What to do if the product is distorted after ultrasonic welding

Update:27 Apr 2019
Summary:

There are three reasons for this deformation: 1). The b […]

There are three reasons for this deformation:
1). The body and the desired fusion or cover cannot match each other due to angle or curvature.
2). The product wall thickness is thin (within 2m/m) and the length exceeds 60m/m.
3). The product is deformed and distorted due to conditions such as injection molding pressure.
Therefore, when our products are deformed by ultrasonic operation, it seems to be the cause of ultrasonic welding from the surface. However, this is only a result. Any factors before the plastic products are not welded, what kind of results are formed after welding. If there is no discussion on the main cause, it will take a lot of time to deal with the problem of the right medicine, and in the ultrasonic indirect conduction welding operation (referred to as remote ultrasound), the ultrasonic pressure below 6kg can not change the flexibility and inertia of the plastic. So don't try to use strong pressure to change the deformation before welding (the maximum pressure of the fusion machine is 6kg), including forced extrusion with a mold fixture. Perhaps we will also fall into a blind spot, which is to explore the cause of the deformation from the surface, that is, the naked eye can not be seen before the fusion, but after the completion of the ultrasonic welding, it is obvious that the deformation is found. The reason is that before the welding, the existence of the fuse line will be difficult to find the cumulative angle of the product itself, the arc and the accumulated error of the residual material, but after the completion of the ultrasonic welding, it will appear to be visible to the naked eye. .
Solution:
1. Reduce the pressure (pressure is preferably below 2kg).
2. Reduce the ultrasonic welding time (reduced strength standard).
3. Increase the hardening time (at least 0.8 seconds or more).
4. Analyze whether the ultrasonic upper and lower modes can be partially adjusted (not necessary).
5. Analyze the main cause of product deformation and improve it.