Thermofit Wraparound Duct Bands

 TWDB for Sealing Industrial HVAC Systems

An installed strip of TWDB (actually 2)

     If you are looking for TWDB - save some time and give us a call!  936/321-3333

     If you are looking for installation guidelines - check HERE

Thermofit Wraparound Heat Shrink Duct Bands (TWDB)*
This is a heat-shrinkable tape used for sealing joints in round air conditioning or heating ducts.

Product Overview:
TWDB is a sealing tape made for duct joints. It has a two-layer design:

• First Layer: Copolymer adhesive.
• Second Layer: A thick, high-density polyethylene material that's been cross-linked with radiation.

TWDB is a hot-applied tape with a heat-shrinkable backing, a heat-resistant pressure-sensitive adhesive, and a closure patch.

How It Works:
To apply, you use a propane torch. First, put the ducts in place. Then, wrap the tape around the joint and apply the closure. When you heat the tape above 120°C (250°F), it shrinks tightly around the duct joint. As it cools, the adhesive softens and bonds strongly to the surface, filling any gaps like interlocking seams. After cooling, the bond stays strong, creating a tough, pressure-tight seal.

Important Note:
This tape isn’t meant for use in industrial environments where there are solvents, oils, or chemicals.

Key Features & Benefits:

• No primer needed, so it’s quick and easy to apply.
• It’s low on preheat sensitivity and works really well, combining easy application with high performance.
• The strong backing resists vibrations in high-velocity systems up to 70°C (158°F).
• It helps cut down on inventory costs since you can cut it to the length you need, no need for different sizes.
• The sealant is specially designed for reliable protection, providing high peel and shear strength after it’s applied.
• No special equipment or skills needed – installation is fast and easy, which helps keep costs low.

Product Specs:

• Max. operating temperature: 70°C (158°F)
• Best for: Sealing galvanized ducts
• Prep: Make sure to remove moisture and surface oils
• Recommended pipe prep: ST3

TWDB is sold as a roll, and these are the available sizes:

• 165 ft roll, 3-inch width
• 165 ft roll, 4-inch width

(Closure patches included!)