Aluminum foil duct tape relies on what’s known as a pressure-sensitive adhesive (PSA) for its inherent stickiness.
Aluminum foil tape is truly intended for sealing air ducts. Aluminum foil duct tape must be permanent and able to withstand the prolonged heat and air pressure for the lifetime of the duct. It may even need to be flame retardant to meet some building codes. Aluminum foil duct tape is the true top of the line, a high tensile, hardworking tape.