GB/T 4668-1995 Determination of density of woven fabrics

This standard specifies three methods for determining the density of woven fabrics. One of them is selected according to the characteristics of the fabric. However, in case of dispute, method A is recommended. This standard is applicable to the determination of the density of various types of woven fabrics. Method A: Fabric decomposition method. Applicable to all woven fabrics, especially complex fabrics. Method B: Fabric analysis microscope method. Applicable to fabrics with more than 50 yarns per centimeter. Method C: Mobile fabric density microscope method. Applicable to all woven fabrics. Note: Three methods for measuring the density of woven fabrics using parallel line grating density microscope, oblique line grating density microscope and photoelectric scanning density meter are listed in Appendix A (reference) for reference. These methods have low measurement accuracy and limitations, but can be quickly and roughly estimated. GB/T 4668-1995 Determination of the density of woven fabrics GB/T4668-1995 Standard download decompression password: www.bzxz.net

1Cs59.080.30
National Standard of the People's Republic of China
GB/T4668-1995
Determination of density of woven fabrics
Textiles-Woven fabrics---Determination of number of threads per unit length
Issued on December 8, 1995
Implemented on May 1, 1996
Issued by the State Bureau of Technical Supervision
National Standard of the People's Republic of China
Determination of density of woven fabrics
TextilesWoven fabrics-Determination of mumber of threads per unit length
This standard adopts the international standard ISO7211/2-1984 Textiles-Determination of the number of yarns in woven fabrics.
1 Subject content and scope of application
GB/T4668—1995
Replaces GB4668-84
GB8678—88
One unit length
Structural analysis method
This standard specifies three methods for determining the density of woven fabrics. One of them is selected according to the characteristics of the fabric. However, in case of dispute, method A is recommended.
This standard is applicable to the determination of the density of various woven fabrics. Method A: Fabric decomposition method. Applicable to all woven fabrics, especially complex fabrics. Method B Fabric analysis microscope method. Applicable to fabrics with more than 50 yarns per centimeter Method C: Mobile fabric density microscope method. Applicable to all woven fabrics. Note: Three methods for measuring the density of woven fabrics using parallel line grating tension mirror, oblique line grating density mirror and photoelectric scanning density meter are listed in Appendix A (reference) for reference. These methods have low measurement accuracy and limitations, but can be used to quickly and roughly estimate 2 Reference standards
GB6529 Standard atmosphere for conditioning and testing of textiles 3 Definitions
3.1 Density: The number of warp yarns and weft yarns contained per unit length of woven fabrics without wrinkles and tension, generally expressed as yarns/10cm.
Warp density: The number of warp yarns contained in the unit length of the fabric in the weft direction 3.2
3.3 Weft density: The number of weft yarns contained in the unit length of the fabric in the warp direction. 4 Principle
Choose any of the following three methods based on the characteristics of the fabric. 4.1 Method A: Decompose a fabric sample of specified size, count the number of yarns, and convert them to the number of yarns in a length of 10cm. 4.2 Method B: Determine the number of yarns seen in the window of the fabric analysis mirror and convert them to the number of yarns contained in a length of 10cm. 4.3 Method C: Use a mobile fabric density microscope to measure the number of yarns in a certain length of the fabric in the warp or weft direction, and convert it to the number of yarns in a length of 10 cm.
Approved by the State Administration of Technical Supervision on December 8, 1995 and implemented on May 1, 1996
Minimum measurement range
Number of yarns per centimeter
25--40
Minimum measurement distance
GB/T4668-1995
Minimum measurement distance
Number of yarns to be measured
50~125
75~120
5.1 For method A, cut a sample containing at least 100 yarns. Precision percentage (counting within 0.5 yarns)>0.5
0. 7 ~ 0. 4
5.2 For narrow fabrics with a width of only 10cm or less, count all warp yarns including the edge warp yarns, and express the result in terms of the number of warp yarns in the whole width.
5.3 When the fabric is composed of a large area pattern with different yarn spacing density, the measured length should be an integer multiple of the complete organization, or the density of each area should be measured separately.
