Thursday, August 4, 2016

Monitor the performance of your Vibration Welding System by utilizing Dukane's patented 'Q' Factor Technology

Dukane’s patented ‘Q' factor technology for Linear Vibration Welders is an algorithm  to help users monitor and maintain the quality of a welding system over its lifetime. ‘Q’ factor is calculated using the resonant frequency of the welding head  of the vibration welder and the time between which its amplitude reaches its peak and declines to half of its peak amplitude. In other words, ‘Q’ factor determines how many cycles of the resonant frequency does it take for the welding amplitude to decline in half. This is system’s resonance quality factor, which determines how quickly a weld fixture’s amplitude decays. The longer it takes for the weld fixture to decay, the higher is the ‘Q’ factor.
Dukane's 5000 Series Vibration welder
Dukane's 5000 Series Vibration Welder

The Plastic Industry uses linear vibration welders to weld two plastic components, by creating linear oscillatory motion of one part relative to another part. The parts are brought together by force, the oscillatory motion generates heat, which melts the adjacent surfaces of the plastic parts and creates a weld after the parts cool. The vibratory movement of one part relative to another part is generated by two electromagnets positioned between moveable and stationary part of the welder. Both electromagnets apply force along the same coordinate line, but in opposite directions. The electromagnets are energized with a 180-degree phase shift so that when the first electromagnet is energized, the second one is de-energized and vice versa.


HMI Screen showing 'Q' Factor
HMI Screen showing 'Q' Factor 
It is important to maintain the frequency of the energizing cycle at the resonant frequency of the movable mechanical part of the welder. This allows for maximum energy transfer to the parts being welded. Any decrease in the ‘Q’ value would indicate that something has deteriorated in the system and that the maximum energy is not been transferred to the plastic components. A typical value of the Q factor for a vibration welder is between 100 and 260. The higher value indicates a more robust system that runs more efficiently with fewer energy losses and is more reliable. This value is measured and stored in the machine process controller (or HMI) during factory testing. As machine ages, the Q factor is monitored and compared to the original value. A decrease can serve as an early warning of the improper tool installation or machine/tool deterioration.

Vibration welders are key  investments for many manufacturers.  Therefore, manufacturers seek ways to optimize their use and get better ROI on these machines. One of the ways to do so is to rotate tools on the same machine and weld various plastic assemblies. However, the challenge is to monitor and maintain the quality of tools and their proper installation during tooling changes. Calculating and storing the ‘Q’ value for each tool helps in monitoring proper installation. When a user changes the tool, a new ‘Q ‘value is calculated, which serves as a quantitative measure of the tool quality. Difference between original ‘Q’ value stored at the time of factory testing of the tool and the new calculated ‘Q’ value after installation at plant floor can indicate improper installation.

‘Q’ factor of a welder is a function of the quality of its springs, coils, lamination carriers, drives, and the actual upper tooling. While springs, coils, lamination carriers and drives have good repeatability and tight tolerances (since they are standard components shared among the machines), the upper tooling is unique to every part being welded. Therefore, the quality of the tooling design, manufacturing, and installation can have a significant effect on the overall welder performance.

For more information of Dukane's Vibration Welding technology and products visit http://www.dukane.com/us/PVI_VibeWeld.htm or call 630-797-4900.

Thursday, May 19, 2016

New White Paper at SPE Events - A Great Platform for Plastic Industry

iQ Series Servo driven Ultrasonic Welding System
with patented Melt-Match® and Melt-Detect™
features
Dukane is participating at two upcoming SPE (Society of Plastics Engineers) events, ANTEC® and SPE Decorating & Assembly Division Topical Conference of 2016. We are presenting a paper on “Generating Stronger and Reliable Ultrasonically Welded parts by Utilizing Advanced Melt Flow Controls of Servo Driven Ultrasonic Welding Equipment.” Chief Engineer for Advanced Technologies, Dr. Alexander Savitski and Sr. Application Engineer, Mr. Kenneth Holt will represent Dukane at these events. 

Attendees will benefit by learning the advanced control capabilities offered by the servo-driven system. Ultrasonic welding of thermoplastics is widely used by many industries to fuse together two parts in a short time without additional consumables. Development of servo-driven ultrasonic welders introduces unique levels of control.  This paper pursues previous research and investigates the capabilities of iQ Series Servo driven ultrasonic welders to produce stronger welds. The focus is to develop a more robust and controlled joining process for medical devices that increases the strength and reliability of welds without fully collapsing the joint or creating excessive weld flash.
  
