Current background

With the upgrading of the automotive industry, the recycling of waste bumpers has become an important issue in the fields of environmental protection and resource regeneration. As a high plastic content component, its paint stripping and recycling have both ecological and economic value: professional paint stripping can block the pollution path of harmful substances in paint, and the separated modified plastic substrate is recycled and returned to the production chain, building a “resource product renewable resource” closed loop.

Recycling process

1、The recycling process begins with crushing materials, breaking down waste bumpers into small pieces to create the foundation for subsequent processes.

2、After crushing, the material enters the dosing screw (2 units) and variable frequency feeding hopper, which precisely controls the amount of material and agent added to ensure stable subsequent reactions. The material is transported by the spiral feeder and enters the abrasive machine to remove the paint on the plastic.

3、In the caustic soda high-temperature paint stripping process, the material is added to the caustic soda high-temperature thick wash through an abrasive machine, with a single treatment of 500kg, lasting for 40 minutes. At high temperatures, caustic soda reacts with paint, damaging its molecular structure and causing the paint to peel off from the plastic substrate, achieving initial separation of paint and plastic and reducing the difficulty of subsequent cleaning, which is the core step of chemical paint stripping.

4、The paint stripping material enters the friction cleaning machine through the spiral feeding machine, and through the synergistic effect of mechanical friction and cleaning agent, deeply peels off the residual paint residue and chemicals on the surface, achieving clean treatment of plastic substrates.

5、25 degree saltwater tank: The dehydrated material is fed into a 25 degree saltwater tank and separated using density differences. Metal, wire, and paint foam sink due to high density and are removed as impurities; Plastic floats up due to its low density and enters the dewatering machine for processing, initially screening out the plastic body.

6、15 degree salt water tank: After dehydration, the material is transferred to a 15 degree salt water tank. A small amount of high-density plastic sinks and separates, and the floating plastic is dehydrated again to further classify and pave the way for precise recycling.

7、The materials processed by the salt water tank enter the clean water tank. Based on density differences, the sinking materials are dehydrated to obtain ABS/submerged PP, and the floating materials are dehydrated to obtain floating PP. Different types of plastics are classified and recycled, and then put back into industrial production, achieving the transformation of waste bumpers into renewable resources.

Advantage

This process establishes an integrated technology system of “chemical paint stripping (caustic soda high-temperature) – physical cleaning (friction+dehydration) – density sorting (saltwater tank+clean water tank)”: high-temperature caustic soda destroys paint molecules to achieve paint plastic peeling, friction cleaning and dehydration improve substrate cleanliness, and then accurately separates ABS/submerged PP and floating PP through density differences. It not only solves the problem of paint pollution, but also converts plastic resources into reusable and renewable raw materials, providing a replicable green solution for the automotive recycling industry, promoting the industry’s transformation from end of pipe treatment to resource regeneration, and realizing the industrialization of “turning waste into treasure”.