A New Process for Plastic Welding

Laser welding has been well known to most people as a welding process for metal materials. However, as a process of plastic welding, it is still relatively advanced, and most people may not know much. Laser welding, ultrasonic welding, vibration welding, hot plate welding, etc. are welding technologies widely used in the field of resin plastics.

In recent years, with the continuous development of domestic laser application technology and the continuous development of laser welding equipment, more and more manufacturers have begun to introduce plastic laser welding technology, and the technology that was originally considered "high-end" has gradually been recognized by the public. Because laser welding technology has the advantages of good welding appearance, fast welding speed and high welding strength, it is gradually adopted in the automotive field.

Classification of laser equipment

Depending on the structure of the laser emitting device, laser irradiation methods can be divided into sequential, reflective, and full-circumferential irradiation types.

Principle of laser welding

Part 1 is a transparent material and part 2 is an opaque plastic. The laser beam passes through part 1 to part 2, and the interface between part 2 and part 1 absorbs the laser energy. When the energy is concentrated to a certain extent, the plastic at the interface will be melted. When a certain pressure is applied to the upper and lower parts, the two parts are fused together, and the two parts are fused together after cooling.

Features of Laser Welding

1advantage

①Short welding time, generally only takes a few seconds ②High degree of freedom of shape, controllable laser path ③Applicable to precision welding ④Good appearance, less burrs, suitable for parts with high appearance requirements ⑤High degree of automation ⑥The heat-affected area is small, and local heating can be achieved.

2limitation

①The upper parts are required to be able to pass through the laser, and opaque plastics cannot be welded by laser. ②The equipment investment cost is high. ③The professional and technical requirements are relatively high, and it is necessary to have a certain understanding of the laser routing route, speed and irradiation time.

Laser welding process

1Four steps of laser welding:

First, the two parts are mounted on the fixture and tightened; second, by controlling the device to emit a laser, it is ensured that enough heat is generated at the interface of the parts to melt the plastic; third, by applying a certain pressure to the parts, the two parts are melted The parts are integrated under the action of extrusion; finally, by turning off the laser irradiation and maintaining a certain pressure for a period of time, the two parts are cooled, and finally the

                                                                                                                 Laser welding process