What is PTFE?
Polytetrafluoroethylene (Polytetrafluoroethylene, abbreviated as PTFE) is generally called "non-stick coating" or "easy to clean materials". This material has the characteristics of acid and alkali resistance, resistance to various organic solvents, and is almost insoluble in all solvents. At the same time, polytetrafluoroethylene has the characteristics of high temperature resistance, and its friction coefficient is extremely low, so it can be used as a lubricant, and it has also become an ideal coating for easy cleaning of the inner layer of water pipes.
PTFE performance: with high hydrophobicity, high and low temperature capability, weather resistance, low friction, insulation and excellent high chemical resistance. PTFE in the range of negative 73 degrees to 204 degrees, its performance is still maintained at a useful level, it has good thermoelectric insulation properties, and the friction coefficient is very low.
PTFE composite fabric is a functional fabric with the functions of waterproof, moisture-proof, wind-proof and warm, which is compounded on the surface of ordinary fabrics by a special process.
Unique properties of PTFE composite fabric:
Water resistance means that the water on the outside of the fabric will not penetrate the fabric and soak into the inside. The PTFE laminated composite fabric is still waterproof even under a pressure of 80lb / m2. Wearing this fabric clothing, even if standing on a wet surface in a storm, people will not feel wet. The reason why this fabric clothing has such a magical function is mainly because the pore size of the PTFE membrane of the fabric main body is 1 / 5000-1 / 20000 of the diameter of water droplets, so even the smallest raindrops cannot pass. PTFE has a low surface energy, and water droplets cannot spread on the film, preventing water droplets from passing through.
The porosity of the PTFE film is as high as 80%, and the average pore size is 0.2 micrometers.
During the stretching process of the PTFE film, a microporous structure is formed in which the nodes are connected to numerous microfibers, and pores are formed between the microfibers, and the pores penetrate each other to form a unique network structure. The wind cannot pass directly, it will change direction when it encounters the barrier, and it can effectively prevent the penetration of air, so it has excellent windproof performance.
The PTFE film has excellent moisture permeability, which can timely transmit the steam discharged from the human body to the outside of the microclimate, prevent water vapor from condensing into liquid water, and reduce the possibility of water conducting heat. Although the surface of the film is dense with a large number of micropores, the wind cannot penetrate, effectively preventing air convection. Tests show that in a strong wind of 25m / s, the warming effect of PTFE composite fabric is 30-40% higher than that of traditional down jackets.
The pore diameter of PTFE film is small (average pore size 0.2micro; m), it can block the penetration of some toxic gases or aerosols, and the low surface can prevent the penetration of some toxic liquids. The non-porous material with high water vapor flux is coated on one side of the film to realize the selective penetration of water vapor and achieve the purpose of complete protection. The nuclear biochemical protective clothing processed by PTFE composite fabric has a variety of functions such as waterproof, moisture permeability, wind resistance, nuclear and chemical protection.
The garment can still maintain the original overall performance of the product after repeated decontamination 20 times.
Safety performance: The fabric has high strength, and it will not tear after high-strength operation after wearing.
Fabrics are widely used:
It can be used in various places with germ threats. It has been maturely used in SARS protection, plague protection, Ebola protection, and influenza protection.
Position in medical protective clothing fabric:
Medical protective clothing is a type of chemical protective clothing, which is mainly used for medical personnel to wear, can effectively block microorganisms, block the penetration of body fluids, and prevent disease transmission of work clothing. GB19082-2009 "Technical Requirements for Medical Disposable Protective Clothing" promulgated by China puts forward more detailed technical requirements for medical protective clothing, stipulating that medical protective clothing should be in flame retardancy, water level, charge density, elongation at break and Water resistance and other indicators.
Looking at all the current fiber fabrics, it is difficult to achieve the standard waterproof and liquid barrier properties. Therefore, it is unavoidable to laminate the fabric or perform coating finishing to improve its particle barrier performance. High-quality medical protective clothing can greatly improve the protective safety performance of medical personnel, and play an effective protective role against some highly infectious bacteria and viruses, minimizing the harm.
Foreign countries have conducted more systematic research on medical protective fabrics and clothing. Currently, most of them use polytetrafluoroethylene (PTFE) material, and have developed corresponding standards according to different needs.
In China, medical protective clothing fabrics and clothing can be roughly divided into three types: coating materials, PU | TPU membrane composite materials and PTFE microporous membrane composite materials from the materials used:
Coating material Most domestic companies use wet or dry polyurethane, polyacrylate, polyvinylidene fluoride to coat and finish the fabric, and then use this fabric to make protective clothing.
2. PU, TPU film composite materials. This composite material has some improvements in moisture permeability and comfort compared to coating materials.
3.PTFE microporous membrane composite material. Polytetrafluoroethylene microporous film can effectively solve the two shortcomings of coating material, PU, TPU film composite material, such as poor durability and poor moisture permeability. The disadvantage of PTFE is its high cost.