19 plastic molding processes

1. Injection molding

It is a method of industrial product production modeling. Rubber injection molding and plastic injection molding are usually used for products. Injection molding can also be divided into injection molding and die-casting. Injection molding machine (injection machine or injection molding machine for short) is the main molding equipment that uses plastic molding molds to make thermoplastic or thermosetting materials into plastic products of various shapes. Injection molding is realized through injection molding machines and molds.

2. Extrusion

It is a processing method that materials are heated and plasticized while being pushed forward by the screw through the action between the extruder barrel and the screw, and are continuously made into products or semi products of various sections through the die.

3. Rotary forming

Also called rotational molding, rotary molding, rotary molding, rotary casting, rotary molding, etc., this molding method is to first add the measured plastic (liquid or powder) into the mold, and after the mold is closed, rotate it along two vertical rotation axes, while heating the mold. Under the action of gravity and heat energy, the plastic raw materials in the mold are gradually uniformly coated, melted and adhered to the entire surface of the mold cavity, forming the same shape as the mold cavity, After cooling, shaping and demoulding, products with the required shape can be obtained

4. Blow molding

Also known as hollow blow molding, it is a rapidly developing plastic processing method. The tubular plastic parison produced by extrusion or injection molding of thermoplastic resin is placed in the split die while it is hot (or heated to a softened state), and compressed air is introduced into the parison immediately after the die is closed, so that the plastic parison is blown and stuck to the inner wall of the die. After cooling and demoulding, various hollow products are obtained.

5. Blister

A plastic processing technology, the main principle of which is to heat and soften the flat plastic hard sheet, absorb it on the surface of the mold by vacuum, cool it, and shape it, and apply it to all walks of life.

6. Molding

Also known as compression molding or compression molding, it refers to the operation of putting powdered, granular or fibrous plastics into the mold cavity at the molding temperature, and then pressing the closed mold to make it molded and solidified. The molding can also be used for thermosetting plastics, thermoplastics and rubber materials.

7. Rolling forming

Melt plasticized thermoplastic is extruded, extended and stretched by more than two parallel and opposite rotating roller gaps to become a continuous sheet product with a certain size and quality requirements, and finally formed by natural cooling. Calendering process is often used in the production of plastic film or sheet.

8. Foam molding

It is the process of adding proper foaming agent into foaming materials (PVC, PE, PS, etc.) to make plastics produce microporous structure. Almost all thermosets and thermoplastics can be made into foam plastics, and foam molding has become an important field in plastic processing.

9. Winding forming

The process is to wind the continuous fiber (or cloth tape, prepreg yarn) dipped in resin glue onto the core mold according to a certain rule, and then obtain the product after curing and demoulding.

10. Lamination forming

It refers to the forming and processing method of integrating multiple layers of the same or different materials under heating and pressure. It is commonly used in plastic processing and rubber processing.

11. Coating and forming

It is a process that uses plastic sol or organic sol to coat the surface of substrate such as cloth or paper to make imitation leather products, lacquered cloth or plastic wallpaper, or powder plastic to coat metal surface. Common plastic coating products include artificial leather, varnished cloth, plastic wallpaper and various metal coating products.

12. Pouring forming

It is a method of plastic processing. In the early stage of casting, liquid monomer or prepolymer was injected into the mold under normal pressure, and then polymerized and solidified into products with the same shape as the mold cavity. Nylon monomer casting appeared in the 1960s. With the development of molding technology, the traditional casting concept of polyamide has changed. Polymer solution, dispersion refers to PVC paste and melt can also be used for casting.

13. Drop plastic

The technology is to make use of the characteristics of thermoplastic polymer materials with variable state, that is, it has viscous flow under certain conditions, but it can recover the characteristics of solid state at room temperature, and use appropriate methods and special tools to spray ink, shape it into a designed shape under its viscous flow state as required, and then cure it at room temperature.

14. Cold compression molding

It is a kind of compression molding. Different from ordinary compression molding, materials are molded under pressure at room temperature. The demoulded molded products can be heated again or ripened by chemical action.

15. Compression molding

It is mainly used in the production of thermosetting plastic products. After heating, the molding is melted, the pressing die is pressed, and then the product is heated, cross-linked, solidified, and demoulded.

16. Resin transfer molding

It is a process method to inject resin into a closed mold to soak reinforcement materials and solidify them. This technology can effectively reduce the equipment cost and molding cost without prepreg and autoclave.

This technology has developed rapidly in recent years, and has been widely used in aircraft industry, automobile industry, ship industry and other fields. It has also developed RFI, VARTM, SCRIMP, SPRINT and other branches to meet the application needs of different fields.

17. Extrusion

It is a pressure processing method that the punch or punch is used to pressurize the blank placed in the female die to produce plastic flow, so as to obtain the parts corresponding to the shape of the die holes or male and female dies. When extruding, the billet will produce three dimensional compressive stress, and even the billet with low plasticity can be extruded.

18. Thermoforming

It is a special plastic processing method for processing thermoplastic sheets into various products. A special plastic processing method for processing thermoplastic sheets into various products. The sheet is clamped on the frame and heated to a softened state. Under the action of external force, the sheet is closely attached to the mold surface to obtain a shape similar to the mold surface. After cooling and shaping, the finished product can be trimmed.

19 3D printing

(3DP) is one of the rapid prototyping technologies. It is a technology based on digital model files, which uses powder metal or plastic and other adhesive materials to construct objects by layer printing. 3D printing is usually realized by digital technology material printer. It is often used in mold manufacturing, industrial design and other fields to manufacture models, and then gradually used in the direct manufacturing of some products. There are already parts printed with this technology.

There are many different technologies for 3D printing. They differ in the way that the available materials are used and the components are built in different layers. Common materials for 3D printing include nylon glass fiber, polylactic acid, ABS resin, durable nylon material, gypsum material, aluminum material, titanium alloy, stainless steel, silver plating, gold plating, rubber materials.