ROTATIONAL MOULDING: FROM DESIGN TO PRODUCT

What is rotational moulding?

Rotational moulding is a production process where a hollow mould is filled with a plastic powder such as polyethylene (PE) or polypropylene (PP). The mould is heated to a high temperature in an oven, while the plastic melts against the wall of the mould due to the rotation and takes on its shape.

The mould is then cooled to let the product harden. This produces a very strong plastic with a particularly long lifespan, in a custom shape. The investments are low compared to other production methods. The freedom of shape is unparalleled and the method also lends itself to small product series. Finally, the end product is easy to recycle.

Design

Rotational moulding offers almost unlimited possibilities and gives the designer a lot of freedom. You can count on our years of experience and tools to support you in developing a new product. We make use of 3D software for the design phase and the drawing work. Our staff will also help you develop the drawing. In order for the interim stage between drawing and final model to run even smoother, we will create a 3D print upon request. What this gets you: a tangible item at scale before you make the full investment.

Is the product part of total engineering? Then we will put you in touch with just the right partners, who will throw their weight behind it too.

Mould.

A mould is needed with rotational moulding for a custom plastic product. The selection and construction of this requires knowledge of the art. A mould can be manufactured in steel or aluminium, often depending on the shape of the product.

Various techniques for constructing moulds exist. With castings, for example, or milled from solid material. A combination of techniques is sometimes used.

Characteristics of moulds for rotational moulding:

  • In at least two parts
  • Threads (both internal and external)
  • Insert holders
  • Various structures and finishings
  • Teflon or insulation to avoid sticking in particular places
  • Connectors
  • Cutting edges

Raw materials and colours

A range of materials are used in rotational moulding, generally with polyethylene and polypropylene as the basis. By supplementing these raw materials with additives, a great many product properties can be achieved. From stiff to flexible. From anti-static to high impact resistance.

Some highly technical materials also exist for specific applications. Trouble choosing? We will help you choose the right raw materials, and align the production process seamlessly to these.

Step 1

The mould is filled with plastic powder.

Step 2

The mould is placed in the oven and rotated around two axes. The powder is distributed homogeneously across the mould surface. The heat changes the powder into a homogeneous shape.

Step 3

The rotated material is cooled and crystallises into a solid final product.

Step 4

The rotated product is removed from the mould.

The major plus points:  
  • Tension-free
  • Relatively low investment costs
  • Great freedom in shape and design
  • Equal wall thickness
  • Favourable price, including for smaller series

Finishing and packaging

Our service provision goes beyond just producing your custom plastic product. At your request, we will handle the finishing and assembly of your products, after thorough quality control. We will guarantee to ship your product to you damage-free, accompanied by the final product packaging and labelling if needed.

  • Plastic welding (extrusion, trident, mirror welding, etc.)
  • Deburring, drilling, sawing, milling and singeing
  • Assembly of components (even into the full product)
  • Polishing and labelling
  • Packaging and shipment, incl. e.g. manuals and price stickers.