6 Humidification and test atmosphere
The humidity and test atmosphere shall adopt the standard atmosphere specified in GB6529, and the arbitration test shall adopt the two-piece standard atmosphere. Routine inspection can be carried out in ordinary atmosphere.
7 Sample
The sample should be flat and wrinkle-free, and without obvious weft bias. Except for the method, no special sample preparation is required, but the measurement should be carried out in no less than five different positions in both the warp and weft directions, and the selection of the position should be as representative as possible. Before the test, expose the fabric or sample to the test atmosphere for at least 16 hours. 8 Method A… - Fabric decomposition method
a. Steel ruler: 5~15cm in length, with millimeter scale on the ruler surface;
b. Analytical needle:
c. Scissors.
8.2 Procedure
8.2.1 Cut a sample slightly larger than the minimum measuring distance from the appropriate part of the sample after conditioning and setting. 8.2.2 Remove part of the yarn at the edge of the sample and measure with a steel ruler so that the sample reaches the specified minimum measuring distance of 2cm, with a tolerance of 0.5 yarn. 8.2.3 Remove the sample prepared above from the edge one by one. For the convenience of counting, the yarns can be arranged in groups of 10 to obtain the number of yarns in the warp (weft) direction of the fabric within a certain length. 8.2.4 If the warp and weft density are measured simultaneously, a rectangular sample can be cut so that the lengths in the warp and weft directions meet the minimum measurement distance. Disassemble the sample to obtain the number of warp and weft yarns within a certain length. 9 Method B——
Fabric analysis mirror method
9.1 Apparatus
9.1.1 Fabric analysis mirror, the window width should be 2±0.005cm or 3±0.005cm at each location, and the edge thickness of the window should not exceed 2
9.2 Steps
GB/T 46681995
9.2.1 Spread the fabric flat, place the fabric analysis mirror on it, select a yarn and make it parallel to one side of the analysis mirror window, and count the number of yarns in the window one by one.
9.2.2 The number of complete weaves in the window can also be counted, and the number of yarns in a complete weave can be determined by analyzing the fabric structure or decomposing the fabric.
Number of yarns within the measuring distance = number of complete tissues × number of yarns in the complete tissues Number of remaining yarns 9.2.3 Place one side of the analysis mirror window parallel to another system of yarns, and count the number of yarns in the system or the number of complete tissues according to 9.2.1 and 9.2.2.
10 Method C - Mobile fabric density microscope method 10.1 Cover
10.1.1 Mobile fabric density microscope, equipped with a low-power magnifying glass of 5 to 20 times. It can be moved on the base of the scale with the help of a screw to meet the requirements of the minimum measuring distance in Chapter 5. There is a marking line in the magnifying glass. Various types of devices that can see the marking line through the magnifying glass when moving with the magnifying glass can be used.
10.2 Steps
Spread the fabric flat and place the fabric density mirror on it. For which system of yarns is counted, the scale of the density mirror is parallel to the other system of yarns. Turn the screw and count the number of yarns within the specified measuring distance. Note: In the case of weft skewness, when measuring weft density, the principle is the same as when measuring warp density. The scale of the density mirror should be perpendicular to the warp direction. The starting point is between two yarns and the end point is on the last yarn. Those less than 0.25 yarns are not counted. 0.25 to 0.75 yarns are counted as 0.5 yarns, and those above 0.75 yarns are counted as 1 yarn. Under normal circumstances, when the marking line crosses the fabric, each yarn passed can be seen and counted. If this is not possible, refer to 9.2.2 for measurement.
11 Calculation and expression of results
11.1 Convert the number of yarns in a certain length measured to the number of yarns contained in a length of 10 cm. 11.2 Calculate the average of the warp and weft densities, with the result being accurate to 0.1 yarn/10 cm. 11.3 When the fabric is composed of a large area pattern with different yarn spacing densities, measure and record the density value in each area. 12 Test report
The test report should include the following items:
Description that the test was carried out in accordance with this standard:
The standard atmosphere used;
The actual method used (A, B or C);
The measuring distance used;
The type and specification of the specimen;
The values ​​and average values ​​of each measurement;
Measurement period;
Any details that deviate from this test method.
