Thermoforming generally encompasses two main types of processes: vacuum forming and pressure forming. These methods differ in the way they apply force to shape the heated plastic material. Here's an overview of each:

Vacuum Forming:

Process: In vacuum forming, a heated sheet of thermoplastic material is draped over a mold. The air is then evacuated from the space between the sheet and the mold, creating a vacuum. The atmospheric pressure forces the heated plastic sheet to conform to the contours of the mold.

Application: Vacuum forming is commonly used for producing large, shallow parts with simple or moderate complexity, such as packaging trays, blister packaging, and some types of disposable containers.

Pressure Forming:

Process: Pressure forming, also known as positive pressure forming, involves applying positive air pressure on the surface of the heated plastic sheet to force it against the mold. This results in more detailed and defined shapes compared to vacuum forming.

Application: Pressure forming is suitable for producing parts with sharper details, deeper draws, and more intricate shapes. It is often used to manufacture products like automotive components, electronic enclosures, and display panels.

While these are the two primary types of thermoforming processes, variations and combinations of these methods can also be employed depending on the specific requirements of the product being produced. Additionally, there's a variation known as twin-sheet forming, where two sheets of plastic are formed simultaneously and fused together to create a hollow part with double-walled construction.