At present, the common types of PLA nonwoven on the market can be mainly divided into two types, one is ordinary PLA nonwoven, and the other is a medical nonwoven fabric.
Since the medical nonwoven fabric is mainly used in medical applications, it has strict requirements for quality. What are other differences between the two?
(1) Antibacterial ability
Since it is a medical nonwoven fabric, the primary criterion is antibacterial ability. Generally, the smmms three-layer melt blown layer structure is used, while the ordinary medical nonwoven fabric uses a single-layer melt blown layer structure.
After comparison, it must be that the antibacterial ability of the three-layer structure is stronger. As for non-medical ordinary PLA nonwoven, because there is no melt-blown layer, it does not have antibacterial ability.
(2) Applicapable for a variety of sterilization methods
Since it has the antibacterial ability, it also needs to have corresponding sterilization ability. A good medical nonwoven fabric can be applied to a variety of sterilization methods. The common ones are pressure steam, hydrogen peroxide, and other plasma sterilization methods. However, ordinary non-medical PLA nonwoven cannot be applied to various sterilization methods.
(3) Quality control
The medical nonwoven fabric needs to pass the certification of relevant product quality control systems, and there are strict standards and requirements for each step in the production process of medical nonwoven products.
The main differences between medical nonwoven fabric and ordinary PLA nonwoven are mainly reflected in these aspects.
PLA nonwoven is an important raw material for making masks. Because masks are used for medical care and public health, the quality must meet relevant standards.
(1) Filtration efficiency
Filtration efficiency is a key indicator for the quality assessment of masks. This is also one of the important quality standards for PLA nonwoven. Therefore, after referring to relevant standards, it is recommended that the bacterial filtration efficiency of PLA nonwoven for masks should be no less than 95%, and the particle filtration efficiency for non-oily particles should be no less than 30%.
(2) Respiratory resistance
Respiratory resistance means when people wear masks, the size of the influence of hindering breathing. Therefore, the respiratory resistance of the PLA nonwoven of the mask determines the breathing comfort when users wear the mask. The recommended indicators of the PLA nonwoven of the mask here are that the respiratory resistance should be ≤350Pa, and the expiratory resistance should be ≤250Pa.
(3) Hygiene indicators
Hygiene indicators are naturally another important indicator of mask PLA nonwoven. The recommended testing items here are mainly initial contaminating bacteria, total bacterial colonies, coliforms, pathogenic pyogenic bacteria, total fungal colonies, escherichia coli, staphylococcus aureus, candida albicans, ethylene oxide residues, etc.
(4) Toxicology test
The skin irritation test is mainly a protective test for people allergic to some materials. The skin irritation test of mask PLA nonwoven is mainly to cut a sample of a suitable area in a cross-section method, soak it with normal saline and stick it on the skin, and then cover it with a patch for testing.
The above are the four indicators for the detection of PLA nonwoven masks. Among the above four detection indicators, the filtration efficiency of PLA nonwoven masks is very important.
For the majority of manufacturers, customers and citizens, when choosing PLA nonwoven, be sure to choose PLA nonwoven or those made of raw materials with good quality and strong filtration performance.