— 搪膠成型

Rotocasting / Soft Vinyl Molding

A molding process that forms hollow plastic parts by rotating a heated mold filled with liquid plastic, ideal for complex, lightweight, and flexible figures and toys.

Hollow & LightweightComplex ShapesDetailed SurfacesFigure ToysFlexible Material

— Cost

Medium

— Lead Time

Sample 20-35 days · Production 30-50 days

— Suggested MOQ

300+

— Materials

3 types

What is it

Rotocasting, also known as rotational molding or soft vinyl molding, is a process used to create hollow, seamless plastic products. The principle involves pouring liquid plastic (typically PVC plastisol) into a mold, which is then slowly rotated along two or three axes while being heated in an oven. During rotation, the plastisol uniformly coats the inner walls of the mold and gradually solidifies under heat. Any excess liquid plastic is then drained. This process is particularly suitable for producing large, complex, and uniformly thick hollow objects, with relatively lower tooling costs, making it popular for figures, toys, and art pieces.

Best for

Collectible Figures
Themed Piggy Banks
Large Soft Vinyl Models
Creative Designer Toys
Medical Teaching Models
Festive Decorations

Materials

PVC Plastisol
PU Resin
PE Resin (limited for small parts)

Advantages

Tooling costs are 30-50% lower than injection molding, suitable for small to medium batch production.
Can produce complex hollow shapes with undercuts, offering high design freedom.
Products have uniform wall thickness and seamless, integral structures.
Excellent surface detail reproduction, faithfully representing prototype designs.
Material is flexible and tough, resistant to drops and breakage.
Allows for multi-part, multi-color production, reducing subsequent painting steps.

Limitations

Longer per-piece production cycle, not suitable for extremely high volume demands.
Product tolerance control is less precise than injection molding, approximately ±0.5mm.
High proportion of manual operation, production costs are significantly affected by labor.
Limited to hollow object production, cannot create solid products.
Mold lifespan is relatively shorter, about 5,000-10,000 cycles.

Frequently Asked Questions

What is the typical Minimum Order Quantity (MOQ) for rotocasting?+

Due to relatively lower tooling costs and process flexibility, the recommended MOQ for rotocasting usually starts from 300-500 pieces. If the quantity is too low, the per-unit cost will significantly increase; if the quantity exceeds 10,000 pieces, it might be worth evaluating a switch to other more efficient molding methods.

What is the controllable wall thickness range for rotocasting products?+

The wall thickness of rotocasting products can typically be controlled between 1.5mm to 4mm. The specific thickness depends on the product size, design complexity, and required strength. Mold design and process parameter adjustments ensure uniform wall thickness, preventing deformation or insufficient strength due to overly thin or thick areas.

Are rotocasting materials safe? Do they comply with international standards?+

The soft vinyl materials (PVC plastisol) used by CTRS can comply with international safety standards, such as EU EN71, US ASTM F963, and Phthalate-free requirements. We provide relevant test reports according to client needs to ensure product safety, especially for children's toys or skin-contact products.