Injection Mold Design Tutorial, Technology and Engineering

collapsible core for demolding/ejection system of internal screw undercut

2011-11-21T15:58:00.000-08:00

one common way used in the ejection system for an internal screw is used collabsible undercut core, which requires collabsible core product generally has the undercut on the inside, for example an internal screw, pipe fittings, elbow pipe, use collabsibe core is not only on the core course , undercut the slider is also often used collabsible cores. video below gives a simple explanation of how

Runner Design in Injection Mold,

2011-06-29T16:58:00.000-07:00

in designing the runner, first-time we must consider items that affecting runnersize, some of which - Volume of part, the greater the volume takes a larger diameter runners anyway. - Weight of part, the heavier parts, it takes a larger diameter runners. - Plastic materials, plastic materials with low viscosity, aqueous requires a smallerdiameter runner. - Wall thickness, the thicker the greater

Lifting bolts hole design in injection mold

2011-03-07T15:35:00.000-08:00

Plate transfer process occurs during the machining and assembly of mold, both for the cavity and mold base plate, especially for the plate with a weight greater than 20 kg, threaded hole necessary to facilitate the transfer process. cause may be in a mold plate having a various of machining processes with different types of machines. Base on position of hole the type of lifting bolts can divided

runner components of injection mold

2011-02-07T05:21:00.000-08:00

Runner components between the two mold plate and three plate mold because there are different functions of these components, but there are several components that can be used in general without looking at the type of mold construction. 1.Runner lock pin The main function of the runner lock pin (RLP) is an pulling runner so the gate can be disconnected/cut from the product, RLP fitted with a

using mold base become locking block of slider unit

2010-12-22T08:05:00.000-08:00

moldbase sometimes can be used for the locking block on the slider unit, this is basedon several reasons, for example, to reduce cost, by reducing the insert locking block, the other reason is required surface area for the locking block. illustration picture above shows the angular pins are bolted to the mold base and the mold base made pocket instead of locking block, to keep the process

Loose core for ejecting undercut at injection mold

2010-11-21T08:40:00.000-08:00

Picture above shows the loose core, or often also called slope ejectors or inclined pin, loose cores is one method to overcome the undercut on the product, particularly undercut the core position facing into the bottom (towards the sprue bush-center of mold) that undercut it can not be made simply by using slider method, part of the loose core complete with mold base include: 1. Top clamping

Loose cavity inner undercut release method in injection Molding

2010-11-12T11:52:00.000-08:00

one way to release the undercut is to loose cavity, the opposite of loose cores, loose inner cavity is used to remove the undercut in the cavity area, note the image below for more details, 1 = top plate 2 = runner stripper plate 3 = cavity plate 4 = core plate 5 = locking block for loose cavity 6 = angular pin for loose cavity system 7 = loose insert cavity some designers also say that with

Top 6 Injection Molding Company

2010-10-02T17:27:00.000-07:00

it's difficult to list all company that provide any solution about injection machine, include manufacturer, injection molder, machine maker, and injection design, based on the survey is limited to friends and colleagues associated with the injection mold, which many ads appear on Google, and companies that contribute most in the book and seeing appear in the books of injection mold, here I will

wall thickness and sink mark estimation

2010-08-17T02:09:00.000-07:00

Uniform wall thickness in plastic part design is critical.Non-uniform wall thickness can cause serious warpage and dimensional control problems.One of the easiest ways to cure this problem is change the part geometry by adding ribs. The use of ribs is a practical way and economical means of increasing the structural strength of a part. it is more economical to use ribs than increase wall

Locking Block With Angular Slider

2010-08-02T15:53:00.000-07:00

What should you do when the slider design and found that the angular slider too long? There are many ways to change the design so that the angular length of the slider pins are still reasonable when compared to its diameter.in design between the angular diameter and length of the slider pins should be noted, the length of angular slider pins that are too long can lead to easily broken when

slider construction : cam or angular pin

2010-06-26T11:34:00.000-07:00

posts related to construction and part-bagianya slider has been my post, about the cooling on the slider, the basic construction for the slider, the slider and the main part, please see previous post to learn the basic construction and when we should use the slider, This post will discuss about when we need to use of the slider that use angular pin or just cam slider, what advantages and

Troubleshooting warpage on injection molds

2010-05-09T11:25:00.000-07:00

Warping, Part Distortion is shows up as parts being bowed, warped, bent or twisted beyond the normal specification outlined on the drawing.Warpage occurs when there are variations of internal stresses in the material caused by a variation in shrinkage. Warped parts may not be functional or visually acceptable. Main Causes1.Non-uniform cooling Temperature differences from one side of the mold to

Troubleshooting weld lines and meld lines on injection molds

2010-03-24T07:48:00.001-07:00

In manufacturing, the Weld line or Knit line or Meld line is the line where two flow fronts meet when there is the inability of two or more flow fronts to "knit" together, or "weld", during the molding process. These lines occurs usually around holes or obstructions and cause locally weak areas in the molded part. A weld or meld line is a weakness or visible flaw created when two or more flow

