Thermoformed articles having an improved insert therein

摘要

The present invention relates to mold inserts suitable for use with thermoformable sheets made of poly(methyl) methacrylate and other thermoplastic sheet material. The inserts become an integrated part of the thermoformed product, and are characterized by having at least one removable portion or plug. The plug(s) are removed during the thermoforming process, and allow the thermoformed sheet material to shrink without creating undesirable levels of stress in the sheet material. This prevents cracking or other failure of the sheet material.