Choosing the right plastic material for your parts is very important. The material should be selected based on the intended application of the part. It must be able to withstand the various conditions the part will be in. Some applications may require a very specialized, high-performance and high-cost material. But for many, one of the common, low-cost, commodity plastic materials will perform adequately in a wide range of applications. Here are five of the most common plastic resins:
Polyethylene – PE Injection Molding
Polyethylene (PE) is the most popular plastic in the world, and accounts for 34% of the total plastics market. There is low-density polyethylene (LDPE) and high-density polyethylene (HDPE). LDPE is manufactured with high pressure and high temperature, whereas HDPE is manufactured with relatively low pressure and low temperature.So be sure to considering LDPE injection molding or HDPE injection molding with your next project.
LDPE is the most flexible type of polyethylene, and it is widely used in packaging. It provides superior moisture resistance, although it should not be used in harsh weather or high temperature conditions. It has high impact strength and good chemical resistance. It is a low-cost option that can be easily processed by most methods.
This versatile resin is used for many everyday products such as plastic bags, plastic films, bottles, containers, lids and caps. It is also used to make six-pack rings, toys and computer components. It is often recycled and made into items such as trash cans, floor tile, paneling and furniture.
Polypropylene – PP Injection Molding
Polypropylene (PP) is the second most widely-produced plastic in the world, after polyethylene (PE). Its behavioral characteristics are similar to PE, but it is slightly harder and more heat-resistant. It is a commodity grade polymer popular in the packaging and labeling industries.
PP is tough, fatigue- and chemical-resistant, but vulnerable to UV radiation and it is flammable. It is a versatile plastic, as it is easily customized with additives. It is naturally white.
Due to the elasticity of PP, it makes a good material for living hinges. It is also used in many common items such as buckets, packaging, bottle caps, toys and many other items.
Acrylonitrile Butadiene Styrene – ABS Injection Molding
Acrylonitrile butadiene styrene (ABS) is also one of the most common, widely-used plastic material in the world. ABS plastic molding is often a standard when it comes to mold making. Impact resistance and toughness are the two most important material characteristics of ABS, and those qualities make it such a popular, low-cost, commodity-level thermoplastic polymer. It is used in a wide range of products in the automotive, appliance and electronics industries, among many others.
ABS provides superior strength and temperature resistance. It combines the strength and rigidity of acrylonitrile and styrene polymers with the toughness of polybutadiene, a rubbery material, even at low temperature. The styrene gives the plastic a shiny, colorfast, high-quality surface finish. ABS molding is on direction to consider.
Polyoxymethylene – POM (Acetal) Injection Molding
Polyoxymethylene (POM) is also commonly known as acetal, and also known as polyacetal and polyformaldehyde. It is considered an engineering grade thermoplastic, a step up from commodity plastics in performance and price. It provides high stiffness, excellent dimensional stability, and is used for precision parts requiring low friction.
POM provides high strength, rigidity and hardness, and it is resistant to chemical solvent. It is opaque white in its natural state, but it is easy to color to any color.
POM is a good choice for high-performance components like small gears and bearings, and other applications where the component comes in contact with other parts, such as plastic gears and ball bearings. It is commonly used in the automotive and consumer electronics industries, and it is used in eyeglass frames, guns, knife handles and other items that require strength and toughness.
Polystyrene – PS Injection Molding
Polystyrene (PS) is a widely-used polymer that can be either solid or foamed. As a solid, it is used to make things like disposable cutlery, and in its foam state (Styrofoam) it can be extruded to make things like packing peanuts and disposable drinking cups.
PS is clear, hard, and fairly brittle (think of how easily the tines can break off of a plastic fork). It is naturally transparent, but can be colored with colorants. It is not biodegradable, so many PS items, especially “single-use” items, contribute to the world’s litter problem. It is also used to make CD jewel cases, license plate frames and plastic model kits.