Heavy Gauge Thermoforming

Heavy gauge thermoforming is a process used to form thicker plastic material between .060” and .25”. These molds are made of materials that can withstand prolonged exposure to high temperatures and can be drilled for vacuum. Some popular materials include acrylonitrile butadiene styrene (ABS), high-density polyethylene resin (HDPE), polystyrene, high molecular weight polyethylene (HMWPE), thermoplastic polyolefin (TPO), polycarbonate, and acrylic.

As opposed to thin gauge, these products are typically intended for more permanent use. Heavy gauge thermoformed parts are popular for the following applications:

  • 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. These thermoformed trays act as highly functional packaging that is engineered to fit the contours of a specific product. Dense pack-outs allow manufacturers to securely and efficiently transport components within a facility or ship finished goods to the consumer with greatly reduced risk of damage.

Cast Aluminum Molds

Cast aluminum molds are perhaps the best and most widely used type of tooling for high production heavy gauge thermoform components, as they are extremely durable with temperature-controlled capabilities. This is critical when reduced cycle times and high-volume production are necessary to complete a project. Cast aluminum molds require the use of a CNC cut pine or foam foundry pattern. The pattern will be engineered slightly larger than the final mold to take into account aluminum shrink during the casting process and plastic material shrink as the end product cools after being formed.

Billet Aluminum Tooling

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 more expensive for  thermoform tooling because it requires CNC machining and gun drilling to the mold block. If dimensional accuracy and mold finish are absolutely critical, billet tooling is an excellent option, as it mitigates some of the inconsistencies that can occur with cast aluminum.

Types of Machinery Used in Heavy Gauge Thermoforming

Rotary Style Thermoformer. This is the most common style of machine used in the heavy gauge thermoforming process. A rotary style thermoformer typically has three stations:

Station 1: Loads and heats the plastic sheet.

Station 2: Contains the mold that will form the sheet.

Station 3: Releases the formed product.

Shuttle Style Thermometer. This type of machine is less common and typically used for smaller batch runs. A shuttle style thermometer is more compact than the rotary style thermoformer, as both the sheet and formed product are 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 often be done manually with a router.

Router Table with a Trim Fixture. Larger production runs benefit from the use of a router table coupled with a trim fixture. The trim fixture uses vacuum to hold the formed part still as the CNC router trims away excess material and adds any cut-outs or holes that the end product may require.

Overall, heavy gauge thermoforming has endless potential adaptations. In recent years, it has become an economical and efficient substitute for injection molding.

Why Choose Castek?

Castek designs and manufactures hundreds of vacuum form mold each and every year for virtually all plastic market segments. Our experienced engineering and manufacturing team can assist with part design guidance through the entire program build to ensure every attention to detail has been addressed thus assuring high quality and on time delivery. 

Send us your part data or project outline and a knowledgeable Castek team member will contact you to discuss how we can help with your project »