Rotomolding Process

What is the Rotomolding Process?

The rotomolding process allows products to be manufactured in a way that creates extremely strong, long lasting, durable parts. Rotomolded parts are resistant to deterioration from chemicals, the elements or environmental stresses. The applications of this process range from playground equipment to nuclear warhead covers, from agricultural tanks to tornado shelters, from furniture to construction materials. The rotational molding process as well as the materials used during rotomolding pair to create these extraordinary parts.


What exactly is Rotomolding? Do you know what makes this very specialized process so different from other types of plastic manufacturing? What kind of products can be made from this process and with what materials? What advantages do rotationally molded parts have? What does a rotomolding facility and the machinery used to manufacture by this process look like? This short video will introduce you to rotational molding and give you a crash course into the stages and steps a part goes through to be manufactured in this way. Click play on the video below to learn more!

Most processing of plastic requires force to be used to mold the plastic.  Rotational molding utilizes movement of the mold to manufacture the part making the rotational molding process stress free.  Once a mold is filled with polyethylene powder it begins to rotate on two axis.  It is moved through the oven where the rotating arm continues to move as the polyethylene powder is warmed and liquifies. This liquid plastic is continually coating the mold building the walls of the part. 

Rotomolding Process Summary

Rotational molding is a four-stage process.

Rotational Molding is a 4 Stage Process, Rotomolding 4 stage process

Stage One: Load powder polyethylene resin into the mold.

The first step is loading the resin in the mold. Pulverized material in a fine powder form is loaded into the prepared mold. The mold is then secured closed and rotated to ensure no powder is able to escape.

Mold loaded and being closed up for Rotational Molding Process

Stage Two: Mold moves into the heating chamber of the oven while rotating on two axes at a low speed.

Rotational Molding Arm Going into Rotomolding Oven

Stage Three: Mold moves into the cooling chamber and is cooled by air or water spray or a combination of both, while still rotating.

Mold for Rotational molding in Cooling Chamber

Stage Four: Mold is unloaded revealing the molded part.

Pulling a part from the Rotational molding Process
Pulling part from a mold at the end of the Rotational Molding process.

Rotational Molding Powder
Material being weighed out for the Rotational Molding Process

A variety of materials are available for rotational molding though the most widely used is polyethylene. This outstanding material is an integral part of the rotational molding process.

Looking for further information on rotomolding? Check out the following pages below:

Request Rotomolding Information

Have a new custom rotomolding project you are looking to tool up and have a manufacturing partner?

Rotomolding, Rotomolding Cooling Chamber, Molds in Rotomolding Cooling Chamber

Request Rotomolding Quote

Do you need a quote on an existing rotomolding project? Do you need a tooling and a rotomolding partner for a new project? Request a rotomolding quote today!

Request Quote

Rotomolding Information

Obtain further information about the rotomolding process!

  • Rotomolding Process
  • Designing for Rotomolding
  • Molds for Rotomolding
  • Rotomolding Products
  • Rotomolding Materials
  • Custom Rotomolding
  • Rotomolding Jobs
  • Rotomolding Contact

  • Rotomolding

    Rotomolding Company

    Rotomolding, Rotational Molding, Rotomoulding, Rotomoulding

    With over 2 decades of rotomolding success, Granger Plastics is a quality-driven, custom rotomolding solutions focused rotational molding supplier.


    Rotomolding Solutions

    Providing complete rotational molding solutions. Rotomolding Design, Mold Fabrication, Secondary Trim & Assembly, Packaging, Drop shipping and more!

    Rotomolding Design, Designed for Rotomoling, Rotational Molding Design

    Rotomolding Design

    Need design assistance from one of the industry's best design teams? Learn more about Rotomlding Design!

    Learn More

    Granger Plastics Rotomolding, Granger Plastics Logo, Granger Plastics Rotational Molding

    Rotomolding Company

    Quality driven, solutions based Rotomolding leader. Complete Rotational Molding Solutions.

    Learn More

    Molds for Rototomolding, Rotomolding Molds, Tooling for Rotomolding

    Molds for Rotomolding

    High quality molds and tooling for the rotomolding process. Also providing modifications and maintenance.

    Learn More

    Looking for a partner for your Rotational Molding project?

    Request Rotomolding Quote