Plastic Material Characteristics and Applications

Plastic Material Overview

PE、PP、PVC、PS、PC、PF、EP、ABS、PA、PMMA all plastic materials (also known as polymer materials) are a type of plastic synthetic materials made from polymer compounds through different processing methods. Plastic materials are well recognized for its light weight, high strength, corrosion resistance, good insulation, etc., and are widely used in packaging, construction, automotive, electronics and other industries.

Polyethylene(PE): a lightweight, flexible thermoplastic with good chemical resistance. According to the density, it can be divided into high-density polyethylene (HDPE) and low-density polyethylene (LDPE).
Polypropylene (PP): relatively high heat resistance, chemical resistance and rigidity, its a common material for automotive parts and household appliances.
Polyvinyl chloride (PVC): come with good chemical corrosion resistance, mechanical strength and electrical insulation, it is commonly used in pipes, wires and cables, and medical equipment.
Polystyrene (PS): It is a transparent, lightweight and well-insulating plastic, widely used in disposable tableware and packaging materials.
Polycarbonate (PC): It is known for its excellent transparency, impact resistance and temperature resistance, it is often used to make eyeglass lenses, bulletproof glass and protective covers.
Polyoxymethylene (POM): It is an engineering plastic with high crystallinity, high strength and high rigidity, suitable for making precision parts and gears.
Phenolic plastic (PF): Also known as Bakelite, it is a thermosetting plastic with good mechanical properties and heat resistance, often used in electrical insulation materials.
Epoxy resin (EP): It is a thermosetting plastic with good bonding properties and electrical insulation, widely used in coatings, adhesives and electronic packaging materials.
Acrylonitrile-butadiene-styrene (ABS): It is a popular thermoplastic polymer with good mechanical properties and processing properties. It is often used to make toys, automotive parts and electronic equipment housings.
Polyamide (PA): Also known as nylon, it is an engineering plastic with high strength, high toughness and wear resistance. It is suitable for making bearings, gears and fibers.
Polymethyl methacrylate (PMMA): Commonly known as acrylic, it is a thermoplastic with excellent transparency and strong weather resistance. It is often used in lighting equipment and billboards.

PE (Polyethylene)
Physical and Chemical Properties
Polyethylene (PE) is a linear high molecular polymer with an extremely simple molecular structure consisting of repeated “-CH2-CH2-” units. This structure gives PE a variety of unique physical and chemical properties:

• Lightweight: PE has a low density of approximately 0.91 to 0.96 g/cm³, making it a representative of lightweight materials.
• Chemical resistance: PE exhibits good chemical stability to most acid, alkali and salt solutions.
• Electrical insulation: As a non-polar material, PE has excellent electrical insulation properties.
• Low temperature resistance: PE can maintain its physical properties at temperatures as low as -70°C.
• Thermoplasticity: PE can be reshaped after heating, making it easy to recycle and reprocess.

Processing methods
Polyethylene can be processed in a variety of ways, mainly including the following:

• Extrusion: used to produce pipes, insulation layers of wires and cables, etc.
• Injection molding: suitable for making small containers, toys, etc.
• Blow molding: used to produce hollow bottles and containers. Compression molding: suitable for making larger plastic parts.
• Thermoforming: used to make thin-walled packaging materials and pallets.

Applications
Polyethylene has a wide range of applications, and the following are some of the main application examples:

• Packaging materials: PE films are widely used in food packaging and commodity packaging because of their light weight and good protective properties.
• Plastic pipes: HDPE pipes are often used to transport water and gas because of their chemical corrosion resistance and abrasion resistance.
• Wires and cables: PE is widely used in the manufacturing of wires and cables as an insulating material.
• Agriculture: PE is used to make agricultural films, such as mulching technology.
• Medical field: Due to its biocompatibility and chemical resistance, PE is also used to manufacture certain medical devices.
• Automotive industry: PE is used to manufacture automotive parts such as fuel tanks and bumpers because of its light weight and impact resistance.

