Highland manufactures ceramic fiber rope in three standard configurations — twisted, round braided and ceramic fiber square braided rope — to meet different sealing requirements. reinforced with fiberglass filaments, stainless steel wire or high-temperature alloy wire. Diameter range: 3–50mm custom. Max service temperature 1260°C (2300°F). Tensile strength ≥5MPa, breaking strength ≥6MPa, linear shrinkage ≤1.5% at 1000°C/5h. Used as furnace door seals, kiln gaskets, expansion joint packing, pipe insulation wrapping, and ceramic fiber rope gasket applications.
ISO 9001:2015 certified. Standard sizes in stock; custom diameters and lengths available. Lead time 30–40 working days. Submit application description for configuration recommendation.
Ceramic fiber rope is a flexible, high-temperature sealing and insulating product braided or twisted from high-purity alumina-silicate fibers, optionally reinforced with stainless steel wire or glass filament. Available in three constructions — twisted, round braided, and square braided — and diameters from 3 mm to 50 mm, ceramic fiber rope is rated for continuous service temperatures up to 1260°C (standard grade) or 1430°C (zirconia-enhanced grade). It is used as a high-temperature gasket, expansion joint packing, furnace door seal, and pipe wrapping in steel, petrochemical, power generation, and ceramic kiln applications.
Ceramic fiber rope — also referred to as ceramic rope or refractory rope in industry specifications — is manufactured from the same alumina-silicate fiber used in ceramic fiber blankets and boards, but processed into a flexible linear form. Unlike blankets (large-area coverage, no structural strength) or boards (rigid panels, cannot bend), rope is designed to fill gaps, seal joints, and wrap around curved or irregular surfaces while maintaining high-temperature resistance. Fine-diameter variants (3–6 mm) are commonly called ceramic fiber cord and serve as gasket material for precision sealing applications.
| Classification Temperature | 1260°C (STD) / 1430°C (Zirconia-Enhanced) |
| Max Continuous Service | 1000°C (STD) / 1300°C (Zirconia) |
| Bulk Density | 500–600 kg/m³ (varies by braiding density) |
| Diameter Range | 3 mm – 50 mm (round) / 6×6 mm – 50×50 mm (square) |
| Reinforcement Options | E-glass filament / SS304 / SS316 / Inconel 600 wire |
| Linear Shrinkage | ≤3% @1000°C × 5h (STD) / ≤2% @1200°C × 5h (Zirconia) |
Conforms to irregular surfaces and maintains compressive resilience through thermal cycling — ideal for furnace door and flange sealing.
Twisted (round), round braided (round), and square braided — select the construction that matches your groove geometry and pressure requirements.
SS304, SS316, or Inconel 600 wire reinforcement provides tensile strength for high-stress installation and vibration environments.
Diameters from 3 mm to 50 mm, continuous lengths up to 50 m per coil. Custom square cross-sections available for rectangular grooves.
Manufactured from high-purity alumina-silicate fibers that meet international biosolubility standards. No ceramic dust emission at operating temperature.
Ceramic fiber rope is a flexible, linear refractory product manufactured from high-purity alumina-silicate (Al₂O₃–SiO₂) fiber. The same raw fiber that is needled into blankets or vacuum-formed into boards is instead spun, twisted, or braided into a rope structure — preserving the fiber's high-temperature resistance while adding the flexibility needed for dynamic seals, curved surfaces, and gap-filling applications that rigid boards cannot serve.
The manufacturing process follows four stages. First, high-purity alumina-silicate fiber is produced by melt-spinning a blend of calcined alumina and silica sand at ~2000°C, producing fibers with diameters of 2–5 μm. Second, the fiber is carded and spun into yarn, optionally blended with reinforcing wire (stainless steel or Inconel) or glass filament during the spinning stage. Third, the yarn is formed into the final rope structure — twisted (multiple yarns plied together by rotation), round braided (yarns woven around a core in a circular pattern), or square braided (yarns woven in an over-under grid pattern). Fourth, each coil is inspected for density uniformity, diameter tolerance, and reinforcement continuity before packaging.
Understanding the distinction between ceramic fiber rope, blankets, and boards is essential for correct product selection:
In industry terminology, "ceramic fiber cord" typically refers to fine-diameter rope (3–6 mm) used for precision gasketing, while "refractory rope" is the broader term used in procurement specifications across steel, petrochemical, and power plant maintenance. All three terms — ceramic fiber rope, ceramic rope, and refractory rope — generally refer to the same product family, with the specific construction (twisted/braided) and reinforcement type being the distinguishing variables.
