Plastic thermoforming is a process of manufacturing where a plastic sheet is heated to a flexible temperature, molded to a specific shape, and trimmed to create an end product. Complex and high-volume plastic thermoforming applications can manufacture thousands of finished products per hour depending on machine, mold size, and the size of the units being formed.
Thin-gauge plastic thermoforming is primarily used to manufacture products for food, medical, and other related industries. Thick-gauge plastic thermoforming is used to manufacture vehicle doors, vehicle dash panels, refrigerator liners, utility vehicle beds, plastic pallets, and other related products.
Thin-gauge plastic thermoforming uses plastic sheets that are fed from a roll or from an extruder into a group of indexing chains that incorporate pins to puncture the sheet and move it through an oven for heating to a molding temperature. The hot sheets are then indexed into a form station where a partner mold and pressure-box close on the sheet, with vacuum then applied to remove trapped air and to pull the material into the mold along with pressurized air to form the plastic to the detailed shape of the mold.
After the form cycle, a gust of reverse air pressure is propelled from the vacuum side of the mold as the form tooling opens to break the vacuum and assist the formed parts off the mold. Stripper plates may be utilized on the mold as it opens for ejection of more precise parts or those with negative-draft, undercut areas. The plastic sheet containing the formed parts then indexes into a trim station on the same machine, and a die cuts the parts from the remaining sheet web, or indexes them into a separate trim press where the formed parts are trimmed. The sheet remaining after the formed parts are trimmed is usually wound onto a reel or fed into an inline granulator for recycling purposes.Most plastic thermoforming manufacturers recycle their wasted scrap by compressing in a baling machine or by feeding into a granulator and producing ground flake, for sale to reprocessing companies, or they re-use it in their own facility. Most scrap and wasted plastic from the thermoforming process is converted back into extruded sheet for forming again.
For plastic thermoforming equipment retrofitting, repair and replacement quotes, contact Precision Electric, Inc.