New plastic materials with antibacterial and bactericidal properties
plastics have increasingly entered people's lives, but general plastics are easy to be contaminated and breed a variety of microorganisms, including pathogenic bacteria, during use, which are harmful to human health. As people pay more attention to the healthy environment, the safety and health of plastic products has become a topic of concern, and antibacterial plastics have emerged
antibacterial plastic is a new type of material with antibacterial and bactericidal properties, which can keep the material clean and reduce cross infection caused by the use of plastic products. In some developed countries in Europe and America, antibacterial plastics have been used more or less on earpieces, computer keyboards, bus handrails and other appliances. At present, antibacterial plastics have been used in large household appliances, communication equipment, automobile manufacturing and other aspects
plastics can resist bacteria because antibacterial agents are added in the production process. In this way, the dosage of antibacterial agent is large, and the cost is increased. In order to reduce the cost, the antibacterial agent with very fine particles can be made into spray liquid, which is sprayed on the surface of the plastic mold. During the molding process, the antibacterial agent penetrates into the surface of the plastic products, and after appropriate heat treatment, the antibacterial agent is combined with the plastic products
antibacterial agents used in plastics are divided into three categories: organic, inorganic and natural. Organic antibacterial agents are mainly composed of organic acids, phenols and alcohols. They have strong bactericidal power and good immediate effect, but they will produce pungent odor during processing, and are easy to migrate in plastics, with poor heat resistance. Natural and macromolecular antibacterial agents have not been widely used in plastics since 2000 due to poor heat resistance and processing difficulties such as collision. These antibacterial agents combined with inorganic antibacterial agents can combine the advantages of both, which not only has the immediate effect and sustainability of organic agents, but also has the safety and durability of inorganic antibacterial agents. Inorganic antibacterial agents load metals or metal ions with antibacterial ability such as silver, copper, zinc on inorganic carriers, and realize antibacterial through slow-release of carriers. Its carriers are mainly zeolite, titanium dioxide, zirconium phosphate, silica gel, etc. Because the toxicity of silver ions is very small, it can help them meet the expected product performance requirements, and it is difficult to accumulate in the human body, so it has been commercialized, and silver antibacterial agents have become the most widely used antibacterial agents
from the perspective of development prospects, the use of inorganic antibacterial agents modified by nanotechnology to achieve the utilization ratio of high-strength steel in automobiles reaching more than 50% is most favored by people. This kind of antibacterial agent increases the contact area with bacteria due to its ultra-fine particle size. At the same time, it can penetrate the cell wall of bacteria into the cell body, destroy the activity of cell synthase, and make the cell lose the ability of division and proliferation and die. Therefore, functional nano inorganic antibacterial agents have extremely excellent antibacterial efficiency, and are safe, non-toxic, long-term, good slow-release effect. They have light stability and thermal stability that ordinary silver antibacterial agents cannot compare. In recent years, the technology of sterilization by photocatalysis of nano semiconductor particles has made progress. The biggest feature of this antibacterial agent is that it can not only kill bacteria, but also completely degrade organic matter, thus avoiding "white pollution"
the technology development and application of antibacterial plastics in China are developing continuously. The National Engineering Research Center of engineering plastics obtains a composite inorganic antibacterial agent with strong antibacterial property, no discoloration and low cost through ion exchange and multi-layer coating technology, and manufactures antibacterial plastics and products through the unique antibacterial masterbatch technology to strengthen the exertion of antibacterial power. After years of research, the center and Haier Group jointly launched domestic antibacterial household appliances. Duckling electric appliance group also applies nano antibacterial materials to washing machines and other fields. But on the whole, the technical development and application of antibacterial plastics in China still need to be strengthened. There are many manufacturers of toys in our country. Besides domestic sales, the export volume is very large. According to statistics, the annual consumption of plastic raw materials required by the domestic toy industry is about 1.5 million tons. However, imported raw materials are widely used in this industry, and domestic raw materials are rarely used. The reason is that the health and safety standards of foreign toys are strict, including the use of toys will not cause bacterial infection, while China's antibacterial plastics suitable for the toy industry can not meet the requirements, so manufacturers have to seek raw materials from abroad. Relevant units should make efforts to actively develop antibacterial plastics
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