Air permeability is an important factor affecting the performance of leather applications, and the principle of differential pressure is usually used to test the air permeability of leather. In this paper, we use the TQD-G1 air permeability tester to test the air permeability of leather for garment use and introduce the test principle, equipment parameters and scope of application, and the test process to provide a reference for the test of air permeability of leather materials. Keywords: leather, air permeability, air permeability, air permeability tester, differential pressure method.
Leather is widely used in the production of clothing, shoes, footbeds, cushions, sofas and other products, how its breathability is an important factor affecting the comfort of the use of products, especially leather used for leather clothing, shoes and other products in contact with the human body, if its breathability is poor, failure to evacuate the sweat and heat discharged by the human body in a timely manner, the wearing process is easy to produce hot and humid feeling, resulting in a poor wearing experience for consumers.
The interstices of the collagen fibres in leather are the apertures through which gases and energy are exchanged inside and outside the leather. The processes of acid and alkaline treatment, stretching, rubbing, fattening, tanning and finishing of leather products can affect the uniformity, size and number of collagen fibre interstices. Therefore, strengthening the test of air permeability can provide a data base for the adjustment and improvement of the production process of leather products, which is conducive to improving the quality of leather products.
2. Test samples
In this paper, a certain kind of leather for clothing is used as a test sample to test its air permeability.
The standard for testing the breathability of leather is QB/T 2799-2006 "Leather Breathability Determination Method", which uses the pressure difference to test the breathability of leather to assess the breathability of the leather. This paper is based on the principles of this standard for testing.
The QS-G1 air permeability tester was used as the test equipment, which was developed and manufactured by QINSUN Instruments.
The QINSUN air permeability tester can be used to test the air permeability of materials using two different principles: the "constant differential pressure and flow method" and the "constant differential pressure and flow method". In the former, the pressure is adjusted so that a constant pressure difference is formed between the two sides of the specimen, and then the airflow through the specimen is measured for a given area perpendicular to the specimen over a certain period of time to calculate parameters such as the air permeability of the specimen; in the latter, the airflow is adjusted so that the airflow through the specimen perpendicular to the specimen is stabilized at a constant flow rate, and then the pressure difference between the two sides of the specimen is measured under these conditions to calculate parameters such as the airflow resistance.