关键词: 棉紧密织物, 孔隙率, 透气性, 纱线直径, 纱线毛羽

Abstract: The cotton tight fabrics are used in outdoor windproof windbreakers, down anti-drill fabrics, high-end shirts, and other fields, and these fabrics will inevitably be affected by airflow in use. 8 pieces of cotton plain tight fabrics and 1 polyester staple fiber fabric were used to study and master the characteristics of the deformation degree and fabric parameters of cotton tight fabric under the impact of airflow. Place each fabric on an LD-1600X3 silent, oil-free air compressor, and set 0.1 MPa air pressure for continuous airflow impact 5 min, 10 min, and 30 min respectively. The air permeability was tested by the fabric breathability meter. The XD-1 microscope was used to observe and compare the image changes of the fabric after the airflow impact. The pictures taken by the microscope were imported into Autocad software to test and analyze the diameter of the warp and weft yarn in the fabric and the pore width between the adjacent warp and weft yarn lines. The center distance and pore area of adjacent warp and weft yarns were tested 10 times for each data and averaged. 
By analyzing the microscope images of each fabric, it can be seen that there are more hairs on the surface of the original cotton fabric, the yarn outline is not clear, and the holes between the yarns are closed by hairs. As 5 minutes, the diameter and shape of the yarns change little, the pores between the yarns become clear, and more through holes are formed, indicating that the effect of airflow in a short time reduces hair in the fabric pores and improves the permeability of the fabric. After 10 minutes of airflow impact, the warp and weft yarns appear straighter, the bending state of warp and weft interweaving is reduced, the pores change from irregular shape to square, and the hair in the pores is reduced. After 30 minutes of air impact, the warp and weft yarn lines become thinner, the hair in the pores between yarns is reduced, and the porosity is further improved. 
The quantitative analysis shows that the diameter of the warp and weft of cotton tight fabric decreases with the increase of air impact time, the distance between adjacent yarns increases, and the porosity of the fabric increases. There is a correlation between the porosity of cotton tight fabric and its air permeability. However, due to the influence of the hair of the fabric and the loose structure of the yarn on the airflow, the correlation between the porosity and the air permeability of the fabric is not high, and the porosity size of the fabric is not the main factor affecting the air permeability of the cotton tight fabric. Under the same conditions, the fabric with a uniform structure has better air permeability and stronger air shock resistance. The tightness and thickness of cotton tight fabric affect its stability after airflow impact, and the tightness and thickness of cotton fabric have little change in air permeability.

Key words: cotton tight fabric, porosity, permeability, yarn diameter, yarn hairiness; , impacts of air flow