reed width required to give a cloth with a loom-state width of 38”, if the weft crimp in the loom-state cloth is known to be 6 percent.

We know
Lf = 38”, and c2 percent = 6; so c2 = 0.06, where c2 weft crimp, and

Ly = Lf (1 + c) = 38 x 1.06 = 40.28”

which is the required reed width.

MATH: Calculate the loom-state cloth width if the reed width is 60”, and the weft crimp is known to be 9 percent.

We know

Ly = 60” and c2 percent = 9; so c2 = 0.09, where c2 is weft crimp, and

Lf = Ly/ (1+c) = 60/1.09 = 55.05”

which is loom-state cloth width.

MATH: Calculate the weft crimp in the loom-state cloth if the reed width is 44” and the loom-state cloth width is 40”.

We know

Ly = 44”, and Lf = 40”.

Therefore (1+c) = Ly/Lf = 44/40 = 1.10, so c2 = 0.10 and c2 percent = 10

which is the weft crimp.

In any of the above examples we could substitute the width of the finished cloth for that of the loom-state cloth, provided that we also substitute the weft crimp in the finished cloth for that of the in the loom-state cloth. The calculation would be valid, if no unrecoverable shrinkage had occurred during finishing, but not, for example for a milled woolen cloth.

EFFECT OF CRIMP OF YARN ON FABRIC PROPERTIES
a) RESISTANCE TO ABRASION: With the increase of crimp %, the abrasion resistance will also increase
b) SHRINKAGE: With the increase of crimp %, shrinkage of fabric will decrease.
c) FABRIC BEHAVIOUR DURING TENSILETESTING: With the increase of crimp%, breaking load of fabric will also increase.
d) FABRIC COSTING: With the increase of crimp%, fabric costing will also increase. Because crimp decrease the length of yarn as a result more yarn will be needed for fabric manufacture in case of more crimp on yarn.
e) FAULTS IN FABRIC: If there is variation of crimp in the threads then the following faults may be found in fabric; A) Reduction in strength may occur, and B) Stripes will be seen in yarn dyed cotton fabric.
f) FABRIC DESIGN: To achieve satisfactory appearance and required shape in finished fabric control of crimp in warp and weft yarn is necessary..
g) FABRIC STIFFNESS: If crimp is increased then stiffness of fabric will decrease.
h) ABSORBENCY: With the increase of crimp % absorbency of the fabric will increase.
i) DIMENSIONAL STABILITY: Dimensional stability will decrease with the increase of crimp%.
j) FABRIC HANDLE: If crimp is increased then the fabric will be soft in handle.
k) DYE TAKE-UP: With the increase of crimp the take-up percentage of dye-uptake will also increase.

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Cover Factor of Fibre, Yarn and Fabric

2013-03-14T22:13:00.002+06:00

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CONCEPT OF SIMILAR CLOTH
Fibre or raw materials of the two cloths may be same but they can differ on other factors, such as:-
i) The yarn count may be different.
ii) The ratio of yarn count in warp and weft may differ.
iii) The warp ratio of yarn spacing may differ.
iv) The average of yarn spacing may differ.
v) The weave design may differ.
vi) The amount of twist in yarn may differ.

If there is similarity in COVER FACTOR of two cloths but they differ in such points as mentioned above then they are called similar cloth.

COVER FACTOR
Cover is the degree of evenness of thread spacing. Good cover gives the effect of a uniform plane surface & it can not be obtained with hard twisted yarn. In case of woven fabric cover factor is a number that indicates the extent to which the area of a fabric is covered by warp and weft threads. For any fabric by introducing suitable numerical constants its evaluation can be made in accordance with any system of counting. It is denoted by k.

Mathematically,

k = d / p;

where, d₁ = Warp dia; d₂ = Weft dia; P₁ = Warp spacing; P₂ = Weft spacing; k₁ = Warp cover factor, and k ₂ = Weft cover factor.

