In rotational molding, a pre-measured amount of plastic material is placed in a cavity of a mold.
The molding machine then indexes the mold into an oven where the mold, and subsequently the plastic, is brought up to molding temperature.
As the mold is heated, it is rotated continuously about its vertical and horizontal axes. This biaxial rotation brings all surfaces of the mold into contact with the molten plastic material.
The mold continues to rotate until the plastic material develops a uniform layer of melt on the inside surfaces of the tooling cavity.
While continuing to rotate, the machine moves the mold out of the oven and into a cooling chamber. Air, or a mixture of air and water, cools the mold and the model plastic material.
This cooling process continues until the part has cooled sufficiently to retain its shape. The machine then indexes the mold to the loading and unloading station. The mold is then opened and the part removed.
A new batch of material is then placed in a cavity, the mold is closed and the process is repeated. |
