Billow forming
From Plastics Wiki, free encyclopedia
Billow Forming - a method of thermoforming sheet plastic in which the heated sheet is clamped over a billow chamber. Air pressure in the chamber is increased causing the sheet to billow upward against a descending male mold.
Similar to vacuum snapback except the heated sheet is blown upward into a bubble shape and then the plug or mold is driven into the pre-stretched sheet from the top plate.
Using compressed air produces greater stretching forces but requires a much stronger pre-stretch box.
Process: Vacuum forming, Plug assist forming, Vacuum snapback, Billow forming, Free forming, Pressure forming, Drape forming, Stretch forming, Matched die forming, Inline thermoforming, Twin sheet forming, Mechanical thermoforming
Equipment: Thermoforming machine, Thermoforming mold
See also: Injection molding • Blow molding • Plastic welding • Plastic extrusion • Rotational molding
