Text | Teng Xiaotao
Produced by Che Tuteng, no reproduction without permission
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Since the new coronavirus pneumonia Since the outbreak of the epidemic, almost all car companies have joined the "fight against the epidemic." In addition to donating money and materials, they also tried their best to provide help. Some car companies even temporarily switched production and invested in the production of masks and disinfectant.
According to data from the Ministry of Industry and Information Technology, there are 353 companies in my country that have obtained mask production licenses, with an average daily maximum production capacity of more than 20 million pieces. However, due to the epidemic, many companies are unable to resume work, and the production capacity recovery rate is only about 60%. Among them, ordinary masks and dust-proof/anti-smog masks of various protection levels are the main ones. The daily production capacity of N95 medical protective masks is only about 600,000. As of February 3, the daily output of masks in 22 key provinces across the country has reached 14.8 million, but the situation of "a mask is hard to find" has not changed intuitively.
According to media reports, the demand for masks by front-line medical staff exceeds tens of millions every day, and as major companies gradually resume work, China's average daily demand for masks may exceed 500 million.
(Photo source: Xinhua News Agency, photo by Wang Zheng)
Car companies can’t sit still.
On February 6, Baojun Motors, a subsidiary of SAIC-GM-Wuling, announced that with the strong support of the Guangxi District and Liuzhou municipal governments, it would join hands with upstream supplier Guangxi Defu Group to produce masks by transforming its production lines.
According to the project plan, the dust-free workshop will be renovated by Guangxi Construction Engineering Group and will be completed and put into use in February. The factory has 14 mask production lines, including 4 N95 mask production lines and 8 general medical protective mask production lines. The daily production capacity is expected to reach more than 1.7 million, which will quickly alleviate the shortage of medical supplies in the Guangxi Autonomous Region. Provide strong support for epidemic prevention and control work.
In addition to SAIC-GM-Wuling, BYD also decided on February 8 to urgently shift to the production of medical supplies such as masks and disinfectants, and is expected to achieve mass production and shipment on February 17. BYD's mask production capacity is expected to reach 5 million pieces per day by the end of February, making it the largest company among more than 3,000 companies that have temporarily decided to switch to mask production. In addition, BYD's disinfectant production capacity will also reach 50,000 bottles/day until the epidemic is alleviated and eliminated.
In addition, according to news on February 12, GAC’s first mask production equipment has been installed and debugged. It is expected that 12 units of the equipment will be completed by February 22, and 30 units are expected to be completed by the end of the month.
It is understood that GAC Group has cooperated with suppliers to produce 30 to 50 self-made mask production equipment, some of which are used for GAC's own production, and some are given to other state-owned enterprises in Guangzhou for mask production.
(The chairman of GAC went to the mask production equipment manufacturer to investigate)
How to switch to the production of medical masks in the short term?
Che Totem understands that the raw material of medical masks basically comes from polypropylene (PP), and the overall structure adopts SMS structure, the most important of which is the barrier layer or meltblown layer M (Meltblown). The fiber diameter of the melt-blown layer is relatively thin, about 2 microns (μm), which is only one-tenth of the diameter of the spunbond layer (Spnubond), which plays a vital role in preventing bacteria and blood from penetrating.
(Schematic diagram of SMS non-woven fabric structure)
Therefore, the thinner the M layer of the medical mask, the better it can block the entry of tiny particles such as bacteria. The N95 mask is a five-layer mask made of polypropylene non-woven SMMMS structure. It can block 95% of tiny particles (0.3 microns) under normal circumstances.
But this does not mean that masks can be produced with polypropylene raw materials. According to regulations, only polypropylene products with high strength, high fluidity, melt mass flow rate of 33-41g/min, and meeting hygiene standards for polypropylene melt-blown non-woven fabrics can be used for civil hygiene and medical purposes. Surgical supplies and other fields.
(Schematic diagram of SMS structure blocking various substances)
As Wuling’s upstream supplier, Guangxi Defu Technology Co., Ltd. is a company specializing in the production of automotive sound-absorbing cotton, sound insulation materials, and NVH materials. and parts companies. Especially in the manufacturing of sound-absorbing cotton, the company has more than 20 patents. More importantly, the main raw material of the first and third layers of sound insulation cotton is polypropylene non-woven fabric. Precisely because it has the filter material for N95 masks and its own technical reserves, the company has the ability to produce disposable medical masks and higher-standard N95 masks.
