Plastic chairs are made in a number of ways, all of which involve metal moulds carved into the desired shape. One of the most popular forms of furniture molding is known as rotational molding, in which a large metal mould is injected with plastic polymer powder. This is then heated to the melting point, and the mold is mechanically turned three-dimensionally in order to evenly distribute the polymers to the inside of the mould. After several minutes of spinning, the mould is cooled off and the rotation stops.
Injection molding is another method of plastic furniture making. This type of mould does not spin, but the polymers are heated at a predetermined rate and temperature. They’re then poured into the mould and cooled. A certain amount of precision must be used with this type of molding process because if the plastic is poured too slowly, it will dry too soon. If it is poured too quickly, the result will not be a uniform configuration of plastic.
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