Rotomoulding is an alternative to thermoforming, blow molding and injection molding, and although it is lower in cost, this process is not as common because of the complex and large machinery required for the fabrication process. Read More…

Leading Manufacturers
Roto Dynamics Inc.
Orange, CA | 877-768-6585As a full-service rotational molding company, Roto Dynamics is your source for high quality, custom rotomolded products. Since our inception, we have continued to earn success by closely working with our customers, developing innovative and tailored solutions. We are with you every step of the way, from design and development to production and assembly. For a complete view of our capabilities and services, check out our website, or submit a request for quote to see how we can serve you!

Sherman Roto Tank
Pearland, TX | 281-648-0909We are a custom manufacturer of rotationally molded products. Our state of the art technology creates precise, cost effective and dependable products. Whether your order is large or small, we want to be sure you are satisfied.

Midwest Rubber Company
Deckerville, MI | 810-376-2085Our award-winning company performs rotomolding making rotationally molded plastic and rubber items. We have produced items for agricultural equipment, automotive, heavy-duty truck and industrial applications. QS 9000, ISO 9001, ISO 14001, TS 16949 certified. We’ve been in business since 1946.

Iowa Rotocast Plastics, Inc.
Decorah, IA | 563-382-9636IRP’s rotational molding is the cost-effective, long-life solution to other forms of molding. When considering any custom molding project for your business, accept no substitutes. We’ve become known for our wide range of products, best-in-class service and a strong commitment to customer satisfaction. Call Iowa Rotocast Plastics today and find out how they can increase your sales tomorrow.

Northwest Plastics Ltd
Port Coquitlam, BC | 800-847-7686Northwest Plastics provides rotational molding services for customers who provide fine products worldwide. We are a Partner in Excellence to our clients. Since no two are alike, we develop a support model for each and every customer. With rotational molding, lead times are quick; tooling is low cost and part complexity is easy to accomplish. Visit our brand new website today!

Roto moulders produce many different parts and products for the food and beverage processing, medical, pharmaceutical, waste management, marine, sporting goods, recreation, toy, packaging, materials handling, automotive, plumbing and construction industries.
They are composed of a series of moulds, an oven, a cooling chamber and large mould spindles that are mounted on a rotating axis. The roto molding process begins with the fabrication of the mould, which is made either of stainless steel or aluminum.
Depending on the complexity, they are either welded or die cast. Aluminum moulds are thicker, since it is a softer metal. The polymer resin, in the form of fine powder, is poured into the mould. The spindles begin rotating in two directions into the oven chamber.
Under high heat, the plastic melts and evenly coats the inside walls of the mould. To cure, the moulds are then taken to a cooling chamber.
There are several different types of roto moulders, and they include rock and roll, clamshell, vertical rotational, shuttle and carousel machines. Rock and roll machines are composed of an arm that holds a large mould.
Clamshell machines are also single-arm configurations and are considered small. Vertical rotational machines are energy efficient and can fit into compact heating and cooling chambers. Shuttle machines move the moulds from different heating and cooling areas.
They can fabricate large numbers of products at once, but require a lot of operating space. Finally, carousel machines, which are the most common type, have several arms that can be in the heating or cooling chambers simultaneously. The cooling process takes about 20 minutes.Once the plastic has cured, the newly formed product is unloaded manually, which can be difficult if the plastic has shrunk during the process. Parts that emerge from roto moulders, if they are intended to have holes or openings, must be sent for additional processing like cutting and surface finishing.