Horizontal comparison of preparation technology of non-woven medical protective materials

Non-woven medical protective materials were developed in the 1990s. At that time, some developed countries in Europe and the United States used advanced non-woven technology to develop a spunlace non-woven fabric with low cost, appearance and feel close to traditional textiles , becoming an excellent material to replace traditional textiles. Up to now, the processing methods of non-woven medical protective materials have been relatively mature. According to the different preparation technologies, there are mainly spunbond, meltblown, SMS composite technology, spunlace and flash evaporation.

Spunbond non-woven technology

Spunbond non-woven material as a protective material can meet the requirements of strength and comfort, but its barrier properties are relatively weak. In response to this problem, fine denier spunbond technology has become a major research hotspot. The two-component spunbond spunlace technology first invented by Freudenberg (Freudenberg) in Germany uses a hollow orange-lobed spinning assembly to extrude a thin stream of melt from the spinneret hole, and then cool and blow air and draft by air. The formed filaments are laid on the netting curtain, and then the high-pressure spunlace technology is used to open the fiber and fix the net. Its barrier properties are relatively better than ordinary spunbond or spunlace non-woven materials, so it can be used as a medical protective material.

Turkish non-woven manufacturer Mogul recently launched a material that can be used in surgical gowns. Its fibers are 100 times thinner than a hair after opening, which can block microorganisms, resist blood and The characteristics of alcohol also have good moisture absorption, air permeability and heat insulation. The microporous structure and protective properties of this non-woven material make it an ideal material for medical protective clothing.

Melt-blown non-woven technology

The biggest feature of the melt-blown method is that the fibers are very fine, the structure is fluffy after self-bonding, the porosity is high, the average pore size is small, and the The barrier properties of the product are not high, but the strength and wear resistance of the product are not high. Some people have made improvements on this basis, drawing on the spunbond technology, and under the condition that the fiber fineness remains unchanged, the melt stream blown by hot air is subjected to short-distance cooling and blowing, and then the fixed mesh is thermally bonded. , it is found that the strength of the product has been improved, and it can be applied to occasions where the strength requirement is not too high.

Considering the problems of thin meltblown fibers and poor compression resilience, 3M company in the United States took the lead in developing the intercalation meltblown technology, that is, in the process of traditional meltblown production, spraying in the meltblown fiber flow Blowing into the hollow elastic short fibers of coarse denier and high crimp, under the same gram weight, the compression resilience of the product is greatly improved, the structure becomes more fluffy, and the air and moisture permeability is also improved; in addition, the particles pass through the material. The tortuous path becomes longer, which increases the interception effect and greatly improves the particle barrier effect.

Another way to greatly improve the performance of blocking tiny particles without changing the air and moisture permeability of meltblown non-woven fabrics is the electret method. The electret meltblown nonwoven can capture more particles with opposite charges through electrostatic adsorption mechanism, thereby greatly improving its filtration performance.

SMS composite technology

In view of the poor barrier effect of spunbond non-woven fabrics and the low strength of melt-blown non-woven fabrics, some people use the strength and durability of spunbond non-woven fabrics. The abrasive property used it as the surface layer, and the barrier property of the meltblown cloth was used as the core layer to prepare the SMS composite nonwoven material. In view of the problem that most of the current SMS composite protective materials use PP as raw materials and have poor protection performance against various radioactive substances, Liu Xing and others from Tianjin University of Technology cooperated with a certain department of the Navy to coat the SMS materials with barium sulfate. It can prevent the penetration of radioactive substances, so it can be used for medical staff to avoid unnecessary radioactive substances interference and cause lesions, which plays a better role in isolation and protection. The coating material can also be made into the shape of slow-release microcapsules for coating. When subjected to external force, the microcapsules are broken and the protective performance is enhanced.

Spunlace non-woven technology

For non-woven materials in which short fibers are combed into a net and then spunlaced to fix the net, although it is soft to the skin, moisture absorption and breathability, etc. It has great advantages, but due to its poor barrier performance, it can only be used as a general medical material, and its protective performance is not very good. As early as 2009, the University of Leeds in the United Kingdom developed a type of functionalized spunlace non-woven material. This material uses a special device to form a cavity structure in the spunlace non-woven material during the spunlace process. Sustained release disinfectant capsules can be added to the structure.

This functional spunlace non-woven material with slow-release disinfectant microcapsules can be made into a cross-infection protection material and placed in the doorknob, handrail and other places where the hospital contacts the human body. When the door is closed or closed, the sick patient will pass the germs to the touch handle by hand. At this time, the microcapsules will release the disinfectant under the action of hand pressure, effectively killing the germs, and other patients or healthy people will touch the handle again. will not be infected. This kind of anti-cross-infection non-woven protective material has been applied in some hospitals in the UK, and the effect is very good.

Flash evaporation nonwoven technology

Compared with SMS, flash evaporation technology is formed by solution spinning method, and the solvent is a volatile organic solvent, which is difficult to recover. The higher concentration of the medium is easy to cause explosion accidents; in addition, in the production process, the control of the spinning speed of the fiber is very difficult. At present, this technology is monopolized by DuPont (DuPont) in the United States. The protective clothing made of its flash evaporation product Tyvek combines protection, durability and comfort to protect workers from particles as small as microns, but the cost is relatively high. higher.