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Rotational molding

Plastic forming process where a molten material is rotated in a closed mold to create a hollow part.

Beskrivning
Illustration of Rotational molding

The process

The starting material [1], typically polymer pellets, are poured into the mold [2]. The mold is heated in a furnace to melt the material while it is rotated about two axes. The angles and rotation speeds can be varied to obtain melt to run around and come in contact with all the mold walls. The mold is allowed to cool and solidify while still rotating then the mold is separated to remove the finished part.

Synonyms

Gjutning
Rotational molding
Process films
Advantages and disadvantages
In comparison with alternative methods
Components that are usually assembled from multiple components can be molded as a single component
Residual stress free end product
Relatively inexpensive molds
Increased production speed
No material waste
Products multilayer possible
Pre-built parts can be supplied to the mold
The entire mold must be cooled and the mold is exposed to long downtime
Limited choice of materials
High material costs due to additives and powders
Some parts of the mold can be difficult to reach and therefore must be compensated through good design