As the application of refractory ceramic fibers and their products becomes more widespread, the variety of products continues to increase. With the development of new refractory ceramic fibers containing various chemical components, it is no longer appropriate to classify refractory ceramic fibers and their products solely based on chemical composition. This is due to the advancement of science and technology, resulting in the emergence of high-performance products. Therefore, a new classification system for refractory ceramic fibers has been established under EN 1094-3:2003 “Insulating Refractory Products Part 3: Classification of Refractory Ceramic Fibers.”
This standard follows the classification principles of EN 1094-3:2003, and according to GB/T 17911-2006, it stipulates that the permanent linear shrinkage of refractory ceramic fibers and their products after heating should not exceed 2%. Additionally, it specifies that the permanent linear shrinkage should not exceed 4% when subjected to temperature fluctuations of ±50°C for 10 cycles. Due to the inclusion of new chemical components, the traditional classification of refractory ceramic fibers into aluminosilicate fibers, high-alumina fibers, and other types based on chemical composition and production processes is no longer applicable. The differences in chemical composition and production processes lead to differences in the permanent linear shrinkage of refractory ceramic fibers after heating. Therefore, this classification system is based on temperature gradients.
This standard establishes a classification system that divides refractory ceramic fibers into grades and labels. It is the first of its kind in the Chinese refractory ceramic fiber industry. To make it easier for users to select the appropriate grade temperature for their intended use and to ensure the safety of the materials, this standard provides recommended usage temperatures to prevent potential damage due to misinterpretation of the grade temperature.
This standard specifies the terms and definitions, classification and labeling, technical requirements, test methods, quality evaluation procedures, packaging, labeling, transportation, storage, and quality certificates for refractory ceramic fibers and their products.
This standard applies to refractory ceramic fibers, including their products such as blankets, felts, boards, papers, textiles, ropes, and other related items.
The following documents are essential for the application of this standard. For dated references, only the edition cited applies. For undated references, the latest edition (including amendments) applies.
– GB/T 2828.1-2003/ISO 2859-1:1999 Sampling Procedures for Inspection by Attributes – Part 1: Sampling Schemes Indexed by Acceptance Quality Limit (AQL) for Lot-by-Lot Inspection
– GB/T 3007-2006 Refractory Materials – Determination of Bulk Density
– GB/T 3923.1-1997 Textiles – Tensile Properties of Fabrics – Part 1: Determination of Breaking Force and Elongation at Break (ISO 13934-1:1999)
– GB/T 4743-1995 Textiles – Determination of Mass per Unit Length and Mass per Unit Area of Fabrics (ISO 3801:1977)
– GB/T 5069 Test Methods for Determining the Chemical Composition of Refractory Materials
– GB/T 6900-2006 Chemical Analysis Methods for Alumina-Silica Refractory Materials
– GB/T 7689.2-2001 Reinforced Materials – Test Methods for Woven Fabrics – Part 2: Determination of Width and Length (ISO 4602:1997)
– GB/T 7689.3-2001 Reinforced Materials – Test Methods for Woven Fabrics – Part 3: Determination of Thickness and Density (ISO 5025:1997)
– GB/T 7690.2-2001 Reinforced Materials – Test Methods for Yarns – Part 2: Determination of Breaking Force and Elongation (ISO 1889:1997)
– GB/T 9914.3-2001 Reinforced Materials – Test Methods for Composites – Part 3: Determination of Shear Strength (ISO 3347:2000)
– GB/T 17911-2006 Refractory Ceramic Fibers and Products – Test Methods (ISO 10635:1999, MOD)
– GB/T 18930-2002 Refractory Materials – Terminology (ISO 836:2001, MOD)
– FZ 01018-1992 Textiles – Terminology
The terms and definitions established in GB/T 18930-2002 and FZ 01018-1992 apply to this standard.
According to GB/T 17911-2006, the classification temperature for refractory ceramic fiber products is determined by the permanent linear change upon heating. The classification temperatures are as follows:
– Refractory ceramic fibers and rigid products: The permanent linear shrinkage upon heating should not exceed 2%.
– Refractory ceramic fibers, blankets, felts, and paper products: The permanent linear shrinkage upon heating should not exceed 4%.
Refractory ceramic fiber products are classified based on the temperature range from 850°C to 1750°C, with the permanent linear shrinkage meeting the requirements of 4.1. The classification intervals are approximately 50°C, as shown in Table 1.
Table 1 Classification of Refractory Ceramic Fiber Products
The main labels for refractory ceramic fiber products are composed of the English name abbreviation of the product and the grade temperature, followed by auxiliary characteristics if necessary, as shown in Table 2.
Table 2 Labeling of Refractory Ceramic Fiber Products
The types and technical indicators for refractory ceramic fiber bulk should meet the requirements specified in Table 3.
The technical indicators for refractory ceramic fiber felt should meet the requirements specified in Table 4.
Table 3 Types and Technical Indicators for Refractory Ceramic Fiber Bulk
Table 4 Technical Indicators for Refractory Ceramic Fiber Felt
Refractory ceramic fiber boards and their components are classified into three categories based on bulk density. The standard bulk density range and tensile strength should meet the requirements specified in Table 5.
The labeling and other technical indicators for refractory ceramic fiber boards and their components should meet the requirements specified in Table 6. Special requirements should be negotiated by both parties.
The dimensional tolerances for refractory ceramic fiber boards should meet the requirements specified in Table 7. The appearance should be consistent, without delamination, cracks, or core layer defects.
The bulk density range for refractory ceramic fiber boards and rigid products should meet the requirements specified in Table 8. Special requirements should be negotiated by both parties.
