Sheets with a thickness between 0.2-0.4mm are mainly used for food packaging, such as disposable transparent food packaging in supermarkets, disposable PP water cups, etc. The main raw materials are homopolymer PP (such as domestic T30S, F401, 2401, etc.), there is also a small amount of random copolymer PP. The sheet with a thickness between 0.5-0.8mm is mainly used for environmental protection. As a water treatment material, the material can be used underwater for seven or eight years, and the raw materials used are mainly copolymerized PP. PP plates/sheets with a thickness of 0.8-6mm are mainly used for chemical tank lining, and can also be used for water treatment in environmental protection. PP sheets with a thickness of about 3 mm are used to make plastic Christmas trees and other accessories. The thickness of PP hollow sheet is generally 2-7mm, which is mainly used for making document package, packing box, greenhouse board, bath pavilion partition, decorative board, exhibition board, wall panel, lighting board, etc. The raw material is mainly block copolymer PP. PP sheets with a thickness greater than 6 mm are mainly used in industrial applications. The sheet materials are generally block copolymerized PP, and some manufacturers use random copolymerization and homopolymer PP.
In the past few years, the production line of PP sheet and sheet was basically imported. Therefore, the imported materials provided by the foreign party were mainly imported from the beginning of the factory. The imported materials were mainly from J340 of Korea Hyosung Company, MFR=1.7g/10min; Japan Yubu Xingchan's OBJ809, MFR=2.0g/10min; Korea Hyundai Petrochemical Co., Ltd. M1250; South Korea's Samsung United Chemical BJ100. With the development of domestic PP industry, random copolymer PP and block copolymer PP have been successfully developed and put on the market, such as EPS30R of Qilu Petrochemical, J340 and F401 of Yangzi Petrochemical, 1340, 1440 of Yanshan Petrochemical, and M180R of Shanghai Petrochemical. It has gradually satisfied the demand for raw materials in the domestic PP board and sheet market, especially Qilu EPS30R. Its processing performance, product appearance quality, low temperature resistance and other indicators have reached or exceeded imported materials, and have been widely praised by users. With the improvement of the quality of domestic PP, the performance of domestic materials basically meets the requirements of use and can replace imported materials.
At present, the main PP production board/chip manufacturers in China include Suzhou Plastics First Factory, Suzhou Plastics Ten Factory, Xiaoshan Datong Plastics Company, Zhejiang Yongqing Plastics Co., Zhejiang Plastics Factory, Hangzhou Ouhua Plastics Co., Ltd., Zibo Plastics No.8 Factory. Longkou Zhongji Recurrence Plastics Co., Ltd., Taizhou Chuangjia Stationery Co., Ltd., etc.
It is particularly worth mentioning that in the mid-to-late 1990s, Europe and the United States and Japan developed PP foam sheets and sheets, which received great attention once they were put on the market. Compared with traditional materials, foamed PP is favored by people for its excellent heat resistance, mechanical properties, low cost and good environmental adaptability, and gradually replaces foaming of PS, PUR, PE, etc. Materials used in packaging, automotive, thermal insulation, environmental protection, sports equipment and building materials industries. In recent years, China has also set off a boom in the development of PP foam materials, and has begun to launch on the market. Degradable PP foamed snack boxes have great potential in China's railway system market. It is understood that the annual consumption of various types of fast food boxes in China is about 15 billion. In addition, foamed PP sheets and sheets will have a large potential market in the fields of automotive interior decoration, construction, vegetable and fruit food packaging, thermal insulation, electrical appliances, etc. As a new generation of foamed PS, it has broad market prospects. .
How do masks play a protective role?
The mask must have at least three layers to work.
The most common medical Surgical Mask is a rectangular mask, which does not fit closely with the face. All masks are divided into three layers, namely outer layer, middle layer, and inner layer, the outer layer has a waterproof effect; the middle layer has
Filtration, 90% of particles larger than 5 microns can be blocked; the inner layer is used to absorb moisture. The main difference between protective masks and medical surgical masks is the intermediate adsorption layer.
When the saliva droplets in the mouth are splashed outward, the outermost layer of the mask can play a certain blocking role, and bacteria and viruses in the air can be adsorbed in the middle layer, which plays an effective filtering role to ensure
We breathe clean air.
How long does the mask need to be replaced?
The study found that the N95 mask was worn for 2 days, the filtering effect remained above 95%, and the respiratory resistance did not change much; the filtering effect was reduced to 94.7% after wearing for 3 days.
Can wearing multiple masks better prevent new coronavirus infections?
As far as medical masks are concerned, any qualified product that is properly worn requires only one to achieve the desired protective effect. The higher the level of protection effect, the greater the breathing resistance of the mask. When we wear
The feeling of experience will be a little bit worse, and the sense of comfort will also be reduced. When people wear a mask and breathe in, the mask will have a certain resistance to the flow of air. When the breathing resistance is too large, people will feel dizzy,
Chest tightness and other discomforts. If you wear an improper mask, not only will it make you breathless, but the air cannot enter the nasal cavity from the front, but only from the side, but it will not play a preventive role.
Therefore, as long as it is a qualified product, medical protective masks and general medical surgical masks can effectively prevent new coronavirus infections, that is, prevent the spread of pathogens carried by respiratory droplets.
Surgical Mask
Medical masks,Disposable medical mask,Mask medical,Disposable mask medical
Shenzhen Comfity Technology Co.,Ltd , https://www.comfitymemoryfoam.com