GB/T 41567-2022 English PDF (GBT41567-2022)

This document describes the slot method for testing fabric stiffness. This document applies to all types of textile fabrics and their products.

GB/T 41567-2022
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 59.080.30
CCS W 04
Textiles - Determination of stiffness of fabrics - Slot method
ISSUED ON: JULY 11, 2022
IMPLEMENTED ON: FEBRUARY 1, 2023
Issued by: State Administration for Market Regulation;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 4
4 Principles ... 4
5 Instruments ... 4
6 Sample preparation ... 6
7 Standard atmosphere for humidity control and testing ... 6
8 Test steps ... 7
9 Calculation of results ... 8
10 Test report... 8
Appendix A (Normative) Schematic diagram of marking and test positions for samples ... 9
Textiles - Determination of thermal blocking property
1 Scope
This document describes the slot method for testing fabric stiffness.
This document applies to all types of textile fabrics and their products. 2 Normative references
The following documents contain the provisions which, through normative reference in this document, constitute the essential provisions of this document. For the dated referenced documents, only the versions with the indicated dates are applicable to this document; for the undated referenced documents, only the latest version (including all the amendments) is applicable to this document.
GB/T 6529 Textiles - Standard atmospheres for conditioning and testing
GB/T 8170 Rules of rounding off for numerical values & expression and judgment of limiting values
3 Terms and definitions
The following terms and definitions apply to this document.
3.1 stiffness
The property of a fabric to resist bending deflection.
4 Principles
Place the sample on the specimen stage, use a plate-shaped measuring head to press the sample into the slot to a certain depth, and then make it return to the initial position; take the maximum force value required in this process to characterize the stiffness of the sample.
5 Instruments
5.1 Instrument structure
5.2.1 Width and length of the slot
The width of the slot shall include three grades of 5.0 mm, 10.0 mm, and 20.0 mm, and the tolerance of the width shall not exceed ±0.05 mm. The length of the slot shall be greater than the length of the plate-shaped measuring head.
5.2.2 Dimensions of the plate-shaped measuring head
The length shall be not less than 120.0 mm, the thickness shall be (2.00±0.05) mm, and the arc radius of the measuring port shall be (1.00±0.02) mm.
5.2.3 Average travel speed and total stroke of the plate-shaped measuring head The average travel speed of the plate-shaped test head shall be (1.20±0.30) mm/s, and the total one-way stroke shall be not less than 12.0 mm.
5.2.4 Indentation depth of the sample
The indentation depth of the sample shall be (8.0±0.5) mm.
5.2.5 Centering of the plate-shaped measuring head
After the plate-shaped measuring head enters the slot, the distance from both sides of the slot shall be equal, and the deviation shall not be greater than 0.05 mm. 5.2.6 Indication error of the instrument
The indication error of the instrument shall be ±1.0%.
5.2.7 Indication repeatability of the instrument
The indication repeatability of the instrument shall be not more than 1.0%. 6 Sample preparation
From the laboratory sample, take 10 representative samples with dimensions of (100±2) mm × (100±2) mm; 5 samples are parallel to the warp (vertical) direction, and the other 5 samples are parallel to the weft (horizontal) direction; ensure that each sample is not in the same warp (vertical) and weft (horizontal) positions. Mark the warp (vertical) direction, weft (horizontal) direction, front side, and reverse side of the sample. 7 Standard atmosphere for humidity control and testing
The samples shall be conditioned and tested under the standard atmosphere specified in GB/T 6529.
8 Test steps
8.1 Set the width of the slot. With the help of distance bolts, set the width of the slot according to the thickness and hardness of the sample, and select the width (5.0 mm, 10.0 mm, or 20.0 mm) of the slot as required. For most fabrics, the slot width of 10.0 mm should be used for testing. If the slot width of 10.0 mm cannot meet the test requirements, the slot width of 5.0 mm and 20.0 mm can be selected.
Note: The situations that the test requirements cannot be met include that the sample is too thick and the slot is too narrow, so the sample cannot be pushed into the slot; or, the sample is too thin and the slot is too wide, so the sample is easy to slip off.
8.2 Place the sample face up on the specimen stage, make the warp (vertical) direction perpendicular to the slot and cover the slot. Make 1/3 of the sample in front of the slot and 2/3 behind the slot (according to the test position 1 in Figure A.1 of Appendix A). Reset the indicating value of the stiffness testing instrument (5.1) to zero. Start the instrument to test, use the measuring head to push the sample into the slot to complete a test, and then make it return to the initial position. Record the maximum reading of the value of the warp (vertical) direction test in which the front side of the sample faces up; the reading is the stiffness value of the warp (vertical) direction with the front side. 8.3 Remove the sample from the slot, turn it 180° along the upper edge, and make the reverse side of the sample face up; adjust the position of the sample, and make 1/3 of the sample in front of the slot and 2/3 behind the slot (according to the test position 2 in Figure A.1). Reset the indicating value of the testing instrument to zero. Start the instrument to test, and record the maximum reading of the value of the warp (vertical) direction test in which the front side of the sample faces down; the reading is the stiffness value of the warp (vertical) direction with the reverse side. 8.4 Remove the sample from the slot, turn it 180° along the upper edge, and make the front side of the sample face up; rotate 90° clockwise, adjust the position of the sample, and make 1/3 of the sample in front of the slot and 2/3 behind the slot (according to the test position 3 in Figure A.1). Reset the indicating value of the testing instrument to zero. Start the instrument to test, and record the maximum reading of the value of the weft (horizontal) direction test in which the front side of the sample faces up; the reading is the stiffness value of the weft (horizontal) direction with the front side. 8.5 Remove the sample from the slot, turn it 180° along the upper edge, and make the reverse side of the sample face up; adjust the position of the sample, and make 1/3 of the sample in front of the slot and 2/3 behind the slot (according to the test position 4 in Figure A.1). Reset the indicating value of the testing instrument to zero. Start the instrument to test, and record the maximum reading of the value of the weft (horizontal) direction test in which the front side of the sample faces down; the reading is the stiffness value of the weft (horizontal) direction with the reverse side.