Thermoforming in a Nutshell
Thermoforming uses heat, vacuum, and pressure to form plastic sheet material into a shape that is determined by a mold. Sheet stock is heated to a temperature at which the plastic softens, but that is below its melting point. Using vacuum or pressure, the plastic is then stretched to cover and duplicate the contours of a mold. Next the plastic is cooled so it retains its shape. Finally it is removed from the mold and trimmed as required to create a finished part.
Thermoforming can accommodate a wide range of sheet thicknesses and part sizes, from thin-gauge sheet used to form small packaging containers to heavy-gauge sheet used to make items as large as pallets, boat hulls and recreational vehicle tops. Known for low tooling costs, short tooling lead times, and great versatility, thermoforming will be a good fit for the following types of applications:
- Handling trays, totes, and bins
- Electronics housings, bezels, enclosures, and display panels
- Packaging and material handling applications
- Point-of-purchase displays
- Lab and agricultural equipment
- Ground effects and recreational equipment
- Exercise machines and video games
- Cases, kanban trays, and storage systems
- Medical, dental, and diagnostic equipment
- Mass transit and heavy truck components
- Specialized aviation applications
You may want to look at injection molding, rather than thermoforming, if you need:
- Very high volumes
- Very low unit prices
- Very complex internal shapes (fins, ribs, bosses, louvers, etc)
As a general rule of thumb, thermoforming is good for low to moderate volumes (up to approximately 100,000 units per year depending on the part). Injection molding is a better approach for very high volumes (100,000 per month), particularly when unit costs need to be quite low. Tooling for injection molding can cost ten times as much as thermoforming tooling, but thermoformed parts can cost several times as much as comparable injection molded components.
« Last Section | Table of Contents | Next Section »