So, k₁ = d₁/P₁ & k₂ = d₂/P₂

Therefore, Fabric Cover Factor = k₁ + k₂.

The ratio of yarn diameter to yarn spacing, d/p, is a measure of the relative closeness of the yarns in the warp or weft of a woven fabric. This ratio also expresses the fraction of the area of the cloth covered by the warp or weft yarns. We may therefore call it the fractional cover, i.e.

Fractional cover = d / p.

Substituting Peirce’s estimate of yarn diameter, d = 1/28 √N, we have

d / p= [1/(28√N) x1/p]

But 1/p = n, where n = threads/in., so

d / p= n/(28√N) ……………………………… (6)

Now d/p has a value of 1.0 when the yarns are just touching. Peirce multiplied eq.(6) by 28 to eliminate the numerical constant, 28, and defined the result as the ‘coverfactor’, K.

Cover Factor, K = n / √N ……………………………………………..(7)

Because we have multiplied by 28, cover factor as defined in eq.(7) has a value of 28 when the yarns are just touching. The relative yarn spacing corresponding to various cover factors are shown below:

It is usual to calculate separate cover factors for the warp and the weft. Using the suffices 1 and 2 for warp and weft, we have

Warp Cover Factor, K₁ = n₁ / √N₁ and

Weft Cover Factor, K₂ = n₂ / √N₂.

The sum of the warp and weft cover factors is known as cloth cover factor, Kc. It is customary and more informative, however, to state the warp and weft cover factors separately. Just as twist factor enables us to compare the relative hardness of twist in yarns of different counts, so cover factor enables us to compare the relative closeness of the yarns in different fabrics.

Math related to cover factor

Compare the relative closeness of the warp yarns in the following two plain cloths; (a) 16s cotton; 50 ends/in; and (b) 36s cotton; 84 ends/in.

We have the cover factor for cloth (a), K₁ = 50 / √16 = 12.5.

And for cloth (b) cover factor, K₂ = 84 / √36 = 14.0

So the ends are more closely spaced in cloth (b) than in cloth (a)

MATH:- Calculate the warp and weft cover factors for the following fabric: 60 denier nylon x 48s worsted; 96 x 72.

60 denier = 5315/60 = 88.57s cotton count.

So, K₁ = 96 / √88.57 = 10.2

40s worsted = 48 x 560/840 = 32s cotton count.

So, K₂= 72 / √32 = 12.7

GENERAL FORMULA FOR CALCULATING COVER FACTORS

Indirect systems direct systems.

K = cn/ √N K = cn √N

Where N is the yarn number in the particular system.

System Value of c System Value of c

Cotton 1.0 Denier 0.01375

Worsted 1.228 Tex 0.04126

Linen lea 1.667 lb/spdl 0.2422

MATH: Calculate the cover factor corresponding to 80 threads/in. of 100 denier.

From the table constant for the denier system is 0.01375.

Therefore, K = 0.01375 x 80 x √100 = 11.0

MATH: How many threads/in. of 5 tex nylon are required to give the same cover factor as 90 threads/in. of 2/100s cotton?

Since the equivalent singles count of 2 /100s is √50 s.

Therefore,

K = 90/ √50.

So, K = 12.7 = 0.04126 x n √5

Therefore the number of threads required

n=12.7/0.04126 x √5 = 138 threads / in.

Thus required thread/in is 138 of 5 tex to give the same cover factor as 90 threads/in. of 2/100s cotton.

This problem can also be solved with reference to the formula for calculating cover factor.

5 tex = 590.5 / 5 = √118 s cotton count.

As before, K = 12.7 = n/ √118.

Therefore n = 12.7 x 118 = 138 as before.

