Dukane Ultrasonic Welding News and Information Channel

Dukane at NPE 2012 in Orlando, FL

noreply@blogger.com (Dukane Ultrasonics) — Fri, 30 Mar 2012 13:52:00 +0000

By Mike Johnston, VP Sales & Marketing, Dukane Corporation

NPE 2012 is next week. This will be the first year that NPE will be held in Orlando Florida. The show claims there will be 55,000 attendees which is up by 10% over 2009. They have posted that there are 1,826 exhibitors. The number of foreign registrants this year is 26% compared to 16% in 2009. They attribute this to a greater number of visitors from Latin America. Stating that the number of running machines has drastically increased, they are basing this on the tonnage of the equipment being brought compared to in 2009. In fact Dukane is bringing 19,146 lbs of equipment!

We are very excited this year, being at a new venue and the fact that we did not attend in 2009. I am confident customers will be interested in seeing what’s new with Dukane. Our booth is 30’ x 50’.

NPE 2012 Booth Concept

Our focus will be on our Ultrasonic Servo welders with Patented Melt-Match® Technology. We will be promoting our Servo Challenge which states “We are so confident in the repeatability & accuracy of our Patented iQ Servo Technology that if we are unable to produce a more consistent weld result vs. your current pneumatic welder...we will give you a pneumatic welder for FREE” We will have a large banner in the booth with a QR code that will direct customers to our website to sign up. We are displaying the whole iQ Servo product family 15, 20, 30, and 40khz. The 40kHz is the A4 version which is mounted on a SRT50 rotary index.

All of the Servo welders have the new color front panel and will be networked with the iQ Explore II software, which will be projected on a 8’ x10’ screen up above the booth. Actually we will have two screens, the second of which will loop our Servo promo movie.

On the vibration welder front we are taking two machines. Our new 5700 LPT machine with its new user interface. The second machine is a frame completely built without the enclosure which will give customers a clear view of the robust quality. We believe this will attract a lot of interest.

Dukane will be the first to launch an Ultrasonic Welding Guide for the iPhone and Android users. Customers will be able to download this application for free to their phones while visiting our booth. The application has Material Compatibility, Amplitude Guide, Booster Gain Calculator and Initial Machine Settings.

In addition we will have an interactive display of the iQLinQ; running EtherNet/IP and Profibus, 20, 30, 40 kHz Hand probes showing patented Trigger by Power, and our new iQ LE Pneumatic press system.

Ken Holt will be presenting a paper; “Advances in Medical Plastics: Benefits of Servo Ultrasonic Welders to Medical Industry — A Case History” at the Antec session on Tuesday.

This should be a fantastic show for Dukane!

Boost Performance, Speed, Economy with Servo-Controlled Welding

noreply@blogger.com (Dukane Ultrasonics) — Thu, 15 Dec 2011 20:20:00 +0000

Ultrasonic welding is one of the most widely used processes for bonding polymers, valued for its speed, flexibility, and low cost. In recent years, there has been greater demand from OEMs and processors for more controlled and consistent ultrasonic welding, especially for production of medical devices and high-value precision components. New developments in electric servo-driven welders are helping to meet this challenge.

Application testing and customer feedback have shown that electric servo-driven ultrasonic welders can provide significantly more consistent results than standard pneumatic ultrasonic welders. Servo-controlled welding is targeted for production of components and assemblies that require precise dimensional tolerances, such as those in medical, electrical, automotive, robotic, and fluid-control systems. Servo-controlled ultrasonics also facilitate production of parts that require FDA validation, where the process affords repeatability and precise documentation.

With servo systems, processors of high-value goods such as medical components have a servo-controlled welding option that brings significant performance benefits over pneumatics. This is a breakthrough development in plastic welding that solves manufacturers’ most pressing challenges: process repeatability, validation, calibration, and manufacturing cost.

SERVO VS. PNEUMATIC
Ultrasonic welding is the joining of thermoplastics through the use of heat generated from high-frequency mechanical motion. Although it was first developed several decades ago and has been widely used in the plastics industry for a number of years, there have been few fundamental design changes in the process since Dukane’s introduction of “Weld by Distance” in 1988.

Servo-controlled ultrasonic welders, like Dukane’s iQ

series with Melt-Match technology, are said to offer

numerous advantages over pneumatics, such as much

more precise control of weld and hold collapse distances.

Ultrasonic welders have long been a popular choice for joining thermoplastics in a broad range of end-use markets, due to several factors. The equipment is compact, easy to incorporate into automation, and economical. Additionally, ultrasonic welders can produce high-quality welds in a short cycle time. The greatest advantage of ultrasonic welding, however, is the ability to use very precise process control.

The welding equipment typically consists of a press, generator, transducer, booster, and horn. The generator converts standard electric line power into high-frequency AC voltage that is then passed through the transducer. The transducer consists of piezoelectric ceramics that expand and contract at the same frequency as the alternating voltage applied to each side of the ceramics. This sinusoidal mechanical vibration is then passed through the booster and horn into the parts to be joined. When force is applied between the parts by the press, these vibrations pass to the weld joint area, where melting occurs. After the vibrations are stopped, the plastic solidifies during the “hold” phase, forming a welded assembly.

The basic function of a pneumatic press is to apply force between the parts using an air cylinder. The amount of force is generally controlled using a pressure regulator and one or more valves. Typical process-control parameters available to the user are ultrasound amplitude, weld pressure (constant or profile), weld time, hold pressure (constant or profile), and hold time. More advanced systems also have the ability to measure distance, allowing a level of control of the weld and hold distances.

Servo-driven welders such as Dukane’s iQ Series, which was introduced in 2009, is different from pneumatic systems because it utilizes an electrical servo actuator in place of the pneumatic cylinder. Instead of controlling the force, the servo system controls the speed of the horn during the weld and hold phases. Typical servo process-control parameters are ultrasound amplitude, weld distance, weld speed (constant or profile), hold distance, hold speed, and static hold time.

SERVO ADVANTAGES
The servo-driven welder provides several advantages over pneumatic systems. The main advantage is significantly more precise control of the weld and hold collapse distances, which stems from the underlying method of distance control. In pneumatic systems, the distance is controlled indirectly by relieving pressure from the air cylinder once the desired distance is achieved. Due to the limited rate at which compressed air can escape the cylinder, as well as other factors, the press typically travels beyond the desired collapse distance by varying amounts.

Conversely, the servo system controls the distance directly through closed-loop servo position control. The servo dynamically seeks to arrive at the desired position, yielding very precise and repeatable results.

Data from an experiment comparing repeatability of distance welding for round polycarbonate filter parts (see Fig. 1) indicate that the standard deviation of the total part collapse was more than 3.5 times smaller for the servo system than a pneumatic system (actual values were 0.00012 in. or 3 μm for the servo vs. 0.00046 in. or 12 μm for pneumatic). The standard deviation of the weld pull strength relative to the average was smaller, as well—2% for servo vs. 4% for pneumatic.

Fig. 1—Experimental data comparing repeatability of distance welding

for round polycarbonate filter parts show that the standard deviation

of the total part collapse was more than 3.5 times smaller for the servo

system than for a pneumatic system.

An example of servo performance in an industrial setting is the welding of the dual check-valve parts shown in Fig. 2 (parts and weld data come from Value Plastics Inc., Fort Collins, Colo.). When programmed to weld by collapse distance of 0.0088 in., the servo system achieved an average collapse of 0.0088 in. (224 μm) with a standard deviation of 0.00008 in. (2 μm) for a 1000-part sample. In addition to the highly repeatable weld collapse performance, the quality of the welds obtained on the servo system was better than with a pneumatic welder due to the elimination of air bubbles near the weld zone (Fig. 3).

