Plastic products can be seen everywhere in our lives, cups, packaging boxes, cold storage boxes, conductive anti-static electronic product packaging boxes, etc., these are all made of plastic sheets through the blister process. Blister is a kind of plastic processing technology. The main principle is to heat and soften the flat thermoplastic plastic sheets such as PVC, PET, PETG, APTT, PP, PE, PS, etc., and then use vacuum to adsorb on the surface of the mold, and then form after cooling. And high-quality plastic sheet depends on the manufacturing process and plastic masterbatch. So what are the types of common plastic masterbatches?
In the plastics and polymer industry, 10 common plastic raw materials:
- PEI polyether
PEI has strong high temperature stability, even if it is non-reinforced PEI, it still has good toughness and strength. The glass transition temperature is very high, reaching 215 °C. Therefore, the superior thermal stability of PEI can be used to make high temperature heat-resistant devices. PEI also has good flame retardancy, chemical resistance and electrical insulating properties. PEI also has very low shrinkage and good iso-directional mechanical properties.
- PET polyethylene terephthalate
The glass transition temperature of PET is around 165 °C, and the material crystallization temperature ranges from 120 to 220 °C. PET is highly hygroscopic at high temperatures. For glass fiber reinforced PET materials, bending deformation is also very easy to occur at high temperatures. Special additives such as mica can be added to PET to minimize bending deformation. The crystallinity of the PET material can be increased by adding a crystallinity enhancer. Transparent articles processed from PET have gloss and heat distortion temperature. Transparent articles can also be obtained using unfilled PET materials if lower mold temperatures are used.
- PETG ethylene glycol modification – polyethylene terephthalate
PETG is a transparent, amorphous material. The glass transition temperature is 88 °C. The allowable range of the injection molding process conditions of PETG is wider than that of PET, and it has the comprehensive characteristics of transparency, high strength and high willfulness.
- PMMA polymethyl methacrylate
PMMA has excellent optical properties and weather resistance properties. The penetration of white light is as high as 92%. PMMA products have very low birefringence and are especially suitable for making video discs. PMMA has room temperature creep properties. Stress cracking can occur with increasing load and time. PMMA has good impact resistance properties.
- POM polyoxymethylene
POM is a tough and elastic material with good creep resistance, geometric stability and impact resistance even at low temperatures. POMs are available as both homopolymer and copolymer materials. Homopolymer materials have good ductility and fatigue strength, but are not easy to process. Copolymer materials have good thermal and chemical stability and are easy to process. Both homopolymer materials and copolymer materials are crystalline materials and do not easily absorb moisture.
The high degree of crystallinity of POM results in a relatively high shrinkage rate, which can be as high as 2% to 3.5%. There are different shrinkage rates for various reinforced materials.
- PP polypropylene
PP is a semi-crystalline material. It is harder and has a higher melting point than PE. Because homopolymer PP is very brittle at temperatures above 0°C, many commercial PP materials are random copolymers with 1 to 4% ethylene or pincer copolymers with higher ethylene content. The copolymer-type PP material has lower thermal distortion temperature (100 ℃), low transparency, low gloss, low rigidity, but has stronger impact strength.
The strength of PP increases with increasing ethylene content. The Vicat softening temperature of PP is 150 °C. Due to the high degree of crystallinity, this material has good surface stiffness and scratch resistance properties. PP does not suffer from environmental stress cracking problems. Typically, PP is modified by adding glass fibers, metal additives or thermoplastic rubber.
- PPE polypropylene
Commercially available PPE or PPO materials are generally mixed with other thermoplastic materials such as PS, PA, etc. These hybrid materials are still generally referred to as PPE or PPO. Hybrid PPE or PPO have much better processing properties than neat materials. The properties vary depending on the ratio of mixtures such as PPO and PS. Hybrid materials with PA 66 are more chemically stable at high temperatures. This material has little hygroscopicity and its articles have excellent geometric stability. The material mixed with PS is amorphous, while the material mixed with PA is crystalline. Adding glass fiber additives can reduce the shrinkage to 0.2%.
This material also has excellent electrical insulating properties and a very low coefficient of thermal expansion. Its viscosity depends on the ratio of the mixture in the material, and an increase in the ratio of PPO will result in an increase in viscosity.
- PS polystyrene
Most commercially available PS is a transparent, amorphous material. PS has very good geometric stability, thermal stability, optical transmission properties, electrical insulating properties and very little tendency to absorb moisture. It is resistant to water, diluted inorganic acids, but can be corroded by strong oxidizing acids such as concentrated sulfuric acid, and can swell and deform in some organic solvents. Typical shrinkage is between 0.4 and 0.7%.
- PVC (polyvinyl chloride)
Rigid PVC is one of the most widely used plastic materials. PVC material is an amorphous material. Stabilizers, lubricants, auxiliary processing agents, pigments, impact resistance agents and other additives are often added to PVC materials in practical use. PVC material has non-flammability, high strength, weather resistance and excellent geometric stability. PVC is very resistant to oxidizing agents, reducing agents and strong acids. However, it can be corroded by concentrated oxidizing acids such as concentrated sulfuric acid and concentrated nitric acid and is not suitable for contact with aromatic hydrocarbons and chlorinated hydrocarbons.
The melting temperature of PVC is a very important process parameter during processing. If this parameter is not appropriate, it will lead to the problem of material decomposition. The flow characteristics of PVC are rather poor and its process range is very narrow. In particular, high molecular weight PVC materials are more difficult to process (such materials are usually added with lubricants to improve flow characteristics), so low molecular weight PVC materials are usually used. The shrinkage rate of PVC is quite low, generally 0.2~0.6%.
- SA styrene-acrylonitrile copolymer
SA is a hard, transparent material. The styrene component makes SA hard, transparent and easy to process; the acrylonitrile component makes SA chemically and thermally stable. SA has strong load bearing capacity, resistance to chemical reaction, thermal deformation resistance and geometric stability. Adding glass fiber additives to SA can increase strength and thermal deformation resistance, and reduce thermal expansion coefficient. The Vicat softening temperature of SA is about 110 °C. The deflection temperature under load is about 100 °C. The shrinkage of SA is about 0.3~0.7%.
DESU is an excellent plastic sheet manufacturer in China. Our plastic sheets use 100% pure plastic raw materials. The plastic sheets we produce are of high quality and guaranteed. We produce high-transparency PET plastic sheets, PP plastic sheets, PS plastic sheets, EVOH high-barrier composite plastic sheets, as well as various printing, coating, anti-static, and conductive plastic sheets. If you need a stable and high-quality supplier, you are welcome to contact us at any time!