Generally speaking, our… Thick-sheet thermoforming Production technology begins with the design and fabrication of molds. First, a thermoforming mold is created based on the customer’s requirements and sample specifications. Under standard conditions, a plaster mold is used to produce a preliminary sample. Once the customer approves the sample and the technical details, wood‑plastic, copper, or aluminum molds may be employed as the final tooling. Now, let’s explore the process flow and applications of thick‑sheet thermoforming!

　　. Thick-sheet thermoforming The thickness typically ranges from 0.14 to 8.0 mm—mainly blister packs made of ABS, PC, PVC, PP, PS (HIPS), PET (including APET and PETG), and other materials.

　　Classified by material type, the primary consideration is that the materials used for conventional thin absorbers and specialized thick absorbers differ to some extent. Among these two categories, PVC, PP, PS, and PET each occupy a distinct position, making them integral members of the absorber‑material family.

　　PVC rigid sheets exhibit moderate toughness and are difficult to ignite; however, their combustion can have a certain environmental impact. PVC is easily heat‑sealed and can be edge‑sealed using sealing machines or high‑frequency equipment, making it a primary material for manufacturing transparent blister packaging.

　　Due to its low density, poor toughness, and flammability—along with the release of styrene gas (a harmful substance) when burned—PS hard sheet is typically used in the manufacture of various industrial thermoformed trays.

　　PET rigid sheets are an environmentally friendly material that boasts excellent toughness, high transparency, and flammability, producing no harmful gases when burned; however, they are relatively expensive and well suited for manufacturing premium blister-packaging products. In Europe and North America, thermoforming typically calls for PET rigid sheets, yet their poor heat‑sealability poses significant challenges to packaging. To address this issue, a PVC film is laminated onto the PET surface, resulting in a material known as PETG rigid sheet—though it comes at an even higher price.

　　Taking plaster molds as an example, for thick‑sheet thermoforming, after the blister‑forming mold is fabricated, it is first allowed to dry naturally until completely dry. Alternatively, once dried, depending on the surface irregularities of the product, numerous small holes—1 to 2 millimeters in diameter—are drilled at low‑lying areas where the product’s packaging pattern would not be adversely affected.

　　For products such as packaging boxes, when produced using vacuum forming, small vent holes must be drilled around the perimeter to allow air to escape. After drilling these holes in the mold, the plaster mold must undergo a hardening treatment. This is typically achieved by immersing the mold in a saturated alum solution and allowing it to dry.

　　. Thick-sheet thermoforming Once the mold‑drying process is fully completed, place the mold on the upper metal plate inside the vacuum chamber. Then, depending on the mold’s dimensions, position the plastic sheet on the appropriate standard‑size fixture. Secure the sheet firmly within a heated wooden frame, and transfer the frame—along with the plastic sheet—to a temperature‑controlled oven for softening. For thick‑sheet thermoforming, after softening, insert the plastic sheet together with its wooden housing into the vacuum chamber, activate the vacuum pump to evacuate the air from the sealed chamber, and allow the plastic to cool. The result is a negative‑shaped package that precisely matches the mold, as well as a corresponding forming die.

　　The above outlines the manufacturing process and applications of thick-sheet thermoforming. For more information, please feel free to contact us!