Different Types of Thermoforming 

Four primary types of forming processes are used for thermoplastics. 

Each process has distinct benefits depending on the size and detail of the part being formed. Thermoforming processes produce uniform and consistent parts with high finish specifications and tight tolerances, similar to what is expected from injection-molded parts. Fine details including undercuts can be achieved using the economical tooling available via thermoforming.


Vacuum Forming 

In the vacuum-forming process, a thermoplastic sheet is heated and pulled against a male or female mold, by pulling a vacuum between the mold and the sheet. This process allows: 


  • Complex Shapes 
  • Fine surface detail 
  • Tight tolerances 

Pressure Forming

In the pressure-forming process, a thermoplastic sheet is heated and pressed against the inside of a female mold. This method uses pressure from above the sheet and pulling a vacuum between the sheet and the mold. This process allows: 


  • Sharp details 
  • Undercuts 
  • Tight tolerances 
  • In-mold texture 

Membrane Pressing 

Membrane pressing is used to encase dimensional surfaces in thermoplastics. The thermoplastic sheet is heated and vacuum-formed over the surface. This process allows: 


  • Forming around top and side surfaces 
  • Complex shapes 
  • Fine details 
  • Sharp or round corners 
  • Embossed brand logos 

Twin Sheet Forming 

The twin-sheet forming process bonds two thermoplastic sheets together to provide additional structural support and rigidity. 

This process allows: 


  • Improved structural support 
  • Increased component rigidity 
  • Ribbing 
  • Surface details 
  • Undercuts 
  • Integrated hardware 
  • Elimination of secondary assembling