There are many ways to prepare food antibacterial packaging films. One is to make the antibacterial agent into an antibacterial masterbatch, which is prepared by extruding or drooling a single layer of the antibacterial agent or the antibacterial masterbatch and the resin, and can also form an antibacterial composite film by co-extrusion as a surface layer and other layers. Another is obtained by coating or evaporating an antibacterial agent on a resin film.
For the antibacterial film made from the antibacterial masterbatch, due to the thin thickness of the film itself, the particle size of the antibacterial particles is required to be small, and the particle size distribution should be relatively narrow or the organic antibacterial agent that can be dissolved in the resin should be used. Generally, the addition of antibacterial agents or antibacterial masterbatches does not have a significant effect on the mechanical properties of the film, nor does it adversely affect the printing properties of the film. However, it has a certain impact on the barrier properties of some films. Therefore, when choosing antibacterial agents and antibacterial masterbatches, pay attention to the influence of the addition of antibacterial agents and antibacterial masterbatches on the performance of the film, and select appropriate antibacterial agents to ensure the performance of packaging. Meet the requirements for use. The commonly used packaging materials are LDPE, LLDPE, EVA, cellulose film, edible film, etc.
For methods of applying or evaporating antimicrobial agents onto films, the barrier properties of different plastics vary widely, and if the substrate is not damaged during the coating and coating process, it can still affect the quality of the final product. The surface properties, performance polarity, surface roughness, percentage of oxygen and nitrogen atoms on the surface of the plastic film will affect the bonding strength of the film and the antibacterial agent, thereby affecting the antibacterial performance. In addition, before coating or evaporating the antibacterial agent on the film, the surface of the film substrate should be pretreated to improve its surface land energy and improve the bonding force. The packaging film substrates used for coating or evaporation generally include PET, PA, PVC, BOPP, LDPE, etc.
In addition to meeting the mechanical properties, printing properties, display properties and other properties that packaging materials must have, food antibacterial packaging films all over the world have high requirements for the hygienic properties of food packaging materials. my country's national standard GB-9687 stipulates the hygienic requirements for food packaging materials, requiring the materials to have normal color, no peculiar smell, no peculiar smell, and no foreign matter, and be free from evaporation residues, potassium permanganate consumption, heavy metal content, decolorization experiments, etc. meet the corresponding requirements. The US FDA has also made specific regulations on the composition of food packaging materials, additive specifications, conditions of use, dissolution requirements, requirements for chronic toxicity testing of food packaging materials leaching, and requirements for subchronic toxicity testing.
The compound antibacterial agent used for food packaging, the organic antibacterial agent triazine antifungal agent and the pyridine antibacterial agent compounded in the Japanese market, the compound antibacterial agent triazine antibacterial agent, its antibacterial effect has improved by 3— 4 times. The antibacterial agent of organic antibacterial agent and inorganic antibacterial agent developed by the National Engineering Research Center of Haierke Chemical Engineering Plastics in China overcomes the problem of single function of KFHS series antibacterial agent. In addition, nano-TiO2 can be added to the inorganic silver-based antibacterial agent in the food packaging film to solve the problem that the antibacterial effect of the silver-based antibacterial agent is slow.
