What are the functions of waterproof and breathable functional fabrics? What is waterproof fabric used for?

What are the functions of waterproof and breathable functional fabrics? What is waterproof fabric used for?

What are the functions of waterproof and breathable functional fabrics? What is waterproof fabric used for? What does waterproof and breathable fabric mean?
2. TPU film
TPU is the abbreviation of thermoplastic polyurethane film, which is a non-porous hydrophilic film. Since the film itself has no pores, the waterproof effect is naturally very good, and it also makes the fabric windproof and warm. Moisture permeability is mainly achieved through its hydrophilic properties. It relies on the difference in vapor pressure inside and outside the clothes to transfer steam from places with high pressure to places with low pressure, thereby achieving the function of moisture permeability. I have also been engaged in the production of TPU composite fabrics for a long time, so I will give a brief introduction.
Product Characteristics:
A. Green and environmentally friendly
B. Excellent breathability and moisture permeability
C. Absolutely waterproof, anti-blood stain, and antibacterial
D. Windproof and cold-resistant, velvet-proof and smooth
E. Durability, super water-repellent finish
F. Easy to decontaminate and clean, can be washed normally
Scope of application:
A. Field military uniforms, firefighting, and military special clothing
B. Protective equipment, military tents, sleeping bags and postal bags
C. Clothing for mountaineering, skiing, golf and other sports
D. Materials for shoes and hats, bags, blackout curtains, anti-UV umbrella cloth
E. Rainproof and breathable ponchos and casual windbreakers
F. Medical supplies
Product specifications:
1. Door width: 1500mm
2. Product thickness: 0.012~0.025mm
3. Low-permeability transparent mask, low-permeability fog mask, low-permeability milky white mask
Moisture permeability index: greater than 1000g/m2*24hrs (ASTME96BW2000 version)
Hydrostatic pressure resistance index: greater than 10000mmH2O (AATCC127)
4. Medium-transparent transparent mask, medium-transparent mist mask, medium-transparent milky white mask
Moisture permeability index: greater than 3000g/m2*24hrs (ASTME96BW2000 version)
Hydrostatic pressure resistance index: greater than 10000mmH2O (AATCC127)
5. Highly transparent transparent film, high-permeable mist mask, high-permeable milky white mask
Moisture permeability index: greater than 5000g/m2*24hrs (ASTME96BW2000 version)
Hydrostatic pressure resistance index: greater than 10000mmH2O (AATCC127)
6. Suitable for laminating various fabrics such as knitted, woven, and non-woven fabrics
The most popular TPU composite fabrics on the market now are:
1. Four-sided elastic + TPU + polar fleece, which is what people often call SoftShell. The four-sided elastic is mainly 75D (for women’s clothing) and 100D (for men’s clothing), and the polar fleece is mainly 75D/72F and 100D/144F. It can have many styles such as plain weave, twill weave, plaid, etc. Because it is waterproof, breathable, windproof and warm, its use is no longer limited to ordinary outdoor sportswear. Many large foreign companies use it as work clothes for their employees. 2. Chemical fiber woven fabric + TPU + Tricot (polyester warp knitted mesh fabric). Woven fabrics mainly include pongee, taslan, oxford, peach skin, nylon, etc. Ordinary ones such as 228T Taslon can be used as the main fabric of jackets; nylon camouflage printed fabrics can be used as military clothing; fluorescent fabrics can be used as police uniforms and other work clothes;
Introduction to testing methods for waterproof and breathable fabrics
At fabric exhibitions in Shanghai, we often encounter customers who need composite fabrics with a waterproof and moisture permeability of 10000/10000. I fainted when I heard it. As I said before, American Gore fabrics can achieve this moisture permeability. The general TPU high-permeability film can only achieve a moisture permeability of 5,000 when made into a three-in-one (surface fabric + membrane + lining). Moisture content. If you use British Porelle or Dutch Sypamtex membrane, the moisture permeability will be higher, but it cannot reach 10,000, and these imported membranes are also expensive. So how do you explain that customers require such high indicators? One possibility is that customers don’t understand this industry and see Gore’s clothes marked with 10000/10000, so they want to set such high indicators; another possibility is that they are laymen What people don’t understand and are often exploited by some is the difference in testing methods.
How many testing methods are there now? I hope you don’t have to hold on to the methods I’ve listed!
1. Cup control method
1.1 Water vapor transmission method
1.1.1 Cup correcting method
A, Chinese national standard: GB/T12704-91B
B, American Society for Testing and Materials standard: ASTME96ProduceBandD
C, Japanese Industrial Standard: JISL-1099A2
D, Canadian Standard: (CGSB)-4.2No.49-99
E, British Standard: BS7209-1990
1.1.2 Cup pouring method (also called moisture absorption method)
A. American Society for Testing and Materials standard: ASTME96BW (1995 and 2000 editions)
1.2 Desiccant method
1.2.1 Cup correcting method
A. Chinese national standard: GB/T12704-91A
B, Japanese Industrial Standard: JISL-1099A1
C, American Society for Testing and Materials standards: ASTME-96A, C, E
1.2.2 Cup pouring method
A, Japanese Industrial Standard: JISL-1099B1, B2
B, American Society for Testing and Materials standard: ASTME-96
C, Belgian UCB company standard: UCB law
D, British Standard: B.T.T.G method
2. Sweating hot plate method, also called skin model method
A, ISO standard: ISO11092
B. Fire protective clothing test: NFPA1971
C, American Society for Testing and Materials standard: ASTMF1868-98B
D, German standard: DIN54010T01-A
3. Sweating dummy method
The sweat dummy dummy is somewhat like a hot plate and is used to simulate the shape and size of a typical human body. The dummy test is more practical than the sweating hot plate test because it can take into account more variables, including the surface area of ​​the body covered by the garment, the number of layers of textiles and the distribution of the air layer on the body’s surface, a loose or tight fit, and different parts of the body. skin temperature difference, body position and movement status, etc. But there isn’t a sweat holiday yet.��Can test evaporative thermal resistance under dynamic conditions such as walking. Fashion Clothing
