Non-woven fabric is a packaging material with a very wide range of applications, and good air permeability is one of its excellent properties. This article takes a medical non-woven fabric as an example, uses the GBPI N900 air permeability tester to test its air permeability, and introduces the testing process, the principle of the equipment used, parameters and the scope of application, so as to detect non-woven fabrics for enterprises The air permeability of cloth materials provides a reference.

    Non-woven fabrics are named after they are not woven into fabrics. They are a new generation of environmentally friendly materials. They are breathable, flexible, non-toxic, tasteless, and inexpensive. They are used in many fields, such as agricultural films, shoemaking, leather making, and beds. Pads, chemicals, automobiles, building materials, etc., and in the medical and health industry can be used to produce surgical gowns, protective clothing, plasters, disinfection packaging, masks, sanitary napkins and other products. Among the many applications of non-woven fabrics, good air permeability is one of the important reasons for its widespread use. Taking related products in the medical industry as an example, if non-woven fabrics have poor air permeability, plasters made from them The user will experience allergic symptoms due to the inability to meet the normal breathing of the skin; poor air permeability of band-aids and other medical tapes will cause microorganisms near the wound to multiply, leading to wound infection; and poor air permeability of protective clothing will greatly affect it. Comfort of wearing. Similar to medical products, the poor air permeability of other non-woven fabrics will also bring many disadvantages to their use. Therefore, strengthening the testing of the air permeability of non-woven fabrics is one of the important measures to ensure that the related products they produce meet the requirements for use.

Test method and instrument

The air permeability (air permeability) involved in this test is to characterize the ability of air to pass through the sample. The test process can be based on the method standard GB/T 5453-1997 "Determination of Air Permeability of Textile Fabrics", which is applicable to a variety of textile fabrics. Including technical fabrics, non-woven fabrics and other breathable textile products.

Executive standard: GB/T 5453, ISO 9237, ASTM D 737, BS 5636

The test was conducted on the air permeability of the sample using the N900 air permeability tester independently developed and produced by GBPI.

N900 air permeability tester is suitable for testing the air permeability and air resistance of automotive interior materials, such as polyurethane foam, PVC, leather, textiles, and non-woven fabrics. Through the measurement, the requirements of controlling the physical properties of the material are met to meet the needs of the actual application of the product. It can also be used to test the air permeability of separation membranes, sponges, carpets, non-woven fabrics, paper and leather.

There are two main methods for testing air permeability, namely constant differential pressure measurement flow and constant flow measurement differential pressure. Among them, the constant pressure difference measurement method is to maintain a constant pressure difference on both sides of the sample, and calculate the air permeability of the sample by measuring the air flow through a given area of the sample within a certain period of time; the constant flow rate measuring the pressure difference The rule is to keep the air flow rate vertically passing through the sample constant, and obtain the air permeability of the sample by measuring the pressure difference between the two sides of the sample under this condition. The detection process in this paper adopts the constant differential pressure measurement flow method.

Test sample and test process

Test sample: a certain brand of non-woven fabric.

Experimental procedure:

(1) From the surface of the non-woven fabric sample, randomly cut 10 samples with a diameter of 50 mm (the sample diameter can be selected according to the specific situation).

(2) Take one piece of the sample and clamp it in the air permeability tester to make the sample flat and not deformed, and the two sides of the sample have good sealing performance.

(3) Set the pressure difference value on both sides of the sample according to the air permeability of the sample or relevant standards. The pressure difference value set in this test is 100 Pa. Adjust the pressure control valve to adjust the pressure difference between both sides of the sample. When the pressure difference reaches the set value, the test stops. The device automatically displays the gas flow through the sample at this time.

(4) Repeat loading and adjusting the pressure control valve until the test of 10 samples is completed.

Test results and analysis

The air permeability test result of the non-woven fabric sample tested this time is 2092.970 L/h (the result is the average of the test results of 10 samples). The difference in the sample diameter and the set pressure difference will affect the test results. Therefore, if you want to compare the air permeability of different non-woven fabric samples, you should keep the sample diameter and the pressure difference on both sides consistent.

Air permeability is one of the excellent properties of non-woven materials, and it is an important factor affecting the safety, hygiene, comfort and other performance of non-woven products. This paper uses the N900 air permeability tester to test the air permeability of a certain brand of non-woven fabric. The test process is simple, the equipment is easy to operate, the test results are repeatable and accurate, and the test accuracy is high, which can truly reflect the test. The air permeability of the sample.

    Guangzhou Biaoji Packaging Equipment Co.,ltd is a professional manufacturer focused on developing and producing mask testing instruments and focused on developing packaging material test instruments  ，Contact us directly for detailed information.