Fig. 2—Another example of servo performance is the welding

of dual check-valve parts molded by Value Plastics Inc. When

programmed to weld by collapse distance of 0.0088 in.,the servo

system achieved an average collapse of 0.0088 in. (224 μm) with

a standard deviation of 0.00008 in. (2 μm) for a 1000-part sample.

Fig. 3—The quality of the welds obtained on the servo

system beat that of a pneumatic welder due to the

elimination of air bubbles near the weld zone.

Another advantage is the ability of the servo press system to change speed rapidly. In certain applications, it is desirable to profile the speed during the weld in order to match the rate of material melting. Since most ultrasonic welds take less than 0.5 sec, it is critical to change speed quickly to achieve meaningful weld profiling. The servo system is capable of accelerations of 50 in./sec2, which is equivalent to changing speed by 1 in./sec in 0.020 sec.

The ability to program independent speeds for up to 10 different segments of the weld, along with the servo system’s ability to dynamically sense when melting is initiated at the beginning of the weld process, is what Dukane terms Melt-Match technology. Although some pneumatic systems are capable of varying the force during the weld, the rate of change is restricted by the time required to move air in or out of the air cylinder. Rapid speed changes on the servo welder also afford the flexibility to achieve hold speeds that are substantially different from the weld speeds.

Versatility is another key advantage of servo systems. Some applications considered very difficult if not impossible to achieve on a pneumatic welder, have been successfully executed on a servo system. One example is sealing and cutting of thin films, where the weld distances and forces are quite small. With precise distance control, the servo system is capable of achieving quality welds.

Other advantages of the servo system include:

Enhanced control capability in the hold phase, which consists of a dynamic stage (parts are collapsed further after ultrasound is turned off) and static stage (servo maintains its final position to allow the solidification process to complete).
Ease of calibration due to the elimination of pneumatic components.
Ease of welder “cloning” due to digital process control (i.e., ability to set up multiple welders to achieve identical performance).

MAJOR ECONOMIC BENEFITS
Servo-controlled welding systems also provide many cost benefits. Due to the high degree of process repeatability, rejects can be reduced. This enhanced ability to maximize yields is especially important in cases where the assembled parts are of high value.

The elimination of compressed air for press actuation can also produce savings. A typical 40-hp compressor can cost approximately $13,000/yr to operate. In addition, the expected maintenance costs are smaller. In typical applications, the servo actuator has a life span in excess of 200 million cycles.

To ensure process repeatability and maintain calibration, the servo system is designed without adjustable mechanical operator controls on the machine. This prevents accidental or unauthorized changes in calibration and validation.

Another key feature that provides tighter process control is Dukane’s patented iQ series power supply. It boasts industry-leading processing speeds of 0.5 millisec. The system also uses iQ Explorer graphical user-interface software for facilitating process setup and weld-data acquisition.

While servo systems are generally more expensive than standard pneumatics without process-control capabilities, they are within the price range of high-end pneumatics with advanced control features. Dukane’s servo-controlled systems have been installed at multiple OEM and processor sites in North America, Europe, and Asia.

About the Author
Paul Golko is senior project engineer at Dukane Corp., St. Charles, Ill., where he has worked on the development of servo-driven welding equipment, including the iQ servo ultrasonic welder.

A Primer to Spin Welding

noreply@blogger.com (Dukane Ultrasonics) — Fri, 23 Sep 2011 19:35:00 +0000

By Jerry Wibben, Regional Sales Manager, Dukane Corporation

Spin welding is a simple process that has been around (pun intended) longer than thermoplastics. Spin welding of metals has been known and practiced for at least a hundred years. It is no surprise, then, that it is one of the oldest methods of joining thermoplastic parts. It is a fast way to join parts that have a circular joint, and is very reliable at delivering a hermetic seal in those products that require one.

The fundamental idea is to spin one part against another under clamp force, the surface friction creating heat that melts the interface, and then to stop rotation and allow the parts to fuse together. It is a process that is deceptively difficult while in truth, as with many materials, it really is quite simple.

The Phases of Spin Welding

The phases of a spin weld are the approach, weld, hold, and retract. There are several ways to begin the rotation. If the part is to be rotated by frictional contact with the spin tool (as opposed to engaging a detail such as drive dogs or hose barbs), the tool can be spinning before contact. Alternatively, the tool can approach not spinning, pick the part up either with friction or vacuum, retract slightly, start spinning, and then extend again; or the tool can apply pressure prior to spinning. Of course, the part also can be directly loaded into the spin tool and held in place by friction or vacuum.

During the spinning portion of the cycle, the first thing that happens is some small amount of heat build-up that softens but does not melt the surface. When this happens, material will be stripped from the surface and rolled up into little balls. This is why spin welding produces particulate. As spinning continues, heat continues to build. Once sufficient heat has built up, true melting of material will occur. At this point, bond line thickness is established; in other words, additional spinning will not add to bond line thickness or strength of the part. Additional spinning, however, will cause the parts to travel toward each other with excess melted material thrown out of the joint in the form of flash and particulate. Concealing this flash and particulate is an important part of designing the joint.

Once true melting is established, rotation can be stopped. It is important to maintain clamp force on the parts and to stop the rotation as abruptly as possible. If spin down occurs in a gradual fashion, the material can start to solidify before rotation stops and the joint interface can be severely weakened by shear forces applied during this cooling period.

Virtually all thermoplastic material can be spin welded if they have a high enough ratio of the coefficient of friction to thermal conductivity. To put is more simply, heat needs to be created faster than it can dissipate. Usually, only materials with very high lubricity are excluded from consideration. Care should be taken to ensure that materials on both sides of the joint are not only chemically compatible, but have similar melt temperatures and similar melt flow indices. If materials are reinforced (i.e. with glass), there will be no benefit of reinforcement in the joint itself; the spin welding process does not promote any fibers crossing the joint line, rather it encourages fibers to lay parallel to it.

The joint itself needs to be a circle, but the remaining part geometry is fair game, as long as it does not interfere with rotation or create a severely out-of-balance condition for the rotating part. This is particularly a concern for small parts, as the rotation speeds may need to be high.

Rotation speed is based on the surface speed at the joint, so smaller parts turn at a higher rate than larger parts. A rule of thumb is that the target rotation speed in rotations per minute should be about 8,000 divided by the joint diameter in inches, or 200,000 divided by the joint diameter in millimeters. This is a ballpark speed, with successful applications running at speed deviating from this rule by 50 percent or more both high and low.

Three Main Classes of Spin Welders

Inertial spin welders typically use an air motor to spin up a flywheel, which can be clutched in, but is more commonly attached to the tool in a fixed manner and engages the part frictionally. The part acts as a brake for the flywheel; so the kinetic energy stored (mass of the flywheel multiplied by the rotational speed) is the energy imparted to the joint. Because of the high speeds air motors can generate, these machines work well for very small parts, and they are simple and reliable. They can, however, be hard to adjust and hard to convert from one job to another. These machines also cannot control radial orientation of the finished part.

Conventional electric direct drive or geared spin welders use AC induction motors to drive the spin tool. They generally use digital motor controllers so rotational speed can be adjusted. Many also have electronic dynamic braking. In situations where dynamic braking is not sufficient, a physical brake may be installed. These machines can be built to any speed or torque requirement, but high torque motors tend to have heavy armatures so they do not stop quickly if turned at high speeds. Induction motors also delivery their highest torque only at high speed; so gearing is often used n high-torque applications (large parts, low rotation speeds) to keep the motor shaft speed up in the high torque part of the power curve. While certain of these machines do have sophisticated controls, many are quite simple. These systems also are not capable of controlling the radial orientation of the finished part.