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SEWING THREAD

2013-03-01T22:50:00.001+06:00

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Sewing threads have to make with the properties by which it can be possible to sewn garments smoothly. It has to be designed for smooth & efficient stitching. It should contain the properties for these it will not break in the time of sewing & after complete the sewing as well as up to buyer use. The composition & the construction have to manufacture as required for the efficient smooth stitching to the proper selection of fabric, based on the seam type.

CONSTRUCTION OF THREAD

Sewing threads are made of cotton, linen, silk, rayon, or polyester or blends thereof. The properties of the fiber determine its use and application. For example, cotton is the most widely used because of its high versatility and low cost; rayon, which is much weaker, is used primarily for fancy stitch work; polyester is used where strength and water repellency are more important.

All sewing threads are made of ply yarns. The single yarns, which may be spun, filament, or multi-component are highly twisted (plied) to form a firmer and more uniform thread than ordinary yarn. Sewing thread may be given special finishes, such as mercerizing, glace or water repellency or swelling to serve particular uses.

THREAD SIZES

The size of spun thread had been expressed in terms of its diameter: the higher the number the finer the thread. At one time, thread had been made only from three-ply spun yarns. Therefore, a spun yarn thread of 50 three ply (50/3) had a ticket number of 50, a thread of 60 three ply (60/3) had a ticket number of 60, and so forth.. Subsequently, the number of plies in sewing thread was extended to, two, three, four and six ply. A ticket number of 50 could therefore indicate a 50 two ply (50/2), a 50 three ply (50/3), a 50 four ply (50/4), or a 50 six ply (50/6); but the thickness of the thread in each case was the same, while each ply was thinner. The greater number of ply yarns implied greater thread strength. The size of mercerized cotton sewing thread were identified by letter as well as number. The range was found from F (coarsest) to A (medium) and then from 0 to 00000 (finest).

Identification of thread size, called ticket number, is undergoing a transition. Different kinds of yarns had different numbering designations. The Thread Institute adopted a standardized ticket numbering system based on the tex system of numbering yarn.

The tex system is intended to give an orderliness by providing one ticket numbering system based upon metric system which is now universally accepted. Since tex is the weight in grams of a 1000-meter length and is a direct numbering system, the greater the weight the thicker the thread and therefore higher the number. Ticket numbers are based on actual tex size of the thread in the griege state, i.e. twisted, braided, or extruded before any dyeing, special processing, or finishing. The purpose of the stipulation is intended to obviate the alteration of the thread’s apparent size by any finish.

STANDARD SEWING THREAD TEX TICKET NUMBER

1 10      35    105    300
2    12    40    120    350
3    14      45    135      380
4    16    50    150    400
5    18    60    180    450
6    21      70    210    500
7    24    80    240    Above 500, in
8    27      90    270   increment of 100
9    30

One important caution should be noted when using the tex ticket numbers. When selecting proper thread size, threads of the same fiber and type must be compared. Since the tex ticket numbering system is based on weight and since different kinds of fibers and/or types have different weights and moisture, the same tex number of threads of different fibers or types will not necessarily be of the same thickness and may therefore not be interchangeable.

THREAD SELECTION

Selection of the appropriate kind and size of sewing thread is important. The thread should be as fine as possible, consistent with the nature of the fabric and the strength requirements of the stitching. Finer threads could be less obvious, they become hidden below the surface of the cloth, and they are less subject to abrasion than heavier threads. Also, finer threads require finer needles which cause less fabric distortion than heavier needles. Threads composed of the same kind of fibre as that of the fabric is also important because of such factors as general appearance, color fastness, finish retention, elasticity and strength.

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Nonwoven Fabrics | Introduction and manufacturing process of nonwoven geotextile fabrics

2013-01-17T01:29:00.001+06:00

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Nonwoven Fabrics

Techniques by which fabrics are made directly from fibers, bypassing both spinning and weaving, have been used for centuries in the production of felt and bark cloth is called nonwoven fabric. It is also called nonwoven geotextile fabric because it is one kinds of geotextile. With the development of manufactured fibers, and, in particular, the synthesis of thermoplastic fibers, technologies have evolved that have made possible the large-scale production of non-woven fabrics. The first non-woven consumer product, an interlining fabric for the apparel industry, was introduced in 1952. Marketed extensively for both durable and disposable items, nonwoven fiber webs range from disposable diapers to blankets, from industrial filters to tea-bag covers.

