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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 17911-2006 Refractory products - Methods of test for ceramic fiber products, with respect to which the following main technical changes have been made:
——the standard name is modified;
——Clause 3 is added; GB/T 18930 is referred to; the definitions of resilience, thermal conductivity, tensile strength and slot content in other clauses are deleted accordingly;
——the requirements for drying test pieces in 6.3.2 are modified;
——the Equation (3) is modified to conform to the international standard;
——the unit of tensile strength is modified to kPa, and the unit of thickness and width of the test piece is modified to mm; Equation (7) is modified accordingly;
——the negative pressure sieve analysis method is added to measure the slot content, and different sieve apertures may be selected according to needs when determining the slot content.
This standard has been redrafted and modified in relation to ISO 10635: 1999 Refractory products - Methods of test for ceramic fiber products.
This standard is changed largely from ISO 10635: 1999 in structure; the comparison table for clause numbers in this standard and those in ISO 10635: 1999 are listed in Annex A.
Technical differences between this standard and ISO 10635: 1999 are marked with perpendicular line (|) in the outside page margin of the provisions concerned. Technical differences between this standard and ISO 10635: 1999 and their reasons are given in Annex B.
Attention is drawn to the possibility that some of the elements of this standard may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This standard was proposed by and is under the jurisdiction of the National Technical Committee on Refractory Material of Standardization Administration of China (SAC/TC 193).
The previous editions of this standard are as follows:
——GB/T 17911.1-1999;
——GB/T 17911.2-1999;
——GB/T 3004-1982, GB/T 17911.3-1999;
——GB/T 3005-1982, GB/T 17911.4-1999;
——GB/T 17911.5-1999;
——GB/T 3006-1982, GB/T 17911.6-1999;
——GB/T 17911.7-2000;
——GB/T 17911.8-2002;
——GB/T 17911-2006.
Methods of test for refractory fiber products
1 Scope
This standard specifies methods for determining the thickness, bulk density, resilience, permanent linear change on heating, thermal conductivity coefficient, tensile strength and shot content of refractory fiber products.
It applies to refractory fiber cotton, blankets, felts, mats, boards, papers and pre-formed products with the exception of products delivered in a wet state.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 6003.1 Test sieves - Technical requirements and testing - Part 1: Test sieves of metal wire cloth (GB/T 6003.1-2012, ISO 3310-1: 2000, MOD)
GB/T 8170 Rules of rounding off for numerical values & expression and judgment of limiting values
GB/T 18930 Terminology for refractories
JJG 139 Tension, compression and inorganic material testing machines
3 Terms and definitions
For the purpose of this document, the terms and definitions specified in GB/T 18930 apply.
4 Preparation of test pieces
The test items of products shall be determined by agreement between the parties. The dimension and number of test pieces shall meet those specified in Table 1.
When the material to be tested is wound, any compressed material at the extreme ends shall be excluded. A strip shall be cut perpendicular to the length across the full material width, of sufficient size for the different tests planned; for unwound materials, sufficient number of test pieces shall be provided. The required number of test pieces of required dimensions shall be cut using a template, a knife, a saw or other method which will not damage the test piece. Avoid excess pressure from damaging the fiber during the preparation of test pieces.
For special-shaped products and products with thickness greater than 50mm and uneven texture (such as with hard shell on the surface), the sampling position for each test item shall be agreed by relevant parties and indicated in the test report.
The test pieces for tensile strength shall be taken side by side and at random along the manufacturing direction (generally the length direction) of the product. The length (230mm) direction of test pieces shall be consistent with the manufacturing direction of the product. By agreement between relevant parties, the length direction of test pieces may be perpendicular to the manufacturing direction of the product, and shall be indicated in the test report.
For test pieces having permanent linear change on heating, the rolling direction of the product shall be marked, and cushion test pieces of the same size and number shall be taken from the same product.
For test pieces for thermal conductivity coefficient, at least 3 layers shall be used when the product thickness is less than 40mm, while two layers be used when the product thickness is 40~50mm and single layer be used when the product thickness is greater than 50mm.
Table 1 List of product types as well as dimensions and number of test pieces applicable to test items
Clause Test item Product type Test piece requirements/mm Number of test pieces
1 Thickness Blanket, felt, mat, board, paper Length ≥100, width ≥100, product thickness 3
2 Bulk density Blanket, felt, mat, board, paper Length ≥100, width ≥100, product thickness 3
3 Resilience Blanket, felt, mat 100×100× product thickness 3
4 Permanent linear change on heating Blanket, felt, mat, board, paper, pre-formed products 100×100× product thickness 3
b Thermal conductivity Blanket, felt, mat, board Length ≥230, width ≥230, thickness: 45~100 1
6 Tensile strength Blanket, felt, paper (230±5)×(75±2)× product thickness 5
7 Shot content Cotton, blanket, felt, mat, paper At least 20g 3
5 Determination of thickness
5.1 Principle
Determination of the thickness of a product subjected to a compressive stress which depends on its nominal bulk density. There are two methods: dial gauge comparator method (see 5.3.1) and needle method (see 5.3.2), of which, the dial gauge comparator method is the arbitration method and is the only method applicable to refractory fiber paper.
5.2 Test pieces
The test pieces shall be prepared in accordance with Clause 4.
5.3 Methods
5.3.1 Dial gauge comparator method
5.3.1.1 Apparatus
Thickness comparator consisting of a reference plate and a dial gauge comparator with a metallic disc, 75±1mm in diameter. The disc shall be capable of applying a 350±7Pa compressive stress to products with a nominal bulk density <96kg/m3 and a 725±15Pa compressive stress to products with a nominal bulk density ≥96kg/m3.
5.3.1.2 Test procedure
Brush the reference plate free of any residual material and check that the disc lies parallel to the reference plate and, when they are in contact completely, the dial gauge reads zero.
Gently raise the disc and slide the test piece on the reference plate; slowly lower the disc, record the dial reading to an accuracy of 0.1mm.
5.3.2 Needle method
5.3.2.1 Apparatus
Needle thickness gauge consisting of a metallic disc with ruler frame and a measuring device with a needle, as shown in Figure 1. The ruler frame is engraved with markings, the metallic disc is 75±1mm in diameter while the needle is 3±0.2mm in diameter. The disc shall be capable of applying a 350±7Pa compressive stress to products with a nominal bulk density <96kg/m3 and a 725±15Pa compressive stress to products with a nominal bulk density ≥96kg/m3.
5.3.2.2 Test procedure
Place the test piece on the flat glass and gently place the disc of the needle thickness gauge on the test piece. Force the needle downward through the test piece, perpendicular to the glass plate. If necessary, to prevent compression of the test piece, first pierce the test piece. When the needle tip touches the glass plate, record the reading to an accuracy of 0.1mm.
5.4 Test report of this item
Report the dimensions of each test piece, the measured individual values and the average value according to the requirements of Clause 12.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Preparation of test pieces
5 Determination of thickness
6 Determination of bulk density
7 Determination of resilience
8 Determination of permanent linear change on heating
9 Determination of thermal conductivity
10 Determination of tensile strength
11 Measurement of shot content
12 Test report
Annex A (Informative) Comparison between this standard and ISO 10635: 1999 in clause number
Annex B (Informative) Technical differences between this standard and ISO 10635:1999 and their reasons
Annex C (Informative) Calculation of the thermal conductivity coefficient as a function of the actual temperature in each point of the test piece
