Rotational Molding Services

The basic process of rotomolding consists of four steps: charging, heating, cooling, and demolding.

1. First, the mold is charged, meaning that a set quantity of powder is added. 
2. Next, an oven heats the mold to a high enough temperature that the powder liquefies and evenly coats the interior of the mold. During this process, a machine rocks the entire form about two axes, which helps regulate the distribution of the liquid. 
3. The mold is then cooled to allow the liquid to re-solidify. The rotation continues during this step to maintain the desired shape. 
4. Demolding is possible once the machinery is stopped and the product has cooled sufficiently.

Plastic rotational molding follows a controlled process that produces consistent hollow plastic components used across multiple industries.

Here are a few reasons to choose rotational molding over injection molding or other alternatives:

• Cost-Effective: The molds used in rotational molding are relatively inexpensive to produce, which decreases the overall cost of the process. There is also little waste as the entire quantity of powder is typically consumed in molding.
• Feasible for Short Production Runs: Many molding processes are cost-prohibitive at smaller quantities. However, because of the low tooling costs, rotomolding is economically viable even for very short runs.
• High-Quality: The end products are extremely low-stress and require little further finishing to achieve a high-quality result.
• Versatile: Rotomolding lacks many restrictions inherent to other production methods. It can be used for parts of almost any size, and although certain geometries are more challenging than others, it’s possible to successfully engineer molds for almost any shape.

At Advanced Prototype Molding, we have extensive experience controlling necessary considerations to create high-quality rotocast components. As a trusted provider of custom rotational molding, we consider mold angles, wall thickness, and corner strength to match production needs. Material variations are also reviewed since they affect final output.

By far, the most common material for rotomolding is polyethylene, making up 85–90% of rotomolded products. However, rotational molding can accommodate a variety of other materials to suit different project specifications.

Materials used in plastic rotational molding include:

• Cross Link Polyethylene
• LDPE
• MDPE
• HDPE
• Polypropylene
• PVC
• Acetal
• Dual Layer – EPA fuel material
• Color compounded material
• Granite Compounded Mixes
• Repro Black MDPE
• Nylon

The rotational molding process can create virtually any hollow shape, regardless of size or complexity.

Rotational molding applications in custom rotational molding include:

• Automotive and Aerospace: ducting, fuel tanks, wheel arches, instrument panels
• Materials Handling: shipping containers, barrels, bins, trash cans
• Consumer Goods: balls, toys, furniture
• Medical: carts, ball syringes, cases, tubs, dental chairs
• Marine: floats, pool liners, kayaks, docking floats, and fenders

At Advanced Prototype Molding, we support custom rotational molding projects from early design through production. The focus is on selecting the right materials, refining mold design, and producing consistent parts that meet application requirements.

As a rotomolding provider in Illinois, the work centers on practical manufacturing output and repeatable quality.