Vacuum Forming Plastic

Vacuum forming is a method of molding sheets of plastic into 3D shapes using the force created by an air vacuum. Depending on quantities and complexity, vacuum forming can be an inexpensive and efficient technique.

Vacuum Forming

When manufacturing plastic products, there are a handful of ways to go about achieving a desired shape. For relatively small quantities of products that do not require complex, multi-directional molds, vacuum forming is generally the method of choice.

Sheet-Stock Plastic

There are countless plastic types, thicknesses, colors, etc.  Your product application, design, budget, and user will all contribute to making a decision on which plastic to use. Once the material selection has been made, you will have sheets like this.

plastic sheet stock


Molds can be made in a variety of ways depending, again, on the project, budget, quantity, and type of plastic being used. There are wooden molds, resin molds where liquid plastic is poured over a form to generate a solid plastic mold, and polished metal molds that minimize blemishes and can be cooled with water for higher production quantities. Typically, molds are a one-time expense and can be reused for all subsequent production.

Female Vacuum Forming Mold

Heating the Plastic

Heat is used to soften the plastic into a pliable state before it is put onto the mold.  The sheet stock is clamped into the vacuum former and is heated to a very specific temperature based on the chemical properties of the type of plastic. Once it is heated, the plastic begins to sag and is dropped onto the mold.

Plastic sheet clamped into the vacuum former

Heated Plastic sheet over the mold


Once the plastic is placed over the mold, the vacuum pulls all of the air from between the plastic and the mold creating a pull action. This force ensures that plastic reaches every detail and crevice leaving a consistent molded form.

Vacuum in action


Once the plastic is molded, it has to cool completely before it is removed from the mold.  This minimizes the chance that the plastic will alter its shape.


After the plastic is cool, it can be removed from the mold and continue through the fabrication process of trimming, polishing, and assembly.

Completed Form

Vacuum Forming is one of the most common and cost effective ways to form plastic. unlike some other forming methods, vacuum forming requires a certain amount of craftsmanship in regards to temperature control, timing, and material selection.

Interested in learning more about vacuum forming and other manufacturing services we offer at Ehren-Haus? Check out our summary of capabilities page and give us a call to discuss your product.

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