PP (Polypropylene)
Physical and chemical properties
Polypropylene (PP) is a linear thermoplastic made from propylene monomers through polymerization. PP has the following significant physical and chemical properties:

• Heat resistance: PP has a melting temperature between 160 and 170°C, and has good heat resistance, making it suitable for manufacturing products that need to withstand high temperature environments.
• Chemical corrosion resistance: PP has good stability to chemicals such as water, inorganic salts, acids and alkalis, but is easily corroded by certain organic solvents.
• Rigidity: PP has high rigidity, which allows it to maintain its shape when subjected to large loads.
• Fatigue resistance: PP has good fatigue resistance and is suitable for applications that require repeated bending or twisting.
• Thermoplasticity: PP can be repeatedly heated and cooled without losing its physical properties, making it easy to recycle.

Processing methods
Polypropylene can be made into different products through a variety of processing techniques:

• Extrusion: used to produce PP pipes, sheets, rods, etc.
• Injection molding: suitable for manufacturing small to medium-sized plastic products such as containers, lids, automotive parts, etc.
• Blow molding: used to produce large hollow plastic products such as bottles and barrels.
• Thermoforming: used to make thin plastic packaging containers or pallets.
• Fiber manufacturing: PP can also be made into fibers through stretching and spinning processes, which are used to make ropes, carpets, etc.

Applications
Polypropylene has a wide range of applications. Here are some of the main examples:

• Automotive industry: PP is widely used in the manufacture of automotive interior and exterior parts, such as dashboards, bumpers, etc., due to its light weight and heat resistance.
• Textile industry: PP fibers are used to make ropes, carpets, clothing, etc.
• Packaging materials: PP is often used in food and non-food packaging materials due to its light weight and chemical resistance.
• Household appliances: PP is used to make household appliance parts such as microwave-safe containers and refrigerator drawers.
• Construction industry: PP pipes and sheets are used in piping systems and decorative materials in buildings.
• Medicals: PP is also used to make some disposable medical supplies, such as syringes and test tubes, due to its biocompatibility.

PVC (Polyvinyl Chloride)
Physical and Chemical Properties
Polyvinyl chloride (PVC) is a polar non-crystalline thermoplastic formed by the polymerization of vinyl chloride monomer. PVC has the following remarkable physical and chemical properties:

• Chemical corrosion resistance: PVC has high resistance to acids, alkalis and salts, but is easily corroded by certain organic solvents.
• Mechanical strength: PVC has good mechanical properties, including tensile strength and impact resistance.
• Electrical insulation: As a non-polar material, PVC has excellent electrical insulation properties.
• Weather resistance: PVC has good resistance to ultraviolet rays and chemicals in the atmosphere, making it suitable for outdoor use.
• Thermal stability: PVC needs to add heat stabilizers during processing to prevent thermal decomposition.

Processing methods
PVC can be made into different products through a variety of processing techniques:

• Extrusion: used to produce PVC pipes, door and window frames, cable insulation, etc.
• Injection molding: suitable for the manufacture of small to medium-sized plastic products, such as toys, electrical housings, etc.
• Blow molding: used to produce hollow bottles, containers and other large products.
• Calendering: used to make PVC films and sheets, often used in packaging materials and decorative materials.
• Thermoforming: used to make products with complex geometric shapes, such as automotive parts and building components.

Applications
The application areas of polyvinyl chloride are wide, following are some major application examples:

• Construction industry: PVC is widely used in piping systems, window frames and flooring materials in the construction industry.
• Medical devices: PVC is used to manufacture disposable medical devices such as blood bags and infusion tubes due to its biocompatibility.
• Automotive industry: PVC is used to manufacture automotive interior parts such as dashboards and door panels.
• Electronic industry: PVC is used for the insulation layer of wires and cables and the casing of electronic devices due to its good electrical insulation.
• Packaging materials: PVC film is used for food and non-food packaging due to its good sealing and chemical resistance.
• Toy manufacturing: PVC is used to produce toys and other entertainment products due to its processing performance and cost-effectiveness.