Selecting the correct rope construction is the single most important specification decision. The three available constructions differ in density, sealing performance, compressive resilience, and abrasion resistance — each suited to a different category of application. The table below compares all three types across six engineering dimensions.
| Dimension | Twisted Rope | Round Braided Rope | Square Braided Rope |
|---|---|---|---|
| Structure | Multiple yarns plied together by rotational twisting | Yarns woven around a core in a circular braiding pattern | Yarns woven in an over-under grid, producing a square cross-section |
| Bulk Density (kg/m³) | 350–450 (lowest) | 500–550 (medium) | 550–650 (highest) |
| Sealing Performance | Fair — fibers can separate under pressure, creating leak paths | Good — interlocked weave structure prevents fiber separation | Excellent — densest construction, minimal gas permeability |
| Compressive Resilience | Low — deforms permanently under sustained compression | Medium — maintains moderate resilience through thermal cycling | High — recovers well after compression, maintains seal over repeated cycling |
| Abrasion Resistance | Low — surface fibers can pull free under friction | Medium — braided skin protects core fibers | High — tightly interlocked surface resists mechanical wear |
| Typical Application | Low-pressure pipe wrapping, thermal insulation of cables and wires, temporary seals | Furnace door seals, expansion joint packing, pipe flange gaskets | High-pressure flange gaskets, blast furnace door seals, structural groove packing |
| Cost Relative | Lowest — simplest manufacturing process | Medium — braiding adds production cost | Highest — densest weave, most fiber per meter |
The selection logic follows directly from the table. For static, low-pressure applications where the rope is primarily serving as thermal insulation rather than a pressurized seal — pipe wrapping, cable protection, gap filling — twisted rope is sufficient and cost-effective. For dynamic sealing applications where the rope must maintain compression through thermal cycling — furnace doors, expansion joints — round braided rope is the standard choice. For high-pressure gasketing where gas permeability must be minimized — flange seals, blast furnace doors — square braided rope is the only construction that delivers adequate sealing performance.
Highland manufactures ceramic fiber rope in two temperature grades. The standard 1260°C grade is suitable for most furnace and kiln sealing applications; the 1430°C zirconia-enhanced grade is specified for applications above 1200°C continuous or where alkali vapor corrosion is a concern. Complete technical data for both grades is presented below.
| Technical Property | Standard Grade (1260°C) | Zirconia-Enhanced Grade (1430°C) |
|---|---|---|
| Classification Temperature | 1260°C | 1430°C |
| Maximum Continuous Service Temperature | 1000°C | 1300°C |
| Peak Temperature (short-term, <2h) | 1100°C | 1350°C |
| Linear Shrinkage | ≤3% @ 1000°C × 5h | ≤2% @ 1200°C × 5h |
| Thermal Conductivity @ 400°C | 0.09 W/(m·K) | 0.10 W/(m·K) |
| Thermal Conductivity @ 800°C | 0.14 W/(m·K) | 0.15 W/(m·K) |
| Thermal Conductivity @ 1000°C | 0.19 W/(m·K) | 0.20 W/(m·K) |
| Al₂O₃ Content (%) | 44–46 | 38–40 |
| SiO₂ Content (%) | 50–52 | 44–46 |
| ZrO₂ Content (%) | — | 15–17 |
| Fe₂O₃ (%) | ≤0.8 | ≤0.2 |
| Al₂O₃ + SiO₂ (%) | ≥96 | ≥99 |
| Standard Diameters (round) | 3, 6, 8, 10, 13, 16, 19, 22, 25, 30, 35, 40, 50 mm | |
| Standard Cross-Sections (square) | 6×6, 10×10, 13×13, 16×16, 20×20, 25×25, 40×40 mm | |
| Coil Length | 10 m / 20 m / 50 m per coil (custom lengths available) | |
| Reinforcement Options | None / E-glass filament / SS304 wire / SS316 wire / Inconel 600 wire | |
| Packaging | Woven bag with inner PE film, fumigated pallet for export | |
All values are measured per ASTM C201 (thermal conductivity) and ASTM C356 (linear shrinkage). Mill test certificates are provided with each shipment, and third-party inspection by SGS, BV, or TUV is available on request.