Servo driven spin welders, whether geared or direct drive, typically can control the finished part radial orientation to within one degree or better – a specification that usually depends more on the tooling than the machine. Servomotors have relatively flat torque curves all the way from a near-standstill to maximum rated speed, so they typically are more versatile than the other types of machines. A servomotor also is typically more compact for a given torque rating than an induction motor, and is much better at staying on speed under load. Machines using servomotors usually have more sophisticated controls and a variety of welding methods. Servomotors also can deliver feedback to the control, so torque ad energy can be monitored during the process. Gearing, if used, is almost exclusively intended to multiply torque rather than simply to change the output speed. These systems are typically very precise and repeatable productions tools.

Spin welding is a simple process that, when coupled with modern servo motor technology, delivers precision and repeatability beyond that dreamed of when it was first tried during the open-cockpit days of the plastics industry. The process is fast and stable, and will continue to be utilized for as long as making products out of thermoplastics maintains its popularity.

What Amplitude is needed to weld my plastic components?

noreply@blogger.com (Dukane Ultrasonics) — Thu, 28 Jul 2011 15:10:00 +0000

What exactly is “Amplitude” and why is it important? Amplitude is the peak-to-peak movement, or expansion/contraction, of an ultrasonic tool stack. Each component can multiply the amplitude that comes from the transducer, the amount of increase or decrease is called "Gain". The total gain of the stack components determines the final amplitude at the working face of the ultrasonic horn, where part contact is made. The ultrasonic tooling stack includes the transducer, booster and horn. Some applications do not require a booster and the horn is attached directly to the transducer. These are usually multi-head automotive applications or packaging applications.

Some customers have tried to save money by not purchasing the correct booster for their particular application. Making sure the ultrasonic tooling stack is producing enough amplitude is one of the most important factors to successfully welding parts.

Yes, there may be a setting or two that can be adjusted in the ultrasonic welding system, like adjusting the pressure, but that doesn’t mean that the material at the joint area is actually co-mingling. If parts are not welded properly, they probably won't pass inspection or may even break apart in your hands. Worse yet is the possibility of your customer returning parts due to poor quality. Insufficient amplitude is often evidenced by not only weak welds but also incomplete welding where the melt around the interface is not completely present. A weld detail, e.g., energy director, may show signs of embedding into the mating surface instead of melting. If you have a weld time that is less than .1 seconds and your process seems to produce erratic results, then possibly your amplitude is too high and a reduction needs to be made.

A chart is included that shows some amplitude requirements of basic materials. Use the example as a guide for your current resin and ultrasonic tooling stack to see if you have enough amplitude for your application. Generally speaking, amorphous plastics require less amplitude than semi-crystalline materials.

Click to enlarge

Dukane’s application engineers can assist you in calculating the proper amplitude for your ultrasonic welding application and quote the proper booster to match up with the horn.

Dukane IAS receives Illinois Export Excellence Award

noreply@blogger.com (Dukane Ultrasonics) — Mon, 18 Jul 2011 15:45:00 +0000

Dukane Corporation’s Intelligent Assembly Solutions (IAS) Division was recognized by the State of Illinois for the significant growth that has occurred in our export sales in recent years. As part of Illinois annual “EXPORT WEEK”, thousands of Illinois based companies who are involved in exporting, are invited to apply for the annual recognition given by the Governor of Illinois to Exporters. Companies can apply for recognition of their efforts as either a new exporter if they have less than three years of export experience, or as an experienced exporter if they have more than 3 years of export experience. Within each company size segment, a board of judges reviews the applications and then select 3 companies. One is given an award as the best “New Exporter”, one is given and award for best “Continued Excellence in Exporting”, and one is given “Best Exporter”. The award is given based upon a number of criteria which include overall growth in export sales in recent years, and the amount of employment related to those export sales. Dukane was recognized as the 2011 Continued Export Excellence Award winner for the mid-size company category. The awards were presented on June 21 by Illinois’ Governor Quinn at the annual Export Week Conference which was held at the Illinois Institute of Technology.

In addition to the awards, there was a conference which included presentations by several of the this year’s award winners. Dukane was represented on the panel by Russ Witthoff, Director of International Sales.

Novel Combination Locking Cap for Prescription Drugs

noreply@blogger.com (Dukane Ultrasonics) — Fri, 29 Apr 2011 13:04:00 +0000

New plastic locking cap uses Dukane's ultrasonic welding systems for speed, accuracy, and precision manufacturing

Cap-N-Lock LLC, Lincoln, Calif., has developed the industry’s first combination locking cap offering maximum security against unauthorized use of prescription medications. The plastic locking cap is claimed to be the safest child-proof cap, provides maximum protection against teen prescription use, and is a senior-friendly packaging option. The device uses precision ultrasonic welding technology from Dukane Corp.’s Ultrasonics Division for speed, accuracy, and precision manufacturing. At the February 2011 Medical Design and Manufacturing West show Dukane demonstrated welding the cap on its new iQ servo welder in its Lean Manufacturing Cell (shown below).

The locking cap has combination dials which create a barrier to entry for young children and teens, according to Joseph Simpson, president of Cap-N-Lock LLC. The company produces the cap and two adapters which fit a wide range of the most common prescription bottles. The locking cap components, molded by Henry Plastics, Fremont, Calif., consist of eight injection molded parts made of lightweight, strong acrylonitrile-butadiene-styrene (ABS) plastic. Assembly and manufacturing is done by Cap-N-Lock LLC.

The locking cap unit is assembled from the bottom up with the locking mechanism (dial numbers included) dropped in first, followed by a tension plate and then the lower twist-on cap. The lower housing ring is then ultrasonically welded to the main housing to complete the assembly.

The speed, accuracy, and precision of the ultrasonic welding process are critical in the production of the locking cap, according to Simpson. “The weld needs to be perfect every time to ensure a high level of quality control,” says Simpson.

Dukane worked with Cap-N-Lock from the concept stage and provided feasibility studies, design assistance, tooling, and on-site support. Dukane ultimately provided a turnkey assembly system which included custom tooling (horn), a custom nesting (holding) fixture, and a press system.

The locking cap is sold as an aftermarket product for $9.99 at Save Mart and Ralph’s supermarkets on the West Coast. It is also available at www.cap-n-lock.com and will soon be offered at pharmacies.

Dukane RFI Filter for Ultrasonic Plastic Welders

noreply@blogger.com (Dukane Ultrasonics) — Wed, 13 Apr 2011 12:35:00 +0000

Dukane Corporation is a global provider of ultrasonic plastic welders for thermoplastic materials. Our welding equipment is designed with a high quality RFI power line filters to meet FCC and CE requirements for conducted emissions. The RFI (Radio Frequency Interference) is an unwanted noise generated by a wide variety of electronic and electrical devices. Ultrasonic welders which generate unwanted radio frequency energy greater than 10 kHz must comply with the government and safety agency requirements. The RFI is the radiation or conduction of radio frequency energy (or electronic noise) produced by electrical and electronic devices at levels that interfere with the operation of adjacent equipment. Frequency ranges of most concern are 10 kHz to 30 MHz for conducted emission and 30MHz to 1 GHz for radiated emission.

Most electrical and electronic equipment can produce RFI noise. The most common sources include components such as switching power supplies, relays, motors, triacs and equipment such as personal computers, printers, medical instrumentation, industrial controls and electronic games. An electrical and electronic device emits RFI in two ways: a) radiated RFI is emitted directly into the environment from the equipment itself; b) conducted RFI is released from components and equipment through the power line cord into the AC power line network. This conducted RFI can affect the performance of other devices on the same network.

Radiated RFI is usually controlled by providing proper shielding in the enclosure of the equipment. Conducted RFI can be attenuated to satisfactory levels by including a power line filter in the system. The filter suppresses conducted noise leaving the unit, reducing RFI to acceptable levels. It also helps to lower the susceptibility of the equipment to incoming power line noise that can affect its performance. Since no electronic equipment operates in total isolation, manufacturers must protect their own equipment from RFI noise produced by other devices functioning in close proximity or on the same power line. They are also responsible for making sure that their equipment does not transmit offending RFI noise, resulting in the malfunction of other devices.

