Injection molding process

1, plastic composition

In addition to polymers, a variety of plastic additives (such as thickeners, viscosifiers, additives, lubricants, modifiers and fillers, etc.). It is generally introduced into the raw materials used in plastic processing to improve the product characteristics of the molding process or reduce the production cost. Mixed with high polymer, symmetrical dispersion into powder, also known as dry mix. Sometimes the powder is mixed and processed into particulate matter. Such powders and particles are called batch or moulding plastics.

2. Plastic molding

The key link of plastic processing. Form various forms of plastic (powder, particulate, water solution or dispersion) into products or embryos that require shape. There are more than thirty molding methods. The selection depends entirely on the type of plastic (thermosetting plastic or thermosetting plastic), the original method, and the shape and size of the product. Common thermosetting plastics plastics processing methods include extrusion, injection molding, die casting, injection molding and thermal molding. In general, rubber and plastic products, transfer molding and injection of rubber and plastic products are used to process thermosetting plastics. Pressing, rubber and plastic products and thermoforming to form plastic in a flat surface. The above plastic processing methods are suitable for plastic processing. In addition, there are also single liquid or polymer as the raw material for casting. In various methods, extrusion molding and injection molding are the most widely used and the most basic molding methods.

3. Tight connection of plastic parts

Methods of joining plastic parts include welding and bonding. The welding methods include hot air welding, hot fusion welding, high frequency welding, friction welding, induction welding, ultrasonic welding, etc. The bonding method can be divided into welding paste, epoxy resin aqueous solution and thermal sol bonding according to the adhesive used.

4, plastic parts installation

The operation of assembling plastic parts into detailed goods by gluing, welding and sleeve joint. For example, plastic aluminum profiles are assembled into plastic Windows and doors according to the steps of sawing, welding and drilling.

Step 5 Process

Using metal and wood processing methods. You can do precise specifications or small amount of plastic products, but also as a molding auxiliary processing technology, such as saw extrusion profiles. Because plastic performance is different from metal and wood, poor thermal conductivity, low coefficient of linear expansion, low elastic mold. The force of fixture or CNC blade is too large, easy to cause deformation, laser cutting when hot melt, stick to the CNC blade. Therefore, when processing plastics, the numerical control blade used and the corresponding cutting dosage should adapt to the characteristics of plastics. Common processing methods include sawing, cutting, punching, turning, planing, drilling, grinding, polishing and screw machining. In addition, plastic can also be broken with lasers, holes, electric welding.

6. Surface modification materials

The purpose is to decorate the surface of plastic products, usually including: mechanical equipment modified materials, refers to through filing, polishing, polishing and other processes to remove the burr and burr in the product, adjust the specifications; Scratch coating, including on the surface of the product with paint, with solution to make the surface bright, on the surface of the product with a decorative plastic film. Coloring, including paint, packaging printing and thermal printing; Metal plating, including plating spraying, plating process and mechanical gold plating, etc. In which the hot printing is in heating and pressing, the hot printing film in the colorful aluminum platinum layer (or other pattern design coating) transferred to the product workpiece. Many electrical products, building products, daily necessities and so on. These are the methods used to get metal texture or wood texture and other patterns.