Ultrasonic Plastic Welding Machine for ABS, PP, PE, Nylon and PA
In the actual production process, not all of the plastic material can be welded, able to be plastic ultrasonic welding are thermoplastics, only the same or similar molecular structure of thermoplastic welding, the welding surface is the chemical combination between molecules, so the more similar matrix material, welding effect is better. The figure below is a comparison of some common plastics welding compatibility.
We also need to consider the factors that affect the welding quality to get better welding results. Pressure, time and heat absorption (melt amount) are the three factors to ensure welding quality when welding.
Applying proper pressure on the welding surface, the welding material will transition from elasticity to plasticity, and it can also promote molecular diffusion and squeeze out residual air in the welding seam, thus increasing the sealing performance of the welding plastic surface.
There should be a proper heat fusion time and sufficient cooling time.When the thermal power is constant, there will be void welding in short time, and if the time is too long, there will be deformation of welding parts, overflow of molten slag, and sometimes hot spots (discoloration) will appear in non-welded parts.It is necessary to ensure that the welding surface absorbs enough heat to achieve a full fusion state, that the welding plastics can be fully diffused and fused among molecules, and that sufficient cooling time must be ensured to achieve sufficient strength of the welding seam.
3. Amount of molten
The heat fusion time and heat power can be adjusted to a super appropriate amount of fusion, so as to ensure sufficient intermolecular fusion and eliminate the phenomenon of virtual welding. In addition to the technical level of welding equipment and operators, various factors coming from inside or outside of plastics have a certain impact on welding quality, which should be paid more attention to.
4. Plastics moisture absorption
If wet plastic products are welded, the moisture content will turn into steam after being heated, and bubbles will appear on the welding surface, which will weaken the sealing performance of the welding surface. The more serious materials are PA, ABS, PMMA, etc. Products made from these materials must be dried before welding.
5. Packing in plastic
Such as glass fiber, talc, mica, and so on, they change the physical properties of the material. The content of filler in plastics is closely related to the weld ability and welding quality of welded plastics. Plastics with less than 20% filler can be welded normally without special treatment. When the content of the filler exceeds 30%, due to the insufficient proportion of plastic on the surface and insufficient intermolecular fusion, sealing will be reduced.
6. Cleaning requirements for welding surfaces
Welding plastic surface must be clean without impurity to ensure sufficient welding strength and air tightness.
Altrasonic Technology co., LTD. Specializes in producing ultrasonic welding machine, such as PP plastic welding machine PE plastic welding machine PC plastic welding machine ABS plastic welding machine, PVC plastic machine nylon PA welding machine PS plastic machine press PMMA machine, POM plastic polyester poly sulfone plastic welding plastics SAN Cellulose ABS and PC composites
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