RFI power line filter consisting of a multiple-port network of passive components arranged as a dual low-pass filter, the RFI filter attenuates radio frequency energy to acceptable levels, while permitting the power frequency current to pass through with little or no attenuation. Their function, essentially, is to trap noise and to prevent it from entering or leaving equipment. RFI is conducted through a power line in two modes. Asymmetric or common mode noise occurs between the line and ground. Symmetric or differential mode is measured from line to line. Common Mode: Also known as line-to-ground noise measured between the power line and ground potential. Differential Mode: Also known as line-to-line noise measured between the lines of power. Power line filters are designed to attenuate either one or both modes of noise. The need for one design over another will depend on the magnitude of each noise type present. The attenuation is measured in dB (decibels) at various frequencies of signal.

Dukane power line RFI filters are designed to meet both FCC and CISPR 11 with 5dB to10dB below the limit. They are generally built with three-pole filter networks to meet greatly varying electromagnetic environments for medical electronic and industrial control equipments.

The governments and safety agencies of major industrial countries, including the United States, Canada, and the European Union have established noise emission regulations that are focused on digital and other electronic equipment. The most important guidelines for Ultrasonic Welder are FCC CFR 47 (Parts 18) in the United States and CISPR 11 in the European Union.

FCC CFR 47 (Part 18) Industrial, Scientific, and Medical equipment (ISM), for Ultrasonic equipment. A category in which the RF energy is used to excite or drive an electromechanical transducer for the production of sonic or ultrasonic mechanical energy for industrial, scientific, medical or other none communication purposes.

The European Union also has harmonized the national regulations and has established the international standard CISPR 11(EN55011) which covers conducted emission for Industrial, Scientific and Medical (ISM) radio frequency equipment.

The following tests were performed to determine that Dukane Ultrasonic products are in compliance with the council of Europe and technical specifications of the EMC Directive 2004/108/EC, Low Voltage Directive 2006/95/EC and Machinery Directive 2006/42/EC.

EN 60204-1   Safety of Machinery - Part 1: Specification for General Requirements.
EN 12100-1 &2   Safety of Machinery – Basic concepts, general principles for design.
ISO 13854   Minimum gaps to avoid crushing of parts of human body.

EN 61000-6-2 and EN 61000-6-4_Generic Emission & Immunity:
EN 55011:          Conducted Emissions – 150 kHz to 30 MHz
                          Radiated Emissions – 30 MHz to 1GHZ
EN61000-4-2:   Electrostatic Discharge (ESD)   4kV (contact), 8kV (air)
EN61000-4-3:    Radiated Radio Frequency Immunity – 80 MHz to 1000 MHz
EN61000-4-4:     Electrical Fast Transient Immunity
EN61000-4-5:     Surge Immunity
EN61000-4-6      Conducted Immunity – 150 kHz to 80 MHz
EN61000-4-8      Magnetic Field Immunity
EN61000-4-11   Voltage Dips, Short Interruptions and Voltage Variation Immunity

Definitions:
Attenuation: The decrease in intensity or absorption of electromagnetic energy. Expressed in dB.
Conducted Interference: Electromagnetic signals entering a device through direct connection.
b: The level of electromagnetic disturbances equipment causes to its environment.
Filter: Remove electrical noise or interference from the power line by cleaning up the sine wave.
Immunity: The level to which equipment is immune to electromagnetic disturbances in its environment
Impedance: Opposition to the flow of electrical current when a given voltage is applied.
Inductor: Passive component that produces a voltage proportional to the change in current. Measured in Henrys.
Insertion Loss: The electromagnetic signal loss resulting from the insertion of a filter in a transmission line. Expressed in dB.

What method would I use for Multiple Slit Applications - Narrow Gauge or Standard Slitting?

noreply@blogger.com (Dukane Ultrasonics) — Wed, 06 Apr 2011 23:12:00 +0000

This question can be answered different ways but let’s discuss the difference from the two methods of Ultrasonic Narrow Gauge Slitting and Standard Ultrasonic Slitting.

Narrow Gauge Slitting is when a series of Individual Slitting Modules are positioned under a Long Ultrasonic Bar Horn usually about 9” in length. Depending on the Centerlines and number of Slits will determine how Modules will be required and how many 9” horns will be required. The actual Slitting anvils are fixed/locked in the module and do not rotate and are spring loaded. The Modules are designed to allow the Slitting anvil to be repositioned to a new working surface once a wear spot occurs on the anvil and then locked back in place. This will allow you to use the full diameter of the Slitting anvil. Once the entire anvil is worn then it would be replaced with a new one. This method is commonly used when Narrow goods are required. Please see attached picture of a Narrow Gauge system these Slits are done off of one Roll approximately 36” wide approximately 21 Slits.

Standard Slitting is a single station Slitter that Slit’s one section of the Fabric. Normally uses a 1” Diameter Horn and also has a fixed anvil that is mounted on an air cylinder. These anvils also have the ability to be repositioned to maximize the working surface of the Anvil once wear occurs. The air cylinder allows for more precise control of Anvil pressure versus the Narrow Gauge spring loaded design modules. Standard Slitting is used when the Slit requirements of the Fabric are wide widths usually greater than 9” wide. Depending on the width of the Roll being slit will determine how many Slitting stations will be required. Please see picture of a UFF1 Slitter Frame.

The two methods mentioned above are typical ways of Ultrasonic Slitting and are very commonly used in the Fabric & Film market. Depending on the requirements of the application we often replace the fixed Anvil method with Individual Driven Rotating Anvils. The rotating anvils in most applications will perform better and usually increase line speeds. Using the driven anvils will require drive motors or can use one common shaft with individual air cylinders. These situations will require qualified machine Builders. Always use either a fixed anvil or a Driven anvil free spinning anvils are not recommended. Please see picture of Driven anvils on a common shaft with individual air pressure.

Dukane Awarded 2010 Ringier Prize for Innovation for Servo Ultrasonic Welding System.

noreply@blogger.com (Dukane Ultrasonics) — Wed, 17 Nov 2010 22:26:00 +0000

At the recent Med Tech show in Shanghai China, Dukane was displaying its new Servo Ultrasonic Welding Press which was awarded the Ringier Technology Innovation 2010 award in the auxiliary equipment category for plastic welding. The winner’s of the Ringier Award in each category are chosen by an independent panel of judges for technical and product excellence, and for making a significant technological contribution to China’s plastics industry.


Russ Witthoff, International Sales Manager Xu Zhenhua, Shanghai Sales Engineer Qian Welin, Assembly Technician

Understanding Ultrasonic Horn, Booster, Transducer Mating Surface Flatness

noreply@blogger.com (Dukane Ultrasonics) — Wed, 06 Oct 2010 13:42:00 +0000

It is essential that the mating faces between an ultrasonic transducer/booster and a booster/horn be flat and parallel. If any air gaps remain, there will be a resultant loss in power output and efficiency. Coupling may be so poor that it might prevent the starting of an ultrasonic stack.

The condition of excessive crowning, or uneven contact surfaces, is normally evidenced by a burnished appearance only around the bolt area of the contact surfaces. This indicates that contact between the components is occurring only at the burnished area and not around the periphery of the surfaces. The contact areas between components can build up excessive heat due to inefficiency of vibratory transmission between the components.

The following flatness tolerances are typically specified:

Transducers: 0.0005 in. for 20 kHz and 0.0005 for 40 kHz
Boosters: 0.0010 in. for 20 kHz and 0.0005 for 40 kHz
Horns (Sonotrodes): 0.0010 in. for 20 kHz and 0.0010 in. for 40 kHz.

Examples of the ultrasonic horn surface not being flat.

Here is an example where there is only 10% of the surface making cont act with the booster interface.

