Air permeability is the ability of a fabric to allow moisture vapor to pass through. It plays a vital role in clothing and medical textiles.     Air permeability has nothing to do with air exchange. Rather, it is the ability of a fabric to allow moisture vapor to pass through.     Fabrics can achieve this in many different ways, and air exchange is only one possible way.     Compared with breathability, moisture vapor permeability (MVP) and moisture vapor transmission (MVT) may be better and more technical.     Neither ASTM nor the Textile Association defines air permeability, but both MVP and MVT are defined in the test standard.     According to EN 31092: 1993, water vapor permeability is "the characteristic of textile materials or composite materials, which depends on the water vapor resistance and temperature. Water vapor permeability is expressed in pascals per square meter hour.     According to BS 3546:2001, water vapor permeability is "the ability of a coated fabric to transmit water vapor to a specified level while maintaining high permeability".     According to the definition in the standard EN 31092: 1993, the water vapor permeability index is the ratio of thermal resistance to water vapor resistance.     According to BS 3546:2001, "The difference in water vapor pressure between the two surfaces of a material divided by the evaporation heat flux per unit area in the gradient direction" can be regarded as the "opposite" of water vapor resistance and air permeability.     Water vapor will transfer from the high concentration (pressure) area to the low concentration area by diffusion. Unobstructed, this can happen easily.     However, barriers like fabric will slow down the rate at which this happens. It is important to remember that steam pressure drives water vapor: humidity is not the key factor.     Modern waterproof and breathable fabrics can be divided into three different types, each of which works slightly differently. The breathability and waterproofness of the fabric is not entirely accurate, because the holes in the fabric structure are large enough to allow     water vapor to pass through, but too small to allow water droplets to pass through     The fabric air permeability tester is a professional and commonly used instrument for measuring air permeability.     GBPI can provide fabric air permeability tester and Water vapor transmission rate tester and oxygen transmission tester for a long time. Welcome to inquire.

    The oxygen transmission rate test system is suitable for plastic films, high barrier materials, solar backplanes, sheets, composite materials, aluminized films, co-extruded films, aluminum foil, sheet materials and plastics, rubber, paper, and glass Oxygen transmission rate test for packaging containers such as bottles, bags, cans, boxes, etc., made of metal and other materials.     There are two methods for testing oxygen transmission rate: equal pressure method and differential pressure method:     In the isobaric test environment, the pre-processed sample is clamped between the test chambers, oxygen or air flows on one side of the film, high-purity nitrogen flows on the other side of the film, and oxygen molecules diffuse through the film to In the high-purity nitrogen on the other side, the flowing nitrogen is carried to the sensor. By analyzing the oxygen concentration measured by the sensor, parameters such as oxygen transmission rate can be calculated; for packaging containers, the high-purity nitrogen is The inside of the container flows, and the air or high purity oxygen surrounds the outside of the container.     In the differential pressure method environment, oxygen will move from the high pressure side to the low pressure side The oxygen flow rate is large, the transmission rate will increase     The GBPI oxygen transmission rate test can be easily installed by the user; the practical built-in operating program reduces operating errors, the prompt screen can remind the operator to input accurately, the safety protection system avoids the sensor damage and does not need to adjust the flow rate. GBPI is a manufacturer specializing in the production of oxygen permeability meters, gas permeability meters, moisture permeability meters, oxygen transmission rate testers, and other packaging testing instruments.

    The water vapor transmission permeability of a polyethylene bottle refers to the amount of water vapor transmission through a sample within a certain time under a specified temperature, relative humidity, and a certain water vapor pressure difference.     The amount of water vapor transmission  permeability of a solid bottle at a specified temperature, relative humidity, and a certain water vapor pressure difference.     The water vapor transmission permeability  of the liquid bottle is within the specified temperature and relative humidity environment, and the percentage of water loss in the bottle within a certain period of time.     The water vapor permeability measurement methods are: cup method, electrolytic analysis method,Weight method.     The water vapor transmission rate of polyethylene bottles actually includes the two meanings of water vapor transmission  permeability and water vapor transmission coefficient. The meanings expressed by these two meanings also have certain differences, but they can be used to represent water vapor transmission. Ability to grow materials.     The water vapor transmission permeability indicates the weight of water vapor transmission material under a certain time, under certain temperature and humidity conditions. The water vapor transmission rate is the standard value of the water vapor transmission rate converted by the coefficient, and corresponds to the standard unit,     Used for comparison between different test results.     GBPI's star products are: precise laboratory instruments such as water vapor transmission rate tester, oxygen transmission rate tester, gas transmission rate tester, etc. More industry knowledge of transmission rate test instruments will be updated next time, more For more details, please pay attention to our official website.

vapor permeation refers to the phenomenon that water vapor molecules penetrate and diffuse from the side with high partial pressure to the side with low partial pressure when the partial pressure difference of water vapor exists on both sides of the envelope. The amount of steam penetration is directly proportional to the breathability of the material of the envelope structure and the difference in partial pressure of steam on both sides, and inversely proportional to the thickness of the structure. vapor permeation is a new gas-phase dehydration membrane separation process. It is based on steam feed. Under the impetus of the partial pressure difference of each component in the mixture, the use of each component in the membrane to dissolve and expand the difference in performance to achieve The mixture separates. The application of vapor permeation technology in the separation of near boiling point, constant boiling point and isomers has its unique advantages, and it can also be coupled with biological and chemical reactions. The continuous removal of the reaction products has significantly improved the conversion rate of the reaction. Its technical and economic advantages are obvious, and it has broad application prospects in industrial fields such as petrochemicals, medicine, food, and environmental protection. GBPI's main products are: water vapor transmission rate tester, oxygen transmission rate tester, gas transmission rate tester, mask detection tester, nozzle bag sealing machine, electronic tension machine etc. If you need to know more product details, please click below to consult.

    BFE is an indicator tested by Labs in Salt Lake City, Utah, USA. It refers to the filtration efficiency of bacteria in maks testing. The test used Staphylococcus aureus with an average particle size of 3 μm as the object. Most BFE masks use polypropylene (PP) as the main protective material. Mainly improve the durability of the mask. Please note that it is "durability", not "protection". Since the standard only uses 3µm test samples, we cannot know in detail the ability of BFE masks to protect against viruses below 3µm. As I said above, the diameter of the droplet is 1~5μm. This is not to say that BFE masks are not anti-virus, but the standards used in the tests are relatively loose. We cannot quantify the protective effect of this mask on coronavirus, but the BFE test does protect the bacteria. It is standard, so if you only prevent the spread of coronavirus, there is no problem. If you are not sure, please use other standard masks.     N95 is not a specific product name. As long as it meets the N95 standard, and products that pass the NIOSH review can be called N95 masks. This standard is one of 9 types of particle protective masks certified by the National Institute of Occupational Safety and Health (NIOSH). "N" indicates oil-resistant particulate matter, and "95" indicates the filtration efficiency of particles with an aerodynamic diameter ≥ 0.3 μm. Above 95%, it can effectively filter out non-oily particles, such as dust, acid mist, paint mist, microorganisms, etc. As can be seen from the above, the N95 mask can prevent coronavirus.     Generally speaking, the higher the protective performance of the mask, the greater the impact on the comfort performance. When people wear masks to inhale, the masks have a certain resistance to the flow of air. When the inhalation resistance is too large, some people will feel dizzy, chest tightness and other uncomfortable conditions. Therefore, the basic principle of wearing a mask is to wear it scientifically and reasonably, to use it in a standardized manner, and to effectively protect it.