The methods of laser welding plastic pepper balls can be divided into non-contact laser welding and laser transmission welding. Here we mainly introduce laser transmission welding. Laser transmission welding refers to the technology that the laser beam passes through the plastic pepper ball shell and reaches the surface of the laser-absorbing plastic. With the help of the heat generated by the laser beam, the contact surface of the plastic pepper ball shell is melted, and then the hot pepper ball shell parts are bonded together. This welding method can be applied to the welding of both lap joints and butt joints.The principle of laser welding plastic pepper indicator is as follows: the upper and lower shells of plastic pepper ball are clamped together under low pressure, and the light beam generated by laser is focused on the area to be welded through an optical path system consisting of a reflector, a lens or an optical fiber, so as to form a thermal action zone, wherein one plastic pepper ball shell is transparent to near-infrared laser, and the other plastic pepper indicator shell absorbs laser, and the plastic absorbing laser energy converts light energy into heat energy, which is melted at the contact surface of the plastic pepper ball shell, and heat is also conducted to the one that transmits near-infrared light. Under the action of clamping force, intermolecular mixing occurs in the melting area. When the melting size reaches the specified requirements, the laser heat source is removed, and under the continuous action of a certain pressure, a weld is formed after cooling, thus realizing the transmission laser plastic pepper ball welding. In order to improve the absorption performance of the upper plastic pepper ball shell, absorbent is often added; In addition, in order to improve the permeability through the plastic pepper ball shell, dyes with high permeability are often added.The main advantages of laser plastic pepper ball welding are:1) Using laser heat source with high energy density, the joint temperature of plastic pepper ball is optimized, so as to ensure the high speed and high precision of laser welding process of plastic pepper ball.2) By changing the shape and size of the laser beam, the heat affected zone and the bonding zone can be controlled to a small extent. No trace of welding and no damage caused by welding can be seen on the outer surface of the welding area.3) Assemble the parts before welding, and the welding process is very easy.4) There is no restriction on the shape and size of parts, which makes the design freedom of parts improve by leaps and bounds.5) There is no vibration in the welding process, which is very beneficial for vibration-sensitive parts such as electronic components and medical instruments.6) Non-contact processing (there is no physical contact between the connected parts and the heat source), which is easy to maintain the hygiene and safety of medical and food equipment.7) The freedom of laser beam transmission is high, and it is easy to realize automation.8) No toxic smoke will be generated, and the welding site is safe and reliable.Transmission laser pepper ball welding heat sourceIn laser transmission welding, infrared laser is selected as the welding heat source, the wavelength is mainly 980nm, and the power level is different according to the welding size and material. Generally, 30W-200W fiber output semiconductor laser is selected. Caplin photoelectric 60W-200W semiconductor laser, integrated with high-precision control system, has the characteristics of non-contact welding, minimal heat affected zone and controllable solder joint temperature, and is applied to the welding of plastic pepper damaged shell.