초록 ▼

A method and apparatus for thermoforming plastic foam articles comprising the sequential steps of (a) preheating the plastic foam, usually supplied in the form of a continuous sheet stock, (b) clamping, in a fixed position, that portion of the stock material which is to be thermoformed, (c) initiall

A method and apparatus for thermoforming plastic foam articles comprising the sequential steps of (a) preheating the plastic foam, usually supplied in the form of a continuous sheet stock, (b) clamping, in a fixed position, that portion of the stock material which is to be thermoformed, (c) initially deforming the preheated foam stock with a portion of a male mold member to form a preform, (d) drawing a vacuum on the interior of the female mold member to assist in completion of the thermoforming operation, and (e) completing formation of the desired article by deformation of the preform between a male and female thermoforming device.

대표청구항 ▼

A method of thermoforming thermoplastic foam articles comprising, in sequence, the steps of: a. preheating a sheet of thermoplastic foam stock material; b. clamping said preheated stock material in a fixed position between matched male and female mold members; c. initially partially deforming said p

A method of thermoforming thermoplastic foam articles comprising, in sequence, the steps of: a. preheating a sheet of thermoplastic foam stock material; b. clamping said preheated stock material in a fixed position between matched male and female mold members; c. initially partially deforming said preheated stock material toward a forming cavity of said female mold by extending a plug member from said male mold member; d. maintaining said stock material in a partially deformed condition with said plug extended for an interval of from about 0.1 to about 2.0 seconds without substantial cooling of said stock material; e. completely forming said article by drawing said partially formed preheated sheet into a forming cavity by vacuum and closing the matched male mold member to chill the stock material and set a final shape therein.