In recent years, there has been little research on the material transfer performance of leather. Although
some people abroad on the permeability of leather shoes were studied,
but the mechanism of its ventilation is not clearly stated. In this paper, the permeability of the leather is studied, and the permeability of the leather is discussed. Tests
show that: the leather ventilation process is the role of air under
pressure in the leather inside and outside the transfer process,
finishing will greatly reduce the permeability of leather. How to ensure that the good breathability of leather under the premise of finishing, should do further research work.
Determination of air permeability:The method used to measure the permeability of leather in this paper is the air volume of air per unit area per unit time in units of mL s-1 cm-2. We use the air permeability tester to measure. The basic principle of the permeability tester is the water vapor displacement method. In the case of constant pressure, the volume of air passing through the sample is equal to the volume of water flowing out. By measuring the volume of water flowing out for a certain period of time, the air volume passing through the sample can be obtained, and the air permeation rate of the sample can be calculated.
Determination of air permeability:Take a small 6cm × 6cm sample, add the distilled water to the U-tube of the air permeability tester, and adjust the liquid level to the scale zero scale line. Close the drain valve, open the funnel valve and the exhaust valve, add distilled water to the storage tank, and fill the hopper valve and the exhaust valve. Rotate the scale to adjust the knob to align the zero line with both sides. Place the test specimen on the end face of the lower side head, tighten and press the sample knob. Loosen the locking knob to adjust the height of the outlet pipe and place the selected cylinder under the outlet pipe. Open the drain valve, open the needle valve, in time t, the water outflow through the water volume of ΔV. Note the time t, the pressure difference ΔP, and the volume ΔV of the water in the cylinder. Adjust the needle valve to adjust the air pressure. Note the relationship between the different pressure ΔP and the time t, the volume of effluent ΔV. Then, the amount of air (permeation rate) per unit area of leather can be calculated from the unit time through the area of the leather (A = 10.75 cm2, instrument parameter) according to the formula Pr = ΔVA · t (1). To analyze the air pressure at the air permeation rate, we can get their relationship curve.
Determination of air permeability:The method used to measure the permeability of leather in this paper is the air volume of air per unit area per unit time in units of mL s-1 cm-2. We use the air permeability tester to measure. The basic principle of the permeability tester is the water vapor displacement method. In the case of constant pressure, the volume of air passing through the sample is equal to the volume of water flowing out. By measuring the volume of water flowing out for a certain period of time, the air volume passing through the sample can be obtained, and the air permeation rate of the sample can be calculated.
Determination of air permeability:Take a small 6cm × 6cm sample, add the distilled water to the U-tube of the air permeability tester, and adjust the liquid level to the scale zero scale line. Close the drain valve, open the funnel valve and the exhaust valve, add distilled water to the storage tank, and fill the hopper valve and the exhaust valve. Rotate the scale to adjust the knob to align the zero line with both sides. Place the test specimen on the end face of the lower side head, tighten and press the sample knob. Loosen the locking knob to adjust the height of the outlet pipe and place the selected cylinder under the outlet pipe. Open the drain valve, open the needle valve, in time t, the water outflow through the water volume of ΔV. Note the time t, the pressure difference ΔP, and the volume ΔV of the water in the cylinder. Adjust the needle valve to adjust the air pressure. Note the relationship between the different pressure ΔP and the time t, the volume of effluent ΔV. Then, the amount of air (permeation rate) per unit area of leather can be calculated from the unit time through the area of the leather (A = 10.75 cm2, instrument parameter) according to the formula Pr = ΔVA · t (1). To analyze the air pressure at the air permeation rate, we can get their relationship curve.
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