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Advantages of Fiberglas Textile Fibers in Harness Assemblies

Updated: Dec 6, 2023

Electrical insulated sleeving is a critical component in many industries and components. It is designed to protect conductors from various environmental factors such as electrical, flame, and extreme temperatures. Varflex Corporation is a leading manufacturer of electrical insulated sleeving. For over a century, they have produced high-quality products which provide reliable protection against these factors and more.

Electrical insulated sleeving from Varflex protects wires and cables by providing an extra layer of insulation. This helps to prevent electrical current from escaping the wires or cables, which can result in short circuits, fires, and other hazardous conditions. Electrical sleeving prevents the flow of electrical current outside the wire or cable to safeguard components of an electrical system and reduce the risk of electrical shock or injury. Varflex offers many variations of electrical sleeving well-suited for heavy duty insulation and subject to high heat and voltage. Their products provide significant protection as a barrier against moisture, this includes the prevention of corrosion of metal components, deterioration of insulation and decreasing the risk of electrical shock or fire.

Extreme temperatures can also cause damage to wire and cable in electrical systems. Excessive heat can cause insulation to melt or degrade, increasing the risk of electrical shorts or fires. Severe low temperatures can also prevent the wire or cable from performing optimally. Varflex’s insulated sleeving is designed to provide the appropriate thermal insulation. Depending on the specific product, their electrical insulated sleeving is designed to provide temperature protection as low as – 80° C and up to 482° C.

Electrical insulated sleeving is primarily made of Fiberglas yarn. The advantages of Fiberglas yarn play a vital role in various applications. Fiberglas is composed of three significant raw materials including silica sand, sodium carbonate and limestone. The material is hard, strong, clear and resistant. These properties increase when the fibers form a flexible, lightweight, processable yarn.

Fiberglas textile fibers have a high strength-to-weight ratio making the sleeving ideal in aerospace along with other high-reliability industries. While the exact strength of Fiberglas varies depending on the specific composition, research proves it outshines other materials. At 1,307 kN m/kg, Fiberglas is much stronger than steel at 63.1 kN m/kg, and also titanium at 260 kN m/kg. The high heat resistance of Fiberglas textile fibers is efficient in manufacturing and also offers improved product performance. Inorganic Fiberglas fibers will not burn or smolder in high temperatures. Fiberglas yarn retains 50% of tensile strength at 650°F (340°C), displaying an outstanding dimensional stability and will not stretch or shrink in atmospheric conditions.

Fiberglas textile fibers do not absorb water. They dissipate heat more rapidly than asbestos and organic textile fibers and are highly resistant to attack by most chemicals. Fiberglas fibers are attractive in many industries including electrical, roofing, filtration, aerospace and defense, construction, decorative fabrics, and recreational apparatuses like boats, skis, surfboards, and sporting equipment.

Varflex manufactures all electrical insulated sleeving in the United States with a heavy emphasis on quality. Varflex’s various coated electrical sleeving protects circuits up to 8,000 volts, through extreme high and low temperatures. They are resistant to radiation, moisture, abrasion, aromatic and aliphatic solvents, fuels, oils and other environmental factors. See more details at

View the original article in Wire Harness News May/June Issue,

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