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Plastics – The Key Considerations

There are a range of plastics which can be used in the injection moulding process. Each of these plastics has different properties and characteristics. The key is to pick the right plastic for the job.

This is easier said than done, especially if you have little or no experience of plastic injection moulding. To a newcomer to the industry, the wealth of different plastic types can be overwhelming.

There are tens of thousands of plastic material options available for commercial use. There are also roughly 45 separate polymer families, which can be broadly separated into two distinct groups: thermosets and thermoplastics.

Choosing the right injection moulding material depends upon several factors, including knowing your application requirements, which can sometimes change between prototyping and production.

RP Technologies – Your Perfect Plastics Partner

That’s where we can help. At RP, we have plastic injection moulding specialists who have worked in the industry for many years, helping to produce some of the most complex components on the market. Their specialist knowledge of process and material enables them to offer best-fit solution and advice on a range of different projects.

We are experts in a wide variety of sectors, including automotive, medical, aerospace and electronics. We have moulded parts of all shapes and sizes, using a range of different materials.

Our “Partners not Suppliers” ethos means that we’ll work with you to understand your needs, and to get a comprehensive idea of what the final component will be used for, and how its construction will impact upon its final performance. This will enable us to advise you on the type of material which will be most suited to the end application, in order to give the part strength, durability and integrity.

We will also carefully consider how the part needs to look. For some parts, aesthetics aren’t important. These parts are solely about functionality and performance. But for other parts, visual presentation may be more significant, and different plastics will provide a different surface finish.

It may be a glossy part with a high shine you’re looking for, or a plastic part that is scratch-resistant. Whatever your requirements, we can work with you to identify the most suitable material option and grading to achieve the specific type of part you are trying to get made.

Polycarbonate (PC) – PC is ideal for parts which require a high cosmetic finish. It also has good heat resistance, low shrinkage and dimensional stability. Like ABS, it is also strong and capable of withstanding force.

Polypropylene (PP) – This is a resin-based material which has high resistance in certain grades. It is wear-resistant, flexible and can be easily manipulated to increase its length. It is unsusceptible to acids and bases, but it can be brittle in cold temperatures.

Polyether Ether Ketone (PEEK) – A high performance resin which is ideal for moulding processes where heat is involved. It offers strength and stability, provides heat resistance and is flame retardant. It also possesses good chemical resistance.

Polyetherimide (PEI) – PEI shares many of the same properties as PEEK, including operating effectively at high temperatures, providing excellent strength and offering chemical immunity.
Aliphatic Polyamides (PPA) – There are many different types of PPA, also known as nylons. Some nylons are abrasion resistant and provide sturdiness and durability.

Acrylic (PMMA) – Acrylic, or polymethyl methacrylate, is a strong, clear thermoplastic that is lightweight and transparent. It has high tensile strength and is ideal for use when tight tolerances are required.

Polyoxymethylene (POM) – Also known as acetal, this plastic is very strong and robust. It is also highly elastic, making it flexible and agile, and its slipperiness makes it ideal for certain applications.

Polybutylene Terephthalate (PBT) – PBT is ideal for automotive applications due to its good electrical components. Its strength ranges from moderate to high depending on glass fill.

Polyethylene (PE) – One of the most widely used plastics, PE has different levels of density, which can control other material properties. High density polyethylene (HDPE) and low density polyethylene (LDPE) both offer chemical resistance, but differ in hardness, flexibility and optical transparency.

Thermoplastic Elastomer (TPE) – Sometimes referred to as thermoplastic rubber (TPR), TPE is a blend of rubber and plastic. TPE has high elasticity and is recyclable. TPEs also have shorter moulding cycles and are easier and less expensive to mould than some silicone-based materials.

Thermoplastic Polyurethane (TPU) – In injection moulding, TPU can be used as a replacement for hard rubber. TPU is sometimes preferable to TPE because it performs better in extreme temperatures and offers good chemical resistance. It is also harder and more robust.

What to Do Next

As there are so many material options open to customers, it is always worth discussing what’s best for your particular project before going ahead with getting parts moulded.

Some customers are well-versed in the injection moulding process and may already know the specific grade of plastic material that will be required for a given project. For those who are not as experienced, choosing a particular type of plastic can be a daunting prospect.

At RP Technologies, we’re more than happy to listen to your requirements and to provide our specialist knowledge and expertise. Upon reviewing your 3D CAD files, we will offer you our advice on the material which we believe would be most suited to your specific needs.

With the help of our trusted supply chain partners, we will then source this material on your behalf at the most competitive price possible.

So, if you’re about to embark upon an injection moulding project and you would like to discuss your requirements with us, please do get in touch by visiting our Contact page and we will be more than happy to help you.