Application of Nano Antibacterial Materials in Packaging Industry (II)

Second, the application of nano-antibacterial materials in the packaging industry (A) nano-inorganic antibacterial plastics Antibacterial materials used in the packaging industry is mainly anti-bacterial plastics, its use in the form of films, hollow containers and turnover boxes. Organic antibacterial agents have been limited in their application to the packaging industry because of their safety issues, and natural antibacterial agents have attracted much attention due to their efficiency and safety.
1. Antimicrobial agents can be applied to plastic products in the following three ways: 1 The antibacterial agent is mixed directly with plastics and dispersed in plastics to make antibacterial plastics; 2 The antibacterial masterbatch and plastics are blended and processed; 3 In the process of forming products The antibacterial agent is embedded in the plastic surface. The direct addition method of the antibacterial agent is simple, but the antibacterial agent is poorly dispersed in the plastic, the antibacterial agent particles are easily agglomerated, the antibacterial effect is poor, the use of the antibacterial agent is insufficient, and the use cost is increased. The core technology of the antibacterial masterbatch method is the development of antibacterial masterbatches. The antibacterial masterbatch is a highly concentrated antibacterial agent dispersed in a carrier resin and contains an antibacterial dose of 10% to 40%. The antibacterial masterbatch is processed together with the plastic or re-dispersed and dispersed together with the plastic, which is beneficial to the dispersion of the antibacterial agent and the exertion of the antibacterial effect. It is a commonly accepted and widely used technical approach, and a reasonable antibacterial masterbatch design and use. , Can greatly save the use of antibacterial agents. The main purpose of processing antibacterial plastic products in the molding stage of the products is to save the amount of antibacterial agents, use antibacterial agents rationally, and control costs. At present, there are two specific implementation schemes: One is to make the ultrafine antibacterial agent particles into a spray liquid and spray it on the surface of the plastic mold. When the plastic is injection molded, the antibacterial agent enters the surface of the plastic part; the other is The antibacterial agent and the plastic are made into a film, and then the film is attached to the surface of the mold. When the plastic is molded, the antibacterial plastic film is bonded to the surface of the article. The use of this antibacterial molding technology can greatly save the amount of antibacterial agents, and the use of antibacterial molding techniques can greatly save the amount of antibacterial agents. However, the current application is not universal, mainly because of the large investment in equipment.
2. The inorganic antibacterial plastic is an inorganic antibacterial agent added to the resin, and the migration of the inorganic antibacterial agent in the resin forms a surface layer having an antibacterial ability on the surface of the resin, and is sterilized by contact with the packaged object. Since the inorganic antibacterial agents are mostly powdery and have a small particle size, it is generally necessary to uniformly disperse these particles into the resin during processing to obtain a desired antibacterial effect. Therefore, the antibacterial agent is generally made into an antibacterial masterbatch, and then blended with the resin in the desired ratio. In addition, the compatibility of the antibacterial agent and the resin needs to be considered. Therefore, the antibacterial agent needs to be pretreated, and the coupling agent must be added. Dispersants, etc.
Experiments showed that the film was tested for basic properties by blending a silver-based antibacterial agent and ldpe resin. The results showed that after the silver-based antibacterial agent was added, the film had good antibacterial properties, but the film was only pulled. Tensile strength, elongation at break, and oxygen permeability slightly decreased. However, it fully meets the production standards and performance requirements of packaging films.
3. At present, antibacterial materials are mainly prepared by adding inorganic nano-antibacterial materials, that is, adding nano-antibacterial materials to plastic raw materials. The antibacterial principle of the new contact inorganic nano-antibacterial materials is different from the traditional dissolution-type organic nano-antibacterial materials and photocatalyst-type inorganic nano-antibacterial materials. The sterilization mechanism is that when a positively charged antibacterial component comes into contact with a negatively charged microbial cell, it adsorbs each other, that is, it effectively breaks down the cell membrane, denatures the cell protein, cannot breathe, metabolizes and reproduces until it dies, and sterilization is completed. . At this point, the antibacterial ingredient does not consume any, and it still retains its original antibacterial ability, so its antibacterial ability can be effective for a long time.