Current situation and development of the hottest p

2022-08-01
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The present situation and development of plastic flexible packaging (Part 2)

a Japanese paper company produces a fruit fresh-keeping packaging box. It is to add a layer of polyethylene film on the corrugated paper lining of the corrugated box, and then apply a waterproof wax coating containing a trace of fruit disinfectant to prevent the evaporation of fruit moisture and inhibit respiration, so as to achieve the purpose of fresh preservation. This kind of packing box can keep the fruit fresh for one month

in order to keep the fruits and vegetables fresh during transportation, an American company has invented a new method to reduce the oxygen content and increase the nitrogen content in the packaging box to keep the fruits and vegetables fresh. This method uses a new type of packing box with air conditioning performance in transportation. This kind of packing has a special layer of film, which can absorb oxygen molecules and allow nitrogen to pass through. In this way, after the air enters the packaging box through the film, the nitrogen content in the box can reach more than 98%, so as to slow down the respiration of fruits and vegetables and achieve the purpose of keeping fresh for a long time

an American company has launched a new type of fresh-keeping plastic bag for fruits and vegetables, which can prolong the fresh-keeping period of fruits and vegetables and reduce the loss of fruits and vegetables caused by too fast ripening. In order not to damage some data collection equipment such as sensors, the seed packaging bag is mixed with natural activated clay and polyethylene, which is like a very fine filter screen. The gas and water generated during the ripening process of fruits and vegetables can pass through the packaging bag. It is not easy to breed fungi in the bag, which can prolong the freshness of fruits and vegetables by more than one time

an American company has developed a plastic fresh-keeping bag that can keep fresh for up to 3 years. This kind of fresh-keeping bag is attached with a layer of plastic film inside the ordinary plastic bag. The film contains oxygen getter, which can absorb the oxygen in the process of food packaging, which makes the microorganisms that cause food decay unable to survive due to lack of oxygen

silicon window modified atmosphere fresh-keeping bag. The silicon window modified atmosphere fresh-keeping bag is filled with silicone rubber film with appropriate area 4 and display range of 0 ~ 99999.9n on the plastic film bag. Silicone rubber film can selectively permeate oxygen, carbon dioxide and nitrogen. This kind of silicon window modified atmosphere fresh-keeping bag has achieved good results in fruit storage. Under certain storage conditions, the appropriate silicon window area can be determined. After being closed for a certain time, the concentration of oxygen and carbon dioxide in the package can be automatically adjusted to the required level. Generally, 1000 kg apples are stored, and a silicon window with an area of 0.6 square meters is set to maintain the appropriate level of oxygen and carbon dioxide. Excess carbon dioxide generated by respiration can be discharged through the silicon window. When the oxygen in the bag is insufficient, it can be penetrated through the silicon window. The key of silicon window controlled atmosphere technology is to select silicon window film, determine the silicon window area, suitable storage capacity and storage temperature

aseptic and antibacterial plastic packaging materials

aseptic packaging can maximize the original nutritional components and flavor of food at room temperature without adding preservatives under aseptic conditions. It can prolong the shelf life and facilitate transportation and storage. Aseptic packaging is mainly used in food, condiment, medicine, cosmetics and other fields. The flexible packaging materials used are paper, plastic, aluminum-plastic composite films, multi-layer co extrusion sterile packaging sheets containing high barrier plastics, etc

antibacterial plastic packaging materials give certain antibacterial properties to plastic packaging materials. Now, a brand-new masterbatch has been developed with silver ions as inorganic antibacterial agents. Silver ions have significant antibacterial effects, which are characterized by long-lasting antibacterial effect, not high due to gasification and migration, and not polluting the environment. The film made from the added silver ion masterbatch (content 1% ~ 3%) or the container with a layer of this film on its surface has been tested. It has been shown that the film containing 1% silver ion masterbatch can completely kill the bacteria that may cause food poisoning within 1 ~ 2 days without nutrient source, and is widely used in the packaging of cooked meat, aquatic products and liquid food. In addition, in foreign countries, films with extracts from some plants as antibacterial agents have also been produced. This kind of antibacterial films are mainly used for the packaging of newly picked vegetables and fruits

high heat resistant plastic packaging materials

heat resistant plastic flexible packaging materials used to be resistant to cooking and sterilization. They meet the packaging requirements for resistance to cooking and sterilization. Under the condition of 120 ℃ and 10 ~ 20 minutes of cooking and sterilization or heating, there is no obvious change in appearance, shape and quality, and the packaged food will not have container damage, content leakage, secondary microbial pollution, light and heat deterioration during storage. Most cooking bags are made of multi-layer composite cooking films with shading aluminum foil as the middle layer, high barrier plastics PA and pet as the outer layer and heat sealing PE and PP as the inner layer. Some new multilayer composites containing high barrier materials such as EVOH, PVDC, MXD6 and silicon oxide evaporation film are also increasingly used

with the increasing popularity of electromagnetic cookers and microwave ovens, there is an increasing demand for packaging containers suitable for electromagnetic cookers and microwave ovens. However, the requirements of electromagnetic cooker and microwave oven for packaging materials are that the packaging materials are not significantly deformed, damaged and the contents (additives) are not volatile under high temperature. In particular, the heating characteristics of microwave oven do not allow the packaging materials to contain metal materials, which limits the use of cooking bags with aluminum foil as the middle layer and PE and PP as the inner layer. Therefore, now, multi-layer composite materials filled with PP and inorganic materials and packaging containers made of crystalline polyester (CPET) sheets are mostly used. New heat-resistant packaging materials with higher temperature resistance, such as polyester film, polyetherimide, poly (4-methylpentene) (TPX)/paperboard, have also been developed. They can withstand temperatures above 180 ℃. Enough to meet the requirements of electromagnetic cooker and microwave oven for packaging materials

special functional materials

functional packaging materials: other flexible packaging materials with special functions include hygroscopic, deodorizing, deodorizing, antistatic, antirust, UV blocking, volatile gas release or adsorption, convenience (easy to open, easy to seal) and edible materials. For example, the film developed in recent years by adding iron, ascorbic acid and other compounds or activated carbon, zeolite, etc. to PE, PP and PVC has the effect of removing odor such as ammonia, mercaptan, hydrogen sulfide and dimethylamine. It is suitable for packaging agricultural and sideline products, aquatic products and raw and fresh food with special odor, and will not cross smell. It is also suitable for garbage bags

nanocomposite packaging materials

nanotechnology is a high-tech emerging in recent years. According to its conversion principle, it is divided into binary ramp method, integration method, parallel comparison method, voltage 1 frequency conversion method and successive comparison method. Polymer based nanocomposites (pnmc) are the most studied nanocomposite packaging materials. Common polymers include PA, PP, PVC, pet, etc. the plasticity, wear resistance, hardness and strength of nanocomposite plastic packaging materials have been significantly improved and enhanced. Compared with ordinary composite PA packaging materials, the PA6 nanocomposite packaging materials first developed by Japan have increased the tensile strength and tensile modulus by 110MPa and 2.1gpa respectively, the thermal deformation temperature by 150%, and the thermal expansion coefficient and water absorption by a large margin. It is reported that China has also developed new nanocomposite packaging materials, which will soon be put into mass production

at present, the development trend of newly developed plastic packaging films at home and abroad is towards the direction of high performance, non-toxic, harmless, green environmental protection, high quality, low price and convenient use. Among them, the flexible packaging materials have been further developed from food packaging to non food packaging fields such as industrial packaging, pharmaceutical packaging, building materials packaging and cosmetics packaging, and their application range and consumption will be larger and larger

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