Insulation Sleeving FAQ: Material Comparison, Selection and Certification

Silicone fiberglass sleeving is a braided fiberglass tube coated with silicone rubber, designed for high-temperature electrical insulation (typically -60 C to 200 C) with good flexibility and abrasion resistance for motor leads, transformer leads and wire harnesses. PTFE tubing is an extruded fluoropolymer tube with higher chemical resistance, lower friction and a wider temperature range (up to 260 C), but less flexible for tight bends. Choose silicone fiberglass sleeving when flexible routed insulation and abrasion protection are needed; choose PTFE tubing when chemical inertness, dielectric stability at very high temperatures or low-friction routing is the priority.

Choose silicone fiberglass sleeving when the part needs flexible routed insulation without heat recovery, for example around motor leads or transformer leads that must remain bendable. Choose heat shrink tubing when the design needs a tight recovered cover, marking, environmental sealing, adhesive lining or terminal strain relief. Heat shrink requires installation access for a heat gun or oven, while sleeving slides over the part directly. For sealed or strain-relief applications, adhesive-lined dual-wall heat shrink is preferred over open-braid sleeving. Read the full sleeving vs heat shrink comparison guide.

Acrylic resin fiberglass sleeving is a braided fiberglass tube coated with acrylic resin, rated for a lower temperature class (typically 155 C) than silicone-coated grades (200 C). It is used in cost-sensitive appliance and general-purpose electrical insulation where the operating temperature stays within the 155 C class. Silicone fiberglass sleeving is chosen when higher continuous temperature, better moisture resistance and superior flexibility are required.

PET braided sleeving (PET woven network tube) is made from monofilament polyester yarn, offering good abrasion resistance, flexibility and expandability for wire harness bundling at lower cost, with a typical temperature range up to 150 C. Silicone fiberglass sleeving is a braided fiberglass tube coated with silicone rubber, rated to 200 C with higher dielectric strength and UL recognition under UL 1441. Choose PET braided sleeving for general harness bundling and abrasion protection; choose silicone fiberglass sleeving when higher temperature, voltage class and UL recognized insulation are required.

Standard corrugated tubing (PA or PP) provides rigid mechanical protection for straight harness runs with limited movement. Flexible corrugated tubing has a corrugated structure that allows bending around corners and along curved routing paths while still protecting against abrasion and impact. Choose standard corrugated tubing for straight protective conduits; choose flexible corrugated tubing when the harness follows a curved or moving path.

Dual-wall adhesive heat shrink tubing has an outer flame-retardant wall and an inner adhesive lining that melts and flows during recovery to create an environmental seal. It is used for wire splices, connector backshells, cable repairs and any application needing both insulation and moisture or fluid sealing. Common shrink ratios are 2:1, 3:1 and 4:1.

Self-wrap sleeving (self-closing braided sleeving) has a split construction that wraps around the bundle and closes itself without tools, allowing easy installation and re-entry for maintenance or wire additions. It is used in automotive, robotics and industrial equipment where harnesses may need modification or inspection after installation.

UL File E233804 is a UL recognized component file for coated electrical sleeving under the UZFT2 category. It means the sleeving construction has been evaluated by UL against UL 1441 requirements for coated electrical sleeving, including dielectric, flame and temperature performance. The file covers the recognized construction, but each product model, wall grade, size and marking must still be verified against the file record and the customer end-product requirements. WCW Flex silicone fiberglass sleeving is produced under UL File E233804 and E233803.

No. UL 94 V-0 is a material or component flammability classification tested on specified specimens under standard conditions. UL 1441 VW-1 is an optional vertical flame test for applicable coated electrical sleeving. They evaluate different specimen arrangements and product contexts, and should not be treated as interchangeable. Review the full standards guidance on the Responsibility page.

WCW Flex operates under an IATF 16949:2016 automotive quality management system alongside ISO 9001 and ISO 14001. IATF 16949 is the automotive industry quality standard that governs product realization, risk management and continuous improvement for automotive wire harness and component supply. Customers should still confirm the certification scope, product model approval and PPAP documentation for the specific automotive or EV project before production.

IEC 60684-2:2025 defines the test methods for flexible insulating sleeving, covering dimensions, thermal behavior, mechanical properties, electrical performance, flame propagation and environmental resistance. The applicable pass limits come from IEC 60684-1 general requirements and the relevant IEC 60684-3 product specification sheets, not from Part 2 alone.

WCW Flex heat shrink tubing and most sleeving products are produced to be RoHS compliant. REACH compliance is confirmed per product family and batch based on the substance list and customer requirement. For regulated applications, request the material declaration, RoHS test report and REACH SVHC statement with the sample or production quotation.

WCW Flex supports automotive project documentation under its IATF 16949:2016 system, including PPAP submission levels and IMDS material data sheets where required. The exact documentation package depends on the customer PPAP level, the product model and the end-product specification.

Send the protected part or assembly description, inner diameter or bundle size, wall requirement, working temperature, voltage or dielectric requirement, routing movement and bend radius, color, cut length, annual quantity, and any customer validation or document requirements such as UL file, RoHS, REACH, IATF 16949 PPAP or IMDS. Including a drawing or photo of the protected part helps the supplier recommend the correct product and sample route faster.

Yes. WCW Flex can review drawings, application conditions, dimensions, colors, cut lengths, packing and sample requirements before confirming a product and validation plan. Contact the Wahchangwei sales team to start a sample request.