Inventory of typical applications and physical and chemical properties of several commonly used plastics

Plasticis a man-made material made of synthetic resins that can be changed in shape as desired. Plastics are used for a wide variety of purposes, including making packaging, home appliances and construction materials, among others. Plastics are often divided into many types, each with its own unique properties.
PC/ABS polycarbonate and acrylonitrile-butadiene-styrene copolymers and blends (ABS sheet extrusion line)

Typical application range:
computer and business machine housings, electrical equipment, lawn and garden machines, auto parts dashboards, interior finishes, and wheel covers).

Chemical and Physical Properties:
PC/ABS has the comprehensive characteristics of both PC and ABS. For example, the easy processing characteristics of ABS and the excellent mechanical properties and thermal stability of PC. The ratio of the two will affect the thermal stability of PC/ABS material. The hybrid material PC/ABS also exhibits excellent flow characteristics.

Blend of PC/PBT polycarbonate and polybutylene terephthalate
Typical application range:
Gearboxes, automotive bumpers, and products requiring chemical and corrosion resistance, thermal stability, impact resistance, and geometric stability.

Chemical and Physical Properties:
PC/PBT has the comprehensive characteristics of both PC and PBT, such as the high toughness and geometric stability of PC and the chemical stability, thermal stability and lubricating properties of PBT.

PE‐HD High Density Polyethylene (PEpipe extrusion)
Chemical and Physical Properties:
The high crystallinity of PE-HD leads to its high density, tensile strength, high temperature distortion temperature, viscosity and chemical stability. PE-HD has stronger permeation resistance than PE-LD. PE‐HD has a lower impact strength. The properties of PH‐HD are mainly controlled by density and molecular weight distribution.
The flow characteristics of this material are very good with an MFR between 0.1 and 28. The higher the molecular weight, the worse the flow characteristics of PH-LD, but better impact strength. PE-LD is a semi-crystalline material with a high shrinkage rate after molding, ranging from 1.5% to 4%. PE-HD is prone to environmental stress cracking, which can be mitigated by using materials with very low flow properties to reduce internal stresses. PE-HD is easy to dissolve in hydrocarbon solvents when the temperature is higher than 60C, but its resistance to dissolution is better than PE-LD.

PE‐LD Low Density Polyethylene
Typical application range:
Bowls, bins, pipe couplings

Chemical and Physical Properties:
The density of commercial PE-LD materials is 0.91-0.94g/cm3. PE‐LD is permeable to gases and water vapor. The high coefficient of thermal expansion of PE-LD is not suitable for processing long-term products. If the density of PE‐LD is between 0.91 and 0.925g/cm3, then its shrinkage rate is between 2% and 5%. If the density is between 0.926 and 0.94g/cm3, then its shrinkage rate is between 1.5% and 4%. %between. The current actual shrinkage rate also depends on the injection molding process parameters. PE‐LD is resistant to many solvents at room temperature, but aromatic and chlorinated hydrocarbon solvents can cause it to swell. Similar to PE-HD, PE-LD is prone to environmental stress cracking.

PEI polyether
Typical application range:
Automotive industry (engine accessories such as temperature sensors, fuel and air handlers, etc.), electrical and electronic equipment (electrical connectors, printed circuit boards, chip casings, explosion-proof boxes, etc.), product packaging, aircraft interior equipment, pharmaceutical industry (surgical instruments , tool housings, non-implantable devices).

Chemical and Physical Properties:
PEI has strong high temperature stability, even if it is unreinforced PEI, it still has good toughness and strength. 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 insulation properties. The glass transition temperature is very high, reaching 215°C. PEI also has very low shrinkage and good mechanical properties in the same direction.

PVC (polyvinyl chloride) (PVC edge banding extrusion line)
Typical application range:
Water supply pipes, household pipes, house wall panels, commercial machine casings, electronic product packaging, medical equipment, food packaging, etc.

Chemical and Physical Properties:
Rigid PVC is one of the most widely used plastic materials. PVC material is a non-crystalline material. PVC materials are often added with stabilizers, lubricants, auxiliary processing agents, colorants, impact agents and other additives in actual use. PVC material has non-flammability, high strength, resistance to climate change and excellent geometric stability. PVC has strong resistance 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 it 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 improper, it will lead to the problem of material decomposition. The flow characteristics of PVC are quite poor, and its process range is very narrow. In particular, PVC materials with large molecular weight are more difficult to process (such materials usually need to add lubricants to improve flow characteristics), so PVC materials with low molecular weight are usually used. The shrinkage rate of PVC is quite low, generally 0.2 to 0.6%.

PMMA polymethyl methacrylate
Typical application range:
Automobile industry (signal light equipment, instrument panel, etc.), pharmaceutical industry (blood storage container, etc.), industrial application (video disc, light diffuser), daily consumer goods (drink cup, stationery, etc.).

Chemical and Physical Properties:
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. As the load increases and the time increases, it can lead to stress cracking. PMMA has good impact resistance properties.