The Bi-TEF family of expansion joint materials is designed to handle the widest range of temperature and chemical conditions of any fabric expansion joint material on the market today. The basic textile component is a monofilament fiberglass cloth woven under the most demanding specifications possible with this type of fabric. The fabric is then coated with a fluoroplastic using a proprietary casting process. The basic product can be varied almost infinitely with different weights of cloth and film.

Any cast fluoroplastic has a tendency to be somewhat porous due to the presence of pinholes which appear during the casting process. Bi-TEF meets this problem with the use of a variety of fluorocarbon films which can be attached on the gas side, or between layers of material to serve as a nearly impermeable vapor barrier.

The Bi-TEF family begins with the basic sintered cloth which is excellent for dry applications. A gas-side film can be added for more demanding applications. Another popular solution is to put the film between two layers of cloth, and at the top of the list, is a product which has two layers of cloth and two films.

For abrasive applications, we can install various weights of fiberglass cloth to protect the Bi-TEF. For higher temperature applications, we can use insulation which is bonded with a unique system of TFE film to make the two products nearly inseparable. These solutions can be varied to meet virtually any service condition possible.