Technical process of plastic bottle manufacturing:
The molding process of plastic bottles refers to the process of making final plastic products from polymers manufactured by synthetic resin manufacturers. Processing methods (commonly referred to as one-time processing of plastics) include compression molding (compression molding), extrusion molding (extrusion molding), injection molding (injection molding), blow molding (hollow molding), calendering, etc.
1. Compression molding
Compression molding is also called compression molding or compression molding. Compression molding is mainly used for the molding of thermosetting plastics such as phenolic resin, urea-formaldehyde resin, and unsaturated polyester resin.
Extrusion, also known as extrusion molding, is a method that uses an extruder (extruder) to continuously pass heated resin through a mold to extrude products of the desired shape. Extrusion is sometimes also used in the molding of thermoset plastics and can be used in the molding of foam plastics. The advantage of extrusion is that products of various shapes can be extruded, the production efficiency is high, and it can be automated and continuous production; the disadvantage is that thermosetting plastics cannot be processed by this method widely, and the product size is prone to deviation.
3. Injection molding
Injection molding is also called injection molding. Injection molding is a method that uses an injection molding machine (or injection machine) to inject thermoplastic melt into a mold under high pressure, and then cool and solidify to obtain a product. Injection molding can also be used for the molding of thermosetting plastics and foam plastics. The advantages of injection molding are fast production speed, high efficiency, automatic operation, and the ability to form parts with complex shapes, which is especially suitable for mass production. The disadvantage is that the cost of equipment and molds is high, and it is difficult to clean the injection molding machine.
4. Blow molding
Blow molding is also called hollow blow molding or hollow molding. Blow molding is a method in which the hot resin parison closed in the mold is blown into hollow products by the pressure of compressed air. Blow molding includes two methods: blown film and blown hollow products. Blow molding can be used to produce film products, various bottles, barrels, pots, and children's toys.
Calendering is to process the resin and various additives through the expected treatment (kneading, filtering, etc.) into a film or sheet through the gap of two or more calender rolls that turn in opposite directions, and then peel it off from the calender roll , A molding method that is cooled and shaped. Calendering is a molding method mainly used for polyvinyl chloride resin, which can produce films, sheets, plates, artificial leather, floor tiles and other products.
6. Foam molding
The process of adding appropriate foaming agents to foaming materials (PVC, PE, PS, etc.) to make plastics have a microporous structure. Almost all thermosetting and thermoplastic plastics can be made into foam. According to the cell structure, it is divided into open-cell foam (most of the pores are connected to each other) and closed-cell foam (most of the pores are separated from each other). This is mainly due to the manufacturing method (divided into chemical foaming, physical foam And mechanical foaming).