Rotational Molding Machine: Crafting Durable Hollow Plastic Products with Precision and Versatility

Rotational molding machines (rotomolding) specialize in manufacturing seamless, stress-free hollow plastic products like tanks, containers, and playground equipment. This process is ideal for large, complex shapes that require uniform wall thickness and high durability.

What is a Rotational Molding Machine?

It heats plastic powder (typically polyethylene) inside a rotating mold, allowing the material to coat the mold’s interior through centrifugal force. The result is a lightweight, corrosion-resistant product with no welded joints.

Types of Rotational Molding Machines

1. Rock and Roll Machines:
   • Rotate molds on two axes (major and minor) for small to medium parts (e.g., kayaks, traffic cones).
2. Clamshell Machines:
   • Open/close molds vertically for easy loading/unloading. Used for large industrial tanks.
3. Carousel Machines:
   • Multiple molds rotate through heating, cooling, and loading stations for high-volume production.
4. Shuttle Machines:
   • Move molds between ovens and cooling chambers, ideal for heavy-duty products.

Key Advantages

• Design Flexibility: Produce complex geometries with undercuts and varying thicknesses.
• Low Tooling Costs: Molds are 30–50% cheaper than injection molding.
• Material Efficiency: Zero waste—excess powder is reused.

Applications

• Agriculture: Chemical storage tanks, irrigation systems.
• Automotive: Fuel tanks, air ducts.
• Recreation: Kayaks, playground slides.

Operation Steps

1. Mold Preparation: Load powder into the mold and secure it.
2. Heating & Rotation: Heat to 300°C while rotating on two axes for 15–30 minutes.
3. Cooling: Gradually cool with air or water sprays.
4. Demolding: Open the mold and remove the finished product.

Sustainability Features

• Recycled Material Use: Up to 100% post-consumer polyethylene.
• Energy Recovery: Capture oven heat for preheating molds.