The difference between an air permeability tester and a breathability tester
Air permeability tester
One of the most important things to test about a material’s physical properties is how well it lets gas through. Permeability testing is the process of checking how certain gases pass through materials that have certain gas barriers. Most of these materials are high molecular polymers or multilayer composites made of high polymers. They are widely used to package products in food, medicine, the chemical industry, electronics, the military industry, and other fields.
Goods that are sensitive to oxygen and water vapor can be packed in materials that let very little air or gas through. It is not only the key direction for the growth of the plastic packaging industry but also the foundation for the creation of new types of packaging, such as packaging that is inflatable, vacuum-sealed, and sterile.
The differential pressure method and the isobaric method are the two main ways to test how permeable a material is. Most of the time, people use the differential pressure method. There are two parts to the differential pressure method: the vacuum differential pressure method and the positive differential pressure method. According to the standard for detection, a very high-resolution vacuum gauge or gauge pressure sensor must be used, and small changes in pressure during the detection process must be recorded.
So, the air permeability tester is a professional testing tool that is used to check how well these barrier materials let gas through. Most of the time, this kind of barrier material is tested with an air permeability tester. Most of the materials are either high molecular polymers or high molecular polymer-based multilayer composites.
Air permeability tester
For materials with high permeability, like plastic foam, leather, textiles, cardboard, paper, porous ceramics, etc., it is necessary to measure the permeability of these materials in some specific fields. For example, the right choice of cigarette paper permeability can have a direct effect on how cigarettes look, how they taste, and what is in the smoke. One of the things that affects how comfortable clothes are is how well they keep air out. A professional permeability tester is needed to do a “permeability test” on this kind of material to see how well it lets gas through.
There are two ways to test the permeability of this kind of material: with a constant flow pressure difference and with a constant pressure difference. Most of the time, the constant flow pressure difference method is used to test polyurethane foam plastics and soft or rigid porous elastic materials made of bovine. Most of the time, the constant pressure differential flow method is used to measure textiles, non-woven fabrics, leather, geotextiles, etc.
For the air permeability test of paper, leather, and other materials, the time it takes for a certain amount of air to pass through the sample at a certain pressure difference needs to be measured. This can be thought of as the flow being measured by a constant pressure difference and then being calculated by the measured flow.
A permeability tester is a professional test tool that is mostly used to find materials that let a lot of gas through. A “permeability test” is a way to find out how well a material lets gas pass through it. The permeability tester works well with things that let air through, like foamed plastics, leather, textiles, paper, cardboard, porous ceramics, and so on. For some fields, it is important to know how much gas can pass through these materials, and the permeability test is a very important way to do this.
For example, how cigarettes look, how they smell, and how much smoke they hold depend on how well the cigarette paper lets smoke through. The main thing that controls how comfortable clothes are to wear is how well they let air through.
So, the air permeability tester, which is also called the fabric air permeability tester, is a tool for testing how well leather, cloth, fabric, paper, paperboard, and other sheet objects let air pass through them.
1) The two test items are not the same. The air permeability test is mostly used to find films, while the air permeability test is mostly used to find porous materials, non-woven fabrics, etc.
2) Permeability tests can find out if oxygen, helium, carbon dioxide, air, and other gases can pass through a material. Permeability tests, on the other hand, mostly find out if air can pass through a material.
3) The length of the test varies a lot. The air permeability test time is long and the air permeability test time is much shorter, mostly because the air permeability of the two test materials is very different.
4) Since the permeability test is mostly used to find materials with high permeability, the equipment doesn’t need a sensitive vacuum gauge or pressure sensor, and the vacuum pumping capacity needs to be low. However, the pressure sensor needs to have a wide range to meet the needs of materials with different permeability.
5) The pressure sensor and vacuum pump are important parts of the air permeability test equipment, but the accuracy and range of the flowmeter are also very important.
6) The units of test data are very different for different types of materials because the test standards and methods are different. For example, air permeability (mm/s) is the final test result for textiles, while air permeability (ml/cm2-h) is the final test result for leather. With the right software, the same transmittance tester can do all of the above conversions.
At the moment, there is a lot of variation in how gas permeability testing equipment is being made. For example, there are many types of breathability testers for textiles and paper on the market, but polyurethane foam and porous elastic materials don’t have a lot of detection equipment.
How to test the permeability of paper
The constant flow pressure difference method and the constant pressure difference method are two ways to test something.
After the sample is clamped, adjust the air flow so that the air going through the sample in a vertical direction stays the same. Then, test the difference in pressure on both sides of the sample under these conditions, and then figure out the resistance to air flow and other parameters.
Constant pressure differential flow method: Once the sample is in place, the pressure is changed so that the difference in pressure on both sides of the sample stays the same. The sample’s air permeability is found by measuring how much air moves through a certain area at a certain time.