Pure ceramic fiber rope has low tensile strength — the alumina-silicate fibers themselves are brittle glass-ceramic strands held together by mechanical interlocking during the spinning and braiding process. For applications involving mechanical stress, vibration, or installation tension, the rope must be reinforced with a metallic or vitreous filament embedded within the yarn during spinning. The choice of reinforcement material is driven by three factors: service temperature, mechanical stress level, and budget.
| Property | E-Glass Filament | SS304 / SS316 Wire | Inconel 600 / 625 Wire |
|---|---|---|---|
| Max Service Temperature | 650°C (softens above this) | 1000°C continuous (SS304) / 1050°C (SS316) | 1100°C+ continuous / 1200°C short-term |
| Tensile Strength of Reinforcement | ~3500 MPa (high, but drops sharply above 500°C) | 520–720 MPa | 655–1035 MPa (retained at high temperature) |
| Corrosion Resistance | Good — inert glass, but vulnerable to alkali attack | Excellent — resists most furnace atmospheres; SS316 adds pitting resistance | Superior — resists chloride stress corrosion cracking, sulfur, and carburization |
| Electrical Insulation | Yes — preferred for electrical heating element applications | No — conductive, avoid near electrical elements | No — conductive |
| Relative Cost (per kg of rope) | Lowest (adds ~$0.5–1.0/kg) | Medium (adds ~$3–6/kg) | Highest (adds ~$20–40/kg) |
| Best Application | Electrical furnace seals, cable and wire thermal protection, low-temperature pipe insulation | Furnace door seals, kiln car seals, boiler expansion joints — the default choice for most kiln applications | Petrochemical cracking furnaces, steel ladle seals, vibration-heavy environments above 1050°C |
Choose E-glass reinforcement when the service temperature is below 650°C and electrical insulation is needed (heating element lead-outs, resistor furnace seals). E-glass is the most economical reinforcement and is standard on twisted rope for low-temperature pipe wrapping.
Choose SS304 or SS316 wire reinforcement for the majority of furnace and kiln sealing applications operating at 650–1000°C. SS304 is the default for clean furnace atmospheres; SS316 is specified when chlorine or sulfur compounds are present in the flue gas. This is the most common reinforcement specification for ceramic fiber rope used in ceramic kiln door seals and boiler expansion joints.
Choose Inconel 600 or 625 wire reinforcement when service temperature exceeds 1000°C, when the rope is subject to mechanical vibration (forge furnaces, steel ladle covers), or when the atmosphere contains chlorides, sulfur, or carburizing gases that would attack stainless steel. Inconel's retained strength at extreme temperature makes it the mandatory choice for petrochemical cracking furnace seals and blast furnace door applications.
Ceramic fiber rope serves as a critical sealing and insulation component across four major heavy industries. The application scenarios below illustrate the recommended rope type and reinforcement for each industry, based on Highland's field experience supplying refractory rope to furnace operators worldwide.
| Industry | Application | Recommended Rope Type | Recommended Reinforcement | Why |
|---|---|---|---|---|
| Steel & Iron | Blast furnace door seal, hot blast stove expansion joint | Square braided — highest density and pressure resistance | Inconel 600 — withstands vibration and temperature spikes above 1000°C | High gas pressure + mechanical vibration from charging equipment requires maximum seal integrity and tensile strength |
| Petrochemical | Cracking furnace flange gasket, reformer door seal | Round braided — conforms to flange irregularities | SS316 or Inconel 625 — resists chloride and sulfur attack | Process gas contains H₂S, chlorides, and carburizing compounds that attack standard SS304; temperature cycling from reformer trips demands high compressive resilience |
| Power Generation | Boiler expansion joint, ductwork penetration seal | Twisted — large-diameter, low-cost packing for non-pressurized joints | E-glass — temperature <650°C in most boiler backup zones | Expansion joints accommodate thermal growth without requiring high-pressure sealing; twisted rope provides sufficient fill at lowest cost |
| Ceramic Kiln | Kiln car perimeter seal, kiln door gasket, pipe penetration | Round braided — balances sealing with ease of replacement | SS304 — standard for clean kiln atmospheres at 1000–1260°C | Kiln car seals are replaced periodically during maintenance shutdowns; round braided rope offers the best combination of sealing performance and installation convenience |
The selection logic shown above is the starting point for procurement specification. Actual requirements may vary based on specific furnace design, operating schedule, and local maintenance practices. Highland's technical team can review your application parameters and recommend the optimal rope type, reinforcement, and diameter — contact us with your application details.
Selecting the correct rope diameter is a straightforward engineering calculation, yet it is one of the most common sources of seal failure. Too small, and the rope cannot fill the groove — hot gas bypasses the seal entirely. Too large, and the rope cannot be compressed into the groove — the furnace door cannot close, or the flange bolts cannot be torqued down. The following guidelines ensure correct diameter selection.
For a round rope installed in a round or square groove:
Rope Diameter = Groove Width × 1.1 to 1.2
This means the rope diameter should be 10–20% larger than the groove width. The compression of 10–20% provides the lateral expansion that fills the groove sides and creates the seal. For square braided rope in rectangular grooves, use the groove's smaller dimension (width or depth) as the multiplier base.
