Application of plasma treatment machine in coating and bonding of automobile interior and exterior decoration

Automobile interior and exterior coating, coating, bonding

The treatment of automotive interior parts before painting is similar to that of automotive bumpers. Many automotive interior parts are made of plastic materials, and most of them are thermoplastic plastics, mainly including PP, PE, PVC, PET, ABS, etc. PU, PA, PC, PBT, PS, etc. are also used. Compared with metal substrates, plastic substrates have low surface free energy (less than 10-5J/cm2), low polarity, and residual release agent on the surface. These factors can easily lead to poor adhesion of plastic coatings.

The traditional method is to use a flame machine for treatment, but the flame machine has a high temperature, plastic parts are easy to deform, and automotive interior parts are strange in shape, so the flame machine cannot handle them properly.

The current mainstream method is to use a low-temperature vacuum plasma cleaning machine, which can not only do a full-scale cleaning of interior parts of various shapes, but also avoid high temperatures, and the interior parts will not deform, which can perfectly meet the standards to be achieved before the car is sprayed. Plasma cleaning can remove hydrocarbon dirt (such as grease and auxiliary additives in plastic materials) on the surface of plastic parts. This process changes the molecular chain structure on the surface of plastic parts, produces free radicals such as hydroxyl and carboxyl that are beneficial to the adhesion of coatings, thereby improving the adhesion of the plastic surface, thereby ensuring that the structural adhesive can fully wet the surface of the substrate.

Car light coating

Before the car light coating, the workpiece is bombarded with plasma, and its bombardment energy can be transferred to the lattice atoms of the substrate, destroying the lattice structure, increasing the micro-roughness of the workpiece surface, making the surface atoms of the substrate completely exposed, increasing the polarizability of the atoms, reducing the distance between the film atoms and the surface atoms of the substrate, and increasing the contact area between the film and the surface, which is conducive to improving the mechanical locking force, thereby greatly improving the adhesion between the film and the substrate.

Automobile light bonding

Basically, any headlamp will be glued to meet the need for leak-proofing between the light distribution mirror and the shell, and car headlights have higher requirements for this. To ensure the long service life of automotive lamps, they must be effectively protected from the ingress of moisture. When bonding headlamps and taillamps made of polypropylene (PP) and polycarbonate (PC), adhesives must have excellent sealing properties and provide reliable bonding. Precise local pretreatment using atmospheric low-temperature plasma surface treatment technology activates non-polar materials in all critical areas, improves the adhesion of the glue, and thus ensures reliable bonding and long-term sealing of the lamps. To ensure this long service life, they must be effectively protected from the ingress of moisture. When bonding headlamps and taillamps made of polypropylene (PP) and polycarbonate (PC), adhesives must have excellent sealing properties and provide reliable bonding. Precise local pretreatment using low-temperature plasma surface treatment technology activates non-polar materials in all critical areas, and thus ensures reliable bonding and long-term sealing of the headlamps.

Sealing strip bonding

In order for the adhesive to adhere well to the sealing strip surface, the flocked surface of the sealing strip is appropriately pretreated before applying the glue. At present, plasma surface treatment is often used in online flocking, that is, a plasma beam with a certain energy 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 bonding strength between the fluff and the adhesive.

Improvement of hydrophilicity of automotive glass before spraying and electroplating

The hydrophilicity of glass is not good before cleaning, and the contact angle between the untreated clean glass substrate and water is 90 degrees. If spraying and coating are carried out directly, problems are likely to occur, such as debonding and shedding. For this situation, the solution of Mercedes-Benz automobile manufacturers is to use a plasma cleaning machine to clean the automotive glass before spraying and electroplating, so that the automotive glass coating can achieve the ideal effect.

The hydrophilicity of automotive glass is mainly related to the hydrophilic group, the most important of which is the hydroxyl group. Since no other element atoms are introduced, the hydrophilic groups on the glass surface before and after low-temperature plasma treatment are mostly hydroxyl groups, and a small number are other hydrophilic groups directly related to hydroxyl groups, such as water molecules adsorbed through hydroxyl hydrogen bonds.