When any of the contact surfaces look like the examples given, please send your tooling to the original manufacturer for re-surfacing. This will extend the tooling life as well as reduce the probability of permanent damage to the components.

What if you can’t spare the time to return the ultrasonic horn, booster or transducer for re-surfacing? If the surfaces are just dirty and not gouged in any way, you may be able to lap the surfaces smooth.

Reconditioning the ultrasonic stack

It is important to check the ultrasonic stack regularly to make sure the components are in good working order. In addition, there are several steps you can take to recondition the stack:

Disassemble the ultrasonic transducer/booster/horn stack and wipe the mating surfaces with a clean cloth or paper towel.

Examine the mating surfaces. If they appear to be in good condition, skip to Step 9. If any surface is corroded or shows a dark, hard deposit, it should be reconditioned (Steps 3 - 8). If the mating surface of any component shows evidence of crowning, cupping, or any other out-of-flatness condition, contact an ultrasonics industry professional for advice. Very small, isolated pits in the mating surfaces are generally not a serious problem.
If necessary, remove the mounting studs.
Tape a clean sheet of #400 (or finer) emery cloth to a clean, smooth, flat surface. A piece of plate glass is usually suitable.
Hold the component at its lower end and carefully stroke it in one direction across the emery cloth. Do not apply pressure as the component's weight alone will suffice. NOTE: Use extreme care to avoid tilting the component. Loss of flatness on interface surfaces may render the welding system inoperative.
Perform a second stroke, then rotate the part one-third turn and repeat.
Turn the part the final one-third and perform the same two strokes. Be certain to perform the same number of strokes (two) at each location.
Re-examine the mating surfaces, and repeat steps 5 through 7 until most of the contaminate has been removed. This should not take more than two or three complete rotations.
Before reinserting a stud, examine it to make sure the threads have not been damaged. Clean all foreign material, grease and oil from the threads of the stud and the threaded hole using a clean cloth or towel.
Replace worn or damaged studs with those specified by the manufacturer. Ordinary steel set screws are not properly heat treated for use as stack studs.
Very lightly coat the flat mating surfaces with high-pressure silicone grease or insert a high-temperature polymer film washer (not both) to promote good transmission of ultrasound and prevent the stack components "cladding" together.
Torque studs and mating surfaces properly, as indicated in the accompanying table showing Correct Torque Values for Stack Component Assembly. Loose studs or joints will cause overloads or intermittent operation, while excessive tightening results in material distortion that shortens component life.

Install the stack in the welder and test ultrasonic operation.

Ultrasonic Boosters

noreply@blogger.com (Dukane Ultrasonics) — Tue, 28 Sep 2010 15:15:00 +0000

The boosters serve two purposes; second mounting point for the stack assembly and either amplify or reduce the amplitude. Like the transducer, the boosters have a nodal point. At the nodal point there is a mounting ring designed to fit into the press system or machine mount applications. There are two types of mounting ring configurations. Standard boosters have a split mounting ring that houses two “O” rings in a similar configuration as the transducer. Resonant style boosters have no “O” rings. These are designed for applications where solid fixed mounting of the stack assembly is critical for the application. An example would be an application requiring two stack assemblies to weld a single part, because near horn proximity, motion in the stack may allow them to touch. Resonant boosters eliminate this problem.

Standard and Resonant Boosters

The boosters are either titanium or aluminum. Titanium boosters, while costly, are more robust and stud thread holes hold up to many assembly and disassembly cycles. In continuous applications where heat dissipation is a benefit, aluminum boosters are recommended.

Boosters come in different “Gain” ratios. The mass of the booster below and above the nodal point determine the amount of gain to the amplitude from the transducer. This is the mechanical means for adjusting the stack amplitude to match the requirement to melt the particular plastic in each application. It is best to use the optimum booster size for the application. Leave the generator amplitude setting close to 100% and only make small generator amplitude adjustments when required. On most horns, the recommended max gain booster size will be stamped on the horn.

Effect of Black Colorant on Ultrasonic Staking.

noreply@blogger.com (Dukane Ultrasonics) — Fri, 24 Sep 2010 16:12:00 +0000

Sometimes it is difficult to disperse black pigments on polymers, resulting in agglomerates or clumps of pigment particles. These can make for places where cracking can occur when the plastic is stressed. This could be worse in the area of the ultrasonic staking, since the polymer is likely somewhat weakened by the welding process.

It is probably more likely that the black pigments could be increasing the thermal properties of the plastic, so that the material is heating faster causing more degradation than the other colored parts. It may be necessary to adjust the ultrasonic staking conditions for black parts with slightly lower amplitude, less energy input or shorter duration.

Finally, there can be problems with the way the color is added. Assuming that they are adding a color concentrate at the molding machine, if they are adding too much or maybe adding a concentrate that has an incompatible carrier polymer, like polyethylene or nylon, they may not fully blend in the plastic, creating contaminated layers of material.

The 6 quick steps to a successful ultrasonic assembly

noreply@blogger.com (Dukane Ultrasonics) — Mon, 13 Sep 2010 21:14:00 +0000

Do you have an application that you think could be ultrasonically assembled? Wondering how to get from a couple of pieces of plastic to an assembled part?

This is how our sales engineers tackle an application. While we don’t expect our customers to perform each of these steps, it’s important they be involved in this process. That way they’ll have a better understanding of their systems and know how to maximize the ultrasonic equipment’s potential.

Step 1 - Determine the feasibility of ultrasonics

First examine the components to be ultrasonically assembled. They must be thermoplastics, and if dissimilar plastics are to be welded, they must be compatible (refer to Thermoplastic Compatibility Guide. The parts must also be designed so ultrasonic energy can be efficiently transmitted to the joint.

Using the Amplitude Reference Chart, determine the amplitude requirements of the thermoplastic you’re using. If possible, process a few parts to verify you have sufficient amplitude. Consider using special ultrasonic horn coatings or horn materials if fillers or additives are used in the plastic components.

The last step is to consider your ultrasonic tooling options. Is it even possible to build an ultrasonic horn that will provide the necessary amplitude to the part? Will you need multiple horns or a composite horn? Can the parts be properly supported in a fixture?

Step 2 – Choose the right ultrasonic welding equipment

Once you determine ultrasonics is a viable assembly method for your application, it’s time to choose your welding equipment. Your application and future project needs will dictate whether you need 15, 20, 30 or 40 kHz equipment. The 20 kHz ultrasonic welding system is more versatile, as it can process a variety of part sizes. It’s also ideal when higher amplitudes are needed to melt the plastic. A 40 kHz ultrasonic welding system is usually used for smaller, more delicate applications. Your application will also determine the wattage of your generator (200 to 5,000 watts). Traditionally, the bigger your part and horn, the more wattage you’ll need to run the horn at full amplitude.

How you’ll apply the ultrasonic energy to your parts is another consideration. Hand-held probes are ideal for applications where it’s more convenient to bring the ultrasonics to the part. When control and repeatability are critical, a press system would be recommended. If production rates require speeds that exceed what could be achieved by a standard press, a rotary index parts handling system should be used. Custom mounting and automation of ultrasonic thrusters are other possibilities.

Your ultrasonic sales engineer can help you design your system to meet other specific application needs such as process control and SPC, cooling requirements, and sound enclosures.

Step 3 – Assemble and Install the ultrasonic tooling

Because transducers alone cannot generate enough amplitude to melt the plastic material, your ultrasonic tooling and applications engineer will determine the gain factor that’s needed from the horn to match the amplitude requirement of the thermoplastic. Based on that gain factor, he or she will select the appropriate booster and horn combination.

You’ll need to assemble the transducer, booster, and horn but first examine all mating surfaces for flatness and cleanliness. Remove any foreign matter from the threaded studs and mating holes. Coat one contact surface of each stack component with a thin layer of high pressure grease – but do not grease the studs. Thread the components together and tighten by applying a torque of no less than 13 foot-lbs (17.63 Newton-meters), but no more than 18 foot-lbs. (24.40 Newton-meters).