The target compression after installation is 10–15% of the rope's uncompressed diameter. Within this range:
For rectangular grooves (common in kiln car perimeter seals), square braided rope with a matching rectangular cross-section provides superior sealing compared to round rope in a rectangular groove. Highland can manufacture custom square cross-sections (e.g., 20×30 mm, 15×25 mm) to match your specific groove dimensions. Minimum order quantity for custom cross-sections: 500 m.
The price of ceramic fiber rope is driven by three variables: rope construction (twisted is cheapest, square braided is most expensive), reinforcement material (E-glass adds the least cost, Inconel adds the most), and temperature grade (zirconia-enhanced fiber commands a 40–60% premium over standard). The table below provides reference price ranges for the most common specifications, quoted FOB Qingdao port, China.
| Rope Type | Reinforcement | Grade | Reference Price (USD/kg) | Key Cost Driver |
|---|---|---|---|---|
| Twisted | None or E-glass | 1260°C STD | $1.50 – $4.00 | Simplest manufacturing process; no braiding equipment required |
| Round Braided | SS304 wire | 1260°C STD | $3.00 – $6.00 | Braiding adds production cost; SS304 wire at ~$3–6/kg is the primary material cost driver |
| Round Braided | SS316 wire | 1430°C Zirconia | $6.00 – $10.00 | Zirconia fiber is 40–60% more expensive; SS316 wire at ~$5–8/kg |
| Square Braided | Inconel 600 wire | 1430°C Zirconia | $10.00 – $18.00 | Densest weave (most fiber per meter); Inconel 600 wire at ~$20–40/kg is the dominant cost |
Pricing notes: All prices are FOB Qingdao port, excluding international freight, insurance, and destination import duties. Volume discounts apply: 5% discount on orders ≥500 kg, 10% discount on orders ≥1,000 kg. Coil packaging, fumigated pallets, and export documentation are included at no additional charge. For a precise quotation on your exact specification (type, diameter, reinforcement, grade, and quantity), contact Highland's sales team — quotations are issued within 12 hours.
Twisted rope is made by plying multiple yarns together through rotation — it is the simplest and cheapest construction, with low density and fair sealing performance. Braided rope (round or square) is made by weaving yarns in an interlocked pattern, producing a denser, more resilient, and higher-sealing product. Twisted rope is suitable for low-pressure insulation and wrapping; braided rope is required for dynamic seals and pressurized gasketing applications.
Yes. Ceramic rope gasket is a common application of ceramic fiber rope in furnace door, flange, and inspection port seals. Square braided rope is the preferred gasket construction because its high density and compressive resilience provide the lowest gas permeability. For gasket applications, always select a rope diameter 10–20% larger than the groove width to ensure adequate compression (10–15%) after installation.
Prices range from $1.50/kg for standard twisted rope to $18.00/kg for zirconia-enhanced square braided rope with Inconel reinforcement. The price is calculated based on three variables: construction type (twisted < round braided < square braided), reinforcement material (none < E-glass < SS304 < SS316 < Inconel), and fiber grade (1260°C standard < 1430°C zirconia). Volume discounts apply at 500 kg and 1,000 kg order quantities. Request a quotation with your exact specification for a precise price.
Verify four items: (1) ISO 9001 certification and mill test certificates per batch — a reliable supplier provides full TDS with Al₂O₃/SiO₂ content, shrinkage data, and thermal conductivity; (2) raw material purity (Fe₂O₃ ≤0.8% for standard, ≤0.2% for high-purity); (3) diameter tolerance (±0.5 mm for ≤13 mm, ±1.0 mm for >13 mm); (4) production capacity and export experience (minimum 10,000 kg/month capacity, documented export track record). Highland meets all four criteria — request our TDS and third-party test certificates.
Standard grade (1260°C): continuous service to 1000°C, short-term peak to 1100°C (<2 hours). Zirconia-enhanced grade (1430°C): continuous service to 1300°C, short-term peak to 1350°C (<2 hours). The classification temperature (1260°C / 1430°C) is the temperature at which the fiber has ≤3% linear shrinkage after 5 hours — it is not the continuous operating temperature. Always specify the rope based on your continuous operating temperature, not the peak.
For detailed engineering data on using these products as ceramic rope gaskets in furnace doors and boilers, please refer to our application guide.
Send us your required rope type (twisted / round braided / square braided), diameter, reinforcement material, grade (1260°C / 1430°C), and estimated quantity. Highland's technical sales team issues a factory-direct quotation within 12 hours, including TDS documentation and free samples for evaluation.
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