In order to improve the performance of plastic molds, 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 most important component of plastic, and its content in plastic is generally 40%~100%. Due to the large content, and the nature of the resin often determines the properties of the plastic mold, people often regard resin as a synonym for plastic. For example, polyvinyl chloride resin is confused with polyvinyl chloride plastic, phenolic resin and phenolic plastic. In fact, resin and plastic are two differences
concept. Resin is a raw, raw polymer used not only to make plastics, but also as a raw material for coatings, adhesives, and synthetic fibers. In addition to a very small part of plastics containing 100% resin, the vast majority of plastics, in addition to the main component resin, need to add other substances. 2. Filler filler is also called filler, which can improve the strength and heat resistance of plastics, and reduce costs. For example, the addition of wood powder to phenolic resin can greatly reduce costs, making phenolic plastic one of the cheapest plastics, while also significantly improving mechanical strength. Fillers can be divided into two categories: organic fillers, such as wood powder, rags, paper and various fabric fibers, and the latter such as glass fiber, diatomaceous earth, asbestos, carbon black, etc.
3. Plasticizer plasticizer plasticizer can increase the plasticity and softness of plastic molds, reduce brittleness, and make plastics easy to process and mold. Plasticizers are generally miscible with resins, non-toxic, odorless, high boiling point organic compounds that are stable to light and heat, and the most commonly used are phthalates. For example, in the production of polyvinyl chloride plastics, if more plasticizers are added to obtain flexible polyvinyl chloride plastics, if no or less plasticizers are added (dosage< 10%), hard polyvinyl chloride plastics are obtained.
4. Stabilizer In order to prevent the synthetic resin from being decomposed and destroyed by light and heat during processing and use, and to prolong the service life, stabilizers should be added to plastics. Commonly used are stearate, epoxy resin, etc.
5. Colorant colorant can make plastic mold have a variety of bright and beautiful colors. Organic dyes and inorganic pigments are commonly used as colorants.
6. The function of lubricant lubricant is to prevent the plastic from sticking to the metal mold during molding, and at the same time to make the surface of the plastic smooth and beautiful. Commonly used lubricants are 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 plastics.