Once you’ve assembled the stack, install it into your system by following the easy directions in the operations manual. Make sure it aligns with the fixture; use feeler gauges or carbon paper if this becomes difficult.

Step 4 – Set up the welding equipment

After following the simple setup procedures in the operations manual, you should be ready to set the initial press force, trigger force, weld time, and velocity. If your application requires precise melt velocity during the weld cycle, use hydraulic speed control, like the Kinechek® option, which is available on Dukane ultrasonic welding systems. Set the mechanical stop (so the horn and fixture don’t accidentally contact), then determine whether the ultrasonics need to be activated before contacting the parts. If so, use the pre-trigger feature.

If you’re using a process controller, determine and set the most effective primary process control. Welding by distance, peak power, and absolute distance are the most common controls, although welding can also be controlled by time and energy.

Step 5 – Adjust the setup

After you’ve set up your ultrasonic tooling and welding equipment, don’t go into full production – run a batch or two of sample parts. Examine and test (as needed) the assembled parts. If process adjustment is needed, refer to the application troubleshooting section in the “Guide to Ultrasonic Plastics Assembly” to help diagnose probable causes and solutions.

Step 6 – Maintain proper operating conditions

Ultrasonics is a low maintenance process, and Dukane’s ultrasonic welding equipment comes with a 3-year warranty. However, to maximize your welding equipment’s life and performance, it’s important to do some minor cleaning and inspecting after every 500 hours of operation. This includes: removing dust/dirt from the guide rods; applying light oil to the exterior of the air cylinder rod; inspecting wiring to the thruster head; inspecting the air filter; tightening the thruster and fixture mounting bolts (if needed); checking the setup parameters; and inspecting, cleaning, lapping and re-torquing the stack. Regional training programs are also available from Dukane, as is an extensive series of training workshops at the St. Charles facility.

How Tight is Tight Enough?

noreply@blogger.com (Dukane Ultrasonics) — Tue, 31 Aug 2010 21:54:00 +0000

It is important to assemble and tighten your ultrasonic tooling stack to a proper torque. Just assembling the tooling stack as tight as possible could be detrimental to the tooling stack components. For example: the threads on an aluminum booster or aluminum horn can be stripped out due to over-tightening. Conversely, not using enough torque could also be detrimental. The components could come loose and cause the generator to overload. Allowing this kind of thought process to prevail can cause damage to one or more components of the tooling stack.

On Dukane's website you will find our Guide to Ultrasonic Plastics Assembly. Scrolling down to page 91 will bring you into our maintenance section describing various problems that could be associated by not tightening the tooling stack to the proper torque specifications.

Correct Torque Values for Stack Component Assembly

Studs in horns and boosters:

Transducer/booster/horn assembly:

Replaceable Tips on Horns:

The following website address will link you to the Dukane Store where you will be able to purchase the recommended tools to properly torque the Transducer/Booster/Horn assembly:

http://www.dukane-store.com/accessories.html

Once the proper equipment has arrived, please inform your maintenance workers of the proper torque requirements of the tooling stack.

Vibration Welding and Compatibility of Materials

noreply@blogger.com (Dukane Ultrasonics) — Fri, 27 Aug 2010 13:38:00 +0000

For most applications you weld the same material to the same material. Example (ABS to ABS) To bond two thermoplastic parts it is necessary that the materials be chemically compatible. Otherwise, even though both materials melt at the same temperature no molecular bond will occur. A good example of this is polypropylene and polyethylene. Both are semi-crystalline materials and have a similar appearance and many common physical properties. However they are not chemically compatible, and therefore are unable to weld to each other.
So we need to look at the chart below for compatible materials. If you notice you see that ABS is compatible to ABS/PC, PMMA, PS, PVC and SAN. If we get these two compatible materials we may be able to weld them together with success. (Click chart for larger view)

Now that you know you have two materials that have similar structure you need to answer two more questions.

What is the melt temperature of each of the materials. These two melt temperatures must be within 40 degrees F (20 degrees C). The reason for this is that we are using a friction based process. If one melt temp is below more than 40 degrees F from the other, the lower melt temperature material will go to a complete melt and not melt the higher melt temperature material. This is true for both Ultrasonic and Vibration welding.
The next question you need to answer is the melt flow of the two materials. This is basically a viscosity rating on the material at its processing temperature. Melt flows in the 0-3 and 20-30 range are extrusion grade materials. Melt flows in the 4-12 range are injection grade materials. For vibration welding these melt flows must be within 3 to 4 of each material. Also know that in ultrasonic welding the melt flows should be within 1 of each other.

So now you are asking where do I find all this information? Well you can contact the material suppliers and they are more than happy to share the data sheets on the materials with you. Also the next best thing is to get some 4” x 6” plaques and weld them together. This way you can see a welded “T” plaque of the two materials. Then you can test these materials as well.

If you have any further question please contact Dukane at (630) 797–4900. Or visit our website at http://www.dukane.com/us

Raymond M. Laflamme
Worldwide Automotive Marketing Manager
47757 West Road, Suite C101
Wixom, MI 48393
(248) 613 - 5722

Dukane black and gold helps the world be more "green"

noreply@blogger.com (Dukane Ultrasonics) — Wed, 14 Jul 2010 18:56:00 +0000

Dukane Ultrasonics is playing a key role in helping companies reduce their carbon foot print and to reduce global warming. It is generally understood that ultrasonics is a far more energy efficient process for welding plastic materials than processes such as heat-staking or hot-air welding. However, in addition to these plastic welding applications, Dukane’s ultrasonic welding equipment is an essential part of the systems being used by leading automotive hybrid battery manufacturing companies to do the ultrasonic metal welding of the internal components in nickel metal hydride batteries and more recently, lithium-ion batteries.

For ultrasonic metal welding applications, Dukane has long partnered with Ultex, a Japanese manufacturer which has led the way in providing ultrasonic metal welding solutions to the automotive industry. Every time you see a Toyota or Honda hybrid vehicle, chances are that the battery providing the electric power was made using a Dukane powered ULTEX ultrasonic metal welding system.

When should I consider using ultrasonics to cut my food product?

noreply@blogger.com (Dukane Ultrasonics) — Wed, 14 Jul 2010 14:31:00 +0000

Ultrasonic food processing involves a vibrating knife producing a nearly frictionless surface to which food products do not stick nor deform. Here are some things to consider when deciding if ultrasonic cutting is the right process for your application.

Is your product sticky and causing excessive downtime for blade cleaning?
Does your current cutting process smear multiple layers causing a visually unappealing product?
Does your current process cause the product to crumble and decrease your yield?
Does your current process crush the product during the cut?

If you answered yes to any of the above, chances are ultrasonics can improve your process, if you answered no to all the questions your current method is acceptable.

Below are some pictures that illustrate the quality of cut with ultrasonics.

Here is an ultrasonic blade horn in action.

See Dukane's Food Processing FAQ page for more information.

Ultrasonic Welding Effects on Hearing

noreply@blogger.com (Dukane Ultrasonics) — Tue, 29 Jun 2010 19:54:00 +0000

In air, sound is usually described as variations of pressure above and below atmospheric pressure. These fluctuations, commonly called sound pressure, develop when a vibrating surface forms areas of high and low pressure, which transmit from the source as sound.

Although noise-induced hearing loss is one of the most common occupational illnesses, it is often ignored because there are no visible side effects, it usually develops over a long period of time, and, except in very rare cases, there is no pain. In its early stages (when hearing loss is above 2,000 Hertz (Hz)) it affects the ability to understand or discriminate speech. As it progresses to the lower frequencies, it begins to affect the ability to hear sounds in general.

The upper frequency of audibility of the human ear is approximately 15-20
kilo-Hertz (kHz).

