b) The softened sheet is placed over a concave mold cavity.
c) A vaccum draws the sheet into the cavity.
d) The plastic hardens on contact with the cold mold surface,
and the part is removed and subsequently trimmed from the web.
There are three methods of the thermoforming process: (1) vacuum thermoforming,
(2) pressure thermoforming and (3) mechanical thermoforming. The principle is
basically the same; heating the plastic and force it to acquire the mold's shape.
Figures describing each method are shown below.
Figure 1: The Vacuum Thermoforming Method
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a) A flat plastic sheet is softened by heating. b) The softened sheet is placed over a concave mold cavity. c) A vaccum draws the sheet into the cavity. d) The plastic hardens on contact with the cold mold surface, and the part is removed and subsequently trimmed from the web. |
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