For engineers and procurement specialists evaluating composite insulation materials, Epoxy Resin Fiberglass Tube provides a compelling combination of high mechanical strength, excellent electrical insulation, and long-term environmental resistance. Kaxite Sealing manufactures and supplies these tubes in a broad range of standard and custom dimensions, making them suitable for everything from high-voltage electrical equipment to lightweight structural components. The epoxy resin matrix bonds continuous fiberglass filaments into a rigid, void-free laminate that holds precise tolerances under load and temperature fluctuation.
This product category covers round and shaped tubes produced through filament winding, pultrusion, or vacuum-assisted processes. Each method yields a different balance of hoop strength, axial stiffness, and surface finish. Kaxite Sealing focuses on consistency in resin content, fiber orientation, and curing to ensure predictable performance batch after batch. The resulting tubes resist moisture absorption, chemical attack, and thermal aging better than many thermoplastic or paper-based insulating alternatives.
Epoxy Resin Fiberglass Tube is a composite cylindrical profile made from continuous glass fiber reinforcement embedded in an epoxy resin system. The glass fibers supply tensile and flexural strength while the epoxy resin transfers stress between fibers and protects them from environmental degradation. The tube form is widely used as electrical insulation, structural support, protective sleeving, and precision spacer material.
In standard production, glass fiber roving or fabric is impregnated with a formulated epoxy resin and then wound or pulled through a heated die. The resin cures into a hard, thermoset matrix that does not melt when reheated. This differs from thermoplastic tubing, which can soften and lose dimensional stability at elevated temperatures. Depending on the grade, the finished tube may contain a fiber content between 55 percent and 78 percent by weight. Higher fiber content generally improves strength but can reduce machinability and surface gloss.
Kaxite Sealing offers both general-purpose and high-temperature grades. General-purpose tubes typically use a B-stage epoxy formulated for mechanical toughness, while high-temperature grades use a modified epoxy or epoxy-novolac system rated for continuous service at higher thermal classes. The choice of resin directly affects dielectric strength, water absorption, and chemical resistance.
The following parameter lists and tables represent the core specifications Kaxite Sealing maintains for its Epoxy Resin Fiberglass Tube product line. Custom values can be achieved through adjusted fiber architecture, resin formulation, and machining. Standard tolerances follow ISO 2768 medium class unless tighter requirements are specified at the time of order.
| Dimension | Range | Standard Tolerance | Precision Tolerance |
|---|---|---|---|
| Inner diameter | 2–30 mm | ±0.15 mm | ±0.05 mm |
| Inner diameter | 30–100 mm | ±0.30 mm | ±0.10 mm |
| Inner diameter | 100–300 mm | ±0.50 mm | ±0.20 mm |
| Outer diameter | 4–50 mm | ±0.20 mm | ±0.08 mm |
| Outer diameter | 50–200 mm | ±0.40 mm | ±0.15 mm |
| Wall thickness | 0.5–10 mm | ±0.20 mm | ±0.10 mm |
| Wall thickness | 10–30 mm | ±0.40 mm | ±0.20 mm |
| Length | 100–1000 mm | ±0.50 mm | ±0.20 mm |
| Length | 1000–3000 mm | ±1.00 mm | ±0.50 mm |
| Property | Test Standard | Typical Value | Unit |
|---|---|---|---|
| Density | ISO 1183 | 1.85–2.00 | g/cm³ |
| Tensile strength, axial | ISO 527-4 | 250–420 | MPa |
| Flexural strength | ISO 14125 | 350–550 | MPa |
| Flexural modulus | ISO 14125 | 18–28 | GPa |
| Compressive strength, axial | ISO 14126 | 180–260 | MPa |
| Impact strength, Charpy | ISO 179 | 50–120 | kJ/m² |
| Water absorption, 24 h | ISO 62 | 0.05–0.20 | % |
| Property | Test Standard | Typical Value | Unit |
|---|---|---|---|
| Dielectric strength, radial | IEC 60243-1 | 12–20 | kV/mm |
| Dielectric strength, axial | IEC 60243-1 | 8–15 | kV/mm |
| Volume resistivity | IEC 60093 | 10¹²–10¹⁴ | Ω·cm |
| Surface resistivity | IEC 60093 | 10¹²–10¹⁴ | Ω |
| Comparative tracking index | IEC 60112 | 200–600 | V |
| Thermal conductivity | ASTM E1530 | 0.25–0.35 | W/m·K |
| Coefficient of thermal expansion | ISO 11359 | 8–15 × 10⁻⁶ | 1/K |
| Continuous operating temperature | IEC 60216 | 155–180 | °C |
Kaxite Sealing uses three primary production methods for Epoxy Resin Fiberglass Tube: filament winding, pultrusion, and roll-wrapping. Filament winding offers the highest hoop strength because continuous glass fibers are wound at controlled angles around a rotating mandrel. Pultrusion delivers excellent axial strength and consistent cross-sections at high production efficiency. Roll-wrapping is preferred for larger diameters and thicker walls where laminate layers are built up from epoxy-prepreg glass fabric.
