What is Slush Molding Process? (Explained!)

Slush molding

What is Slush Molding Process?
Slush molding process is a type of plastic molding process in which hollow plastic components are manufactured.
In slush process, the molten polymer is poured in the mold and it is allowed to cool for a very short time such that only the outer surface polymer gets solidified.
The excess molten polymer is then poured out of the hollow shell.
And finally, the hollow component is obtained when the halves of mold are separated.

Slush molding is used to manufacture various hollow components like rain boots, toys, shoes, dolls, etc.

The main advantage of slush molding is that it uses less material as compared to that of solid components. Thus the final molded part is lighter and cheaper.

For small scale production, slush molding is a single hand operation, while for large scale production, this process can be made semi-automatic in industries.

Slush molding can be done in a single-pour as well as multi-pour. In single-pour molding, the parts are manufactured in one slushing step. While in multi-pour molding, the parts are manufactured in two or more slushing steps.

The wall thickness of the slush molded plastic depends on following factors;

  • Thickness of metal mold
  • Preheated temperature of the mold
  • Type of polymer used in slush molding

In slush molding process, the molds in which the polymer is poured are made up of machine or electroformed aluminum.

The porosity in the mold leads to reduced surface gloss, pin holing and voids in the molded components.

Advantages of Slush Molding

The advantages of slush molding are mentioned below.

  1. The main advantage of slush molding is that it produces hollow components which are light in weight.
  2. Use of raw material (polymer) is also less as the components are hollow.
  3. Slush molding is cheaper as compared to other polymer molding processes.
  4. The die used in slush casting process is simple and of low cost.
  5. Accurate outer geometry can be obtained on the molded components by using this process.
  6. Good surface finish is also obtained by this process.

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