Process for thermoforming a hollow plastic article using an extendible porous male mold assembly

摘要

Process for thermoforming hollow articles having large length to diameter ratios. A male mold assembly having an extendible head portion formed of a porous metal is employed with the male mold being passed through the plane of a heated plastic sheet while a vacuum is drawn through the porous metal head portion to draw the sheet against the male mold. The extendible head portion is extended to increase the depth of the formed article.