Tape Insulation and Tape Jacketing
Insulation and jacketing provide important layers of mechanical and electrical protection for a cable. Choosing the appropriate materials for each can be an important decision.
Insulation: Extruded Vs. Tape
The two main types of insulation are defined by the manner in which they are applied. Tape jackets are wrapped and taped around the cable while extruded jackets are pressed or forced around the cable during the manufacturing process. See below for some of the advantages and disadvantages of each type of insulation to determine which is right for your application.
- Extruded: This type of insulation less expensive than tape and are easier to apply. Extruded insulations also weigh less, are less flammable, and are more easily repaired than tape insulations.
- Tape: Tapes are usually specified for demanding or high-performance applications. Their manufacturing involves wrapping the tape around the cable followed by a process in which the layers of tape are fused together to create a solid, uniform wall. Because its application takes more time and care than extrusion, it is generally more expensive. Tape, however, is common in cables that must perform in challenging environments.
Types of Tape Jackets and Insulation
There are several different material options that can be used for tape jackets and insulation.
- Mylar tape: Mylar is characterized by its excellent tensile strength and durability, and is often used as cable insulation. Its maximum operating temperature is 150 degrees Celsius for performance without diminished properties.
- Aluminum mylar: This tape consists of aluminum foil, laminated with a polyester film. It reflects heat and light while providing chemical and flame resistance.
- PTFE tape: PTFE tape is a superb insulator. It offers a wide temperature range, low dissipation, low smoke generation and flame resistance, chemical and moisture resistance, and solvent resistance, but it has poor cold flow resistance. Usually, PTFE tape is heat-sintered to provide improved abrasion resistance, uniformity, and performance. Unsintered PTFE tape, however, is often used to reduce loss in high-speed data cables.
- Polyester tape: Although this tape is not usually used as primary insulation, it is appropriate for shield isolation and insulation protection. It creates a thermal barrier between the two cable components and its tough material provides the cable with additional mechanical strength.
- Kapton Tape: This tape is mechanically tough, increasing abrasion, cut-through and impact resistance. It also improves the cable’s weather and chemical resistance, although it is susceptible to deterioration from strong bases. It has an impressive operating temperature range of -200 degrees Celsius to +200 degrees Celsius. This tape is radiation-resistant and will not burn. Kapton Type F also has excellent electrical properties.
- TFE Tape: TFE tape can be used as primary insulation. It provides extreme abrasion and abuse resistance, as well as chemical, heat and moisture resistance. It boasts excellent electrical properties and is rated for use up to 260 degrees Celsius under Mil-Spec standards and up to 250 degrees Celsius, according to UL specifications.
- Mica Tape: This is a composite tape with a glass scrim backing for mechanical strength. It can be used as primary insulation. It is rated by the UL to 450 degrees Celsius but can resist temperatures much higher. It has great moisture and radiation resistance and can withstand harsh electrical and thermal overloads.