There are many types of plastics, including PE, PP, PS, ABS, PC, PVC, etc. Most waste plastics are in an non degradable state, which can easily cause environmental pollution, cause fires, waste energy, and recycling and utilization is a very important process. The paint layer includes PU paint, rubber paint, UV paint, etc. There are many methods to remove old paint films, commonly used include: paint remover, alkali solution, paint remover, organic solvent, flame, manual chipping, sandblasting, etc. In the traditional plastic granulation machine processing, the plastic needs to be crushed first, which will damage the substrate. After peeling off the paint, it also needs to be reshaped, which increases the cost and process.
Studying a paint remover that does not cause damage to the substrate and does not require reshaping is even more important. The new high-efficiency paint remover can effectively compensate for the series of problems existing in traditional methods. Using high-efficiency paint removers for paint removal has the advantages of extremely low cost, good effect, high efficiency, and no volatility.
The solvent that causes paint to peel off is mainly used in the anti-corrosion industry. By utilizing the organic solvents in the paint remover to swell most of the coatings, the effect of removing old coatings on the substrate surface is achieved.
When the paint remover penetrates into the polymer chain gaps of the coating polymer, it will cause the polymer to swell, causing the film volume to continuously increase. During the process of increasing the polymer volume of the film, internal stress will also be generated, weakening and damaging the adhesion of the film to the substrate. After the film expands from a point like solvent, it develops into a flake solvent, causing the film to wrinkle, completely damaging the adhesion of the film to the substrate, biting and removing the film.
According to the different removal of film-forming substances, they can be divided into:
① It is formulated with organic solvents such as ketones, benzenes, and coolants, as well as volatile inhibitor paraffin wax, commonly known as "white medicine solution", and is mainly used to remove old coatings such as oil-based, alkyd, and nitrolacquer. This type of high-efficiency paint remover is mainly composed of volatile organic solvents, which have problems such as flammability and toxicity, and are relatively cheap.
② Chlorinated hydrocarbon paint remover, commonly known as "water impact paint remover", is prepared with dichloromethane, paraffin and cellulose ether as the main components. It is mainly used to remove old cured coatings such as epoxy asphalt, polyurethane, epoxy phthalamide, amino alkyd resin, etc. High paint removal efficiency, low toxicity, and wide application. The paint removers with dichloromethane as the main solvent can also be divided into neutral paint removers (pH=7 ± 1), alkaline paint removers (pH>7) and acid paint removers according to different pH values.
