Solutions for precision laser welding of plastics

Plastic laser weldingThere are specific requirements for welding plastics to ensure that the welding process goes smoothly and obtain high-quality welded joints. Here are some key requirements for welding plastics:

1. Material compatibility

1.1 Compatibility

The plastic materials to be welded should have similar chemical structures and melting points to ensure that the two materials can be effectively fused when heated by the laser. For example, the same plastic or different grades of the same plastic usually have good compatibility, such as PC (polycarbonate) with PC, PP (polypropylene) with PP.

1.2 Compatibility Combinations

Some different types of plastics can also be welded, but their chemical compatibility and melting behavior need to be carefully evaluated. For example, PA (polyamide) can be welded with certain modified PP, but this depends on the specific application and welding process.

2.Optical properties

2.1 Laser absorbency

For effective laser welding, at least one of the welding surfaces needs to be able to absorb the laser energy. For transparent or translucent plastics, absorbents such as carbon black or special dyes can be added to increase the absorption rate.

2.2 Light transmittance

In transmission laser welding (TLP), the upper plastic needs to have high light transmittance to allow the laser to pass through and heat the bottom plastic. The bottom plastic needs to have good laser absorption ability.

3. Thermal properties

3.1 Melting point and thermoplasticity

The plastic materials to be welded should have appropriate melting point and thermoplasticity to ensure that the materials can melt and fuse with each other when heated by the laser. The melting temperature range of the material should adapt to the energy input of the laser.

3.2 Thermal conductivity

Plastics with high thermal conductivity can help evenly distribute laser heat, reduce heat accumulation and thermal damage, and improve welding quality. For example, PA and PC have high thermal conductivity and are suitable for laser welding.

4. Mechanical properties

4.1 Welding strength

The mechanical strength and toughness of the material should meet the strength requirements for use after welding. The welded joint should have good tensile strength, shear strength and impact toughness to ensure that it is not easy to break or damage during use.

4.2 Fracture toughness

The welding material should have good fracture toughness to prevent brittle fracture during the welding process or in use.

5. Chemical and environmental stability

5.1 Chemical resistance

The welding materials should have good resistance to the chemicals in the use environment to ensure that the welding joints will not be corroded or degraded when exposed to chemicals.

5.2 Environmental stability

The material should be able to withstand the temperature, humidity, ultraviolet rays and other conditions in the use environment, and maintain the stability and durability of the welded joint.

6.Material Purity and Quality

6.1Material Purity

Welding plastics should have high purity to avoid impurities and additives that negatively affect the welding process and results. Impurities and incompatible additives can cause welding defects such as bubbles, cracks and incomplete welding.

6.2 Material consistency

Use plastic materials from the same batch or specification to ensure the consistency and repeatability of the materials, thereby ensuring the stability of welding quality.

Plastic selection in practical application

鈻燛lectronics Industry

In the electronics industry, commonly used welding plastics include PC, PBT (polybutylene terephthalate) and LCP (liquid crystal polymer), which have excellent mechanical strength and heat resistance and are suitable for precision welding.

鈻燤edical Devices

Commonly used plastics in the manufacture of medical devices include PE (polyethylene), PP, PC and polyurethane. These materials have good biocompatibility and chemical resistance and are suitable for medical applications.

鈻燗utomobile Manufacturing

Commonly used welding plastics in the automotive manufacturing industry include PA, PP and PC/ABS (acrylonitrile-butadiene-styrene copolymer). These materials have high strength, heat resistance and chemical resistance, and are suitable for welding automotive parts.

Plastic Laser WeldingThe requirements for welding plastics cover many aspects, such as material compatibility, optical properties, thermal properties, mechanical properties, chemical and environmental stability, and material purity and quality. Selecting the right plastic material and optimizing the welding process can achieve high-quality and efficient welding results to meet the needs of various applications. By strictly controlling these factors, the reliability and durability of plastic laser welding can be ensured.