These include self-heating packages made of electrically conductive polymer materials (EPM) with wire and plug. For the manufacture of such materials, dispersed fillers are introduced into polymers (thermoplastics, thermosets, rubbers and rubbers): carbon black (soot), graphite, carbon fibers or metals. They create a continuous chain structure necessary for the passage of electric current. For self-heating packages, compositions based on polypropylene and carbonyl nickel powder are most often used as an electrically conductive dispersed filler. To heat the contents, the package is connected to a regular electrical outlet. It is convenient to take such packages with you on the road.
In contrast to self-heating, there are cryogenic packages that freeze food (meat, fish, etc.). They use materials with high physical and mechanical properties, especially puncture resistance and frost resistance.
In our country, a new cryogenic technology has been developed, thanks to which a convenient and economical film coating is obtained from polyvinyl alcohol, a water-soluble synthetic polymer, which helps to maintain the quality and freshness of fish during fishing.
Today, there are products in "medical" packaging. The protein additive introduced into the polymer film absorbs it upon contact with milk or dairy products containing an increased amount of cholesterol. The product from such a package does not pose a cholesterol threat to the human body, which is similar to taking drugs, but much more pleasant and safer for health.
In conclusion, I would like to note that packaging, like any product, process or living being, has the moment of origin (birth), service life (life) and the end - destruction or death. Most types of packaging are born from oil, which is currently practically the only source of monomers, which are converted into polymers through complex syntheses. Compositions are obtained from them in the form of a finished product - granules. And, finally, one or another packaging (bags, boxes, boxes, cups, etc.) is produced from granules using various methods and on various equipment.
The service life of a package is determined by the material from which it is made, the manufacturing technology, the type of the packed product, the conditions of its transportation and storage. If the product in the package is stored incorrectly and, moreover, the expiration date has been exceeded, toxic substances released from the polymers that are harmful to human health begin to penetrate into it. Remember this!
The last stage in the existence of packaging is handling it after the product is removed, when it is thrown into the trash bin, and then it goes to the landfill, polluting the environment and releasing toxic substances (packaging materials occupy more than 50% of the structure of technical household waste!). This problem, which has not yet been resolved in our country, requires a separate discussion.