Nonwoven fabrics are textile structures “produced by bonding or interlocking of fibers, or both, accomplished by mechanical, chemical, thermal or solvent means and combinations thereof” (ASTM 1998). This excludes fabrics that have been woven, knitted, or tufted. The Association of the Nonwovens Fabrics Industry (lNDA) in the United States and the European Disposables and Nonwovens Association (EDANA) help to further define what may be called a nonwoven fabric Oirsak and Wadsworth 1999). Over 50 percent of the weight of a non woven must be comprised of fibers with an aspect ratio (length to diameter ratio) of 300. This excludes paper products that are normally made of extremely short fibers. In additi”on nonwovens must have a density less than 0.4 grams per cubic centimeter, and felted fabrics are usually much heavier.

American Fabrics (1974) magazine recommended that nonwoven fabrics be classified as durable products or disposable products. They defined a durable product as “one which is multi-use. It is not manufactured to be thrown away after a single application” (p. 40). Examples of this type of product are blankets, carpet backings, and furniture padding. Disposable products were defined as “made to be disposed of after a single or limited number of uses”. These are exemplified in disposable diapers, towels, or tea-bag covers. American Fabrics pointed out that some items are disposable not because of their durability but because of their purpose. Medical gowns, for example, or airplane and train headrests, might withstand multiple use, but for sanitary reasons they have limited use periods.

Manufacture of nonwoven fabric

There are two steps involved in manufacturing nonwoven fabrics:

(1) preparation of the fiber web and

(2) bonding of the fibers in the web.

A number of possibilities exist for each step, and in addition, the two stages may be distinct or can be carried out as a more or less continuous process.

Fiber Web Formation Staple fiber webs are produced by either dry firming or wet firming. Dry-forming processes are carding, also called dry laying, and air laying. Carded webs are made in a manner similar to the process for felt webs and slivers for yarn spinning. Thicker webs can be built up by layering the carded webs. In air laying, the fibers are opened, suspended by air, and then collected on a moving screen. The wet laid process is similar to paper making in that a mixture of fibers in water is collected on a screen, drained, and then dried.

Webs can also be made by the direct extrusion processes of spunbonding and melt blowing. Spunbonded fabrics are manufactured from synthetic filament fibers. Continuous filaments are formed by extrusion through spinnerets, and the filaments are blown onto a moving belt where they form a web. As the still hot and partially molten filaments touch, they bond. Polymers most often used are polypropylene and polyester. Spun bonded fabrics are strong because of the filament fibers and are not easily torn. They are used for a wide variety of products ranging from apparel interlinings, carpet backing, furniture and bedding to bagging and packing material. Spunbonded fabrics may be used in geotextiles to control erosion or in constructing roads.

Some spun bonds made from olefins are used as a tough, especially durable substitute for paper in wall coverings, charts, maps, tags, and the like. Melt blowing also forms fabrics directly from fibers, but it differs from spun bonding in that molten fiber filaments are attenuated and broken into short lengths as they exit from the spinnerets. Cool air distributes the fibers onto a moving screen.

As the fibers cool they bond, forming a white, opaque web of fine fibers. Because the fibers in melt-blown nonwovens are fine, the fabrics make good filter materials. Specialty products can also be made by layering spun bonded and melt blown fabrics or by entrapping absorbent fibers or other materials within the melt blown structure.

