Vacuum forming process producing studded plastic sheet, employs flexible molding studs deforming under vacuum and subsequently reverting to original form

摘要

The molding studs (24) are flexibly-compliant. During stressing under vacuum, they deform, then revert back to their original shape when the vacuum is removed. The finished studded sheet is then withdrawn. An Independent claim is included for the corresponding vacuum forming equipment. The positive mold has deformable studs at given locations on a base plate (22). Preferred features: After vacuum application, the effect of spontaneous stud restoration slightly raises the studded sheet (11). The sheet is first heated to facilitate vacuum forming, and is then subjected to increasingly-reduced pressure. Studs are attached by fastenings (23) on the vacuum side of the base plate. Studs are made by casting, injection molding, thermoforming or other like processes. The stud is a deformable molding forming a radially-projecting section (26). It includes at two layers of differing hardness. Further variants of the process and equipment are described, based on the foregoing principles.