To cope with the changeable weather when traveling outdoors, waterproof jackets, trousers and even shoes are very important, but I believe that many people are not particularly clear about the concepts of waterproof fabrics and waterproof fabrics. Faced with the increasing number of claims that their products are waterproof When it comes to functional outdoor brands, there will be some doubts. Which fabrics are really waterproof? Why should the products that already use waterproof fabrics be treated with water repellent? Let me give you a brief introduction to the difference.
Waterproofing of fabrics usually means that the fabric itself has the function of waterproofing. After the waterproof fabrics have experienced the initial compact fabrics and coated waterproof fabrics, they are now mainly pasted film-type fabrics. functional film.
The adhesive film fabrics that initially occupy the largest market share are basically PTFE (polytetrafluoroethylene) films, which are microporous films. The waterproof performance is expressed by the water pressure value it can withstand, not 100. % waterproof, and according to European environmental studies, PTFE materials produce environmentally harmful compounds when manufactured, landfilled and incinerated. In recent years, the environmental protection community has increasingly questioned PTFE materials, and some countries have begun to restrict the use of PTFE materials. Landfill and incineration are the main domestic waste disposal methods in the world, and these two disposal methods will produce perfluorinated compounds when dealing with PTFE materials. Fluoride will pollute the atmosphere and land. Due to the long period of natural decomposition of fluoride, The environmental pollution caused by PTFE material will be lasting and long. In comparison, another kind of film that has been used by more and more brands in recent years-non-porous hydrophilic film is not only non-porous and 100% waterproof, making the waterproof performance of the product more reliable, and some non-porous hydrophilic films are more reliable. Because of its environmental protection and harmless to human body, it is favored by more people in the industry, such as Sympatex film, which is a molecular compound of polyether and polyester, absolutely does not contain PTFE (polytetrafluoroethylene) components, and can directly contact the skin , harmless to the body, and can be recycled like a PET plastic bottle.
Usually, these fabric manufacturers with film technology do not directly sell the film to clothing brands. They compound the film with other material fabrics through the pasting process to form a composite fabric (as shown in the picture above, the middle layer is a film), and the brand only needs to Buy these composite fabrics to make waterproof clothing products directly. These fabrics used for compounding with the film are not waterproof themselves, such as polyester fiber, nylon, etc., so when we wear waterproof clothing and encounter wet weather, we will see water seeping into the clothing, just like clothing made of ordinary fabrics , but the inner layer of the garment is dry, and no water seeps in, which is the role of the waterproof film in the middle of the composite fabric.
What we see is that the water is dispersed into small water droplets on the clothing and then slips off (as shown in the above picture), usually because the fabrics used have been treated with water repellency. The water repellent treatment is actually a special layer covering the surface of the fabric. Treatment, usually adding DWR (Durable WaterRepellency) when the finished fabric is finalized, so as to obtain durable water repellency. The purpose of using DWR coating is that when water drips onto the surface of the garment, it can form small water droplets or slide directly from the surface of the garment to prevent the fabric from absorbing water, and at the same time, it also makes it easier to remove the oil stains attached to the surface of the garment. Most waterproof clothing adopts this DWR water-repellent treatment, and the advantage of using DWR treatment is that the surface layer of the clothing can not absorb water, so as to ensure that the waterproof fabric can achieve good breathability, so that the human body has a very good wear. feel.
DWR technology can be classified into two types in terms of related properties: fluoride-containing DWR and fluoride-free DWR. Fluoride-containing DWR refers to the surface treatment of DWR based on fluoropolymers, such as PFOA (perfluorooctanoate), which is widely used in the clothing industry. The quasi-elements have the problem of not being easily degraded, and can be released into the water source and the atmosphere through various factors such as heat, water immersion, and ultraviolet rays, causing harm to humans and other animals and plants. Scientists have already detected the presence of this compound in human and animal blood samples around the world. Although so far there is no basis for pointing out the carcinogenic risk of PFOA and the relevant regulations for the restriction of PFOA, the German Federal Environment Agency (UBA) has proposed to include PFOA in the list of chemicals suspected of being toxic to the reproductive system.
At present, DWRs without fluorocarbons are common: wax, paraffin, polyurethane, dendrimers or siloxanes, etc. to replace fluorocarbons as basic elements as water repellent recovery agents for outdoor products. Since SympaTex? Since mid-2008, it has begun to provide consumers with an environmentally friendly, fluorocarbon-free DWR water-repellent product. This product is an environmentally friendly product for textiles developed together with partner Rudolf Chemie: BIONICFINISHECO?. In fact, SympaTex? is also the first company to develop non-fluorocarbon-based DWR water-repellent technology products for textiles.
In the US EPA 2010/2015 PFOA regulatory process, major chemical manufacturers, including DuPont, Clariant, also voluntarily committed to completely eliminate PFOA toxic chemicals in production by 2015, and use more environmentally friendly and low-emission products instead.
It is worth mentioning that the DWR water repellent treatment is not permanent, but the correct washing method and ironing method can prolong the effect of the DWR water repellent treatment, and if your clothing loses the water repellent effect, don't worry, at present DWR coating restorers are commercially available.
So you can see that the clothing using waterproof fabrics can basically meet the functional requirements of 100% waterproof (PTFE film products under certain conditions, non-porous hydrophilic films under any conditions), but in order to obtain a more comfortable wearing experience , so that these waterproof fabrics have a good breathable effect, and DWR water-repellent treatment is also necessary.
In addition, the complete waterproofness of clothing has a lot to do with the waterproof performance of the glue strips and zippers used at the seams, because the waterproofness and water repellency of the fabric refer to the functionality of the fabric itself, the needle holes at the seams or the gaps of the zipper. It is not possible to achieve 100% water resistance without treatment of the garment.