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Production of filament yarn with man-made fibre by Emulsion spinning and Wet spinning

2013-01-15T23:43:00.002+06:00

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In melt spinning the fiber polymer is melted and the molten solution is forced through the spinneret. As the soft filaments emerge from the spinneret into the cooler environment, they harden into a standard filament form. Melt spinning requires no chemical change & any kind in the polymeric material from which the fiber is formed. It does require that the fiber polymer can be melted without altering the chemical state of the material. Fibers formed by this process are Nylon, Polyester, and glass.

Emulsion Spinning

Emulsion spinning is not used to a great extent but it is important for selected types of specialty fibers. Some raw polymeric materials cannot be processed by wet/dry/melt methods, because they either breaks drown when heated to a melting temperature or are not soluble in solution that can be used. For these substances the emulsion process is necessary.

The polymer dispersed or emulsified into a solution, the dispersion or emulsion is then forced through a spinneret, and as the emulsion leaves the spinneret, the polymer form into a fibrous shape. Depending on the type & fiber, the fibrous form produced by this method may be staple / filament length. Teflon is an example of a fiber spun by the emulsion process. First, polymers, whether natural or synthetic, must be converted into liquid form to be spun. This is done either by dissolving the polymer in a suitable solvent or by melting it. This polymer solution or polymer melt is sometimes referred to as the spinning dope. Cellulose, the raw material for most naturally derived manufactured fibers, is not easily dissolved. Accordingly, the cellulose polymer is usually modified before it is dissolved. Synthetic polymers are put together in the plant before the dissolution or melting step.

Before actually forming the fiber, certain characteristics can be added to the polymer material. Many manufactured fibers are naturally bright, with a high luster. If dull or semi-dull fibers are wanted, delustering agents can be added to the molten polymer to break up light rays and decrease shine. Colored pigments, flame retardants, and compounds to absorb ultraviolet light can also be added. Occasionally substances are added during polymer synthesis so that they are incorporated into the polymer molecules themselves.

Wet Spinning

Wet-spun polymers are, like dry-spun polymers, converted into liquid form by dissolving them in a suitable solvent. The polymer solution is extruded through a jet into a liquid bath. The bath causes coagulation and precipitation of the fiber. Solvents are usually recovered from the liquid bath and are recycled. Viscose rayon and some acrylics are wet spun.

It is possible to add special chemical reagents to the liquid bath that produce selected changes in the fiber. This is done in the manufacture of some high-strength rayons, for example; into a liquid bath. The bath causes coagulation and precipitation of the fiber. Solvents are usually recovered from the liquid bath and are recycled. Viscose rayon and some acrylics are wet spun. The polymer or substance to be used is making the fiber is dissolved into some type & solution, then is forced through the spinning jet into another liquid, which react with fiber solution the process involves one & the following reaction:

(a) The fiber polymer may have been chemically changed in order to make it soluble in the solvent used when this occurs the fiber solution reacts with the receiving solution & reverses the chemical reaction so that the material is reformed into a fiber shape. The difference is that in reforming, a filament fiber shape has been made rather than a polymer in some other form, such as fibrous mass, chip or pellet. This process refers to the fiber solution as a derivation & the fiber form, the solution into which this passes is the coagulating bath & the actual process is typically called regeneration.

(b) Wet-spinning may also be used when the fiber solution does not change the chemical form of the fiber. The solution is forced into a coagulating bath, which reduce the concentration of the fiber solution sufficiently to reform the fiber, this time in a filament form Fibers formed by wet spinning are rayon, acrylicA variant of wet spinning, called dry-jet wet spinning, has been developed to produce some of the newer fibers such as the aramid. Instead of the spinneret being immersed in the spinning bath, it is placed slightly above the bath so that there is a small air gap, usually less than an inch. The fibers exiting the spinneret can be stretched to orient the molecules before they enter the bath to be solidified.

