Introduction to the structure of plastic molds


Plastic mold is an abbreviation for a combined mold use […]

Plastic mold is an abbreviation for a combined mold used for compression molding, extrusion molding, injection, blow molding and low foam molding. The coordinated changes of the mold convex and concave molds and the auxiliary molding system can process a series of plastic parts of different shapes and different sizes.
Plastic mold is the mother of industry, and now the release of new products will involve plastic.
It mainly includes a female mold with a variable cavity composed of a female mold combined substrate, a female mold component, and a female mold combined card board. The male mold combined substrate, a male mold component, a male mold composite card, a cavity cutoff component and A punch with a variable core composed of side-cut composite plates.
In order to improve the function of plastics, various auxiliary materials, such as fillers, plasticizers, lubricants, stabilizers, colorants, etc., must be added to the polymer to become a plastic with outstanding functions.

1. Synthetic resin is the most important component of plastics, and its content in plastics is generally 40% to 100%. Because the content is large 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 small part of plastics containing 100% resin, most plastics require other substances in addition to the primary component resin.
2. Filler Filler, also known as filler, can improve the strength and heat resistance of plastics and reduce costs. For example, the use of wood powder in phenolic resin can greatly reduce the cost, making phenolic plastic one of the cheapest plastics, and at the same time it can significantly improve the mechanical strength. Fillers can be divided into two types: organic fillers and inorganic fillers, the former such as wood flour, rags, paper and various fabric fibers, and the latter such as glass fiber, diatomaceous earth, asbestos, carbon black and so on.
3. Plasticizers Plasticizers can increase the plasticity and flexibility of plastics, reduce brittleness, and make plastics easier to process and shape. Plasticizers are generally high-boiling organic compounds that are miscible with resins, non-toxic, odorless, and stable to light and heat. The most commonly used are phthalate esters. For example, in the production of polyvinyl chloride plastics, if more plasticizers are added, soft polyvinyl chloride plastics can be obtained; if no or less plasticizers are added (amount <10%), rigid polyvinyl chloride plastics can be obtained .
4. Stabilizer In order to prevent the synthetic resin from being decomposed and damaged by the effects of light and heat during processing and use, and to extend the service life, it is necessary to add a stabilizer in the plasticizer. Commonly used are stearate and epoxy resin.
5. Coloring agent Coloring agent can make plastics have various gorgeous and beautiful colors. Commonly used organic dyes and inorganic pigments as colorants.
6. Lubricant The effect of the lubricant is to prevent the plastic from sticking to the metal mold during molding, and to 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-mentioned additives, SPC can also participate in flame retardants, foaming agents, antistatic agents, etc.