Principles of Laser Welding

Plastic laser welding is the process of combining two plastic parts to be welded with external pressure, and then projecting a short wavelength infrared laser directionally onto the area to be welded, achieving plastic laser welding. The laser beam passes through the upper transparent material, and then the lower material absorbs the short wavelength infrared laser. After the laser is absorbed, the conversion of light energy into heat energy is achieved. Due to the bonding of the upper and lower layers of materials through external pressure, the two layers of materials melt and bond together. At the same time, due to the thermal expansion and expansion of the material itself, internal stress and external pressure work together to ensure that the bonding surfaces of the two materials are fully bonded, melted, and solidified, thus achieving the plastic laser welding process. For the product material itself that does not absorb short wavelength infrared, our company provides long wavelength 2 micron plastic laser welding or coating laser additives to achieve the plastic laser welding process.

Welding method
1. Contour welding: The laser welding head moves along the welding ribs of the absorbing layer (transparent layer) to melt it, gradually melting the transparent layer and the absorbing layer; Or for products such as circular sleeves, the laser moves along the fixed laser beam along the interlayer to achieve welding purposes.
2. Quasi synchronous welding: The laser welding head does not move, and welding is achieved by quickly moving a laser beam along the welding rib. The welding trajectory is processed by the PC terminal on the vector file, and the laser beam moves at high speed along the graphic trajectory shown in the vector file, which is the welding rib of the product, to achieve welding.
3. Mask welding: This welding method is often used in medical products, especially products with microfluidic structures such as microfluidic control. This welding method is similar to the quasi synchronous welding method, with the biggest difference being the mask. The mask can be compared to a sunshade with a watermark, where the light in the watermark cannot pass through - the mask is coated with reflective laser materials, and the laser reflection cannot pass through areas on the product that do not need to be welded, The part without reflective material is welded using laser.
4. Synchronous welding: synchronous welding is similar to ultrasonic welding, but synchronous laser welding has no amplitude, which means that the welding joint does not directly contact the product during non-contact processing. Synchronous welding emits laser through multiple laser welding joints at the same time. After certain shaping, the laser is guided along the contour line of the welding layer, while generating heat at the welding site, so that the entire contour line can be melted and bonded at the same time.

Welding method
1. Contour welding: The laser welding head moves along the welding ribs of the absorbing layer (transparent layer) to melt it, gradually melting the transparent layer and the absorbing layer; Or for products such as circular sleeves, the laser moves along the fixed laser beam along the interlayer to achieve welding purposes.
2. Quasi synchronous welding: The laser welding head does not move, and welding is achieved by quickly moving a laser beam along the welding rib. The welding trajectory is processed by the PC terminal on the vector file, and the laser beam moves at high speed along the graphic trajectory shown in the vector file, which is the welding rib of the product, to achieve welding.
3. Mask welding: This welding method is often used in medical products, especially products with microfluidic structures such as microfluidic control. This welding method is similar to the quasi synchronous welding method, with the biggest difference being the mask. The mask can be compared to a sunshade with a watermark, where the light in the watermark cannot pass through - the mask is coated with reflective laser materials, and the laser reflection cannot pass through areas on the product that do not need to be welded, The part without reflective material is welded using laser.
4. Synchronous welding: synchronous welding is similar to ultrasonic welding, but synchronous laser welding has no amplitude, which means that the welding joint does not directly contact the product during non-contact processing. Synchronous welding emits laser through multiple laser welding joints at the same time. After certain shaping, the laser is guided along the contour line of the welding layer, while generating heat at the welding site, so that the entire contour line can be melted and bonded at the same time.