In automobile manufacturing, interior products are composed of skeleton and surface decoration materials. The skeleton and the surface decoration material are bonded through styrofoam, glue, etc. Before bonding, the skeleton needs to be pretreated. The traditional process is flame method or polishing.    Automotive interiors are usually made of plastic materials such as polypropylene (PP), with weak surface dispersion and poor adhesive properties on the surface of the material, making it difficult for coating materials (such as leather, etc.) to adhere firmly without treatment. On the interior trim, and it is prone to degumming and cracking under the sun. Especially for automobile instrument panels, because they contain complex structures such as multiple curved surfaces, protrusions and grooves, surface treatment is more difficult.    The traditional treatment method uses flame method to improve surface energy, but due to its low production capacity and high flame temperature, problems such as material appearance can easily be caused.    sindin large cavity vacuum plasma cleaner can process large size curved, uneven and non-planar materials. It can be used for pre-coating treatment of automobile instrument panels, and can achieve efficient and uniform surface activation treatment.    Before coating the automobile instrument panel, surface treatment with sindin vacuum plasma can effectively improve the surface activity of PP and other materials, making it easier to combine with the coating material, thereby improving the firmness and durability of the coating.