PS (Polystyrene)
Physical and Chemical Properties
Polystyrene (PS) is a thermoplastic known for its transparency, light weight and easy processing. PS has the following notable physical and chemical properties:

• Transparency: PS has good transparency, especially in thinner sheets or containers.
• Processability: PS is easy to process and can be processed by a variety of methods such as injection molding, extrusion, and blister molding.
• Insulation: As a non-polar material, PS has excellent electrical insulation properties.
• Impact resistance: PS has good impact resistance at room temperature, but this property decreases as the temperature decreases.
• Thermal stability: PS may undergo thermal degradation when exposed to high temperatures for a long time, so the temperature needs to be controlled during processing and use.

Processing methods
Polystyrene can be processed by the following methods:

• Injection molding: suitable for the production of various plastic products with complex shapes, such as toys, container lids, etc.
• Extrusion: used to produce PS films, sheets, pipes, etc.
• Blow molding: used to make hollow plastic bottles and other containers.
• Thermoforming: used to produce thin-walled products such as disposable tableware and trays.
• Compression molding: suitable for the production of products with high transparency requirements, such as transparent packaging boxes, etc.

Applications
Application areas of polystyrene include:

• Packaging materials: PS is often used to make disposable tableware, food containers, etc. due to its transparency and lightness.
• Electronic products: PS is used to make housings and components of electronic devices, such as mobile phone cases, computer accessories, etc.
• Medical devices: Transparency and chemical resistance make PS suitable for parts of certain medical devices.
• Construction industry: PS is used to produce insulation materials, decorative panels and other construction products.
• Toy manufacturing: PS is widely used to make children’s toys due to its processability and cost-effectiveness.
• Optical products: Highly transparent PS is used to make optical products such as eyeglass lenses and CD cases.

PC (Polycarbonate)
Physical and Chemical Properties
Polycarbonate (PC) is an amorphous thermoplastic with high transparency and excellent mechanical properties. The physical and chemical properties of PC are as follows:

• Transparency: The light transmittance of PC can reach 90%, making it an ideal material for making transparent plastic products.
• Impact resistance: PC has extremely high impact strength and can maintain its impact resistance even at low temperatures.
• Heat resistance: The glass transition temperature of PC is around 150°C, and it has good short-term heat resistance and is suitable for high temperature environments.
• Weather resistance: PC has a certain tolerance to ultraviolet rays, but long-term exposure to sunlight may cause degradation.
• Mechanical properties: PC has good tensile strength, flexural strength and compressive strength.

Processing methods
Polycarbonate can be made into a variety of products through the following processing technologies:

• Injection molding: suitable for the production of precision plastic products such as eyeglass lenses, mobile phone housings, etc.
• Extrusion: used to produce PC films, pipes, rods, etc.
• Thermoforming: used to make large plastic products such as automotive parts and protective covers.
• Compression molding: suitable for making thick-walled or complex-shaped plastic products.
• Blow molding: Although not commonly used for PC, it is also used in some special applications.

Applications
Polycarbonate has a wide range of applications, and the following are some of the main application industries:

• Eyewear industry: PC is often used to make safety glasses lenses due to its light weight and impact resistance.
• Automotive industry: PC is used to make parts such as car headlights, taillights and windows.
• Electronic appliances: PC is used to make housings and protective covers for electronic devices such as computers, mobile phones, and televisions.
• Construction industry: PC sheets are used for skylights, skylights, and guardrails in buildings.
• Medical devices: The transparency and chemical resistance of PC make it suitable for the manufacture of some medical devices and containers.
• Safety equipment: PC is used to make bulletproof glass, helmets and other protective equipment.

PF (phenolic plastic)
Physical and chemical properties
Phenolic plastic (PF), also known as bakelite, is a thermosetting plastic widely used in the industrial field for its excellent mechanical properties and heat resistance.

