Rotational Molding
Why Forté Products for Custom Rotational Molding?
Primarily, our customers appreciate our flat organizational hierarchy that promotes direct communication and unparalleled responsiveness. In addition, we offer more than a dozen, various-sized machines in two Midwest plants. Our expertise comes from manufacturing nearly 300,000 custom, rotationally molded plastic parts each year. We serve hundreds of customers, across dozens of industries. We have particular expertise with large, commercial parts: fertilizer and water tanks; waste receptacles; foam-filled boats as examples. If you can imagine it, we can mold it for you.
Forté Products Rotational Molding Highlights
2 Separate Facilities in the Midwest
A dozen machines molding parts up to 288” x 120”
Expertise with LLDPE, HDPE, XLPE and Nylon
In-house resin pulverizing and color blending
5-Axis CNC trimming/finishing
Foam Filling expertise
“Moldability” Engineering Assessment
In-house tool maintenance
design & fabrication OF FINishING FIXTURES
Rotational molding basics
Rotational molding is a thermoplastic process that makes hollow parts by heating a mold containing plastic powder while rotating on two axes, then cooling before demolding.
• It’s commonly used for seamless, one-piece hollow parts.
• Cycle time is usually longer than high-speed processes like injection molding.
• Common resins include polyethylene grades (such as LLDPE/HDPE) and, for some applications, nylon.
Rotomolding is simply another name for rotational molding; it refers to the same heated, rotating-mold process used to form seamless hollow plastic parts. You’ll also see “roto molding” and “roto-molding” used as shorthand spellings. The term usually implies thermoplastics (like polyethylene) rather than curing resins.
How the process works
The mold is charged with measured polymer (often powder), heated while rotating on two axes so it coats the walls, then cooled while still rotating and opened to remove the part.
• Load: Add a measured charge of polymer to the mold, then clamp shut.
• Heat + rotate: The polymer melts and builds up on the inner mold surface.
• Cool + rotate: Rotation continues to reduce sagging while the part sets.
• Demold: Open the mold and remove the finished hollow part.
Materials
LDPE (low-density polyethylene) is a polyethylene plastic made from ethylene with more chain branching than HDPE, giving it lower density and a more flexible, ductile feel.
HDPE (high-density polyethylene) is a polyethylene plastic made from petroleum known for its high strength-to-density ratio, impact resistance, and chemical resistance.
• LDPE is one member of the polyethylene family; LLDPE and HDPE are other common variants.
• Material choice depends on the balance you need between stiffness, impact resistance, and processing behavior.
• For rotomolding, polyethylene grades are widely used, but the exact grade is application-driven.