Vacuum forming is the process in which a sheet of plastic is heated and then pressed against a model by a vacuum to create a mold.
How the Process Works
First, the desired model is made from a material such as wood or foam. It’s sides should be shaped at an angle so that the formed plastic can be easily removed.
A clamp frame is applied to hold down the plastic sheet. The heater then heats up the plastic to make the sheet moldable.
Once the plastic is heated to a malleable state, the mold is lifted to the sheet from below and a vacuum is applied to eliminate trapped air and suck the sheet into the mold.
The sheet is then cooled and ejected from the frame, having been formed to the shape of the model. (Sometimes, fans or nozzles are used to speed up the cooling process, by spraying a water mist onto the mold.)
After the mold is formed, excess material can be removed and recycled.
The materials used for vacuum forming are thermosoftening, so that they become pliable when heated to a certain temperature and can solidify after cooling.
Common Materials Used:
Acrylonitrile Butadiene Styrene ABS Polyester Copolymer PETG Polystyrene PS Polycarbonate PC Polypropylene PP Polyethylene PE Polyvinyl Chloride PVC Acrylic PMMA
What It's Useful For
The vacuum forming process is useful as an easy way to create molds for unusual shapes. It allows for the creation of cohesive forms from multiple smaller parts, and provides for inexpensive and quick fabrication.
Vacuum forming is used for a wide range of products such as packaging, medical equipment and vehicle parts. On campus, it is most likely useful for architecture and design, to produce parts for models and prototypes.
Some typical applications include:
Machinery Guards Electrical Enclosures Parts for medical devices Bath & shower Trays Parts of vehicle cabs Packaging Signage
Problems that can occur during the vacuum forming process include webs forming around the mold if parts are too close together or plastic is overheated, and bubbles emerging from absorbed moisture, which weakens the plastic material.
On campus, the vacuum forming machine is free if you are an architecture student, and in general, the process is not expensive, (it only requires the cost of the plastic sheet & energy to heat up).
Introduction to rapid design through virtual and physical prototyping. The class will cover the design process, problem solving methods, interdisciplinary team work, current industrial practice, an...more