Each method begins with strict incoming inspection of glass fiber roving, fabric, and epoxy resin. The resin is mixed under vacuum to remove entrapped air and then applied through a controlled impregnation bath. After forming, the tube passes through a staged curing cycle that gradually raises temperature to optimize cross-link density without creating thermal stress. A post-cure step may be used for high-temperature grades.
Quality control includes ultrasonic testing for voids and delamination, dimensional inspection with coordinate measuring equipment, and batch testing of mechanical and electrical properties. Kaxite Sealing maintains full material traceability from raw resin and fiber lots through finished tube serial numbers. This allows customers in regulated industries to validate compliance with specific standards and to maintain consistent process documentation.
Epoxy Resin Fiberglass Tube is used across a wide range of industries because it combines electrical insulation with structural capability. The following applications illustrate the product’s versatility:
The tube form is especially useful when a component must pass wiring, fluid, or mechanical linkage through its center while maintaining electrical isolation or structural stiffness. Because the inner surface can be honed or polished, it can also serve as a low-friction guide or bearing surface in certain low-load applications.
Selecting a Kaxite Sealing Epoxy Resin Fiberglass Tube delivers measurable advantages compared to metallic, ceramic, or low-cost plastic alternatives. The first benefit is high strength-to-weight ratio. A fiberglass epoxy tube typically weighs roughly one-fourth as much as steel at equivalent volume, yet it provides sufficient compressive and flexural strength for many load-bearing applications. This reduces shipping cost, simplifies assembly, and improves dynamic performance in rotating or moving equipment.
The second benefit is reliable electrical insulation. The epoxy-fiberglass laminate provides dielectric strength above 12 kV/mm in most grades, with low moisture absorption maintaining insulation integrity in humid conditions. Unlike paper-based or phenolic tubes, it does not soften or shrink significantly when exposed to transformer oil, mild acids, or alkaline cleaning solutions.
The third benefit is dimensional stability across temperature and humidity cycles. The thermoset epoxy matrix resists creep and does not melt. A properly post-cured tube maintains roundness and wall thickness within tight tolerances even after repeated thermal shock. This makes it suitable for precision applications such as sensor housings, coil forms, and machined insulators.
Kaxite Sealing further supports these benefits through CNC machining, drilling, slotting, and surface grinding services. Customers can receive finished parts with chamfered edges, radial holes, or custom cut lengths ready for assembly. This reduces secondary work and ensures that the final dimensions match the design intent without damaging the fiber structure.
Kaxite Sealing applies a documented quality management system to every Epoxy Resin Fiberglass Tube order. Incoming raw materials are verified against certificates of analysis, and each production batch is tested for resin content, fiber content, density, and dimensional conformity. Electrical grade tubes receive additional dielectric strength testing on samples from the same cure lot. Mechanical grade tubes are tested for flexural strength and modulus to confirm that the laminate meets the specified minimum values.
For demanding applications, Kaxite Sealing can provide third-party test reports, material safety data sheets, and RoHS or REACH declarations. Finished tubes are packed with protective end caps and cushioned packaging to prevent transit damage. Custom labeling, barcoding, and batch traceability are available for customers that manage large inventories or require full production lot documentation.
Q: What standard sizes are available for epoxy resin fiberglass tubes?
