Laser welding is becoming a new trend of plastic welding
Release date:2019-08-30 15:13
First, we need to find out the welding method.
Hot plate welding is one of the earliest and simplest welding technologies in plastic welding technology. With the development of technology, vibration friction welding and ultrasonic welding are the most widely used welding methods at present. Laser welding technology has been paid more and more attention.
Laser welding is a technology that uses the heat generated by laser beam to melt the plastic contact surface, and then combines the thermoplastic sheet, film or die. It first appeared in the 1970s, but because of its high cost, it can not be compared with the early plastic welding technology such as vibration welding technology, hot plate welding technology. However, since the mid-1990s, laser welding technology has been gradually popularized due to the reduction of equipment cost required by laser welding technology.
Laser welding technology can be used to bond plastic parts to very precise materials (such as electronic components) or to require sterile environments (such as medical devices and food packaging). Laser welding technology is fast, especially suitable for automobile plastic parts assembly line processing.
From a material point of view, what else should we pay attention to?
1. Laser welding is also affected by the compatibility and melting temperature difference of the two polymers. The better the compatibility or the closer the melting temperature is, the easier the laser welding process will be and the higher the welding strength will be. As shown in Figure 2, PC can be well welded with PBT, ABS and PBT, PC/ABS and PMMA or PC.
2. When the absorber polymer converts laser energy into thermal energy, the volume will expand. Therefore, it is necessary to apply a certain clamping force to the upper and lower layers through fixtures to avoid expansion and deformation of the welding interface. This is not only to ensure better heat transfer between the two layers, but also to ensure that the two polymers can melt at the same time. To obtain higher welding strength.
In addition, when selecting laser welding technology, too high laser power or too long welding time can easily lead to excessive melting of materials and lead to deterioration. In order to achieve ideal welding quality, appropriate laser power, scanning speed and welding time should be selected.