Troubleshooting short shot problems on injection mold

2010-03-03T04:10:00.000-08:00

The term "short shot" or "short mold" is used to refer to a phenomenon where plastic being injection molded does not reach certain portions of the inside of the die before solidifying. or it means that not enough resin has flowed into the mold to fill it adequately. The main causes for short shot are the mold condition or flowability problems with the resin. The problem is alleviated when a

Stripper Ejector Construction (step by step mold design) part 8 : add return pin

2010-02-19T07:09:00.000-08:00

In ejector system, return pin is important, i was post about ejector system, include the function of each part, see it at this link, previous post is adding ejector pin and ejector guide bush in the mold, now next step is adding return pin, when we use mold standard or mold base blank, return pin always include in those mold base blank, if you have the catalog, return pin symbol is always RP,

Stripper Ejector Construction (step by step mold design) part 7

2010-01-30T04:23:00.000-08:00

Ejector Guide Pin and Bushin this part, we will design ejector guide pin, EGP bush, bolts for stripper plate and bottom plate. first learn ejector system and part at link below3D ejector drawinghope you can understand ejector system and ejector guide pin (EGP) function, Ejector guide pin located between ejector plate and ejector stripper plate, to fit the ejector pin, we can add bolt at the

Stripper Ejector Construction (step by step mold design) part 6

2009-09-13T08:17:00.000-07:00

now, after put sprue bush and locating ring at top plate, let's design core side, like cavity block, core block also need bolts to attach the core block to core plate, see picture belowat those picture i use M10 bolts type, this bolts use to attach the core block to mold base plate, don't forget to give chamfer of each side of core bolts, this chamfer very useful in assembly mold processing, this

Stripper Ejector Construction (step by step mold design) part 5

2009-09-04T09:24:00.000-07:00

next step let's put sprue bush at top plate until directly to product, beside sprue bush i put locating ring, this two part important become guide between mold and injection machine, sprue bush will guide molded plastic to runner, because this product use direct gate, runner also direct from runner to product. see picture below for detail Locating Ring Typei use 120 mm diameter of locating ring,

Stripper Ejector Construction (step by step mold design) part 4

2009-08-31T09:13:00.000-07:00

on the step below we design bolts position to hold the cavity insert to top plate of mold base, i use M10, or you can use other bolts base on your strength calculation and available market, there are various bolts type available on the market, i prefer use socket head screw in mold design, see link below for reference about this type of boltshttp://www.engineersedge.com/

Circular H type Runner Layout in Mold Design

2009-05-27T14:01:00.000-07:00

It’s called H type because the runner shape from the top similar with “H”, it’ use in both circular layout and rectangle layout system, in circular type the runner doesn’t similar with H but it more similar with fork, circular type use in various type of product, like gear, cylinder shape, etc. Total length of H circular type in each part of runner8.801 x 16 = 140.8167.491 x 8 = 119.85618.83 x 8

direct circular runner system and direct rectangle runner system in mold design

2009-05-19T09:34:00.000-07:00

continuing previous post about sleeve ejector system in mold, now let's learn how to choose runner layout, and lay outing the cavity and core,From picture above space that available for layouting cavity core is 40 mm X 40 mm, from those available space we must design effective and cheap runner cost, effective design for runner mean that total runner length designed as short as possible, and

Mold Cavity Core Construction for Sleeve Ejector System

2009-05-14T10:03:00.000-07:00

continuing from previous post about sleeve ejector system, below the explanation of cavity and core constructions Cavity Construction Basically cavity consist of : cavity main insert, and cavity insert, for this product, we use cavity main insert shape like pin, and to release air trap, we put cavity insert pin (pink color) with gas vent land. Gate located at cavity main insert that one position

Sleeve ejector system

2009-05-06T02:49:00.000-07:00

This system use when part have tolerance or good dimension so, so we can’t put ejector in those face, or ejector prohibited in that face other reason is part have hole and face that can touch with ejector is very small and surrounding the hole. Look at picture below Red face indicated that ejector is prohibited, for that reason the only way to eject those part is using sleeve ejector that will

Stripper Ejector Construction (step by step mold design) part 3

2009-03-01T05:25:00.000-08:00

after make insert like in posting number 2, let's make main construction of ejector stripper plate, simple ejector stripper plate consist of three main part 1. ejector plate2. bolts for clamp3. ejector pinthose plate main function is to push product when ejecting, isn't need much part of plate surface that contact with bowl surface, only 0,8 mm product will able to eject from core insert

Step by Step Mold Design (part 2), Insert Design

2008-12-21T03:47:00.000-08:00

continuing with the previous post, now let's make some insert in core side, this insert very simple and easy in machining process. from the core block side we divide at the circle line of side of bowl, why ?, because we will eject the product using stripper plate, stripper plate construction will eject the product by touching the thin face in all around of bowl.insert functionthere are two