So, how are masks made?
After the melt-blown fabric, non-woven fabric and other raw materials are ready, the three layers of non-woven fabric raw materials will be laminated together through the production machine.
(Three layers of non-woven fabrics laminated)
We know that there is a bendable metal wire on the upper part of the mask. When wearing it, you need to pinch the nose clip and fix it to the bridge of the nose. Ensure the tightness of protection. Without this layer of structure, the protective effect will be directly affected.
The way it is implemented is that the wire threading machine matches and transports the metal wire along one side of the non-woven fabric, and then rolls the non-woven fabric while sewing, and the nose clip process is completed.
(Threading silk into the mask)
The main part of the mask adopts a layered structure. When pulled open, it can completely cover the mouth and nose, no matter how big your face is. Therefore, there is a need for a machine folding link. There are three adjustable slopes on the production equipment. Workers only need to set the slope angle and let the large piece of non-woven fabric pass along the slope that gradually narrows from left to right to form a "folded structure".
(Machine folding link)
Then the details remain, including the individual cutting and hemming of the mask. Most of these links are fully automated and without manual processing. Different masks have subtle processing differences. Some have seamed edges, and some have hot-pressed gluing to fix the ear straps to the mask. At this point, the overall processing of a mask is completed.
(Hot-pressed fixed ear hanging rope)
The production process of open masks (N95 or with breathing valve) is similar to that of medical masks, but there are more layers of non-woven fabrics. The metal wire at the nose clip will also be made during the lamination process.
Different from ordinary medical masks, the open design of the open mask is made of flat fabrics that are folded together through a V-shaped structure, and then cut into individual pieces. The next step is similar to medical masks. Trimming and sewing, and the production of reinforced ear sealing lines.
On the whole, the technical barriers to the production of medical masks are not high. The automatic production line for masks uses rolls of non-woven fabric, which is automatically cut into the shape of the mask, laminated and then welded to the ear straps, which undergo disinfection and other procedures. The entire process of packaging finished products is fully automated. For an automobile company that has always been known for its highly intelligent factories, the automation level of its production lines is significantly better than that of other industries. In addition, the production workshop itself has high dust-free standards, so in theory, ordinary medical masks are not difficult to produce. .
(? Data map: Automobile spraying workshop with dust-free standards)
Someone may want to ask, since the production process of medical masks is not complicated, even the technological content of N95 is not It’s not high, but why is the shortage so serious? In fact, masks cannot be sold immediately after they are made, and they must go through ethylene oxide gas disinfection and sterilization.
After the masks are sterilized for 16 hours and the analysis library evaporates the sterilization gas for two weeks, masks that meet relevant standards can officially enter the market. Therefore, even if medical masks are put into production immediately, the first batch of products leaving the factory will have to wait until half a month later. This is the main reason why medical masks are in short supply.
Another bottleneck in mask production lies in medical qualifications and raw material supply. The raw materials required for medical surgical masks include non-woven fabrics, melt-blown fabrics, filter materials, ethylene oxide sterilization, paper and plastic packaging materials, ear straps, etc. The timely supply of raw materials and the availability of personnel are important factors that determine the current production capacity recovery rate.
According to the latest news, Telford has established a new medical machinery company and has completed relevant qualification certification. In the future, the factory will become a long-term professional manufacturer of masks and other related medical equipment.
For Deford, with the field equipment, the only thing missing is manpower. To this end, SAIC-GM-Wuling specially dispatched engineers related to workshop management, production management and quality control, plus a total of 92 production employees. At the same time, Deford also openly recruited 85 temporary workers from the public to ensure smooth production.
Written at the end:
Xu Haidong, assistant secretary-general of the China Association of Automobile Manufacturers, said that there are many upstream and downstream supply chain companies in the automotive industry, and some can switch to producing masks. At the same time, car companies are improving quality control, etc. There are conditions and advantages in this regard.
We have seen that with their global layout and procurement advantages, as well as their own capabilities in production management, market collaboration, and technology output, SAIC-GM-Wuling and BYD have integrated raw material procurement, equipment manufacturing, and product production. We will wait for the entire industrial chain to quickly give full play to our advantages, increase the production and supply of materials from the source, and supplement the capacity of anti-epidemic materials.
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