Some of the plastic itself is pure resin, such as polyethylene, polystyrene, etc., known as a single plastic components. Some plastic in addition to the synthetic resin, also contain other auxiliary materials, such as plasticizer, stabilizer, colorants, all kinds of packing, etc., known as multicomponent plastic.
(a) synthetic resin
Synthetic resin refers to coal, calcium carbide, oil, natural gas, and other agricultural and sideline products as the main raw material, made first with a range of synthetic conditions of low molecular compounds (monomer), and then by chemical, physical methods such as synthesis of high molecular compound. The characteristics of these compounds similar to natural resin (e.g., rosin, amber, shellac, etc.), but the performance is more superior than natural resin. For example: synthetic resin teeth.
The content of synthetic resin in the plastic, accounting for 40% of all components of a l00 % bond role, it decides the main properties of plastic, such as mechanical strength, hardness, aging resistance, flexibility, chemical stability, photoelectric property, etc.
(2) plastic additives
Plastic additives into plastic additives purpose is mainly to improve processing performance, improve the use efficiency and reduce cost. Proportion of additives in the plastic material is less, but has a great influence on the quality of plastic products. Different kinds of plastic, on the basis of different processing methods and conditions of use, the variety and dosage of additives needed is also different. The main agent has the following categories:
1. The plasticizer
Plasticizer can increase the flexibility of plastic, extensibility, plasticity, reduce the plastic flow temperature and hardness, is advantageous to the molding of plastic products. Common phthalate esters, sebacic acid esters, chlorinated paraffin and camphor. We are one of the most common camphor.
2. The stabilizer
We all know plastic products in the processing, storage and use process, under the action of light, heat, oxygen, fade, embrittlement, cracked aging phenomenon will happen. To slow down and stop aging phenomenon, must add stabilizer. Is mainly used to prevent thermal aging, heat stabilizer; Aging is mainly used to prevent oxidation, called antioxidants; Is mainly used to prevent light aging, called light stabilizer, they are collectively known as stabilizer. Today's performance is the best plastic stabilizer methyl tin heat stabilizer (181), rolling of hard polyethylene (PVC), extrusion, injection molding and blow molding are very effective. And due to its high safety, so special used in food packaging and of high definition polyethylene products, at the same time, it is also widely used in plastic doors and Windows, water pipes, decoration materials, plastic heat stabilizer to replace other highly toxic. In the United States, Europe, Japan has been widely used. In recent years, methyl tin heat stabilizer 181 began a large number of applications in our country.
3. The flame retardant
Can improve the plastic additives called flame retardant flame resistance. Containing flame retardant plastic most has the self-extinguishing, or burning rate slows, etc. Commonly used flame retardants have antimony oxide and aluminum, boron compounds, halide, phosphate and tetrachlorophthalic anhydride, four Australian benzene second anhydride, etc.
4. The antistatic agent
Antistatic agent plays to eliminate or reduce plastic products surface electrostatic effect. Antistatic agent, mostly electrolyte, intermiscibility of them with synthetic resin is limited, so that you can migrate to the surface of plastic, reach the role of moisture absorption and eliminate static electricity.
5. The foaming agent
Plastic foaming agent is a certain temperatures can gasification low molecular organic compounds, such as the dichlorodifluoromethane; Or will break out of the heated gas of organic compounds. These gases in the plastics substrate and formed many small bubbles of the structure of the foam. Commonly used with azo compound, nitroso compound, etc.
Colorants used in plastics coloring. Main beautify, decorate role. About 80% of the plastic products is made of final products after coloring.
Lubricant is to improve the plastic thermoforming when demoulding and improve surface finish of the product and add material. Commonly used lubricants are: stearic acid and its salts, paraffin wax, synthetic wax, etc.
8. Reinforced material and packing
In many plastics, reinforced material and packing occupies considerable proportion, especially reinforced plastics and plastic materials. Main purpose is: to improve the strength of the plastic and rigid, general to join all kinds of fibre materials or inorganic matter. The most commonly used reinforced material are: fiber glass, asbestos, silica, carbon black, silicate, calcium carbonate, metal oxide, etc.
- Plastic Items Introduction To The
- Plastic Products Performance Charac...
- The Development Trend Of Plastic Pr...
- Plastic Products Production Methods
- Plastic Cups To Paper Cups Are Safer
- Pay Attention To The Maintenance On...
- Woodcarving Maintenance
- Silver Plated Glass Mirror Began In...
- The Optical Properties Of The Mirror
- The Classification Of The Mirror
- Plastic Items The Scope Of Application
- Mirror A Brief Introduction
- Bath Accessories How To Buy
- Plastic Items Exhibition Trend