In order to improve the performance of the plastic in the injection mold, various auxiliary materials, such as fillers, plasticizers, lubricants, stabilizers, colorants, etc., must be added to the polymer to become a plastic with good performance.

1. Synthetic resin is the main component of plastics, and its content in plastics is generally 40% to 100%. Because of the large content and the nature of the resin often determines the nature of the plastic, people often regard the resin as a synonym for plastic. For example, polyvinyl chloride resin and polyvinyl chloride plastic, phenolic resin and phenolic plastic are conflated. In fact, resin and plastic are two different concepts. Resin is an unprocessed raw polymer that is not only used to make plastics, but also a raw material for coatings, adhesives, and synthetic fibers. In addition to a very small part of plastics containing 100% resin, most plastics need to add other substances in addition to the main component resin.

Injection mold

2. Filler Filler is also called filler. Plastic molds can improve the strength and heat resistance of plastics and reduce costs. For example, the addition of wood powder to the phenolic resin can greatly reduce the cost, make the phenolic plastic one of the cheap plastics, and also improve the mechanical strength.

3. Stabilizer In order to prevent the synthetic resin from being separated and damaged by light and heat during processing and use, and to extend the service life, a stabilizer should be added to the plastic. Commonly used are stearate and epoxy resin.

4. Colorants Colorants can make plastics have various bright and beautiful colors. Commonly used are dyes and inorganic pigments as colorants.

5. Lubricant The role of the lubricant is to prevent the plastic from sticking to the metal mold during molding, and at the same time make the surface of the plastic smooth and beautiful. Commonly used lubricants include stearic acid and its calcium and magnesium salts. In addition to the above additives, flame retardants, foaming agents, antistatic agents, etc. can also be added to the plastic.