The dimensional tolerances for refractory ceramic fiber boards and rigid products should meet the requirements specified in Table 9. Rigid products should have consistent dimensions without delamination, cracks, or core layer defects, and the length of the cracks should not exceed 60 mm.
Refractory ceramic fiber papers are classified by raw material fiber grades and different types. The flatness, roll consistency, and thickness tolerances should meet the requirements specified in Table 10. Other technical indicators should meet the requirements specified in Table 11.
Table 5 Classification, Tensile Strength, and Bulk Density of Refractory Ceramic Fiber Boards and Their Components
Table 6 Other Physical and Chemical Indicators for Refractory Ceramic Fiber Boards and Their Components
Table 7 Dimensional Tolerances for Refractory Ceramic Fiber Boards
Table 8 Bulk Density Range for Refractory Ceramic Fiber Boards and Rigid Products
In units of kilogram per cubic meter (kg/m³)
Table 9 Dimensional Tolerances for Refractory Ceramic Fiber Boards
Table 10 Labeling and Thickness Indicators for Refractory Ceramic Fiber Paper
Table 11 Technical Indicators of Other Ceramic Fiber Papers
Ceramic fiber yarn is classified by raw materials into glass fiber (G) reinforced and high-temperature stainless steel (S) reinforced. The product specifications are based on the yarn count (tex) and reinforcement type (G or S), as shown in Table 13.
Ceramic fiber yarn technical indicators should meet the requirements of Table 12. The appearance should be consistent with the specified requirements.
Table 12 Appearance Requirements for Ceramic Fiber Yarn
Table 13 Specifications and Technical Indicators for Ceramic Fiber Yarn
Ceramic fiber cloth is classified by the type of yarn used, either glass fiber (G) reinforced or high-temperature stainless steel (S) reinforced. The product specifications are based on the fabric density and reinforcement type (G or S), as shown in Table 15.
Ceramic fiber cloth technical indicators should meet the requirements of Table 15. The appearance should be consistent with the specified requirements.
Table 14 Appearance Requirements for Ceramic Fiber Cloth
Table 15 Specifications and Technical Indicators for Ceramic Fiber Cloth
Ceramic fiber tape is classified by the type of yarn used, either glass fiber (G) reinforced or high-temperature stainless steel (S) reinforced. The product specifications are based on the tape width and reinforcement type (G or S),and width. See Table 17.
The appearance of fire-resistant ceramic fiber belts should comply with the specifications in Table 16.
The technical indicators of fire-resistant ceramic fiber belts should comply with the specifications in Table 17, and also be suitable for the corresponding usage temperature.
Table 16 Appearance Requirements for Fire-Resistant Ceramic Fiber Belts
Table 17 Specifications and Technical Indicators for Fire-Resistant Ceramic Fiber Belts
Fire-resistant ceramic fiber braided ropes are divided into glass fiber (G) reinforced and high-temperature stainless steel (S) reinforced types based on the fiber yarn used. Product specifications are marked by diameter or perimeter and reinforcement type (G or S). See Table 19.
The appearance of fire-resistant ceramic fiber braided ropes should be smooth, clean, and consistent with the specifications in Table 18.
The technical indicators of fire-resistant ceramic fiber braided ropes should comply with the specifications in Table 19, and also be suitable for the corresponding usage temperature.
Table 18 Appearance Requirements for Fire-Resistant Ceramic Fiber Braided Ropes
Fire-resistant ceramic fiber braided ropes are classified based on the fiber yarn used into glass fiber (G) reinforced and high-temperature stainless steel (S) reinforced types. Product specifications are marked by diameter or perimeter and reinforcement type (G or S). See Table 21.
The appearance of fire-resistant ceramic fiber braided ropes should be uniform, smooth, and clean, with tight and even braiding, and should comply with the specifications in Table 20.
The technical indicators of fire-resistant ceramic fiber braided ropes should comply with the specifications in Table 21, and also be suitable for the corresponding usage temperature.
Table 19 Specifications and Technical Indicators for Fire-Resistant Ceramic Fiber Braided Ropes
Table 20 Appearance Requirements for Fire-Resistant Ceramic Fiber Braided Rope
Table 21 Specifications and Technical Indicators for Fire-Resistant Ceramic Fiber Braided Rope
The water content and firing shrinkage of the yarn, fabric, belt, rope, and felt, excluding the high-temperature stainless steel or glass fiber reinforcement, should be measured.
Products of the same type, specification, and quality level produced under stable production conditions should be grouped into batches according to Table 22.
Table 22 Maximum Batch Size
The acceptance evaluation can adopt the supplier’s declaration and can be conducted in the form recognized or certified by a third party.
Table 23 Appearance Inspection Sampling Plan and Acceptance Criteria
Table 24 Product Inspection Items
Packaging materials should have moisture-proof, rainproof, and sealing capabilities. Special packaging should be agreed upon by both parties.
External packaging should include:
Transportation should be covered to prevent moisture, rain, and snow. Handling should avoid collision and damage.
Products should be stored in a dry, moisture-proof warehouse.
A quality certificate should be issued by the supplier’s quality supervision department upon shipment.
Preparation Method for Testing Permanent Linear Shrinkage of Fire-Resistant Ceramic Fiber
Measurement Method for Unit Length Mass of Fire-Resistant Ceramic Fiber Yarn, Fabric, Belt, Rope, and Felt
Sample length should be 2 m, with 2 samples taken each time.
The mass per unit length is calculated according to formula (B.1):
P.=m/2
Where:
P,–the mass per unit length of the sample, in grams per meter (g/m);
M–the mass of the sample, in grams (g);
2–the length of the sample, in meters (m).
Report the arithmetic mean of the two measurement results to an accuracy of 0.01g/m.
