The production process of plastic products
The production of plastic products usually includes plastic composition, molding, processing, joining, modification and assembly. After molding plastic into a product or semi-product, four processes are performed, which is also known as plastic secondary processing.
The key link of molding compound processing in the production of plastic products, various forms of plastics are made into products or blanks of the desired shape, and there are as many as 30 molding methods. Its selection mainly depends on the type of plastic, the initial form, and the shape and size of the product. Common methods for plastic processing of thermoplastics include extrusion, injection molding, calendering, blow molding and thermoforming.
Plastic processing of thermosets typically uses compression molding, transfer molding and injection molding, lamination, molding and thermoforming to form plastics on flat surfaces, all of which can be used for rubber processing. In addition, there are castings that use liquid monomers or polymers as raw materials. Among these methods, extrusion molding and injection molding are commonly used, which are also basic molding methods.
Machining of plastic product production uses plastic processing methods such as metal and wood to produce plastic products with precise dimensions or small quantities. It can also be used as an auxiliary process for forming, such as sawing extruded profiles, due to the properties of plastics that differ from metals. and wood properties, therefore plastics have poor thermal conductivity, low thermal expansion coefficient and low elastic modulus.
When the fixture or tool is under excessive pressure, it is easy to cause deformation. And it melts easily when heated during cutting and sticks easily to the tool. Therefore, when machining plastics, the tools used and the corresponding cutting speeds must be suitable for the characteristics of the plastics. Commonly used machining methods for plastic parts include sawing, shearing, punching, turning, planing, drilling, grinding, Polishing, threading, etc. In addition, plastic fittings can also be laser cut, punched and welded.
In the production of plastic products, there are welding and bonding methods for plastic parts joining. Welding methods are: hot air welding using electrodes, hot melt welding using hot electrodes, and high frequency welding, friction welding, induction welding, Ultrasonic welding, etc., the bonding method can be divided into flux, resin solution and hot melt adhesive bonding, according to the adhesive used.