This process develops high orientation and crystallinity in one step, rather than drawing in a separate step Although melt-, dry-, and wet-spinning techniques are used to form the vast major-ity of manufactured fibers, several other spinning techniques also exist and may be applied in a limited number of specialized situations. High-molecular-weight poly-mers, such as those in Spectra@ polyethylene, are formed by solution spinning or gel spinning. As in wet and dry spinning, the polymer is dissolved in a solvent. The polymer and solvent together form a viscous gel that can be processed on conventional melt-spinning equipment to form a gel-like fiber strand. Later in the processing, the solvent is extracted and the fibers stretched. Fibers made from polymers that have extremely high melting points and are in-soluble present obvious difficulties in spinning. Such materials may be spun by a complex process called emulsion spinning in which small, fibrous polymers are formed into an emulsion, aligned by passing the emulsion through a capillary, then fused or sintered (combined by treating with heat without melting), passed through the spin-neret into a coagulating bath, and subsequently stretched

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Production of filament yarn with man-made fibre by Melt spinning and dry spinning

2013-01-15T23:29:00.001+06:00

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Man Made Fiber Formation

Man-made fibers are polymeric forms that are produced by some type of chemical which or by the regeneration & natural polymers in a new physical form. The polymer is connected into some type & liquid / fluid state and forced through a spinnerette. Although most spinnerette are made with round openings, some may use orifices & other shape is order to produce fiber with special characteristics.

The basic steps in producing manufactured fibers are as;

The liquid polymer is then extruded through a spinneret. Each spinneret has a number of holes, and each hole produces one filament. As they exit the spinneret the filament fibers are solidified by cooling of melted polymers, by evaporating the solvent, or by precipitating the polymer from solution. These methods of solidification are the bases of the three primary fiber manufacturing processes. Other spinning methods that have been developed are described later in this chapter.

Filament yarns are described by denier (that is, size) and number of filaments; for example, filaments described as 70/34 represent 70 denier/34 filaments. When fibers being extruded are intended for conversion into staple lengths, spinnerets with larger numbers of holes are used to produce more filaments that are later cut into staple lengths. Spinneret holes are spaced to allow the filaments to be extruded without touching each other. The holes must be exactly the same size to produce uniform fibers. The metal used in the plate must be capable of withstanding high pressures or corrosive spinning solutions.

Most fiber spinning processes include a final step of drawing in which the filaments are stretched around rollers.

Melt Spinning

Melt spinning take advantage of the thermoplastic characteristics of polymers. Chips of solid polymer about the size of rice grains are dropped from a hopper into a melter where heat converts the solid polymer into a viscous liquid. The liquid forms a “melt pool” that is pumped through filters to remove any impurities that, would clog the spinneret and is delivered to the spinneret at a carefully controlled rate of Row. Melt spinning is simpler and cheaper than other spinning methods; therefore, it is used except when polymers cannot be melt spun.

The spinneret holes are usually round, but noncircular holes are also used to make filaments of various cross-sectional shapes. Melt-spun fibers may be made through Y-shaped holes that yield a three-lobed fiber or C-shaped holes to produce a hollow filament, for example; The diameter of the fiber is determined by the rate’ at which the polymer is supplied to the hole in the spinneret and the windup speed, not by the diameter of the hole. When the molten polymer emerges from the spinneret hole, a cool air current is passed over the fiber, causing it to harden. Failure to maintain constant feeding speed of molten polymer or changes in the temperature of cooling will cause irregularities in the diameter of the fiber. Nylon and polyester are the most common melt-spun fibers. One of the latest developments in melt spinning has been the significant increase in spinning speeds. Processing speed has increased from less than 1,000 meters per minute in the 1960s to over 7,000 meters per minute today. This is the equivalent of a car traveling over 250 miles per hour. Higher-speed spinning is cost-effective and up to a certain point increases the orientation of the polymers in the fibers. Beyond a speed of about 6500 meters per minute, however, this advantage disappears as there is not enough time for the polymers to crystallize and the fibers may break.

