The car dashboard, abbreviated as, is an important component of the car interior. It is a special component that combines safety, functionality, comfort, and decoration. Using plastic materials instead of metal materials can reduce weight, lower costs, improve design flexibility, and enhance component integration. With the rapid development of the automotive industry, customers have increasingly high requirements for automotive products. At the same time, the dashboard is an exterior component, so it is required to have good aesthetics, excellent surface feel, and high scratch resistance. To achieve these goals, it is necessary to use special adhesives to apply soft skin foam technology on the plastic body of the dashboard, in order to meet the requirements of aesthetics, tactile sensation, and scratch resistance

At present, ABS plastic (acrylonitrile butadiene styrene copolymer) and PP plastic (polypropylene composite) are mainly used to make instrument panels, among which PP plastic is gradually becoming the preferred material in the automotive industry due to its better performance and lower price. However, the characteristics of both materials do not meet the requirements of the foaming process. In order to facilitate foaming, the surface tension value of the plastic should meet the production requirements, generally requiring 45 dynes. The surface tension value of PP plastic itself is only 31 dynes, far from meeting production requirements. Plasma treatment can improve the adhesion on the surface of plastic parts and compensate for their insufficient surface tension. Therefore, plasma treatment technology is needed to change their surface tension and make their surface density exceed 48 dynes.

The surface treatment of car dashboard generally adopts flame treatment technology. This treatment method uses a high-temperature gas flame to oxidize the surface of the plastic and dissolve the solvent on the surface. The flame activates oxygen molecules in the air, forming polar groups with carbon molecules on the surface of the material. The increase in surface molecular polarity and oxidation reduces the surface tension of the plastic, thereby improving the adhesion between the body and the coating. However, existing flame treatment technologies have low cleaning efficiency, require the use of flammable and explosive gases, and require different process parameters for different products, resulting in low production efficiency and gas pollution.

Principle of plasma treatment for automotive dashboard

Using plasma treatment technology to treat the surface of automotive dashboard; The plasma generator, in a vacuum state, uses the high-voltage alternating electric field generated by the radio frequency power supply to oscillate the process gas into ions with high reactivity or energy, which then react or collide with organic pollutants and micro particle pollutants on the surface of the car dashboard to form volatile substances. These volatile substances are then removed by the working gas flow and vacuum pump, thereby achieving the goal of cleaning and activating the surface of the car dashboard.

The high-energy particles in the plasma, especially electrons, collide with the surface of the material, causing etching of the plastic surface. In addition, the migration of free radicals and impurities generated after plasma treatment leads to the growth of surface crystalline components, resulting in an increase in surface roughness of the material, generally greater than, and an increase in surface adsorption force.

Plasma treatment technology can efficiently, safely, and pollution-free treat the surface of automotive instrument panels, with high cleaning efficiency. Compared to flame treatment processes, it can achieve simultaneous treatment of multiple products at once. Compared to flame treatment processes, which require the use of flammable and explosive gases, plasma treatment only requires the use of conventional compressed gases, increasing the safety factor of use. Compared to flame treatment processes, which require the debugging of different programs for different products, plasma treatment equipment only needs to be easily removed and placed, without the need to create separate programs, reducing the manufacturing cost of each product.