Summary
The non-woven fabric is an important raw material for mask manufacture. According to relevant reports, due to the impact of the epidemic in Wuhan, more than 3000 enterprises have to cross the border to manufacture masks. Many enterprises are trying their best to produce masks. Although they can alleviate the tight supply and demand of masks, the uneven industry situation also brings challenges to mask detection.
Although there are many standards for the inspection of finished masks in China. However, there is no clear standard to query for the non-woven fabric of respirator, which brings some confusion to the purchaser or manufacturer of respirator raw materials. This paper analyzes the key indicators of the non-woven fabric of respirator for your reference.
First of all, we should know that the scientific name of nonwovens is nonwovens, so the standards of nonwovens are mostly named after nonwovens. The non-woven fabrics used in mask production are mainly polypropylene spunbond nonwovens and polyester nonwovens. Here we recommend to refer to the textile standard FZ / T 64033-2014 spunbond hot rolled nonwovens.
According to the provisions of FZ / T 64033-2014, the internal quality inspection items of the mask non-woven fabric mainly include width deviation, mass deviation rate per unit area, mass variation coefficient per unit area, breaking strength and elongation at break. Appearance quality inspection items mainly include color difference, edge cutting defect rate, joint, fuse block, foreign matter, auxiliary network defect rate, soft fold, etc.
Of course, because there is no clear standard, the engineers of standard technology of information technology hereby sum up the previous experience of respirator testing and non-woven fabric testing, and put forward several important testing indicators, namely, four major projects of filtration efficiency, respiratory resistance, health indicators and toxicology test.
1、 Filtration efficiency
As we all know, filtration efficiency is the key index of mask quality evaluation. This is also one of the important quality standards of non-woven fabrics, so with reference to relevant standards, we recommend that the bacterial filtration efficiency of non-woven fabrics of masks should not be less than 95%, while the particle filtration efficiency for non oily particles should not be less than 30%.
2、 Respiratory resistance
Respiratory resistance, for people wearing masks, the size of the impact of respiratory obstruction. Therefore, the non-woven respiratory resistance of the mask determines the respiratory comfort when wearing the mask. Here we recommend that the inspiratory resistance should be ≤ 350pa, and the expiratory resistance should be ≤ 250pa.
3、 Health indicators
Health index is another important index of non-woven fabric. In this paper, we recommend that the detection items mainly include initial pollution bacteria, total bacterial colonies, coliform bacteria, pathogenic suppurative bacteria, total fungal colonies, coliform bacteria, Staphylococcus aureus, Candida albicans, ethylene oxide residue, etc.
4、 Toxicology test
Skin irritation test is mainly a protective test for people who are allergic to some materials. Refer to GB 15979. The non-woven skin irritation test of respirator is mainly to cut the sample of appropriate area in a cross-section way, apply it to the skin after being soaked with normal saline, and then cover it with spot sticker for test.
Among the above indexes, the filtration efficiency of non-woven fabric is undoubtedly the most important one in the detection of these indexes. For specific detection methods, please refer to YY / T 1497-2016 test method of Phi-X174 phage test method for evaluation of virus filtration efficiency of medical protective mask materials and YY / T 0866-2011 test method for total leakage rate of medical protective mask.