Forum

Davison PVC Welding Machine is a natural white and very brittle May 24, 2017 10:43 PM

By : julylee

Polyvinyl chloride (PVC Welding Machine) is one of the world's most commonly used thermoplastic polymers (only a few more widely used plastics such as PET and PP). It is a natural white and very brittle (before plasticizer) plastic.

Even with a straight or smooth curve path, constant repetitive frequency laser ignition results in unequal spacing of solder joints due to the limited acceleration and deceleration rates of moving system components moving the laser beam along the weld profile. Only when the relative movement of the laser beam relative to the component is at its target speed, the laser pulses at a constant rate produce the correct spaced solder joints. Since the speed of the laser beam along the weld profile is less than the target speed, these points are more closely spaced during acceleration and deceleration of the moving system components. The close spacing of the solder joints may cause these areas to overheat because more heat is applied to the smaller part of the welding path. And this overheating can affect the quality of PVC welding, and even damage the internal parts of the welding equipment.

Between PVC welding and simple curves, a balance between the burning rate and component speed can be achieved to produce "close enough" welds. With other shapes, it is much harder to break this balance. In order to keep the focus, the laser focus head must always be kept at a distance from the part being welded. In addition, in many cases, the laser beam must strike the surface of the component with a constant angle of incidence. These limits can impose a serious burden on the motion system components by requiring each component (movement phase) to accelerate or decelerate under its capacity constraints. For example, even in the case of seam welding with a rounded corner of the rectangular package, one or more stages must try to "instantly" change the direction at some critical point while maintaining a constant speed. The physical stage can not do that.

 


To post a comment please register or sign in