In thermoforming, based on the raw material form of the product—whether sheet or roll—it can be classified into two major categories: thick-wall and thin-wall. Thick-sheet thermoforming This refers to materials with a thickness exceeding 2 mm, which cannot be thermoformed on fully automatic machines. Instead, they are formed using semi‑automatic thermoforming equipment designed for thick sheets.

　　The principle of thick-sheet thermoforming is essentially the same as that of conventional thermoforming. Plastic sheets are cut to specified dimensions and heated until they soften. A pressure differential between the two sides of the sheet, or mechanical pressure, is applied to deform it, after which it is adhered to a specialized mold. The formed part is then cooled and trimmed along its contour to produce the desired final product.

　　Currently, there are two main types of thermoforming processes on the market. One involves sheets with a thickness of 2.5 mm or less, typically formed using roll‑fed sheet material. The other is for thick blister packs, with thicknesses ranging from 3 to 12 mm, which are produced by processing sheet stock. These two processes require different machinery, so when selecting a supplier, be sure to distinguish between their respective production capabilities.

　　Advantages of thick-sheet thermoforming:

　　1) Mold costs are lower than those of injection molding, and the development cycle is shorter, making it suitable for small-batch production.

　　2) A single set of molds can produce products of different materials and thicknesses.

　　Today, the thermoforming industry is steadily growing, with an increasing number of product components being manufactured using thermoformed parts. Examples include automotive interior and exterior trim, rear housings for rear-projection TVs, illuminated ceiling panels, and casings for various medical devices—all of which are produced on thick‑sheet thermoforming machines. Many may not be familiar with these machines, so we at Teshuo will introduce their structure and key functions, hoping this information proves helpful.

　　 Thick-sheet thermoforming The machine typically consists of a sheet‑metal positioning system, a plastic‑mold positioning system, a frame system, a heating system, a cooling system, and an electrical control system.

　　(1) It consists of a well‑shaped blank holder, a power cylinder or hydraulic cylinder, and a balancing and synchronization mechanism. Its function is to securely clamp the plastic sheet in place. In the traveling‑frame heating type, the blank holder adopts a lifting structure and incorporates a horizontal locking mechanism to ensure a tight seal between the blank holder and the platen. The frame can be adjusted according to mold size and is available in manual and automatic versions.

　　Thick-film thermoforming

　　(2) It consists of upper and lower mold platens, upper and lower mold hydraulic cylinders or pneumatic cylinders, and a synchronization mechanism. Its function is to securely position the plastic part and to connect the mold to the vacuum piping. Positioning can be achieved via manual screw tightening or pneumatic automatic locking. The synchronization mechanism ensures that the upper and lower molds rise and fall in unison, thereby guaranteeing the precision of plastic molding.

　　3) It consists of a profile frame, a sealed enclosure, and a protective door. The protective door is available in automatic and manual versions.

　　(4) The heating assembly consists of a heating brick or heating tube, an oven frame, a power cylinder, or an electric motor;

　　(5) Cooling consists of ductwork, water pipes, and spray nozzles;

　　(6) Electrical control, in conjunction with pneumatic or hydraulic systems, ensures that the thermoforming machine meets its process requirements—temperature, speed, and timing—and executes various programmed operations.