Plastic processing is also known as plastic molding processing. It is a general term for various processes that convert synthetic resins or plastics into plastic products, and is a large production department in the plastics industry. Plastic processing generally includes compounding, molding, machining, joining, trimming, and assembling of plastics. The last four processes are carried out after the plastic has been formed into a finished product or semi-finished product, also known as secondary plastic processing.

In addition to polymers, the raw materials used in plastic processing are generally added with various plastic additives, such as stabilizers, plasticizers, colorants, lubricants, reinforcing agents and fillers, to improve the molding process and products. improve the performance or reduce the cost of the product.

The key link in plastic processing is molding. Various forms of plastics, such as powders, granules, solutions, dispersions, etc., are made into products or blanks of desired shapes. There are as many as thirty kinds of molding methods, and its choice mainly depends on the type of plastic, thermoplastic or thermosetting; the initial shape and the shape and size of the product. Commonly used methods for processing thermoplastics include extrusion, injection molding, calendering, blow molding, and thermoforming. Thermosetting plastics are generally processed by molding, transfer molding, and injection molding.

Machining is the use of metal and wood processing methods to manufacture plastic products with very precise dimensions or a small number of plastic products. It can also be used as an auxiliary process for forming, such as sawing of extruded profiles. Because the performance of plastic is different from that of metal and wood, plastic has poor thermal conductivity, low thermal expansion coefficient, and low elastic modulus. When the fixture or tool is pressurized too much, it is easy to cause deformation, and it is easy to melt when heated, and it is easy to adhere to the tool. superior. Therefore, when plastic is machined, the tools used and the corresponding cutting speed must be adapted to the characteristics of the plastic. Commonly used machining methods include sawing, shearing, punching, turning, planing, drilling, grinding, polishing, threading, etc.

Joining is the joining of plastic parts, which is divided into welding and bonding. The welding methods are hot air welding using an electrode, hot melt welding using a hot electrode, and high frequency welding, friction welding, induction welding, ultrasonic welding, and the like. The bonding method can be divided into flux, resin solution and hot melt adhesive according to the adhesive used.

The purpose of surface modification is to beautify the surface of plastic products, usually including mechanical modification, that is, to use filing, grinding, polishing and other processes to remove burrs, burrs, and size correction on the parts; finishing, including coating with paint The surface of the piece is brightened with a solvent, and the surface of the product is covered with a patterned film; color application, including color painting, printing and hot stamping; metal plating, including vacuum coating, electroplating and chemical silver plating, etc. Among them, hot stamping is to transfer the colored aluminum foil layer (or other patterned film layer) on the hot stamping film to the product under heat and pressure. Many household appliances, building products, daily necessities, etc., use this method to obtain patterns such as metallic luster or wood grain.

Assembly is the process of assembling finished plastic parts into a complete product using methods such as gluing, welding, and mechanical connection. For example: plastic profiles, which are assembled into plastic window frames and plastic doors after sawing, welding, drilling and other steps.