In this new coronavirus epidemic battle, masks are currently the most in short supply. Major physical stores and e-commerce platforms are in a state of difficult to find a mask. Many people are anxious about not being able to buy a mask. With the end of the resumption order, major enterprises will usher in a wave of work, and masks are even more difficult to find. What is gratifying is that many companies have changed their production lines and joined the ranks of producing masks. Now let’s take a look at the materials and production process of disposable medical masks.
Material and structure of disposable medical mask
General medical masks are composed of 3 layers, the inner and outer layers are spunbond non-woven fabrics, with a layer of melt-blown non-woven fabric between them. The outer non-woven fabric can prevent droplets, the inner non-woven fabric can absorb moisture, and the middle layer is a filter layer, and the antibacterial effect can reach 99.99%. Some of the larger particles can be filtered out by the mechanical sieve of the filtering material, just like we use a sieve to sieve things out. Part of the particles pass through the mesh channels of the filter material, and the particles hit the fibers and are adsorbed by the molecular gravity. In addition, some particles with small-scale and low-speed particles are adsorbed by fibers during Brownian diffusion. In addition, the electrostatic effect of the fibers can also adsorb particles. This is why the medical masks have better antibacterial effect than the ordinary masks we usually wear. Back to the structure, we can find that the main material of medical masks is non-woven fabric.
So what is non-woven fabric?
The so-called non-woven fabrics are not bonded by warp and weft threads, but are bonded together by physical methods. It is a non-woven fabric formed by air or mechanical netting, and then reinforced by hydroentanglement, needle punching or hot rolling. To put it simply, it is like directly letting the cotton structure be tangled and consolidated together to form a flat cloth. Our common tote bag is made of non-woven material. Spunbond non-woven fabrics and melt-blown non-woven fabrics are both types of non-woven fabrics formed through different processing techniques. The main materials of spunbond non-woven fabrics are polyester and polypropylene, which are formed by spunbonding. Melt-blown cloth is mainly made of polypropylene and is formed by melt-blown method. Meltblown cloth has good filtering and shielding properties.
Production process of disposable medical masks
With the raw materials and equipment, the production of masks is much easier. The melt-blown cloth and the non-woven fabric that are divided into small rolls are first put on the production line. First, three layers of non-woven fabric materials need to be laminated together and made into a mask body by high frequency welding.
The masks are of a laminated structure, so that the mouth and nose can be completely covered after being pulled out. This requires a machine to fold the masks. The machine uses 3 adjustable slopes to set a small bevel in advance. The cloth gradually narrows down through the inclined surface to fold out the folded structure. The folded structure is then compacted.
With this process, one side of the non-woven fabric is matched with the wire and then stitched by crimping.
Subsequently, the ear cord was worn at the edge of the mask, and the edge was then compacted. After passing the sterilization inspection, it went on the market.
Disposable medical masks have high requirements on equipment, production environment and personnel requirements.