At our plastic moulding company the materials we use for injection moulding are normally referred to as “Thermoplastics”. Materials are normally made up of long chain molecules that are connected by intermolecular forces – when heat is applied to this molecules the forces that “hold them together” are weakened and allow the material to soften and become almost a liquid – this is then injected into the mould tool to form the component shape and cooled before ejecting off.
Our Plastic Moulding Company Uses Two Types of Plastics
Thermoplastics fall into two distinct categories, both with different structures and properties – Commodity Polymers and Engineering Polymers – the choice of which to use is dependent on the end use of the product / component
Commodity polymers are generally lower cost, off the shelf polymers where the mechanical properties of the material are not critical to the end use product performance. The material will still be of a good quality and will still have many specific attributes and benefits. Commodity polymers are generally used in plastic injection moulding for products that are mass produced and are often referred to as “throw-away” single use components, such as drinks bottle or disposable food trays for example.
Examples of widely used commodity polymers are :
High Density Polyethylene (HDPE)
Low Density Polyethylene (LDPE)
Acrylonitrile Butadiene Styrene (ABS)
When a specific mechanical property is required, in challenging applications or environments engineering polymers, as opposed to commodity polymers would be used. Specific properties such as strength, metal replacement, chemical stability and lubrication are examples of where an engineering polymer would be selected. Often, due to the costs involved in manufacturing this higher spec of material means higher volumes are not used in engineering polymers and smaller volumes of manufacture are seen. Specific properties that can be used in Engineering Polymers include for example Flame Retardant, Glass Filled, Chemcially Lubricated.
Examples of Engineering Polymers :
Polyamide (PA – Nylon)
Polyamide Glass Filled (PA 6 – PA66)
Polyoxymethylene (POM – Acetal)
Polybutylene Terephthalate (PBT)
Polyether Ether Ketone (PEEK)
At Moldwel we can advise you on the best thermoplastic to use for your products and can produce for you in a wide range of plastics. To find out more about our plastic injection moulding services read more here on our website or give us a call on 01922 631252.
If you enjoyed reading this article you may also like to read our previous post on Injection Moulding vs Vacuum Forming