1. Process misunderstanding of welding workpiece

Ultrasonic energy is instantaneous. The welding line should be a point or line and the distance of transmission must be in line with the ultrasonic welding method. Some people think that as long as it is a plastic material, no matter how the joint surface can be welded well, this is a wrong understanding. When the instantaneous energy is generated, the larger the joint area, the more serious the energy dispersion, the worse the welding effect, or even the failure Ultrasonic waves propagate longitudinally, and the energy loss is proportional to the distance, and the long distance should be controlled within 7.5 cm. The welding line should be controlled between 0.3-0.8mm for the best condition, and the wall thickness of the workpiece should not be less than 2mm, otherwise it cannot be welded well, especially for products that require water and air tightness.

2. Misunderstanding of workpiece material

Ultrasonic welding machines have requirements for the material of the workpiece to be welded. Not all materials can be welded. Some people think that any material can be welded. This is a big misunderstanding. Some materials can be welded well, and some can basically be welded. Some are incompatible. The melting point of the same material is the same, and it can be welded in principle. But when the melting point of the welded workpiece is greater than 350 degrees, it is not suitable for ultrasonic welding. Because ultrasound melts the molecules of the workpiece in an instant, the judgment basis is within 1-3, and it cannot be welded well, so other welding processes should be selected, such as hot plate, rotary melting, vibration and friction, etc. Generally speaking, ABS material is the easiest to weld because of its low melting point and hard hardness. On the contrary, nylon is the most difficult to weld.

3. Misunderstanding of ultrasonic selection

How much output power to use, the oscillation frequency, and the amplitude range should be considered according to the material of the workpiece, the area of the welding wire, whether there are electronic components in the workpiece, and whether it is airtight or not. Misunderstood that the greater the power, the better. This is also a misunderstanding. If you don’t know much about ultrasound. It is best to consult a regular ultrasonic production plant engineering and technical personnel. If possible, it is best to communicate with the manufacturer on-site, and do not blindly follow the misleading of some informal ultrasound sales staff. At present, the companies that produce related equipment are particularly complex, most of which are family-style workshops, which mimic circuits mechanically and do not understand the working principles. The imitated equipment has a fatal flaw. One is that the quality of the purchased raw materials cannot be guaranteed, and the second is that the core technology of the production process is not mastered. The equipment is often unstable in medium power and high power work, and the product qualification rate is low. Sometimes the equipment is damaged. Such as transducer power transformer, the magnetic material parameters used cannot be measured, magnetic saturation magnetic flux density (Bs), magnetic induction intensity (Bm), effective magnetic permeability (Ue), residual magnetic flux density (Br), coercive force (A/M) etc. The winding process is quite complicated, and these family workshops cannot do it. Therefore, when buying ultrasound, it is best to understand the company's situation first, not to blindly follow the salesperson's praise, and do not just want the price. Only in this way can we reduce unnecessary troubles in the future.