Automotive trim parts have the function of decorating and beautifying cars, and the quality of their decorative effect directly affects the internal and external image of the car. Automotive trim parts are composed of various materials, ranging from custom-made metal blanks to sheet-molded composite materials (SMC) and glass fiber reinforced plastics (GFRP), to composite plastics, which have extremely different surface properties. However, the surface energy of these raw materials is relatively low, so before using structural adhesives, the surface needs to be properly treated to remove surface dirt, dust, oil, grease, moisture, mold release agents, plasticizers, etc., and at the same time, increase the surface energy of the substrate to make it higher than the surface energy of the structural adhesive, thereby ensuring that the structural adhesive can fully wet the surface of the substrate. This is crucial for achieving a strong, reliable, and durable bond. 

Plasma activation technology mainly bombards the plasma onto the surface to be treated, and forms highly active chemical bonds with the treated surface. Highly active chemical bonds are more prone to react with other substances and form stable chemical bonds, thereby achieving the goal of improving adhesion and bonding effects. Plasma surface treatment can be used to replace the existing primer-assisted adhesion process and improve the bonding stability of automotive trim parts.

In the automotive industry, plasma treatment technology has innovated the pretreatment process of automotive sealing strips before flocking or coating, which avoids material loss and dust pollution while improving the treatment effect. Plasma treatment also allows lamp manufacturers to choose cheaper PP materials to replace ABS materials, and there is more space in the choice of glue system ; in the parts of automobile parts that need to be bonded and assembled, such as the processing of door panels, the processing of airbags, the bonding of sealing strips and decorative strips, plasma surface treatment can simplify the processing process while improving the quality. In automobile spraying, plasma treatment allows manufacturers to save the primer, so that the product and the process itself are more environmentally friendly.

Sealing strip flocking 

In order to make the adhesive adhere well to the surface of the sealing strip, the surface of the sealing strip was properly pretreated before gluing. Pretreatment is generally divided into mechanical bristling and plasma treatment. Mechanical bristling is polished by a metal brush to make the surface of the flocking part of the sealing strip rough, so that the adhesive can penetrate into these uneven grooves. After curing, the tooth force is generated in the bonding interface area, so as to obtain good bonding strength. Plasma treatment is to discharge gas on the surface of the sealing strip through a high-voltage electrode to produce a polar surface, so that the adhesive and the rubber sealing strip have good adhesion strength. At present, plasma surface treatment is often used in on-line flocking, that is, a certain energy of plasma beam is used to bombard the surface of the sealing strip to improve the wettability of the sealing strip surface and increase the surface tension, thereby enhancing the adhesion strength between the fluff and the adhesive. 

Plasma surface treatment of various automotive seals, after the determination of surface energy can reach > 60dynes / cm, can remove the grinding or coating polyester process, without primer, and according to the speed of extrusion or flocking machine to do online processing, improve production capacity, reduce costs, do not damage the strip surface, and meet the environmental protection requirements of coating water-soluble adhesive.