• Heat resistance: PF has a high heat deformation temperature, usually above 150°C, which enables it to remain stable in high temperature environments.
• Mechanical properties: PF has high hardness and strength, and can maintain these properties in long-term use and is not easy to deform.
• Electrical insulation: As a non-polar material, PF has good electrical insulation properties and is suitable for electrical insulation materials.
• Chemical corrosion resistance: PF has good stability to most chemicals, including acids, alkalis and organic solvents.
• Thermosetting: PF will not melt again after processing and molding, and has irreversible thermosetting properties, which makes it have good dimensional stability after molding.

Processing methods
The processing methods of phenolic plastics mainly include compression molding, transfer molding and injection molding.

• Compression molding: It is the most commonly used processing method for PF, which is to put the raw materials into the mold and then apply high temperature and pressure to solidify it.
• Transfer molding: Suitable for manufacturing products with complex shapes or fine patterns. It is formed by heating the raw materials and transferring them to the mold under pressure.
• Injection molding: Suitable for mass production of small products. It is formed by injecting the raw materials into the mold and quickly curing them under high temperature and high pressure.

Applications
Phenolic plastics have a wide range of applications, including:

• Electrical industry: PF is widely used to manufacture various electrical insulation materials and electronic equipment housings due to its excellent electrical insulation properties and heat resistance.
• Automotive industry: PF is used to manufacture automobile ignition system components, heaters and other high-temperature resistant components.
• Construction industry: PF is suitable for manufacturing pipes, valves and decorative materials due to its heat resistance and chemical corrosion resistance.
• Aerospace: PF is used to manufacture non-structural components such as insulation materials and decorative panels inside aircraft.
• Industrial products: PF is used to manufacture various industrial machinery parts, such as bearings, gears and pump parts.
• Daily necessities: PF is also used to manufacture some daily necessities, such as electrical switches, buttons and handles.

EP (Epoxy Plastic)
Physical and Chemical Properties
Epoxy plastic (EP) is a thermosetting plastic based on epoxy resin with the following remarkable physical and chemical properties:

• Adhesive properties: EP has extremely strong adhesive ability and can be firmly bonded to a variety of materials, including metals, glass and various plastics.
• Mechanical strength: Cured EP exhibits excellent mechanical strength and hardness, suitable for applications with high loads.
• Chemical corrosion resistance: EP has good stability to most chemicals, including acids, alkalis and organic solvents.
• Electrical insulation: As a non-polar material, EP has good electrical insulation properties and is suitable for electronic and electrical applications.
• Temperature resistance: EP has good heat resistance and can be used for a long time within a certain temperature range without loss of performance.

Processing methods
The processing methods of epoxy plastics mainly include the following:

• Casting molding: After mixing epoxy resin and curing agent, pour it into a mold for curing and molding, which is suitable for manufacturing large or complex-shaped products.
• Prepreg: Epoxy resin is pre-impregnated on reinforcing materials (such as glass fiber or carbon fiber), and then formed by hot pressing or rolling.
• Lamination: Multiple layers of prepreg are stacked and heated and pressed to form the desired thickness and shape.
• Coating: Epoxy resin can be used as a coating to provide protection and insulation by coating on the surface of the substrate.
• Adhesive: Used as an adhesive to bond two materials together.

Applications
The application areas of epoxy plastics are very wide, and the following are some major application examples:

• Electrical insulation: EP is widely used as insulation material for motors, transformers and cables due to its excellent electrical insulation properties.
• Composites: EP is combined with reinforcing materials to make high-strength and high-rigidity composite materials, such as aircraft components, automotive parts and sports equipment.
• Coatings and adhesives: EP is used as coatings and adhesives for surface protection and fixation of various metals and non-metals.
• Electronic packaging: In the electronics industry, EP is used to encapsulate semiconductors and circuit boards to provide protection and insulation.
• Construction industry: EP is used to make flooring, tile adhesives and reinforcement materials for building structures.
• Crafts and decorations: EP is also used to make various crafts and decorations, such as jewelry and artwork reproduction.
• Repair materials: EP is used to repair and reinforce structural parts, such as bridges and buildings, due to its good bonding properties and mechanical strength.

