Twin sheet thermoforming has advantages over other methods of thermoforming and other plastics manufacturing processes depending on the part and its use.
- Has a lower tooling cost – about 20-30% less than blow molding
- Yields parts with high structural integrity and rigidity compared to single walled thermoforming
- Allows for an enclosed cavity
- Can include various internal reinforcements, including structural elements and rigid foam components
- Can have molded-in attachments and other features
Typical Application:
To Produce Hollow Molding Parts, Structural Products.
Working Of Twin Sheet Thermoforming Process:
Twin sheet forming is a process of vacuum and compression forming two sheets of plastic simultaneously with a separate mold on the top platen and a separate mold on the bottom platen. Once the plastic sheets have been vacuum formed, they remain in their respective molds. While both sheets still remain at their forming temperature, the two molds are brought together under high platen pressures and the two sheets are bonded together wherever the mold-designed knit areas dictate. This will result in one single product with hollow areas and no secondary bonding required.The twin sheet process creates 3-dimensional parts with formed features on both sides.
The production of twin sheet pallets up to 4 pallets per cycle are being made giving an individual cycle per part in seconds, not minutes. Production capacity therefore can be as large as required by sizing the equipment as required.
Methods:
- Vacuum Forming
- Pressure Forming
- Mechanical Forming
Properties:
- The parts are typically very strong, rigid and lightweight.
- Increased Structural Integrity
- Enclosed Cross-Section Capability
- Low Tooling Cost
- Internal Reinforcement Options: Structural Member, Rigid Foam, Etc.
Materials:
HIPS, Acrylonitrile Butadiene Styrene (ABS), TPO, High Density Polyethylene (HDPE), Polypropylene (PP), TPU, & PETG
Important Points:
After forming of the bottom sheet and the entry of the top sheet into the forming area, there is an opportunity to insert other items such as wood, metal, foam etc. These can be inserted to add strength, give the ability to attach the final product to other items after forming, such as door hinges or even give the final product the ability to float as in the manufacture of floating docks. Also engineering plastics can be thermoformed by this method into detailed technical twin sheet parts.
Application:
- Pallets,
- Industrial drainage,
- Portable toilets,
- Medical housings,
- Surfboards,
- Fuel tanks,
- Air/ventilation ducts,
- Electrical enclosures,
- Recreational boats,
- Cases,
- Toys,
- Marine products,
- Doors,
- Tables,
- Spine boards and
- Numerous transportation-related products.