Currently, there are no design standards and testing procedures for sweat dummies. And because sweating dummies are more complex and expensive, dummy testing is more expensive than the hot plate method.
4. Other methods
A, Watkins method
B, Mernander method
C, Farnworth method
D, VanBeest method
E, Ruchman method
F, Gibson method
Let’s take a closer look at a few relatively useful methods:
1. Commonly used methods: ASTME96BW, American Society for Testing and Materials standards, water vapor cup method.
Since the United States has always been in the leading position in this industry, and the country’s market is also very large, the data tested by this method is also relatively high, and the ASTM standard has naturally become a commonly used method. Most customers now use this method for testing.
The test principle is as follows: Cover the fabric to be tested on a moisture-permeable cup filled with distilled water, fix it and turn it upside down, weigh it using a top-loading balance with an accuracy of 0.001g, and place it in the position of the wind tunnel row. Before the cup enters an environmental chamber with a temperature of 23°C, a relative humidity of 50%, and a wind speed of 2.5m/s for weighing, record the temperature and relative humidity of the environment. The weight of each cup and the time it took to weigh it were recorded. Record the weight at 3h, 6h, 9h, 13h, 23h, 26h, and 30h, and use the formula WVT=24*△m/(s*t) to calculate the water vapor transfer rate. The average value of 6 samples is used as the test result. The average value is multiplied by 24 and converted to the result in g/m2*24h.
It should be pointed out in particular that the ASTME96BW method has 1995 and 2000 versions. The test conditions of the 95 version are immature and the relative test data is relatively high. Now the 2000 version is basically used.
2. Methods with high test results: JISL-1099B1, B2 Japanese Industrial Standard
The test principle is as follows: Use potassium acetate as a desiccant. Hoop the PTFE film around the plastic cup with a rubber ring to create a water vapor-permeable cup. Before wrapping the film on the cup, put enough potassium acetate solution into the water vapor-permeable cup to fill about 2/3 of the cup. Take 3 samples of 20cm*30cm square from each fabric. Each sample is placed on a test support frame. All coated or laminated fabrics are secured to the support frame with rubber rings, with the coated or laminated side facing outward. The installation of the sample support system shall be subject to being able to float in a water tank with a water temperature of 23°C. After testing the quality of the test cup (including sample, desiccant and film) with the film facing upwards, quickly turn the test cup upside down and place it into the sample holder. This assembly method is placed in a constant temperature device of 30℃±2℃. After 15 minutes, take the test cup out of the thermostatic device, turn it upside down and measure its weight. Water vapor permeability is calculated according to the formula WVT=24*△m/(s*t).
In the moisture permeability test, Japan’s desiccant pouring cup method seems to be more favored by manufacturers because it can be quickly tested on smaller samples, does not require control of the relative humidity in the environment, and the test device and Consumables are relatively cheap. This method gives high moisture vapor transmission values, which is preferred by manufacturers, and correlates well with the perspiration hot plate method (used by many researchers). ,
3. Testing method that attracts attention: ISO11092 sweating hot plate method
The hot plate test method is a device used to test and simulate the heat and mass transfer process that occurs close to the skin. From the testing principle, the sweating hot plate test method belongs to the evaporative heat transfer impedance method, which is used to measure the resistance of different types of fabrics to water vapor (water vapor impedance refers to the vapor pressure difference on both sides of the fabric divided by the direction of the pressure gradient. Total evaporation heat flow per unit area). The higher the evaporation resistance, the worse the breathability of the fabric; the lower the evaporation resistance, the better the water vapor permeability, or the sweat hot plate method tests the vapor heat transfer resistance. The evaporation resistance test value (Ret value) range is generally 148.7~3.9m2Pa/w.
When the Ret value is less than 6, it is considered extremely breathable and comfortable to wear at high exercise levels; when it is between 6 and 13, it is very breathable, with average wearing comfort at high exercise levels, but comfortable to wear at ordinary exercise levels; Between 13 and 20, it is breathable, which is uncomfortable to wear at high exercise levels, but comfortable to wear at normal exercise levels; between 20 and 30, it is low breathability, very uncomfortable to wear at high exercise levels, but comfortable to wear at normal exercise levels. Generally comfortable at low activity levels; above 30 it is non-breathable and uncomfortable at all activity levels.
The sweating hot plate method is being adopted by more and more businesses because it is more reasonable. However, the big problem facing China is that there is currently no testing agency that can do this test, and Hong Kong can’t do it either. Taiwan’s Textile Association can do it, but it doesn’t have the qualifications for certification. Because of this, domestic fabric manufacturers do not know enough about this test and are unable to determine how to choose the correct film and process. This year, a brother company suffered heavy losses because it could not reach a Ret value of 13.
There are many different methods for testing fabric moisture permeability, and the results of various testing methods are not relevant or comparable. Therefore, determining the testing method is the prerequisite for all indicators. We often see how high the waterproof and moisture permeability indicators are on some brands, but they do not indicate which testing method to use. HRpZa8Ey

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