Comparison of material weldability in quasi-simultaneous plastic laser welding

Laser's research results and product series in plastic laser welding have attracted the attention of customers. Faced with the difficulties and challenges of reduced product welding width, product curved surface design, and ultrasonic and conventional laser welding that cannot be achieved, the project team worked hard to learn, strive for excellence, customize laser performance parameters, and develop precision tools, achieving a technological breakthrough in laser precision space curve welding and meeting customer needs.

Compared with traditional plastic joining technology, plastic laser welding machines have advantages in product physical properties, process performance, aesthetics and cost performance. The design concept of plastic welding technology is shifting towards laser welding. In terms of materials, plastic laser welding machines can not only laser weld materials that are sufficiently transparent, but also laser weld the upper layer of black or other color materials. Laser Laser has developed a series of fully transparent plastic laser welding products suitable for the medical industry, and surface beam quasi-synchronous plastic laser welding equipment suitable for the automotive lighting industry.

Plastic Laser Welding Principle:

A well-known form of laser welding is called "penetration laser welding." In the plastic laser welding process, the two plastic parts to be welded are first tightly combined by mechanical clamping, and then after the laser penetrates the upper workpiece, the energy is absorbed and melted by the surface of the lower workpiece, and then the upper material is melted by heat conduction.

During the welding process, local heat causes the material to expand, generating internal welding pressure, and external mechanical clamps apply pressure to ensure that the weld is firm and stable. Lasers can weld almost all thermoplastics and thermoplastic elastomers, including glass fiber reinforced plastics, which are usually equal to or greater than the strength of the parent material.

Interwelding performance of commonly used plastic combinations:

Laser welding is affected by the compatibility of the two plastics and the melting temperature difference. The better the compatibility of the two plastics or the closer the melting temperature, the easier it is for the plastic laser welding process to obtain higher quality welding strength. The optical properties of the material combination are very important for the welding process. The laser welding effect of the two-layer workpiece determines the selective absorption and transmission of the material to the laser.

Melting temperature of transparent parts and light-absorbing parts:

Thermoplastics are used for plastic laser welding, which is characterized by not changing the physical properties of the material itself, and entering a melting state as the temperature rises. Light-absorbing materials and light-transmitting materials need to have a common melting temperature interaction range, which is a necessary condition for forming a weld. In addition, for welding different materials, although sometimes both can be welded, they are defined as light-absorbing parts or light-transmitting parts. Different melting temperatures may also affect the selection of laser technology and the setting of parameters.

The quasi-synchronous plastic laser welding machine is combined with moving welding parts, with simple and compact structure, easy operation, safety and stability.

The system uses a high-speed scanning of plastic laser with a vibrating mirror, and can be equipped with a high-precision sag value measurement sensor to accurately control the welding slump value. It can be welded on any plane track within the scanning range of the vibrating mirror, and can be equipped with general fixtures and special fixtures to weld various products.