Get a Quote

THE PROCESS

What is Rotational Moulding?

A complete guide to the rotational moulding process — how it works, what it produces, and why it’s the right choice for your product.

Talk to an Expert
THE BASICS

How Does Rotational Moulding Work?

Rotational moulding (also known as rotomoulding or rotocasting) is a plastics manufacturing process used to create hollow, seamless products. A measured quantity of plastic powder is placed inside a hollow mould, which is then heated in an oven while being rotated simultaneously on two perpendicular axes.
As the mould rotates, the plastic melts and coats the interior surface evenly. The mould is then cooled while still rotating, causing the plastic to solidify into the shape of the mould. The result is a seamless, hollow product with consistent wall thickness throughout.

ADVANTAGES

Why Choose Rotational Moulding?

Rotational moulding offers a unique combination of design freedom, structural integrity, and cost-effectiveness that makes it the ideal process for a wide range of products.

No Weld Lines or Seams

The rotational moulding process produces seamless, one-piece products with no weld lines — resulting in superior structural integrity.

Cost-Effective Tooling

Tooling costs are significantly lower than injection moulding or blow moulding, making rotomoulding ideal for low to medium volume production.

Design Flexibility

Complex shapes, undercuts, inserts, and varying wall thicknesses are all achievable — giving designers exceptional freedom.

Consistent Wall Thickness

The rotation process ensures even distribution of material, producing consistent wall thickness across the entire product.

Wide Material Range

HDPE, LLDPE, nylon, polypropylene, and many other materials can be processed — each offering different performance characteristics.

Large Product Capability

Rotational moulding can produce very large products — from small containers to tanks holding thousands of litres — in a single piece.

powder
MATERIALS

Materials We Work With

At Crompton Mouldings, we work with a wide range of polyethylene (PE) and engineering-grade polymers to suit different industries, environments and product requirements. Material selection varies depending on the application, performance expectations and operating conditions of the finished product.

LLDPE (Linear Low-Density Polyethylene)

More flexible than HDPE with excellent impact resistance. Used for products requiring flexibility or complex shapes.

HDPE (High-Density Polyethylene)

The most commonly used rotomoulding material. Excellent chemical resistance, UV stability, and impact strength. Ideal for tanks, containers, and outdoor products.

Polypropylene

Good chemical resistance and high-temperature performance. Used for chemical storage and process equipment.

Nylon (Polyamide)

High strength, excellent wear resistance, and good chemical resistance. Used for demanding industrial applications.

OUR PROCESS

From Concept to Delivery

We manage every stage of the rotational moulding process in-house — giving you a single, accountable partner from design to dispatch.

1. Consultation & Design

Our engineers work with you from concept to specification, ensuring your product is designed for optimal performance and manufacturability.

2. Tool Manufacture

We design and build precision tooling in-house, giving us full control over quality, lead times, and cost.

3. Production & Delivery

High-capacity rotational moulding machines deliver consistent quality at volume, with full finishing, storage, and distribution services.

Ready to Work With Us?

Contact our team today to discuss your project requirements. We offer free, no-obligation consultations.
Get in Touch