Metal was always the traditional choice for heavy-duty, load-bearing, or high-temperature engineering components. That default has changed over the years.
Advancements in polymer science have introduced a class of “ultra-polymers”, such as PEEK (Polyether ether ketone), that allow manufacturers to replace traditional metal assemblies with injection-moulded plastics. This resulting in significant weight reduction and production costs without compromise to structural integrity.
Peek has been around since the late 70s, and became commercially viable as a lightweight, heat-resistant, and chemically durable alternative to traditional metals in the 1980s. Its popularity grew in the 1990s when it was FDA-approved for medical implants, and again in the 2010s with the rise of industrial 3D printing.
Among high-performance plastics, PEEK is widely considered the gold standard for situations where standard polymers might deform or degrade.
Temperature resistance: PEEK retains its mechanical properties at continuous operating temperatures of up to 250°C, and can withstand short-term exposure up to 300°C.
Chemically inert: It is highly resistant to aggressive chemicals, solvents, and acids, making it ideal for environments where metals would corrode.
High strength-to-weight ratio: PEEK provides the structural rigidity of lightweight metals (like aluminium) at a fraction of the physical weight.
In disciplines such as aerospace and motorsport, every gram saved directly translates to better performance. While standard commodity plastics are light, they lack the structural integrity required for heavy mechanical loads. PEEK bridges this gap perfectly by offering a massive weight advantage over traditional materials.
To put the physical savings into perspective, PEEK has an approximate density of just 1.3g/cm, compared to 2.7g/cm for aluminium and a heavy 8g/cm for stainless steel. This means swapping machined metal components with injection-moulded PEEK can radically slash assembly weights down to a fraction of their original mass without sacrificing an ounce of strength.
Time is money. Machining metal components is relatively slow, inefficient, and wasteful. Injection moulding, by contract, allows for high-speed, repeatable production of complex geometries in a single cycle. Furthermore, where metal parts may have required welding or fastening, they can be redesigned into a single polymer moulding, simplifying production and reducing assembly labour.
High-performance polymers do not rust, oxidise, or experience galvanic corrosion when exposed to moisture or chemicals. PEEK also features excellent natural lubricity, meaning parts like gears, bearings, and seals experience minimal friction and wear, significantly extending the operating lifespan of the product.
PEEK is not your standard injection moulding material. It has a high melting point (around 343°C) and rapid crystallisation rates, meaning it needs specialised, high-temperature tooling, precise thermal control, and a team that knows what they’re doing. Like us.
We’ve been working with PEEK for more than twenty years. And for the medical and life science sectors, our ISO 13485:2016 certification is a clear indication that we have the necessary in-house traceability and strict quality controls.
Choosing the right polymer is rarely simple. While PEEK is incredibly capable, it is just one option in a broad range of engineering plastics. The best way to balance performance, weight, and cost is to involve our team at the earliest stages of your design. We are always happy to offer advice, review your concept blueprints, and help you select the exact material needed to make your project a commercial success.
For further enquiries or more detailed information please call us on 01473 828000 or email us at sales@skar.co.uk