GB/T4668—1995
Appendix A
Methods for measuring density using grating densitometry and photoelectric scanner (reference)
A1 Method D—Parallel line grating densitometry
This method is suitable for fabrics that can produce interference fringes that are easy to be observed. A1.1 Principle
When a parallel line grating densitometry is placed on the fabric, the number of yarns can be determined by observing the interference fringes produced. A1.2 Apparatus
Parallel line grating densitometry.Divided into several grades according to different specifications A1.3 Determination method
Select an appropriate grating density mirror and place it on the fabric, with its lines parallel to the yarn of the system being tested. If the grating is selected appropriately, many stripes parallel to the grating lines can be seen, and the number of yarn roots can be counted according to the following rules: A1.3.1 When the grating and the fabric being tested are rotated at a small angle, if horizontal stripes (vertical grating lines) appear, the density of the fabric being tested is equal to the number of the grating
A1.3.2 When the grating is slightly rotated, if the moire is in the same direction as the grating rotation, the density of the fabric being tested is equal to the number of the grating minus the killing effect number,
A1.3.3 When the grating is slightly rotated, if the moire is in the opposite direction of the grating rotation, the density of the fabric being tested is equal to the grating number
A1.4 The calculation and expression of the results and the test report shall be in accordance with the contents of Chapters 11 and 12 of this standard. A2 Method E - Oblique grating density microscope method
This method is only applicable to fabrics that can produce easily visible interference fringes. A2.1 Principle
When the oblique grating density microscope is placed on the fabric, the number of yarns is determined by observing the interference pattern produced. A2.2 Device
The oblique grating density microscope is divided into several grades according to different specifications. A2.3 Determination method
Put the fabric flat and select a suitable grating density microscope to place it on it. Make the long side of the grating parallel to the yarn to be measured. At this time, a nearly symmetrical curved pattern will appear. The scale reading indicated by the short arm at their intersection is the number of yarns per centimeter of the fabric. A2.4 Calculation and expression of results and test report shall be in accordance with the contents of Chapters 11 and 12 of this standard. Photoelectric scanning density Instrument method
A3 Method F—
This method is applicable to the density determination of various types of plain and twill fabrics. A3.1 Principle
The incident light is directed to the fabric sample through a condenser. The reflected light of the warp or weft yarn in the fabric forms a unidirectional grating stripe image through the optical system. The image is converted into an electrical pulse signal by photoelectric scanning. After amplification and shaping, the digital tube is driven by the counting system to directly display the number of warp (weft) yarns of the fabric within 5 degrees.
A3.2 Installation
Photoelectric scanning fabric density instrument, the minimum measuring distance is 5cmA3.3 Determination method
GB/T4668—1995
A3.3.1 Turn on the power and turn on the power switch of the host. At this time, the digital tube and The light source is on. A3.3.2 Place white paper under the instrument and adjust the output voltage to about 4.5V. A3.3.3 Select the measurement gear
Select the first gear for measuring light-colored fabrics. Select the second gear for measuring dark-colored fabrics. 43.3.4 When measuring plain fabrics, the red dot mark on the bias wheel is in the center of the notch. This position is parallel to the warp or weft of the fabric, and the image is clear in this state.
