Plastics are the materials commonly used in the production of parts for the construction of industrial machinery and equipment, as well as consumer goods such as household articles or electronic devices. Multitude of types of plastics with a wide range of mechanical properties, processing capabilities, temperature and environmental resistance and the possibility of material modification allow plastics to be used in all branches of industry.

BUT WHAT EXACTLY ARE PLASTICS?

Plastics are a group of synthetic or semi-synthetic materials that are made from polymers. Polymers are large molecules that are composed of repeating structural units, known as monomers. There are many different types of polymers, and they can be classified based on their technological processing properties.

One way to classify polymers is based on their response to heat and pressure. Thermoplastics are a type of polymer that can be melted and reshaped multiple times without losing their original properties. Examples of thermoplastics include polyethylene, polypropylene, and polystyrene.

On the other hand, thermosets are a type of polymer that cannot be melted once they have been cured. They are crosslinked, meaning that the chains of monomers are chemically bonded together, forming a three-dimensional network. Once this network is formed, it cannot be undone, the material cannot be reshaped. Examples of thermosets include polyurethane and epoxy.

Thermoplastics and thermosets have different properties and are used in different applications. Thermoplastics are often preferred for their versatility, as they can be molded and shaped into a variety of products. They are also easier to recycle compared to thermosets. On the other hand, thermosets are known for their high strength and durability, making them ideal for use in structural and load-bearing applications.

WHAT ARE THE MOST FREQUENTLY USED PLASTICS?

Polyethylene (PE): This is a lightweight plastic that is highly resistant to water and chemicals. It is often used in packaging materials, such as plastic bags and films.
Polypropylene (PP): This plastic is similar to polyethylene, but it has a higher melting point and is more rigid. It is often used in the manufacture of automotive parts, packaging materials, and textiles.
Polyamide (PA), also known as nylon, is a type of plastic that is known for its high strength, flexibility, and resistance to wear and abrasion. It is often used in the manufacture of automotive parts, such as engine belts and gears, as well as in the production of textiles, ropes, and cords. PA is also used in the production of 3D printing filaments, due to its high strength and ability to produce fine details.
Polystyrene (PS): This is a lightweight plastic that is commonly used in the production of disposable cups and cutlery, as well as insulation and packing materials.
Polyvinyl chloride (PVC): This plastic is known for its strength and durability, as well as its resistance to water and chemical damage. It is often used in the construction industry for pipes, window frames, and siding.
Polycarbonate (PC): This plastic is known for its high impact resistance and transparency. It is often used in the manufacture of electronic devices, such as smartphones and laptops, as well as in the construction of safety glasses and CDs.
Polyoxymethylene (POM): This plastic is known for its high strength and rigidity, as well as its low friction. It is often used in the manufacture of mechanical parts, such as gears and bearings.
Polymethyl methacrylate (PMMA): This plastic is known for its transparency and is often used in the manufacture of windows, skylights, and other transparent products.
Polyethylene terephthalate (PET): This plastic is known for its strength and durability, as well as its resistance to water and chemicals. It is often used in the production of drink bottles and packaging materials.
Polyetheretherketone (PEEK): This plastic is known for its high strength and temperature resistance, making it ideal for use in the aerospace and automotive industries.
Polytetrafluoroethylene (PTFE): This plastic is known for its high temperature and chemical resistance, as well as its low friction. It is often used in the manufacture of gaskets, seals, and bearings.

COPOLYMERS AND COMPOSITE POLYMERS

The dynamic development of the material industry has allowed us to obtain materials that combine the features and desired properties of the given materials.Copolymers are polymers that are composed of two or more different types of monomers that have been chemically bonded together. These monomers can be arranged in a variety of ways, such as in a random, alternating, or block pattern. The properties of copolymers depend on the type and arrangement of the monomers, as well as the ratio at which they are present.

One example of a copolymer is acrylonitrile-butadiene-styrene (ABS). ABS is a terpolymer that is made from three monomers: acrylonitrile, butadiene, and styrene. It is known for its toughness, resistance to impact, and ability to withstand high temperatures. ABS is often used in the production of automotive parts, toys, and electronic housings.

Another example of a copolymer is styrene-acrylonitrile (SAN). SAN is a copolymer of styrene and acrylonitrile, and it is known for its transparency, rigidity, and resistance to heat and chemicals. It is often used in the production of food packaging, automotive parts, and household appliances.

Thermoplastic polyurethane (TPU) is another example of a copolymer. It is made from a combination of polyether and polyester, and it is known for its excellent elasticity, toughness, and resistance to wear and abrasion. TPU is often used in the production of footwear, automotive parts, and industrial hoses.

Composite polymers, on the other hand, are polymers that are reinforced with other materials in order to improve their mechanical properties. These materials are typically in the form of fibers, particles, or sheets, and are incorporated into the polymer matrix in order to enhance the strength, stiffness, or toughness of the composite. The properties of composite polymers depend on the type and orientation of the reinforcing material, as well as the properties of the polymer matrix.

Fiberglass reinforced plastic (FRP): This composite material is made up of a polymer matrix (usually a thermosetting resin) reinforced with fiberglass fibers. It is often used in the construction of boats, car parts, and other structural components.
Carbon fiber reinforced plastic (CFRP): This composite material is made up of a polymer matrix reinforced with carbon fibers. It is known for its high strength and stiffness, and is often used in the aerospace and automotive industries.
Kevlar reinforced plastic: This composite material is made up of a polymer matrix reinforced with Kevlar fibers. It is known for its high strength and toughness, and is often used in the manufacture of bulletproof vests and other protective gear.
Wood plastic composite (WPC): This composite material is made up of a polymer matrix reinforced with wood fibers. It is often used in the manufacture of decking, fencing, and other outdoor construction materials.

CONCLUSION

Plastics are an incredibly versatile material that are used in a wide range of applications due to their unique properties. Knowledge of material science is crucial for the designer to select and apply material that fulfills project requirements and also is a sustainable cost-effective solution. While plastics have many advantages, it is important to use them responsibly and recycle them when possible to minimize their environmental impact.

Whether you require a strong, flexible material for the design of the product's housing, a transparent impact-resistant plastic for screen shielding or any other applications of plastics for your project Mindsailors engineering team will help you to select materials that will meet your requirements within the product development process.