Application of air permeability and permeability testers
Air permeability test
There are a lot of different kinds of face masks. Masks can be divided by what they are made of: non-woven masks, cotton masks, pulp masks, biological fiber masks, silk masks, etc. The new takes the place of the old. Mask makers are always thinking about how permeable the mask is, because a good permeable mask lets the skin breathe and keeps the metabolism running normally.
But the mask doesn’t let much air through, especially if it’s been on the skin for a long time. Not only does it make the user feel dull and heavy, but it is also an unpleasant experience. It could even stop the skin’s normal metabolism and cause allergies, acne, and other problems on the user’s skin, which would have a big effect on how well the product works.
The mask’s air permeability is how hard it is for air to move through the mask from one side to the other. The mask is good at letting air through, which means that gas can easily pass through from both sides. The mask lets a fair amount of air through, and the pressure difference between the sides is not too great. So, you can find out how permeable a mask is by measuring the flow of gas through a certain area of the mask or the difference in pressure on the sides of the mask.
Diaper permeability test
Diapers are one-time-use items for babies and young kids. They are slowly replacing traditional diapers because they are easier to use, can be taken with you, and are cleaner. Diapers usually have three main parts: the coating on the outside, the absorbent core layer, and the bottom cloth. The coating on the top of the bread is close to the bodies of babies and small children. Its main jobs are to help urine soak in quickly, stop urine from getting back into the diaper, and keep the surface of the diaper dry.
In the market right now, non-woven fabric is mostly used as a surface coating. The absorbent core layer is one of the most important parts of a diaper. Its main jobs are to catch and quickly absorb urine, spread urine through the whole core layer using capillaries, and finally absorb and store urine. The main ingredients that make up the absorption core layer are pure wood pulp and super absorbent resin. The outer layer of a diaper is the bottom cloth, which mostly keeps the diaper from leaking. Most of the time, PE film or non-woven fabric made of polyethylene is used.
Diapers mostly let air through because of how they are coated on the outside and how they are made on the inside. If the diapers don’t let enough air through, even after the urine is absorbed, heat and moisture will still build up in the diapers, which will irritate the skin very much. At the same time, it is easy for bacteria, red buttocks, eczema, and other problems to grow in these places.
So, good air permeability is one of the basic requirements for diapers, and it is also an important product performance that diaper makers try to achieve. The air permeability tester has the advantages of a simple test process, test results, and high test efficiency when testing the air permeability of diaper samples. It is a piece of testing equipment that is used to check how well textiles, leather, sponges, and other things let air through.
Paper permeability test
The ability of paper to let air through is closely linked to how tight it is. The fewer holes there are in the paper, the tighter it is. In general, the less well paper lets air through, the When glue is put on paper, it makes it much harder for air to pass through.
Medical dialysis paper is cheaper and easier to use than fabrics that are not made of fibers. PE, PP, and other membrane materials can be used to heat seal them or glue them together. In the medical packaging business, it is often used as a way to sterilize the packaging for medical devices.
At the moment, the ETO (ethylene oxide) method and the high-temperature damp heat steam method are the most common ways to sterilize packaging materials in China. So, medical dialysis paper has to have a certain amount of air permeability and small pores so that bacteria and dust can’t get through but ethylene oxide gas or steam can.
There are many things that affect how well paper lets air through, such as the raw materials, the way the paper is made (such as pressing pressure, drying method, calendaring, etc.), and the way the paper is made. At the same time, the sterilization packaging of medical devices needs to be able to seal completely, protect the contents of the package, keep the contents in place, resist being stabbed, and not get damaged by friction. So, the strength and resistance to breaking of medical dialysis paper
How well paper lets air through has a big effect on how it is used. Some papers and paperboards have to let a lot of air through. For example, the air permeability of paper bag paper must be more than 200 ml/min so that air can easily escape during automatic bagging of cement without spraying back at the mouth of the bag and making dust fly.
Printing paper also needs to have a certain number of holes in it so that it can absorb ink during the printing process. By measuring how much air the paper lets through, you can find out how much air it lets through. Under a certain area and vacuum, the paper’s ability to let air through is measured in ml/min or S/100 ml.
Papers like cement bag paper, paper bag paper, cable paper, copy paper, and industrial filter paper can all be tested with the paper permeability tester.
How to use an air permeability tester for an experiment?
1) Cut 5 samples with a diameter of 20 cm from the surface of the sample.
2) Take one of the samples and clamp it to the test chamber of the equipment.
3) Adjust the pressure control valve to adjust the pressure difference on both sides of the sample. When the set pressure difference is reached, the test stops, and the equipment records and displays the airflow through the sample under the set pressure difference.
4) Repeat the operations of 2) and 3) to test the air permeability of the remaining 4 samples.