Characteristics And Applications of Several Common Plastic Materials

PE Plastic – Polyethylene

Introduction: Polyethylene (PE) is one of the five major synthetic resins and has the largest production capacity among synthetic resins in my country. Polyethylene is mainly divided into three categories: linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), and high-density polyethylene (HDPE). Polyethylene (PE) has a huge consumption among the five major general plastics. Pipes made by extrusion molding process and film products made by calendering molding process account for a high proportion of consumption. There are also hollow products made by blow molding process. Including bottles, cans, barrels, etc.; the injection molding process can make more barrels, basins, and daily gadgets according to the shape of the mold; high-density polyethylene can also be used as a high-frequency electrical insulating material and is used in radar and television .

Features: PE plastic is odorless, non-toxic, feels like wax, has low temperature resistance (the lowest operating temperature can reach -100~-70°C), has good chemical stability, and is resistant to erosion by most acids and alkalis (not resistant to Oxidizing acid), insoluble in general solvents at room temperature, low water absorption, and excellent electrical insulation. When undyed, low-density polyethylene is transparent, while high-density polyethylene is opaque.

Scope of application: PE plastic has a wide range of uses and can be processed by blow molding, extrusion, injection molding and other methods. It is widely used in film manufacturing, hollow products, fibers and daily necessities, etc. It is divided into high-density, low-density and linear PE. The most common daily application is processing into various plastic films and plastic cloths. High-density PE plastic is suitable for making shock-absorbing, wear-resistant and transmission parts.

PET plastic - polyethylene terephthalate (PET)

Introduction: Polyethylene terephthalate (PET), with the chemical formula (C10H8O4)n, is made by ester exchange of dimethyl terephthalate and ethylene glycol or esterification of terephthalic acid and ethylene glycol. It is prepared by synthesizing bishydroxyethyl terephthalate and then carrying out polycondensation reaction. It is a crystalline saturated polyester. It is a milky white or light yellow, highly crystalline polymer with a smooth and shiny surface. It is a common resin in life and can be divided into APET, RPET and PETG.

Features: recyclable (PET is one of the most recyclable plastic resins), excellent chemical resistance, hard and durable, excellent surface polishing, good pressure resistance.

Application scope: Soft drink bottles are the most common. It has applications in other film sheets, electronic products, auto parts, mechanical equipment, etc.

PP plastic-Polypropylene (PP for short)

Introduction: Polypropylene (PP) is a thermoplastic resin made from the polymerization of propylene. Polypropylene is a non-toxic, odorless, tasteless, milky white, highly crystalline polymer, and is one of the lightest varieties of all plastics. PP has good water stability, stable chemical composition, good anti-corrosion effect, and good heat resistance. Although polypropylene has good moldability, due to its large shrinkage (1% to 2.5%), thick-walled products are prone to dents. For some parts with high dimensional accuracy, it is difficult to meet the requirements, but the surface gloss of the products is good.

Features: Colorless, translucent thermoplastic, lightweight general purpose plastic. It has chemical resistance, heat resistance, electrical insulation, high strength mechanical properties and good high wear resistance processing properties.

Scope of application: Polypropylene is often used in the production of disposable tableware and is easy to recycle. However, it should be noted that recycled plastic products can no longer be used in the production of tableware. At the same time, due to the high temperature resistance of PP plastic, it can be used in plastic products that require microwave heating. At the same time, it has applications in furniture, packaging, lighting equipment, food packaging, table mats, folders, etc.