A: Kaxite Sealing stocks standard inner diameters from 2 mm to 500 mm, outer diameters from 4 mm to 520 mm, and wall thicknesses from 0.5 mm to 50 mm. Standard tube lengths range from 100 mm to 3000 mm, but custom lengths and oversized diameters can be produced on request. If your design requires a non-standard combination, the tube can be machined from a larger blank or produced as a custom filament-wound part with a specific mandrel size.
Q: What is the maximum continuous operating temperature for this tube?
A: General-purpose epoxy resin fiberglass tubes from Kaxite Sealing are rated for continuous operation at 155°C, corresponding to thermal Class F. High-temperature grades using an epoxy-novolac resin system can operate continuously at 180°C, corresponding to Class H. Short-term excursions above these temperatures are possible, but prolonged exposure above the rated class can reduce mechanical strength and lead to gradual resin degradation.
Q: Can epoxy resin fiberglass tubes be machined or drilled after purchase?
A: Yes, the material machines well with carbide or diamond-coated tools. Common operations include cutting, drilling, turning, milling, slotting, and threading. However, machining generates fine glass dust, so proper ventilation and respiratory protection are required. It is also important to avoid overheating during aggressive cuts because local temperatures above the resin glass transition can cause surface discoloration or micro-cracking. Kaxite Sealing offers CNC machining as an optional service to deliver ready-to-install parts.
Q: Are these tubes suitable for outdoor or high-humidity environments?
A: Yes. Epoxy resin fiberglass tubes absorb very little moisture, typically below 0.2 percent after 24 hours of immersion. This low water absorption preserves dielectric strength and dimensional stability in humid or outdoor conditions. For prolonged UV exposure, a UV-stabilized epoxy or a protective coating is recommended to prevent surface chalking. Kaxite Sealing can apply acrylic or polyurethane coatings to improve weathering resistance where needed.
Q: What dielectric strength can I expect from an epoxy resin fiberglass tube?
A: The radial dielectric strength of a standard Kaxite Sealing tube typically ranges from 12 kV/mm to 20 kV/mm, depending on wall thickness and resin formulation. Axial dielectric strength is slightly lower, usually between 8 kV/mm and 15 kV/mm, because fiber orientation and end effects can influence breakdown behavior. For high-voltage applications, the tube should be tested under actual operating conditions with appropriate safety margins.
Q: How do I choose the correct wall thickness for my application?
A: Wall thickness should be selected based on three main factors: required electrical insulation level, mechanical load, and machinability. For electrical standoff use, divide the working voltage by a safe design dielectric strength, typically 2 to 4 kV/mm, to determine minimum wall thickness. For mechanical loading, calculate the bending or compressive stress and compare it to the material’s flexural or compressive strength with a suitable safety factor. A thicker wall increases rigidity and insulation but adds weight and cost. Kaxite Sealing technical staff can help review your load cases and recommend an efficient wall thickness.
Q: Does Kaxite Sealing offer custom cut lengths, colors, and special grades?
A: Yes. Kaxite Sealing can supply tubes cut to any specified length, with chamfered or square ends, and in standard colors such as natural green, amber, or black. Custom colors are available for volume orders. Special grades include flame-retardant UL 94 V-0 epoxy, high-temperature epoxy-novolac, and high-strength S-glass fiber reinforcement. Tubes can also be supplied with inner surface grinding, outer surface polishing, or specific resin content to match electrical, mechanical, or cosmetic requirements.
Q: What is the difference between filament-wound and pultruded epoxy resin fiberglass tubes?
A: Filament-wound tubes are built by winding resin-impregnated glass fibers around a rotating mandrel at controlled angles. This process yields excellent hoop strength and is well suited for round tubes that must resist internal pressure or external radial loads. Pultruded tubes are formed by pulling continuous glass fibers through a resin bath and a heated die, creating a highly aligned axial fiber orientation with strong longitudinal properties. Pultruded products usually have a smoother outer surface and are more economical for long, straight runs, while filament-wound products allow more flexibility in diameter, wall thickness, and fiber angle. Kaxite Sealing selects the best method based on the performance requirements and production volume of each order.
