High-performance functional package material green (4)

Heat-resistant packaging material
Heat-resistant plastic flexible packaging materials used to be resistant to retort sterilization, to meet the retort sterilization requirements of packaging at 120 °C, 10 to 20 minutes retort sterilization or heating, the appearance of the shape, quality have no significant changes, packaging foods in No damage to the container, leakage of contents, secondary contamination of microorganisms, deterioration of the contents due to light and heat, etc. occurred during storage. Basically, a light-blocking aluminum foil is used as an intermediate layer, a high-barrier plastic PA and PET are used as the outer layers, and a heat-sealing PE and PP inner layer multi-layered composite cooking film is used most often for cooking bags. Some new multi-layer composite materials such as EVOH, PVDC, MXD6, and silicon oxide evaporated films containing high barrier materials are also being used.

With the increasing popularity of microwave ovens and microwave ovens, there is an increasing demand for packaging containers suitable for use in induction cookers and microwave ovens. The requirement for packaging materials for induction cookers and microwave ovens is that they should not be deformed or damaged at high temperature, and the contents (additives) should not be volatilized. In particular, the heating characteristics of microwave ovens do not allow metal materials to be included in the packaging materials. This limits the The use of aluminum foil as the middle layer, PE, PP as the inner cooking bag. Therefore, a packaging container made of PP, a multilayered composite material in which inorganic matter is filled with PP, and a crystalline polyester (CPET) sheet is often used. New heat-resistant packaging materials that are resistant to higher temperatures, such as polyester films, polyetherimides, and polytetramethylpentene (TPX)/paperboard, have also been developed, and they are all capable of resisting temperatures above 180°C. Sufficient to meet the requirements of electromagnetic ovens, microwave ovens for packaging materials.

Sterile and Antibacterial Plastic Packaging Materials
Sterile packaging can be aseptic conditions, without adding preservatives, at room temperature to maximize the retention of the original nutrients and flavors of food. The shelf life can be extended for transportation and storage. Aseptic packaging is mainly used in food, condiments, medicine and cosmetics. The flexible packaging materials used are paper, plastic, aluminum-plastic composite films, multi-layer co-extruded aseptic packaging sheets containing high barrier plastics, and the like.

Antibacterial plastic packaging material is to give a certain degree of antibacterial properties of plastic packaging materials, and now has developed a new type of masterbatch containing silver ions as an inorganic antibacterial agent, silver ions have a significant antibacterial effect, characterized by long-lasting antibacterial effect It will not be high due to gasification and migration and will not pollute the environment. A thin film prepared by adding a silver ion-containing master batch (a content of 1% to 3%) or a container coated with a layer of this thin film on the surface shows that in the case of a non-nutrient source, a 1% silver ion mother was used. The film of the material can completely kill the bacteria that can cause food poisoning within 1 to 2 days, and is widely used for packaging of cooked meat, aquatic products and liquid foods. In addition, extracts from certain plants in foreign countries have also been produced as antibacterial films, and these antibacterial films are mainly used for the packaging of newly picked vegetables and fruits.

Nano composite packaging material

Nanotechnology is a high-tech science and technology that has emerged in recent years. The most studied nanocomposite packaging material is polymer-based nanocomposite (PNMC). Commonly used polymers are PA, PP, PVC, PET, etc. The plasticity, wear resistance, hardness, and strength of nano-composite plastic packaging materials have been significantly improved and enhanced. Japan's first PA6 nanocomposite packaging material successfully developed compared with ordinary composite PA packaging materials, the tensile strength and tensile modulus were increased by 110MPa and 2.1GPa, respectively, the heat distortion temperature was increased to 150%, and the coefficient of thermal expansion and the water absorption rate were greatly reduced. . According to reports, China has also developed a new nano-composite packaging material, which will soon be put into large-scale production.

In general, at present, the development trend of newly-developed packaging materials at home and abroad is toward the development of high-performance, non-toxic, environmentally-friendly, inexpensive, and easy to use green packaging. Among them, the functional packaging materials have been developed from the past to the single industry and further to the industrial packaging, pharmaceutical packaging, building materials packaging, cosmetics packaging, food packaging and other packaging areas, the scope of its use and the amount will be greater and greater. In addition, intelligent functional packaging materials developed at present are made by compounding functional materials such as photoelectric, temperature sensitive, humidity sensitive and packaging materials. It can identify and indicate some important parameters such as temperature, humidity, pressure, degree of sealing, and time of packaging space, and provides a broader arena for the development of smart packaging materials.