Dry Spinning

In dry spinning the fiber solution is forced through the spinneret into a warm air chamber. The warm air causes the solvent used to make the fiber solution evaporate & the filament fibers are formed & hardened. This process, too may involve converting the fiber polymer into a different chemical form that is soluble in a suitable liquid As the solvent evaporate, the fiber polymer is reconstituted & return to its original chemical form, but now it is in a filament shape.

Many polymers are adversely affected by heat at or close to their melting temperatures. Polymers that cannot be melt spun undergo other methods of spinning, such as dry spinning, to produce filaments. Dry spinning requires the dissolving of the polymer in a solvent to convert it into liquid form. Substances used as solvents are chosen not only because they will dissolve the polymer but also because they are safe and can be reclaimed and reused.

The polymer and solvent are extruded through a spinneret into a circulating current of hot gas that evaporates the solvent from the polymer and causes the filament to harden. The solvent is removed and recycled to be used again. Dry-spun filaments generally have an irregular cross section. Because the solvent evaporates first from the outside of the fiber, a hard surface skin of solid polymer forms. As the solvent evaporates from the inner part of the fiber, this skin “collapses” or folds to produce an irregular shape. If the rate of evaporation is slowed, the cross section of the filament will be more nearly round. Acetate fibers and some acrylic fibers are dry spun.

Fibers formed are: acetate, triacetate, acrylic, modacrylic, aramid fibers.

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HOLLOW FIBERS | BI-COMPONENT FIBERS

2013-01-15T22:08:00.003+06:00

HOLLOW FIBERS

Hollow fibers are made of a sheath of fiber material and one or more hollow spaces at the center. These hollows may be formed in a number of different ways. The fiber may be made with a core of one material and a sheath of another, and then the central material is dissolved out. Alternatively, an inert gas may be added to the solution from which the fiber is formed, with the gas bubbles creating a hollow area in the fiber. Other experimental or proprietary techniques have been used to make hollow fibers. One involves spinneret holes with solid cores around which the polymer flows.

Hollow fibers provide greater bulk with less weight. They are therefore, often used to make insulated clothing. For absorbent fibers such as rayon, hollow fibers provide increased absorbency. Some have been put to such specialized uses as filters or as carriers for carbon particles in safety clothing for persons who come into contact with toxic fumes. The carbon serves to absorb the fumes Bi-component Fibers

The American Society for Testing and Materials (ASTM) defines a bi-component fiber as “a fiber consisting of two polymers which are chemically different, physically different, or both. Bicomponent fibers can be made from two variants of the same generic fiber (for example, two types of nylon, two types of acrylic) or from two generically different fibers (for example, nylon and polyester or nylon and spandex). The latter are called bi-component bi-generic fibers.

Components in bi-component fibers may be arranged either side by side or as a sheath core. In making a side-by-side bicomponent fiber, the process requires that the different polymers be fed to the spinneret together so that they exit from the spinneret opening, side by side. Sheath-core bi-component fibers require that one component be completely surrounded by the other, so that the polymer is generally fed into the spinneret as shown in Figure. Variation in the shape of the orifice that contains the inner core can produce fibers with different behavioral characteristics.

BI-COMPONENT FIBERS

As the technology for producing manufactured fibers has become more highly developed, manufacturers have turned to increasingly sophisticated techniques for creating new fibers. Not only are new generic fibers being created but also different polymers or variants of the same polymer can be combined into a single fiber to take advantage of the special characteristics of each polymer. Such fibers are known as bi-component fibers. The American Society for Testing and Materials (ASTM) defines a bi-component fiber as “a fiber consisting of two polymers which are chemically different, physically different, or both. Bi-component fibers can be made from two variants of the same generic fiber (for example, two types of nylon, two types of acrylic) or from two generically different fibers (for example, nylon and polyester or nylon and spandex). The latter are called bi-component bi-generic fibers.