This is not a set limit and some individuals may have higher or lower
(usually lower) limits.

The frequency limit normally declines with age.

Most ultrasonic welders have a fundamental operating frequency of 20 kHz. However, a good deal of noise may be present at 10 kHz, the first sub-harmonic frequency of the 20 kHz operating frequency, and is therefore audible to most persons. Ultrasonic welding uses intermittent energy. Only the noise generated during the few seconds of each cycle when the equipment is energized causes exposure to noise. The individual energy cycles are accumulated to equal the duration of exposure. Most of the audible noise associated with ultrasonic sources, such as ultrasonic welders or ultrasonic cleaners, consists of sub-harmonics of the machine's major ultrasonic frequencies.

In extreme cases, this can be disturbing, causing hearing discomfort, occasionally nausea, and sometimes a temporary shift in the threshold of hearing (sound pressure level, or loudness, that can be heard).

Many countries control the amount of audible noise that a worker can receive. In the United States 90 dBA noise level can be maintained continuously for 8 hours. Higher noise levels are permissible for shorter periods of time, typically:

If there is a line operator or other employees in close proximity to an ultrasonic welding system experiencing discomfort, then hearing protection is recommended. Sound enclosures are also available in most cases that would minimize any discomfort to workers near the welding system. For additional information, please read our White Paper titled “Effects of Ultrasonics on Health”.

Myths and Tricks to Successful Thermal Heat Staking

noreply@blogger.com (Dukane Ultrasonics) — Tue, 29 Jun 2010 18:39:00 +0000

It is a known fact that applying a specific amount of heat to plastic resin using a heated tool will change the characteristics and shape of it, but did you also know that fine tuning the temperature and dwell time it takes to heat that resin can lead to stronger and more cosmetically appealing welded parts?

There are several myths regarding thermal heat staking and tricks to establishing quicker, stronger, and more cosmetically appealing thermal heat welded parts. Here are a few examples:
Myth 1: Post cooling a thermal tip is required on all resins to reduce or eliminate stringing and over welding of a stake or swage.
The Truth: Post cooling only needs to be introduced in a heat welding process when resins, such as Acrylic, are used that require quick cooling.
The Trick: Fine-tune the temperature below the actual resin processing temperature by making very slight changes of 10°F at a time. Each time a temperature change is made, wait 15 to 20 minutes for the changes to take effect in the heated tip. The dwell or (weld time) will need to be adjusted as well to prevent the resin from stringing or burning.

The use of a dual pressure thermal heat staking machine can also eliminate the need for post cool. This feature allows the post to be heated at a lower temperature with a small amount of pressure for a programmed time. After a small amount of time, a greater amount of pressure is applied during the dwell time, collapsing the resin with minimal amount of heat and no post cooling.

Myth 2: Large percentage glass filled or chrome plated studs lack strength and cosmetic appeal after heat staking.
The Truth: Even resins with fillers and coatings can look esthetically pleasing.
The Trick: Use a Pre-Heat to slowly heat up a stud that is to be staked. The resin starts to melt where the glass or chrome plating will not. After the Pre-Heat times out, an appropriate amount of dwell or (weld time) will fully collapse the stud with the correct amount of force applied. This will melt the remaining resin while the glass or chrome plating act as a shell to hold the resin together without melting.

Jerry Downing
Sr. Project Engineer
Dukane Corp. IAS

Tony and Paul pull an all-nighter

noreply@blogger.com (Dukane Ultrasonics) — Wed, 16 Jun 2010 14:24:00 +0000

While it may not be obvious from the picture, this photo was taken at 3:30AM on a Saturday morning. It was a long day that started at 8:30 AM on Friday and would not end until about 8:30 AM on Saturday. This effort was the culmination of what had already been a week of long days which included working through a holiday weekend. However, our customer needed to have their vibration welding machine completed and on a truck by that Saturday afternoon, and Tony and Paul were among a group of individuals who personally lived our Division’s goal of delivering superior customer service and value.

This commitment not only comes from our factory team, it also occurs regularly in our sales team. In the same week that Tony and Paul pulled this all-nighter, two of our sales engineers, Ray and Keith, drove a large vibration welding tool down to a customer to get it installed and running before the next morning, when our customer had to be able to show his end-customer that the tool was in place and ready for production. Ray and Keith left our factory at about 5 PM, drove 5 hours, and then helped install and qualify the vibration welding tool. We got a text message from them at 3:45 AM informing us that the tool was in, and qualified.

While these examples are the exception, the fact that they happen says a lot about the passion and commitment Dukane has when it comes to providing superior customer service. In both cases, it would have been easy to say, “It’s late, let’s finish this tomorrow”, but in both cases that would have meant that the customer would not have been able to meet their commitments. So, Tony, Paul, Ray and Keith went the extra mile to meet the requirements of our customers. Sometimes that means an all-nighter, but is indicative of the heart and soul of our company.

Thermal Heat vs Ultrasonics

noreply@blogger.com (Dukane Ultrasonics) — Tue, 01 Jun 2010 15:17:00 +0000

Thermal heat can provide solutions to many staking, swaging, inserting, and de-gating applications that ultrasonics cannot.

Thermal heat should be considered when working with inserts or stakes that are of various diameters, and/or located on multiple planes and must be processed in a single cycle.

Thermal heat is primarily used when limitations with ultrasonic horns (size, multiple planes, and consistency) are a factor. Other considerations include cosmetic appearance of completed swages or stakes, as well as higher tolerance for glass content and chrome plated parts.

Using thermal heat staking, swaging, and inserting processes can also eliminate particulate that is detrimental to applications such as medical, fluid filters and consumable packaging.

For many customers, the reduction in noise level from ultrasonic inserting or staking of glass filled parts is a significant advantage to switching to a thermal process.

The use of thermal heat also eliminates any vibration concerns that are associated with staking PCB’s to other components. Heat is applied directly to stakes quickly enough that components surrounding the staking post are not damaged.

Overall, when considering heat vs. ultrasonics, review all of the requirements for your application as you may find thermal heat to be the best process.

Jerry Downing
Sr. Project Engineer
Dukane Corporation IAS Division

The Benefit of Resilient Fixtures for Ultrasonic Plastic Welding

noreply@blogger.com (Dukane Ultrasonics) — Tue, 25 May 2010 20:45:00 +0000

When is it a better choice to use a resilient fixture made from a Polyurethane casting in place of using aluminum or stainless steel? This question needs to be answered with a series of other questions. The most important of those are: what is the shape of the part, the material being welded, the process being used and the wall thickness?

Parts that have special shapes or that are not flat on the bottom would be considered contoured parts. The shape of these parts could be machined into aluminum or stainless steel but would require programming a CNC machine to cut the detail. Another added step would be that fixture would also need to have the machine tool marks polished out. Pouring a Polyurethane fixture would eliminate the need for programming time and polishing. Although the Polyurethane would need to cure (harden) overnight, this additional time spent is still less costly than programming, machining and polishing. When cured, the Polyurethane casting just needs minor machining before being mounted to a leveling plate.

Amorphous materials and most semi-crystalline materials are good candidates for Polyurethane fixtures. The exceptions are Polypropylene (PP) and Polyethylene (PE) parts; which are considered “softer” materials. Since PP and PE already absorb much of the ultrasonic vibrations, Polyurethane is normally not recommended. If the parts have a textured surface, the texture could be damaged if using aluminum or stainless steel. Using a Polyurethane fixture instead could significantly reduce the surface damage. The reason is that the Polyurethane is poured directly onto a production part (always preferred) so that the textured surface is somewhat incorporated into the casting.

The process being used is important in that normal ultrasonic welding of two plastic components is usually successful if thought out properly. However, when inserting brass or steel inserts, there are times when this process could be problematic due to excessive heat build-up directly under the inserting area that could cause the Polyurethane material to distort and become damaged. In some cases, Brass “plugs” can be added to the fixture directly under the inserting area to eliminate excessive heat and damage to the Polyurethane material.

