The term “thermoforming” is a rather broad term which essentially means “to shape a sheet of plastic by using heat and gravity”. From this basic term comes the more advanced practices of shaping a plastic sheet such as “vacuum”, “drape forming” and “pressure forming”. All of these methods however do so with the use of a “mold” or “pattern”. The “mold” or “pattern” are what gives the heated plastic sheet its’ desired shape. The addition of vacuum and or pressure allows greater control and flexibility when manipulating the heated plastic sheet over the “mold/ pattern”. Many modern thermoforming companies also employ the use of “assist plugs” during the “forming” stage. “Assist plugs” are used to further control the distribution of material into “pockets” or other areas of the “mold/ pattern” which would otherwise be difficult to draw material into with the use of vacuum and pressure alone. Assist plugs also help to provide more even and consistent side wall thickness on finished parts. he “mold/ pattern”, “pressure box”, “trim die” and “assist plugs” are all a part of thermoformed tooling. Thermoformed tooling can be made from a variety of material including, but not limited to: aluminum, epoxy, nylon, steel and wood. Generally the most accurate and durable thermoformed tools are CNC machined out of solid blocks of aircraft quality aluminum. The assist plugs can also be CNC machined out of blocks of aluminum, nylon or syntactic foam. The pressure box portion of the tooling, when utilizing pressurized air as well as vacuum during the forming process, can be made from welded and machined aluminum or steel. Trim dies which are used to remove the finished part from the plastic sheet can be either what are referred to as “steel rule” or “match metal” dies. Steel rule dies are less expensive and also less accurate than “match metal” dies. These type of cutting dies are primarily associated with “inline thermoforming”. "inline thermoforming” is the term used to describe plastic converting companies that form and cut parts from large rolls of plastic. This type of thermoforming process is best suited for medium to high volume manufacturing of blisters, clamshells, cups and trays. These rolls come in thicknesses from .0075-.080” as well as a wide range of colors and plastic materials such as HDPE, PET, PVC, PC, PP, and PS. “Heavy gauge”, “rotary” or “sheet forming” refers to plastic converting companies that work with large sheets of plastic instead of rolls. This type of thermoforming process is best suited for extremely large and/ or thick parts such as truck “bed liners”, hot tubs, and medical equipment housings. These sheets come in a wide variety of colors, materials and thicknesses ranging from .080” up to a few inches thick. For more information regarding the purchase of “plastics” or “plastic packaging” or to receive more information about “thermoforming”, “vacuum forming” and “pressure forming” please visit the link(s) below: Website content provided and sponsored by Dordan Manufacturing. > |
