Molded parts production method
Plastics production generally includes plastic ingredients, molding, machining, joining, trimming and assembly. The last four processes are performed after the plastic has been molded into a product or a semi-finished product, which is also referred to as secondary plastic processing.
Molding of plastic products The key to plastic processing. Various forms of plastics (powders, pellets, solutions or dispersions) are made into the desired shape of the article or blank. There are up to 30 types of molding methods. Its choice mainly depends on the type of plastic (thermoplastic or thermosetting), the starting form and the shape and size of the product. Plastics The commonly used methods of thermoplastics include extrusion, injection molding, calendering, blow molding, and thermoforming. Plastics thermosetting plastics are generally molded, transfer molded, and injection molded. Lamination, moulding and thermoforming are plastic moldings in a plane. The above plastic processing methods can be used for rubber processing. In addition, there are castings using liquid monomers or polymers as raw materials. Among these methods, extrusion molding and injection molding are used most often and are also the most basic molding methods.
Plastics production of mechanical processing Plastics processing methods such as metal and wood are used to produce plastic products with very precise dimensions or small quantities. They can also be used as forming auxiliary processes, such as sawing of extruded profiles. Because the properties of plastics are different from those of metals and woods, plastics have poor thermal conductivity, low coefficient of thermal expansion and low modulus of elasticity. When the clamps or tools are pressurized too much, they are prone to deformation, easily melted during cutting, and tend to adhere to the tool. on. Therefore, when plastics are machined, the tools used and the corresponding cutting speeds must be adapted to the characteristics of the plastics. The commonly used machining methods include sawing, shearing, punching, car, planing, drilling, grinding, polishing, thread processing, and the like. In addition, plastics can also be laser cut, punched and welded.
Joints for the production of plastic products Plastics processing Joining of plastic parts involves welding and bonding. The welding method is hot air welding using electrodes, hot-melt welding using hot electrodes, 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 of plastic products production is to beautify the surface of plastic products, usually including: mechanical modification, that is, the use of boring, grinding, polishing and other processes to remove the raw burrs, burrs, and correction of the size; coating, including coating with the system The surface of the part is brightened with a solvent, and the surface of the product is covered with a patterned film; the color is applied, including painting, printing, and hot stamping; and the metal plating includes vacuum coating, electroplating, and chemical silver plating. The plastic processing hot stamping is to transfer the colored aluminum foil layer (or other patterned film layer) on the hot stamping film to the parts under heating and pressure. Many home appliances and building products, daily necessities, etc., are used to obtain patterns such as metallic luster or wood grain.
Assembly of plastics production Assembly of finished plastic parts into finished products by means of bonding, welding and mechanical joining. For example, plastic profiles are assembled into plastic window frames and plastic doors through steps such as sawing, welding, and drilling.