Ultrasonic welding operation on PA66 GF30
Does anybody have experience about Ultrasonic welding operation on PA66?. The material is Rodia Technyl PA66 GF30. It is an automotive component. We are still investigating to increase welding quality. What would effect on this? Humidity? Weld force? weld collapse distance?
Well, all the points have a cause during the welding but for me (at least for my experience) humidity and distance are the main points to keep in mind to achieve a good welding surface.
When you talk about to increase the welding quality, I suposse that you are talking about the final surface aspect.
Understanding that the humidity environment is under control (less of 30% ideally) then make some differents weldings with some differents highs and you could have the first impressions and results to continue working on this way.
If any other test has made, will be nice to hear about to focus your problem and to try to help you.
Look forward for your comments.
I think you can consult with Brasion. They are very professional on it.
Since the Ultrasonic welding have the energy ribs. That should be matched very well. So the parts deformation and energy ribs shape are in good status that will be very important. Especially this material have two main trouble, one is the absorted water, the other is deformation. So this two main points you should overcome.
The process is very new for our company. We need some experience on it. But honestly speaking I didn't know the humidity effect on welding quality. That means we have to keep the components away from humidity, Also probably the both components have to have similar humidity content.
Actually we are trying to define what the welding quality is. Our main criteria is (accoring to customer expectation) is pull force of welded components. Also we are trying to have weld whole surface equally. Branson will come for consulting soon. I ll let you know.
If the main problem is pull-out force, then the most important issue is the geometry of the wave leaders and the booster you have chosen. Off course, you need a machine with substantial power...
In addition, extremely important is the clean condition of the welding area. The purity of the welding area should be maintained against humidity and anyother foreign substance.The most common defect is the presence of mold release agents...
Do not count too much on Branson. EMERSON, as all "big" companies have "narrowed" their engineering departments. During the 90's a visit from Branson was already enough to start feeling relieved. Now, it is not exactly the same. You should listen carefully, but keep your mind fully operational! It is strongly possible that the final detail that will solve your problem shall be investigated by yourself.
My company G&G Engineering produces amongst other also assemblies for the automotive industry and we build moulds, press tooling, assembly machines as well as actually do mould, press/stamp and assembly. As G&G is often involved with the actual component designer on the concept we are very familiar with the pit falls when heat-staking especially PA66 GF (G&G uses amongst others a 40% GF PA66).
Every point our colleagues have made is very valid and greatly influences the end results.
One addition point I would like to raise is, that PA as an water absorbing material will alter its properties in the time between moulding and welding (at least until it has absorbed as much moisture as it can).
For best results you need a continues process, where you have "no" moisture in the component, or a controlled environment with a controlled amount of humidity and then give the component time to acclimatise for a week or 2 before processing.
I did not notice what exactly you are welding (thickness shape, size), what the requirements are (i.e. just joined or water tight etc), or if these are seem welds, or heat stakes. All this has also an influence on your end result and the condition (environment and machine) which are required.
I hope this helps a little further.
Thanks for the commands. We are sealing the bags after the moulding. Water content in components are below %1. At the last production, One component has %0,2, the other one has %0,9 water content. I guess those values are acceptable for the process.
The parts are connectors for the cooling system in the car engine. We weld a ring into a pipe. So the shapes are diameters. The hardest point to do is welding the components parallelly.
We have worked more on process recent weeks. Working with experienced colleagues and branson expert helped to improve our process. There were a few points which were not okay.
- Part design. Weld horn and part surface has too small contact area. Our part design has changed
- The fixtures were not good. we developed better fixtures. (I can easily say that, handling this point improved %50 of our process)
- we discover that the welding machine cylinder diameter is too big for our application. We can not set the weld pressure precisely. we will purchase a smaller one.
- We found out that increasing of weld force affects negatively on pull out results.
- Some more fine tuning on tools.
You all are right. This is a complex process that many little points can dramatically effect on quality. We are still learning it.
Check that your head is properly guided i.e. that the cylinder piston has two guided and cant "wobble" around.
Presently I can't see where else you might have problems.