ABS (Acrylonitrile-Butadiene-Styrene)
Physical and Chemical Properties
Acrylonitrile-Butadiene-Styrene (ABS) is a common thermoplastic polymer, which is copolymerized by three monomers: acrylonitrile, butadiene and styrene. ABS combines the characteristics of the three monomers and has the following remarkable physical and chemical properties:

• Comprehensive performance: ABS has good mechanical properties, such as high strength, high toughness and good hardness, making it the material of choice for many applications.
• Impact resistance: Due to the addition of butadiene, ABS has excellent impact resistance, which can be maintained even at low temperatures.
• Processability: ABS is easy to process and can be formed by injection molding, extrusion, thermoforming and other methods.
• Thermal stability: ABS has good thermal stability during processing, but the long-term use temperature is usually not more than 80°C.
• Electrical insulation: As a non-polar material, ABS has good electrical insulation properties.
• Chemical corrosion resistance: ABS has good stability to chemicals such as water, inorganic salts, acids and alkalis, but is easily corroded by certain organic solvents.

Processing methods
ABS can be processed in a variety of ways such as the following:

• Injection molding: The most commonly used processing method for ABS, suitable for the production of various plastic products with complex shapes, such as toys, automotive parts, etc.
• Extrusion: Used to produce ABS pipes, rods, plates, etc.
• Thermoforming: Used to manufacture large plastic products, such as automotive parts and protective covers.
• Blow molding: Although not commonly used for ABS, it is also used in some special applications.
• Compression molding: Suitable for the production of high transparency products, such as transparent packaging boxes, etc.

Applications
ABS has a wide range of applications. Here are some of the main application examples:

• Automotive industry: ABS is widely used in the manufacture of automotive interior and exterior parts, such as dashboards, bumpers, etc., due to its light weight and impact resistance.
• Electronic appliances: ABS is used to manufacture the housing and protective covers of electronic devices such as computers, mobile phones, and televisions.
• Office equipment: ABS is often used to manufacture the housing and internal parts of office equipment such as printers and copiers.
• Toy manufacturing: ABS is widely used to manufacture children’s toys and game consoles due to its processability and cost-effectiveness.
• Packaging materials: ABS is used to manufacture packaging containers and display racks with certain special requirements.
• Construction industry: ABS is used to produce insulation materials, decorative panels and other construction products.
• Medical devices: Transparency and chemical resistance make ABS suitable for components of certain medical devices.

PA (Polyamide)
Physical and Chemical Properties
Polyamide (PA), commonly known as nylon, is a synthetic polyamide plastic with excellent physical and chemical properties:

• High strength and toughness: PA contains amide groups in its molecular chain, which makes it very strong and tough, especially in low temperature environments.
• Wear resistance: PA has a low friction coefficient and good wear resistance, making it suitable for manufacturing bearings and gears, etc.
• Chemical corrosion resistance: PA has good resistance to most organic solvents, alkalis and salts, but is susceptible to corrosion by certain acids and oxidants.
• Thermal stability: PA can be used at higher temperatures, but thermal degradation may occur if exposed to high temperatures for a long time.
• Hygroscopicity: PA has a certain hygroscopicity, which may affect its mechanical properties and dimensional stability.

Processing methods
Polyamide can be made into various products through the following processing techniques:

• Injection molding: Suitable for the production of various plastic products with complex shapes, such as gears, bearings, etc.
• Extrusion: Used to produce PA pipes, rods, monofilaments, etc.
• Blow molding: Used to make hollow plastic bottles and other containers.
• Thermoforming: used to produce large plastic products, such as automotive parts and protective covers.
• Compression molding: suitable for the products with high transparency requirements, such as transparent packaging boxes.

