With the deepening and promotion of the 2019-nCoV prevention and control work, the demand for prevention and control materials such as face masks and protective clothing continues to grow, which has led to the demand for raw materials for production also continues to grow. At present, I have compiled the raw materials for the production of protective clothing and face masks, and categorized them for a brief introduction, for your reference.
Chinese national standard GB 19082-2009, “Medical disposable protective clothing technical requirements”, specifies the requirements of medical disposable protective clothing, test methods, marking, instructions for use, packaging, and storage. This standard applies to medical disposable protective clothing that provides barriers and protection against potentially infectious patient blood, body fluids, secretions, airborne particulate matter, etc. when medical personnel is exposed to them at work.
The European EN standard stipulates that chemical protective clothing must comply with the European standard for personal protective equipment (PPE) in the highest hazard protection, and “Ⅲ” category requirements, and defines six different types of protective clothing. Through the fabric performance test and the finished product comprehensive performance field test, the protective clothing into the following six categories.
Protective clothing type, EN standard
|Description||Protective clothing type, EN standard||Description|
|Type 1 EN 943-1/2||Airtight protective clothing||Type 4 EN 14605||Aerosol tightness protective clothing|
|Type 2 EN 942-1||Non-airtight protective clothing||Type 5 EN ISO 13982-1/2||Protective clothing against solid particles|
|Type 3 EN 14605||Liquid Tightness Protective Clothing||Type 6 EN 13034||
Mild chemical splash protection
The performance of other relevant standards is as follows.
EN 1149-1: Anti-static properties
EN 1073-2: Protection against radioactive particulate matter
EN 14126: Protection against infectious bacteria
EN 11612: Limited performance of protective clothing against flame spread
Medical protective clothing as a kind of protective clothing, mainly used for medical personnel to wear, not only to drain moisture and breathable, comfortable to wear, but also to protect medical personnel from viruses, bacteria and other pollutants in the course of diagnosis and treatment, to resist the invasion of water, alcohol, oil, and effective anti-static, and even prevent dust from entering.
What kind of material is the medical protective suit made of that can achieve such an effect?
Medical protective clothing can be divided into woven, non-woven, and composite materials according to the organizational structure of the fabric. Medical protective clothing can be divided into disposable use, limited-use, and reusable according to the service life. Medical protective clothing can be divided into finishing, coating, and laminating according to the processing composite technology.
Protective clothing has different properties due to the different raw materials used, and the following materials are used in several medical protective clothing currently being sold and developed in the market.
Polypropylene spunbond fabric
Polypropylene spunbond fabric is made by stretching polypropylene to form a filament, laying it into a mesh, and then bonding it into a nonwoven fabric. Polypropylene spunbond cloth can be treated with antibacterial and antistatic treatment and made into antibacterial protective clothing, antistatic protective clothing, etc.
Compared to traditional cotton protective clothing, polypropylene spunbond protective clothing is certainly a step forward. Because of its low price and disposable use, it can greatly reduce cross-contamination rates and has been heavily pushed abroad for a considerable period of time since its introduction. However, the material has a relatively low hydrostatic pressure and a poor barrier efficiency against viral particles, and can only be used as a general protective item such as sterile surgical gowns and sterile wraps.
Nonwovens made of polyester fiber and wood pulp
The material is a non-woven composite reinforced with polyester webs entangled with wood pulp paper using a hydroentanglement technique and is made from polyester staple and wood pulp fibers. The material is soft to the touch, close to traditional textiles, and can be treated by three anti (anti-alcohol, anti-blood, anti-oil) and antistatic, antibacterial, etc., can be disinfected with γ-rays, but its antistatic pressure is also relatively low, the barrier efficiency to viral particles is also poor, so it is not particularly ideal medical protective clothing materials.
Polypropylene spunbond-meltblown-spunbond composite nonwovens, i.e. SMS
The meltblown nonwovens are made by drawing a fine melt stream of polymer extruded from the die’s spinneret holes by means of a high speed hot air stream, from which microfine fibers are formed and collected on a curtain or roller and bonded to themselves.
The characteristics of meltblown nonwovens are fine fiber diameter, large specific surface area, fluffy, soft, good drape, low filtration resistance, high filtration efficiency, strong hydrostatic pressure resistance, but low strength, poor abrasion resistance, which to a considerable extent limits the development of its applications. The spunbond fiber threads are denser, and the web is made up of continuous filaments, whose break strength and elongation are much greater than meltblown cloth, which can precisely compensate for the shortcomings of meltblown cloth.
In addition, SMS nonwovens can be treated with triple resistance (anti-alcohol, anti-blood and anti-oil) and anti-static, anti-bacterial, and anti-aging treatments to suit different applications. This material has the following excellent properties.
1 Uniform and aesthetically pleasing appearance
2 High hydrostatic pressure resistance
3 Soft feel
4 Good breathability
5 Good filtering results
6 Strong acid and alkali resistance
High polymer coated fabrics
Polymer-coated fabrics are made by laminating ordinary fabrics with a special film through a lamination process. There are many types of coatings used for protective fabrics, including PVC, polyethylene, polychloroprene and various other synthetic rubbers.
This material is made of protective clothing, waterproof, barrier against bacterial particles is very good, can be reused, but the moisture permeability is poor, the large amount of human sweat can not be excreted, wearing comfort performance is poor. The use of rubber-coated fabrics for protective clothing during SARS was a last resort. The latest development at home and abroad is the use of microporous Teflon film and fabric composite to obtain waterproof and breathable function, but as a disposable product expensive.
To fight the 2019-nCoV, medical personnel mainly used the mask: disposable medical masks, medical-surgical masks, medical N95 masks. The main body is made of three layers of non-woven fabric, using SMS structure, the material is spunbond non-woven fabric + spunbond non-woven fabric + spunbond non-woven fabric, the outer layer of anti-droplet, middle filter, the inner layer of moisture absorption. Medical N95 masks are 5 layers, on the other hand, SMMMS.
Therefore, the two most important raw materials for the production of medical masks are spunbond nonwovens and meltblown nonwovens. The outer and inner layers of spunbonded nonwovens are mainly made of polyester and polypropylene, while the middle layer of meltblown nonwoven is mainly made of high fusion finger polypropylene. If you want to make antiviral face masks, you need to purchase these raw materials: polypropylene nonwovens, meltblown filter cloth, nose clip bar, and earrings, etc.
The meltblown nonwoven fabric is an ultra-fine electrostatic fiber cloth that traps dust (droplets containing pneumonia virus are electrostatically adsorbed to the surface of the nonwoven fabric when they are near the meltblown nonwoven fabric and cannot be penetrated). If you want to know exactly how meltblown nonwovens filter viruses, check out this article: How does the antiviral face mask filter the 2019-nCoV? How to judge?