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Composition of pp hollow sheet
- Oct 19, 2018 -

Synthetic resin

Synthetic resin is the most important component of plastics, and its content in plastics is generally 40% to 100%. Resin is often regarded as a synonym for plastics because of its high content and the properties of resins which often determine the properties of plastics. For example, PVC resin and PVC plastics, phenolic resin and phenolic plastics confuse. In fact, resin and plastics are two different concepts. Resin is a raw, unprocessed polymer used not only in plastics, but also as a raw material for coatings, adhesives, and synthetic fibers. In addition to a very small part of the plastic containing 100% resin, the vast majority of plastic, in addition to the main component resin, but also need to add other substances.


Filler is also called filler, it can improve the strength and heat resistance of plastics, and reduce the cost. For example, adding wood flour into phenolic resins can greatly reduce costs, making phenolic plastics one of the cheapest plastics, while significantly improving mechanical strength. Filler can be divided into organic filler and inorganic filler, the former such as wood powder, rags, paper and various fabric fibers, the latter such as glass fiber, diatomite, asbestos, carbon black and so on.


Plasticizers can increase plasticity and softness of plastics, reduce brittleness, and make plastics easy to process and shape. Plasticizers are generally high boiling point organic compounds which can be miscible with resin, non-toxic, odorless, stable to light and heat, the most commonly used is phthalate esters. For example, in the production of PVC plastics, soft PVC plastics can be obtained by adding more plasticizers, and rigid PVC plastics can be obtained if plasticizers are not added or less (dosage < 10%).


In order to prevent the synthetic resin from being decomposed and destroyed by light and heat in the process of processing and using, and prolong its service life, stabilizers should be added to the plastics. Commonly used stearate, epoxy resin and so on.

Coloring agent

Colorants can make plastic with various bright and beautiful colors. Common organic dyes and inorganic pigments are used as coloring agents.


The function of lubricant is to prevent plastics from sticking to metal molds while forming, and to make the surface of plastics smooth and beautiful. Commonly used lubricants are stearic acid and calcium magnesium salts.


Prevent plastic from being heated and oxidized during heating or high temperature use, so that the plastics will become yellow and crack.

In addition to the above additives, flame retardants, foaming agents, antistatic agents can be added to the plastics to meet different requirements.