Vacuum forming is a manufacturing process in which a sheet of plastic is heated and then formed over a tool to create a part. Vacuum forming tooling is relatively inexpensive when compared to other manufacturing processes and parts can be made very quickly.
For prototyping, this manufacturing method is especially useful as true thermoplastic materials can be used as opposed to 3D printed materials or cast urethanes. Vacuum forming is commonly used to create a range of items from small product packaging to large panels and housings in the automotive and medical industries.
How it works:
Tooling – As low pressure and temperature is required, tooling can be made quickly from relatively inexpensive materials. In most cases, the tooling cannot have any undercuts, or areas of geometry that would not be able to pull directly off of the tool as the part is removed. Ideally, all vertical walls should have a minimum of 3-5 degrees of draft. For applications where a more textured surface finish is desired, more degrees of draft may be needed.
Forming – After the tool has been placed on the platen, a sheet of thermoplastic material is clamped over top of it. The sheet is heated to the required temperature, which is material specific. Then the tool is pushed into the heated sheet and the vacuum is turned on. The vacuum causes the heated sheet to stretch and form around the shape of the tooling.
Post Processing – Vacuum formed parts can be trimmed in a variety of ways, depending on the production level. During mass production, they may be stamped with a die or trimmed on a CNC milling machine. For prototypes, trimming processes may include the use of a band saw, hand trimming with a dremel, fixtured hand trimming, and possibly CNC machining depending on the quantity of parts.
Vacuum Forming and your Project
At Touchstone 3D, we use vacuum forming to quickly test product concepts, evaluate material properties, make our own tooling for other parts, and produce production quality parts in low volumes for early field testing. Contact us today at email@example.com to see how your project might involve vacuum forming.