Like other plastic forming processes like extrusion and injection molding, rotational molding involves the heating of plastic beyond its melting point in order to shape the plastic into a useful product. 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.
ASH Industries
Lafayette, LA | 800-598-2774ASH Industries is a manufacturer of injection molded plastic components and a producer of molds. We process a vast selection of injection moldable materials; vinyl and vinyl ester, thermoplastic elastomers, styrenics, polymide, polyolefins, phenolic and liquid crystal polymers.
Hedstrom Plastics
Ashland, OH | 888-434-5891Here at Hedstrom, we specialize in engineering, designing and manufacturing rotationally molded plastics; chemical and fuel tanks; retail displays; lawn and garden items; medical supplies; recreational, toy, sport and playground objects, plus more. Contact us about your roto molding needs.
Rotational Moulding - Sherman Roto TankAlthough extrusion and injection molding are similar on many levels, rotational moulding is among the most distinct plastic shaping processes. The process is used to create hollow, often large plastic products like tanks and even light watercraft hulls.
Rotational moulding can also be used to create small plastic products in large quantities. Sporting equipment, plastic construction indicators like cones and pylons, trash collection bins and even garden flamingos can all be produced by rotational moulding processes.
A wide variety of industries make use of rotationally moulded plastics. The construction industry, manufacturers, warehouses and many other operations require rotationally moulded plastic products for many purposes.
Rotomolded products are also widely used in commercial contexts and in consumer products markets. Rotational moulding is valued because of the consistency with which it can shape plastic products and its aptitude for creating short product runs easily.
A rotational moulding machine may seem elaborate, but its principle of operation is quite simple. A rotational moulder involves a mold, a heat source, a collection of raw plastic, mold movement machinery and cooling equipment.
At the beginning of the process, raw plastic material is loaded into a half-constructed hollow mold. Once the plastic is loaded in, the mold halves are joined together, sealing the plastic inside.
The mold is then heated, causing the plastic to become molten. Many plastics, when molten, are easily formed and will keep their shape upon cooling. Such plastic varieties are called thermoplastics and include polyethylene of high and low densities, PET, PVC and many other materials.
In order for the molten plastic to take the shape of the mold, the mold is rotated by arms or other equipment that causes the molten plastic to come into contact with all of the surfaces of the mold. Once the plastic has coated the mold, the rotation slows and the mold is subject to a cooling process.
Once cooled, the plastic is ejected from the mold as a newly rotationally molded plastic product. If necessary, the product can be sent for further processing like cutting and painting, or it can be prepared for shipment to customers.