During a typical ultrasonic welding cycle most of the plastic melting takes place in the energy director body, and its molten material forms a bond. Generating maximum weld strength when using pneumatic welding systems typically requires that the weld distance be set close to the nominal energy director height, so the energy director is completely melted. Failure to achieve full melt often results in lower strength, incomplete welds, and poor appearance of welded assemblies. As the actual height of the energy director varies, there is always a risk that some of the parts with a shorter energy director will have excessive flash, and if the programmed weld distance is reduced to avoid that, then there is a risk of generating non-hermetic welds. This paper investigates the effect of weld velocity profiling on developing a more robust and controlled joining process capable of achieving strong and reliable welds without fully collapsing the joint while minimizing the risk of excessive flash.  

ANTEC Indianapolis 2016
Experiments were completed in which the weld velocity was varied, and the resulting strength and appearance of the welds were evaluated against the intense requirements of the medical industry. Analysis of weld cross sections suggests that higher weld strength was associated with a linearly increasing weld velocity profile.

Details and key findings of these experiments will be shared at these events. ANTEC® 2016, produced by the SPE (Society of Plastics Engineers) is the largest, most respected, and well-known technical conference in the plastics industry. This year it will be held in Indianapolis, IN from Mar 23rdth – 25th. Dukane has been a part of ANTEC® for a significant number of years. SPE Decorating & Assembly Division Topical Conference will be held in Franklin, TN from June 5th-7th. TopCon will include more than 20 papers on the latest technologies in plastics decorating and assembly. 

Please find the white paper by visiting http://www.dukane.com/us/WP-Servo-driven-ultrasonic-welding.htm or call 630-797-4902 for more info. 

Wednesday, February 24, 2016

A Success Story about Team Work and Tenacity - Vibration Welding Toyota Tonneau Cover

Dukane feeling honored and proud to be part of this award winning team for Tonneau cover assembly on the 2016 Toyota Tacoma pickup. This winning team in eleven months designed and created a Tonneau cover that is not only flexible and light weight but also provides the required strength and security to the end user. All these unique features have made the Tonneau cover a winner in Parts Competition in Exterior Trim Category at 2015 SPE TPO Automotive Engineered Polyolefins Conference.   

SPE Trophy for the winning team 
New Toyota Tonneau cover has a trifold design, which can be easily secured or removed from the vehicle. Thermoplastic polyolefins is injection molded to form the upper and lower panel of these three folds. Injection molding was the choice, to get consistent thin wall and dimensional stability.  Further these panels are trimmed for additional weight savings. Aluminum bars, “T” nuts and nut plates are placed on the panels for required strength.  All the three panels have more weld area on the right and left side to prevent the use of a crow bar to pick up or pry open the assembly and provides security from theft.

Initially, leading suppliers of Vibration Welding technology from the plastic welding industry, including Dukane, felt that this application was a low frequency weld application. Due to the high cost of the low frequency Vibration Welders and the extra expense required to build the larger tooling, it was evident that using low frequency equipment would be a very expensive way to weld these panels.  However, Dukane’s technical experts kept an open mind and tested the application using both high and low frequency Vibration Welders, proving it could be done by a high frequency welder.  Finally, Dukane built a standard 240 Hz Dukane Vibration Welding machine and kept the cost to a minimum.

Two versions of the assemblies were designed one for short bed truck and another for long bed truck. Dukane built three panels per version which means six vibration tools to weld the six individual parts. Dukane’s customer Nyloncraft, welds these parts in batches. The quick tool change feature of Dukane’s Vibration Welders allow Nyloncraft to weld all the three panels of bed cover using the same welder. Tools are typically changed in less than ½ an hour much less than the changing of the mold tools.

Inductive part sensing capabilities of Dukane’s Vibration Welders are used to make sure that all aluminum bars, “T” nuts and nut plates are placed securely before welding the upper and lower parts. Dukane’s proprietary HMI software is programmed to look for upto 15 parts before welding the upper and lower molds of the cover panels. There is somewhere between 55 and 70 square inches of weld area on each assembly.  Some panels are larger so they are closer to the 70 square inches of weld.

Initial challenges on this project were met with team work, persistence and clear vision. The result is an award winning product that helps Toyota meet stringent CAFÉ (Corporate Average Fuel Economy) standards for mpg of fleet vehicles.

For more information on Dukane's Vibration Welding technology visit http://www.dukane.com/us/PVI_VibeWeld.htm or call 630-797-4902