Multi-directional test method for fabric stiffness
by:GESTER Instruments
2022-07-30
The ability of a fabric to resist the shape change in its bending direction is called flexural stiffness or stiffness, which is often used to evaluate the softness of the fabric, and also determines the drape and feel of the fabric [1-2]. Therefore, the study of fabric bending stiffness has been widely concerned. Yang Zhenwei et al. [3] used a self-made fabric saddle bending test device to study the mechanical properties of the fabric in the actual bending state. Liu Chengxia et al [4] conducted a new exploration of the water drop method to test the flexibility of fabrics. He Qihui et al [5] proposed a method to indirectly test the bending properties of fabrics by using the actual bending shape of the fabric under the action of its own weight. Li Yanfang et al. [6] adopted a new test method and made a test device to test and study the dynamic bending properties of cotton fabrics. Bilisik [7] analyzed the relationship between the stitching method and the bending properties of woven fabrics. Chen Zhihua et al. [8] studied the effect of blending ratio on the bending properties of cotton, bamboo pulp and cotton yarn interwoven fabrics. Du Zhaoqun et al. [9] proposed a test system that can simultaneously evaluate and characterize the bending properties of yarns and fabrics. To sum up, whether it is a variety of new testing methods proposed by many scholars recently, or the commonly used bevel method, heart-shaped method, and fabric style test method, each time, only a single direction stiffness index can be obtained. Now the national standard It is stipulated that the bending index of the fabric in the warp and weft directions is used to characterize the stiffness of the fabric. However, due to the anisotropy of the fabric, the stiffness in different directions is quite different, so the bending in the warp and weft directions may not be able to fully reflect the whole piece. The stiffness of the fabric. To fully understand the bending properties of fabrics in different directions, multiple measurements are required, which consumes a lot of manpower and material resources. In view of the above situation, this paper proposes a simple method that can simultaneously test the stiffness of fabrics in multiple directions. 1. Experiment 1.1 Selection of samples A total of 15 kinds of cotton, linen and other fabrics with large differences in stiffness were selected, and the specific structural indicators are shown in Table 1. 1.2 Test fabric stiffness in five directions by inclined plane method Although the national standard stipulates that fabric bending and stiffness are only tested in two directions of warp and weft, in order to make the research more in-depth and comprehensive, this paper adds another three direction. Refer to ZBW04003—1987 'Fabric Stiffness Test Method Inclined Cantilever Beam Method', test fabric 0°(Weft), 22.5°, 45°, 67.5°, 90°The bending length and bending stiffness in these five directions (warp direction) are measured by a YG(B)022D automatic fabric stiffness tester. The measured results are shown in Table 2. Table 2 shows that the flexural rigidity of the fabric is different in different directions. For example, if the average flexural rigidity in the warp and weft directions is only taken for the 1 sample, the result is 792.38cN.·cm, and the average bending stiffness in 5 directions is 554.48 cN·cm, there is a big difference between the two. 1.3 Test method for multi-directional stiffness of fabric 1.3.1 Principle The principle of test method for multi-directional stiffness of fabric is to place a heavy object at the center of a circular sample fixed around it and suspended in the middle, and the center of the fabric will be in the center of the weight. Under the action of the material, it sags and produces bending deformation. The deformation amount is the result of the resistance of the fabric to external forces in multiple directions. Therefore, the comprehensive stiffness of the fabric can be characterized according to the degree of deformation of the fabric. Therefore, this method is named the sag method. 1.3.2 Experiment preparation a) Experimental tool: concave test bench (the test bench is made of plexiglass, as shown in Figure 1(a). The upper end surface is square, and the center has a hollow circle with a diameter of 6 cm) ; 5 digital cameras (respectively placed directly above the concave test bench and around the appropriate position); weights of suitable quality. b) Atmospheric environment: standard atmospheric conditions of constant temperature and humidity, and uniform and sufficient light. c) Specimen specifications: Cut the fabrics in Table 1 into circular samples with a diameter of 10 cm, and prepare 3 samples for each fabric. The mass of the weight used in this paper is 3g. Before the formal experiment, in order to determine the diameter of the circular hole in the center of the upper end face of the test bench, the diameter of the circular hole is from 3cm to 8cm, and pre-experiments are done every 1cm. When the diameter is between 3 and 4 cm, for medium-thick fabrics, the depth of depression and the height of the warp are not obvious enough. When the diameter of the round hole is between 7 and 8 cm, for thin and soft fabrics, under the action of the gravity of 3g, it will be excessive. Sag or even slide down, so it is more appropriate to choose a diameter of 5cm and 6cm. Considering the fabric selected in this paper and the diameter of the sample cut, the diameter of the circular hole is finally set at 6 cm. 1.3.3 Test step a) Make warp and weft marks on the diameter direction of the sample to be tested, and place it under standard atmospheric conditions for 24 hours;
Competitiveness policy of GESTER International Co.,Limited is about existing clusters as a platform for upgrading microeconomic fundamentals, where structural policies aim to change the industrial composition of an economy more directly.
To live healthy, you need to eat healthy; to eat healthy, you need to think healthy; to think healthy, you need to read health; to read healthy, you need to follow GESTER Instruments.
textile testing equipment can be applied in different ways as tensile tester manufacturers.
textile testing equipment receives the updates through industry associations, internal legal counsel, regional associations and legal publications.
GESTER International Co.,Limited, a manufacturer of textile testing equipment, might emphasize less hassle or less wasted time rather than emphasizing reliability or quality.
Competitiveness policy of GESTER International Co.,Limited is about existing clusters as a platform for upgrading microeconomic fundamentals, where structural policies aim to change the industrial composition of an economy more directly.
To live healthy, you need to eat healthy; to eat healthy, you need to think healthy; to think healthy, you need to read health; to read healthy, you need to follow GESTER Instruments.
textile testing equipment can be applied in different ways as tensile tester manufacturers.
textile testing equipment receives the updates through industry associations, internal legal counsel, regional associations and legal publications.
GESTER International Co.,Limited, a manufacturer of textile testing equipment, might emphasize less hassle or less wasted time rather than emphasizing reliability or quality.
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