Because of our years of experience and continued investment in the latest equipment and technology, PDI routinely provides clients with high quality products at a lower cost and faster turn-around time than other thermoforming companies in the industry. Following are common terms used in the vacuum forming process: Clamping The clamp frame ensures the plastic sheet is held firmly in place during the forming process. Heating Radiant heaters are normally used to heat the sheet which has been positioned above and below the plastic sheet material. Common types of heaters used are calrod, ceramic or gas. Pre-stretch Is used to achieve "even" wall thickness. Air is introduced to blow a small "bubble" and the mold is then raised into the pre-stretched sheet. Plug Assist Where a deep draw is required a top "plug" may be used to push material into the mold during the forming process. Vacuum A vacuum is applied, the sheet is drawn into intimate contact with the mold and the mold detail is picked up. Pressure When greater detail is required including sharp corners, texture or lettering, pressure can be applied to the non-mold side of the sheet to highlight the details. Cooling and Release The material is allowed to cool. The cooling process may be shortened with blown air or even a fine water spray. The molding may then be released from the mold by introducing a small stream of air pressure. Finishing After molding, any final detail finishing may be performed such as trimming, cutting, drilling, polishing, decorating, etc... |