Applications
The application areas of polyamide are very wide. The following are some major application examples:

• Automotive industry: PA is widely used in the manufacture of automotive interior and exterior parts, such as engine parts, door handles, etc., due to its light weight and impact resistance.
• Electronic appliances: PA is used to manufacture insulating parts of electrical equipment and housings of electronic equipment.
• Textile industry: PA fibers are used to make wear-resistant clothing fabrics, carpets and fishing nets, etc.
• Packaging materials: PA is used to make food packaging and industrial packaging materials, such as food films and heavy-duty packaging bags.
• Mechanical industry: PA is used to manufacture bearings, gears and other mechanical parts due to its wear resistance and self-lubricating properties.
• Consumer goods: PA is used to manufacture various consumer goods, such as toothbrushes, combs and sporting goods.

PMMA (Polymethyl Methacrylate)
Physical and Chemical Properties
Polymethyl Methacrylate (PMMA), also known as acrylic, organic glass or acrylic, is a transparent, thermoplastic plastic with high transparency, low price and easy mechanical processing. It is often used as a substitute for glass.

• Density: The density of PMMA is about 1.15-1.19g/cm³, which is lighter than glass.
• Mechanical Strength: With a high relative molecular mass and long-chain polymer structure, PMMA has high strength, and its tensile and impact resistance are 7 to 18 times higher than ordinary glass.
• Melting Point: The melting point of PMMA is low, much lower than about 1000°C of glass.
• Transmittance: The transmittance of PMMA is as high as 92%, which is better than ordinary glass.
• Chemical Stability: PMMA has good resistance to most inorganic acids, alkalis and salts, but is easily corroded by certain organic solvents such as acetone and chloroform.

Processing methods
PMMA can be processed by a variety of methods:

• Casting: suitable for manufacturing large products, such as bathtubs, large lamps, etc.
• Injection molding: suitable for mass production of small products, such as toys, small appliances, etc.
• Machining: can be cut, drilled, etc. by tools such as lathes and drill presses.
• Thermoforming: suitable for manufacturing products with complex shapes, such as automotive parts, aviation parts, etc.
• Blow molding, injection, extrusion: suitable for manufacturing pipes, bars, plates, etc.

Applications
PMMA has a wide range of applications, including:

• Construction industry: used for building lighting, transparent roofs, sheds, telephone booths, stairs and room wall panels, etc.
• Automotive industry: used to manufacture car lights, windows, etc.
• Medical equipment: Due to its good transparency and chemical stability, PMMA can be used to manufacture medical equipment and instruments.
• Optical products: Due to its high light transmittance, PMMA can be used to manufacture eyeglass lenses, optical instruments, etc.
• Advertising industry: used to make advertising light boxes, signs, signs, etc.
• Household items: such as decorations, bathroom facilities, crafts, etc.
• Lighting equipment: used to manufacture transparent covers for various lamps.

Identification methods

Differentiating different plastic materials can usually be achieved using specific testing methods, such as density testing, infrared spectroscopy, hardness testing, chemical resistance testing, mechanical properties testing, and other specific equipment and expertise. There are also some basic methods used to distinguish these common plastic materials:

Appearance and touch

1. PE and PP usually appear as translucent white or waxy materials.
2. PVC can be hard or soft, hard PVC is usually transparent, soft PVC is opaque and has good flexibility.
3. PS is a colorless and transparent hard material.
4. PC is colorless and transparent, with high transparency and impact resistance.
5. POM is white or black, with good hardness and strength.
6. EP is usually opaque, with good mechanical strength and chemical resistance.
7. ABS is usually opaque, with good impact resistance and processing performance.
8. PA is translucent, with good toughness and chemical resistance.
9. PMMA is highly transparent and is called “plastic glass”.

Burning test

1. PE and PP produce paraffin-like droplets when burning, and the flame is blue.
2. PVC produces irritating hydrogen chloride gas when burning, and the flame is green. PS will have thick smoke when burning, and the flame is yellow.
3. PC burns with a yellow flame and fewer droplets.
4. POM burns with a blue flame and a formaldehyde smell.
5. EP is not easy to burn and produces a special smell when burning.
6. ABS produces black smoke and a special smell when burning.
7. PA has a blue flame and a faint smell of burning wool when burning.
8. PMMA has a blue flame and a strong pungent smell when burning.