There are two general thermoforming process categories: thin (1.5mm, 0.06in and below) and thick (heavy, 3mm, 0.12in and above) gauge thermoforming. Thin-gauge thermoforming is popular for disposable packagings. Thin-gauge parts are usually the final products when trimmed from the molds. Heavy-gauge parts often requires additional drilling, cutting, or finishing after trimming to final shape. Heavy-gauge parts are often considered permanent components of a product.
In its simplest form, a small tabletop or lab size machine can be used to heat small cut sections of plastic sheet and stretch it over a mold using vacuum. This method is often used for sample and prototype parts. In complex and high-volume applications, very large production machines are utilized to heat and form the plastic sheet and trim the formed parts from the sheet in a continuous high-speed process, and can produce many thousands of finished parts per hour depending on the machine and mold size and the size of the parts being formed.