Thin wall sections may need extra support that the Polyurethane may not be able to provide. In this case, a combination of Polyurethane and aluminum or stainless steel can be used to stabilize the thin wall areas of the assembly.

These are just some of the basic guidelines. Every application is examined on an individual basis to determine which fixture material will produce the best results.

Dynamic Balancing of Linear Vibration Weld Tooling

noreply@blogger.com (Dukane Ultrasonics) — Tue, 11 May 2010 22:16:00 +0000

The balancing of Vibration Weld Tooling is critical to the longevity of any manufacturer’s vibration welding equipment. With proper design of the moving half of the vibration tools used in the Linear Vibration Welder, the manufacturer can expect a much longer life from his welding equipment. Also by running unbalanced tools you can significantly shorten the life of your machine and incur tens of thousands of dollars in repair costs.

First let’s discuss the dynamics of the moving half of the tool in a vibration welding tool set. Usually this is the upper half of the tool. The partial g loading chart below shows that at 1.8 mm amplitude and 240 Hertz we get 208 g’s of dynamic load. Therefore, a 100 pound tool moving at 240 Hertz and 1. 8 mm peak to peak displacement becomes 20,800 pounds of dynamic load on the machine.

The following table is g loading calculations (click table for larger view):

So let us assume that a tool is 20 pounds out of balance, 12 inches from the center line of the tooling. This would mean that we have:

(20 pounds) X (12 inches) X (208g) = 49,920 inch pounds of torque on the machine.

This will cause the Linear Vibration head to move in a non linear fashion. It will damage components in the head and make the frequency drives work harder to keep the tool running the application. This eventually will take critical components in the vibration head to a fatigue failure point, thus causing the expensive repair bills.

If you look at the weld tool representation, you will see lightening holes on the upper tooling plate to the back side of the tool. These are there to counter balance the thick portion of the poured urethane nest, thus bringing the tool into balance.

Extensive use of tool balancing was used on the tool illustrated below. Here, not only was the tool plate lightened but the tooling segments themselves needed to be weight reduced to balance the tooling.

The use of steel counter balances can also be used, just remember the upper tool must fall within the manufacturer’s recommended tool weight specifications. The use of good CAD tools can also aid in the balance analysis of a tool before you even cut the materials.

Finally, the tool being balanced in the direction of welding is not as critical. The tool balance from front to back in most machines or 90 degrees to the direction of vibration or along the direction of the weld axis is what must be considered for all good vibration tooling.

For further information contact:
Ray Laflamme
Worldwide Automotive Marketing Manager
Dukane Corporation

Composite Ultrasonic Horns

noreply@blogger.com (Dukane Ultrasonics) — Tue, 04 May 2010 19:09:00 +0000

A composite horn is actually a half-wave “coupler” horn with two or more half-wave, tuned horns attached to it. This technology was patented by Dukane in 1973. Because composite ultrasonic horn designs can often eliminate the need to invest in additional assembly systems, they reduce equipment costs and minimize production time for customers.

Composite ultrasonic horn designs are common on applications that cover a large surface area and on applications where there are multiple insertion, staking, or welding points. Some of automotive customers use composite ultrasonic horns to attach insulator pads to door panels.

Another common application that benefits from composite ultrasonic tooling is clamshell packaging (a vacuum-formed blister package). The composite horn saves manufacturers production time and costs, as it welds the package simultaneously at several different points, instead of using a multiple-head system or having an operator weld each point separately.

Composite ultrasonic horns are also instrumental in applications where it’s difficult to create enough amplitude to weld. The amplitude at the face of a composite horn is higher than what could ever be achieved by a single large horn. The amplitude is designed into each of the individual half-wave horn attachments, not the coupler, a higher amplitude is generated at the weld area; this avoids causing excessive stress to the coupler horn.

Although composite horns can eliminate the need for additional assembly systems, cut production times, and lower labor costs, they are more expensive than standard horns. The added cost is due to the extra metal and machining the composite horns require.

Typical composite horns have aluminum couplers and titanium half-wave attachments. In addition to the expense of titanium, all of the half-wave attachments must be tuned within 50 cycles of each other. And they must be properly mounted onto the coupler horn.

The most common mounting method utilizes a 1/2- or 3/8-inch threaded stud at the top of the half-wave attachment; it’s screwed into a threaded hole at the output face of the coupler. It’s also possible to use a “tuned bolt” to fasten the half-wave attachments. The bolt is mounted through the coupler; then the horn attachments are bolted to the coupler. The “tuned bolt” method is primarily used on composite horns that have two or more blade horn attachments.

In addition to the extra metal and machining that’s required, composite horns have more design considerations than a standard horn. We always have to make sure the horn we’re designing is balanced. But when we deal with composite horns, all of the horn attachments have to be positioned evenly around the coupler, so the weight is evenly distributed. Sometimes the attachments are different lengths and different shapes, but you still have to keep the horn balanced.

But despite the added challenges in the design and manufacture of composite horns, they have provided consistent performance and productivity for Dukane customers. If an application can use a composite horn, the increase in productivity and the cost savings are so great that the initial added cost in tooling is more than justified.

For more information on ultrasonic assembly and other horn designs, you can view our Guide To Ultrasonic Plastic Assembly.

Dukane Participated in 2010 UIA Symposium

noreply@blogger.com (Dukane Ultrasonics) — Tue, 04 May 2010 14:05:00 +0000

The 39th Annual UIA (Ultrasonic Industry Association) Symposium held in Cambridge, MA, included 80 participants from 48 organizations representing 11 countries. The program included one day of industrial presentations on Monday April 12th, two workshops, a poster session on Tuesday April 13th and a day of medical presentations on April 14th.

Dukane was a proud Sponsor, as well as an exhibitor and presenter in a poster session. Our poster presentation was “What is New in iQ Series Ultrasonic Systems?”

Dukane made equipment was used in several presentations, including the keynote presentation of the industrial session by Prof. Avi Benatar of OSU (see below). Other presentation, where Dukane ultrasonic generators and transducers were used included the following: “Determining Bond Quality from VHPUAM Process Parameters” by Matt Short, EWI, The Ohio State University; “UAM Fabrication of Metal-Matrix Smart Material Composites” by R. Hahlen and M. Dapino (presented by Mark Norwood), EWI, The Ohio State University; “Advanced Analysis and Characterization of the UAM, VHP UAM Bonding Process” by D. Schick, R. DeHoff, M. Sriram, M. Dapino and S.S. Babu (presented by Mark Norwood), EWI, The Ohio State University.

Both the Newcomers to Ultrasonics Workshop and the Finite Element Modeling Workshop were highly rated by symposium participants. Keynote presentations by Prof. Avi Benatar, The Ohio State University on “Servo-Driven Ultrasonic Welding of Semi-Crystalline Thermoplastics” and Robin Cleveland, Boston University on “Medical Applications of Shock Waves” provided fascinating information on diverse ultrasonic applications.

“Protease Inactivation in Milk by Thermosonication and Impact on Milk Characteristics” by Sakthi Vijayakumar, David Grewell, Stephanie Jung, and Stephanie Clark, Iowa State University represented an evolving ultrasonic application. “Propagating Ultrasound Energy through a Catheter Around Bends” by David Constantine, James Sheehan and Jeffrey Vaitekunas presented a unique medical ultrasound application.

An electronic copy of the proceedings on a flash-drive pen is available for $95 from UIA by emailing uia@ultrasonics.org

The 40th UIA Symposium will be held in Glasgow, Scotland, UK on 23 – 25 May 2011. Professor Margaret Lucas, University of Glasgow, will serve as the Symposium Chair. For a copy of the Call for Presentations, go to www.ultrasonics.org or contact UIA at +1.937.586.3725.