Rotation molding

Rotation molding in short:

  • Resin powder is used
  • The resin melts in the molds
  • The mold has a biaxial rotation
  • Operating pressures are relatively low, allowing molds to be made from less expensive materials.
  • Rigid, resilient, hollow bodies are formed by powdered plastic material in heated molds, which are rotated simultaneously in two planes perpendicular to each other.
  • The plastic particles make contact and melt on the inner surfaces of the hot molds and fuse in layers until all the powder is fused and the desired end product and wall thickness is obtained. The wall thickness is controlled by the amount of powder placed in the mold.
  • Rotationally molded pieces are stress-free except for slight shrinkage forces because the pieces are produced without any external pressure.
  • There is practically no scrap in rotational molding.
  • The uniformity of wall thickness can be maintained to within ±10 percent
  • Most resins used in rotational molding are powders ground to 35 mesh
    and ranging in diameter from 74 microns to 2000 microns.