Heavy Gauge Thermoforming

Heavy gauge thermoforming, as the name suggests, is a process for forming thicker plastic material (typically between .060” up to .25”). Some popular materials used for heavy gauge thermoforming include: ABS, HDPE, Polystyrene, HMWPE, TPO, Polycarbonate, and Acrylic. As opposed to thin gauge, these products are typically intended for more or less permanent use.  Heavy gauge thermoformed parts are popular for applications such as: cosmetic panels, automotive interior trim pieces, pickup truck liners, hydroponic trays, refrigerator liners, shower enclosures, housings for electrical equipment, promotional and advertising items, retail displays, kiosks, material handling equipment. Another popular application of heavy gauge thermoforming is for the production of plastic dunnage trays. Plastic dunnage provides an effective way for manufacturers to transport components or finished goods safely and securely. Plastic dunnage trays are engineered to fit the contours of a specific product in a space efficient and secure manner. This allows manufacturers to transport goods either throughout the production process or to the end consumer efficiently with greatly reduced risk of damage.

Heavy gauge thermoforming molds can be made out of a variety of materials provided they can withstand prolonged exposure to high temperatures and can be drilled for vacuum. Pine is a cost-effective material that can be used for small batch test runs, but is not resilient enough for full production. Ren materials such as Ren 440 or Ren 472 is a much more durable material, that although more expensive and difficult to machine than pine, is still a more cost-effective option than aluminum “hard tooling”. Cast aluminum molds are perhaps the best and most widely used type of tooling for high production heavy gauge thermoform components. Cast aluminum molds have the benefit of being extremely durable, as well as the option of having cast in cooling lines allowing for temperature control. Temperature controlled aluminum molds are critical when reduced cycle times and high-volume production are necessary to the project. Cast aluminum molds require the use of a CNC cut pine or foam foundry pattern. This pattern will be engineered slightly larger than the final mold to take into account aluminum shrink during the casting process, and plastic material shrink which will occur as the end product cools after being formed. Billet aluminum tooling is another option to consider in heavy gauge thermoforming. Although billet tooling is more commonly used in thin gauge thermoforming, it does have its applications in heavy gauge as well. Billet aluminum tooling is typically the most expensive of thermoforming tooling options because it requires CNC cutting 100% of the mold surface, this can be costly especially with molds that are significantly tall or deep. Billet tooling is an excellent option if dimensional accuracy and mold finish are absolutely critical, as working with billet material mitigates some of the inconsistencies that can occur with cast aluminum. There are two basic styles of machine used in the heavy gauge thermoforming process. The most common being a rotary style thermoformer. This type of thermoforming machine typically has three stations; one station for loading and heating the plastic sheet, a second station containing the mold which will form the sheet, and a third station that will release the formed product. Another type of machine that is less common, and typically used for smaller batch runs is a shuttle style thermoformer. This type of machine is more compact than the rotary style, as both sheet and formed product is loaded and removed from the same position. Regardless of mold or machine style, most formed heavy gauge products will require some degree of trimming or finishing after being ejected from the machine. During smaller production runs this can usually be done by hand with a router. Larger production runs benefit from the use of a router table coupled with a trim fixture. This trim fixture can be built from a variety of materials and uses vacuum to hold the formed part still as the CNC router trims away excess material and adds any kind of cut outs/ holes that the end product may require. Overall heavy gauge thermoforming has almost endless potential adaptations and in recent years has become an economical and efficient substitute for injection molding.