When measuring twill fabrics, rotate the red dot mark on the bias handwheel to a position parallel to the fabric structure constant. A3.3.5 During the test, the fabric must be laid flat and wrinkle-free. The instrument is placed on the fabric to be tested, the instrument is reset, and the scanning button is released. The scanning probe moves quickly parallel to the warp or weft of the fabric, and the number of yarns within the 5c length measurement distance is automatically displayed and counted. If the fabric to be tested If it is twill, multiply the displayed number by the corresponding constant to get the number of warp and weft yarns within 5cm. Table A1 Constants of several common weave fabrics
Weave weave
Number of fabric tapes
Warp weight Flat
2/1 Twill
2/2 Twill
A3.4 The calculation and expression of results and the test report shall be in accordance with the contents of Chapter 11 and Chapter 12 of this standard. Additional notes:
This standard is proposed by the Science and Technology Development Department of the China National Textile and Apparel Council. This standard is under the jurisdiction of the Standardization Institute of the China National Textile and Apparel Council. This standard was drafted by the Standardization Institute of the China National Textile and Apparel Council and the Shanghai Textile Standard and Metrology Institute. The main drafters of this standard are Zheng Yuying and He Jieren. This standard was formulated in 1988 and revised in 1995. 3/1 twill
People's Republic of China
National standard
Determination of density of woven fabrics
GB/T 4668-1993
Published by China Standards Publishing House
No. 16, Sanlihebei Street, Fuxingmenwai, Beijing
Postal code: 100045
Tel: 8522112
Printed by Huangdao Printing Factory of China Standards Publishing House
Distributed by Beijing Publishing House of Xinhua Bookstore Sold by Xinhua Bookstores in various places Proofreading and proofreading No ketone printing
Format 880×12301/16
First edition in August 1996
Printing sheets 17
Number of words 10,000 words
First printing in August 199%
Print run 1-2 50
Book number: 1550661-12549
Price: 5.0 yuan
Title 289·042
1661894 The calculation and expression of results and the test report shall comply with the contents of Chapter 11 and Chapter 12 of this standard. Additional remarks:
This standard was proposed by the Science and Technology Development Department of the China National Textile and Apparel Council. This standard is under the jurisdiction of the Standardization Research Institute of the China National Textile and Apparel Council. This standard was drafted by the Standardization Research Institute of the China National Textile and Apparel Council and the Shanghai Textile Standard and Metrology Research Institute. The main drafters of this standard are Zheng Yuying and He Jieren. This standard was formulated in 1988 and revised in 1995. 3/1 twill
People's Republic of China
National standard
Determination of density of woven fabrics
GB/T 4668-1993
Published by China Standards Publishing House
No. 16, Sanlihebei Street, Fuxingmenwai, Beijing
Postal code: 100045
Tel: 8522112
Printed by Huangdao Printing Factory of China Standards Publishing House
Distributed by Beijing Publishing House of Xinhua Bookstore Sold by Xinhua Bookstores in various places Proofreading and proofreading No ketone printing
Format 880×12301/16
First edition in August 1996
Printing sheets 17bZxz.net
Number of words 10,000 words
First printing in August 199%
Print run 1-2 50
Book number: 1550661-12549
Price: 5.0 yuan
Title 289·042
1661894 The calculation and expression of results and the test report shall comply with the contents of Chapter 11 and Chapter 12 of this standard. Additional remarks:
This standard was proposed by the Science and Technology Development Department of the China National Textile and Apparel Council. This standard is under the jurisdiction of the Standardization Research Institute of the China National Textile and Apparel Council. This standard was drafted by the Standardization Research Institute of the China National Textile and Apparel Council and the Shanghai Textile Standard and Metrology Research Institute. The main drafters of this standard are Zheng Yuying and He Jieren. This standard was formulated in 1988 and revised in 1995. 3/1 twill
People's Republic of China
National standard
Determination of density of woven fabrics
GB/T 4668-1993
Published by China Standards Publishing House
No. 16, Sanlihebei Street, Fuxingmenwai, Beijing
Postal code: 100045
Tel: 8522112
Printed by Huangdao Printing Factory of China Standards Publishing House
Distributed by Beijing Publishing House of Xinhua Bookstore Sold by Xinhua Bookstores in various places Proofreading and proofreading No ketone printing
Format 880×12301/16
First edition in August 1996
Printing sheets 17
Number of words 10,000 words
First printing in August 199%
Print run 1-2 50
Book number: 1550661-12549
Price: 5.0 yuan
Title 289·042
166189
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