Bi-component fibre

Components in bi-component fibers may be arranged either side by side or as a sheath core. In making a side-by-side bi-component fiber, the process requires that the different polymers be fed to the spinneret together so that they exit from the spinneret opening, side by side. Sheath-core bi-component fibers require that one component be completely surrounded by the other, so that the polymer is generally fed into the spinneret as shown in Figure. Variation in the shape of the orifice that contains the inner core can produce fibers with different behavioral characteristics.

POLYMER SPINNING | DRAWING OR STRETCHING AND HEAT SETTING OF POLYMER YARNS

2013-01-15T21:56:00.002+06:00

POLYMER SPINNING

Polymer spinning is important part of man made fiber and yarn manufacturing technology. Polymer spinning is very popular and result oriented synthetic spinning method. Although melt- spinning, dry-spinning, and wet-spinning techniques are used to form the vast majority of manufactured polymer fibers, several other spinning techniques also exist and may be applied in a limited number of specialized situations. High-molecular-weight polymers, such as those in Spectra@ polyethylene, are formed by solution spinning or gel spinning. As in wet and dry spinning, the polymer is dissolved in a solvent. The polymer and solvent together form a viscous gel that can be processed on conventional melt-spinning equipment to form a gel-like fiber strand.

Later in the processing, the solvent is extracted and the fibers stretched. Fibers made from polymers that have extremely high melting points and are insoluble present obvious difficulties in spinning. Such materials may be spun by a complex process called emulsion spinning in which small, fibrous polymers are formed into an emulsion, aligned by passing the emulsion through a capillary, then fused or sintered (combined by treating with heat without melting), passed through the spinneret into a coagulating bath, and subsequently stretched.

DRAWING OR STRETCHING OF POLYMER YARN

Both crystalline and amorphous arrangements of molecules exist within newly formed filaments. It is possible to orient these molecules to make them more parallel to the walls of the filament, and therefore more crystalline and stronger, by stretching the filament before it is completely hardened after polymer spinning.

Newly formed filaments are, therefore, subjected to drawing or stretching. Depending on the fiber type, this may be done under cold or hot temperature conditions and has the additional effect of making the filament both narrower and longer. Fibers made from polymers that have a low glass transition temperature, such as nylon, can be drawn at room temperature.

In case of polymer spinning, The polymers are mobile and can be pulled into positions parallel to the fiber length. Polyester, on the other hand, has a higher glass transition temperature and so must be heated to be drawn. Drawing is accomplished by stretching the fibers between two rollers, called Codet rolls, with the second roller rotating faster.

Not all yarns are drawn to the maximum amount possible, because when a fiber reaches its maximum length, the extensibility of the yarn and fiber are lowered. Yarns that have not been fully drawn are called partially oriented yarns (POY). Those that have been fully drawn are called fully oriented yarns (FOY). Lower speeds in melt spinning produce fibers with lower orientation. As is true of many other textile processes, precise control of the process must be maintained so that the manufacturer can achieve the qualities needed in the final product.

Other steps may be added, such as texturing (in which crimp is added to the filaments) or heat-setting treatments to ensure very low shrinkage as is required in fibers for automobile tires. Sometimes two or more steps may be combined into consecutive operations to reduce manufacturing costs, so that the fibers may go from spinning directly to drawing or from spinning to drawing to texturing.

HEAT SETTING AFTER POLYMER SPINNING

Thermoplastic manufactured fibers may shrink when exposed to heat. To prevent shrinkage, such fibers are treated with heat during manufacturing to “set” them into permanent shape. Exposure during use and care to temperatures greater than the heat-setting temperature will counteract the heat setting, resulting in fiber shrinkage or loss of heat-set pleats or creases.

As the technology for producing manufactured fibers has become more highly developed, manufacturers have turned to increasingly sophisticated techniques for creating new fibers. Different fiber shapes and sizes, as well as unique combinations of polymer types in the same fiber, are but several examples of these techniques.