A vacuum forming machine shapes a heated sheet of thermoplastic into a mold by sealing the softened sheet over the mold's cavity and then evacuating the air between the sheet and the mold with a vacuum pump, so atmospheric pressure presses the sheet down to take the mold's exact shape. The technique grew out of general thermoforming methods developed in the early twentieth century and became industrially significant in the 1950s as cheap, moldable thermoplastic sheet became widely available, since a vacuum former needs only a single-sided mold and comparatively low forming pressure compared with matched-mold or compression methods. Vacuum forming remains a common way to produce items such as plastic packaging trays, disposable cups, and large, thin-walled parts like vehicle interior panels and bathtub liners, where its low tooling cost matters more than the tighter dimensional precision of injection molding.
Facts
Disputed
YearAnsini says G.W. Borkland filed a vacuum forming machine patent in 1947, but also says the first vacuum forming machine was patented in 1964; the origin year is unsettled. Connections
Sources
1. Ansini: Vacuum Forming History
Main body narrative, post-war paragraph
In 1947, 2 years since the second World War ended, G.W. Borkland filed a patent for a vacuum forming machine
In Group: Plastics and Composites Moulding, Page text
The very first thermoforming patents were then filed by H.L Helwig of the Rohm & Hass Company, as well as R.E. Leary, who was an engineer at DuPoint.
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