Classification of Transportation Packaging Technology (Part 2)
5. Insect proof packaging technology
insect proof packaging technology, commonly used is insect repellent, that is, put drugs with certain toxicity and smell in the packaging, and use the volatile gas of drugs in the packaging to kill and drive away all kinds of pests. Commonly used insect repellents include tea, para dichlorobenzene, camphor, etc. Vacuum packaging, inflatable packaging, deoxygenation packaging and other technologies can also be used to make pests have no living environment, so as to prevent pests
6. dangerous goods packaging technology
there are thousands of kinds of dangerous goods. According to their dangerous properties, they are divided into ten categories according to the regulations of the transportation and public security fire department, namely, explosive goods, oxidants, compressed gases and liquefied gases, spontaneous combustion goods, goods that burn in water, flammable liquids, flammable solids, toxic goods, corrosive goods, radioactive goods, etc. some goods have more than two kinds of dangerous properties at the same time
the package of toxic goods should be clearly marked with toxic signs. The main measures of anti-virus are tight packaging and airtight control. For example, potassium dichromate (potassium jarosite) and sodium dichromate < sodium jarosite) are red with transparent crystals and toxic. They should be packed in solid barrels, with the barrel mouth tight, and the thickness of the iron plate for barrel making should not be less than 1.2 mm. Commodities such as organic pesticides should be put into asphalt gunny bags with tight seams. If it is packed in plastic bags or asphalt paper bags, it should be packed in gunny bags or cloth bags. Zinc phosphide, which is used as a rodenticide, is highly toxic. It should be tightly sealed in plastic bags and then put into wooden boxes. The boxes are padded with two layers of kraft paper, moisture-proof paper or plastic film to isolate them from the outside world
for corrosive goods, we should pay attention to chemical changes in the materials of goods and packaging containers. Metal packaging containers should be painted on the container wall to prevent the corrosion of corrosive goods to the container. For example, the inner wall of the iron bucket for packaging synthetic fatty acids should be coated with an acid resistant protective layer to prevent the iron bucket from being corroded by the commodity, so that the commodity will also deteriorate. Another example is hydrofluoric acid, an inorganic acid corrosive substance, which is highly toxic and can corrode glass. Instead of using glass bottles as packaging containers, it should be put into metal barrels or plastic barrels, but then into wooden cases. Formic acid is volatile and its gas is corrosive. It should be put into a good acid resistant jar, glass bottle or plastic bucket, sealed tightly, and then put into a solid wooden box or metal bucket
for the packaging of yellow phosphorus and other goods prone to spontaneous combustion, it is advisable to put them into an iron bucket with a wall thickness of not less than 1 mm, which will directly affect the working efficiency of the machine. The inner wall of the bucket must be coated with an acid resistant protective layer. The bucket is filled with water, and the water surface is immersed in the goods. The bucket mouth is tightly closed, and the net weight of the barrel is not more than 50 kg. Another example is the water bow [inflammable items such as calcium carbide will decompose and produce flammable acetylene gas when encountering water. They should be packed in solid iron drums and filled with nitrogen. If the barrels are not filled with nitrogen, vent pistons should be installed.
for inflammable and explosive goods, such as those with strong oxidation, they will decompose rapidly when encountering trace impurities or products that cause explosion when heated. The effective method of explosion proof packaging is to use plastic drums for packaging, and then put the plastic drums Put it into an iron bucket or wooden case, each with a net weight of no more than 50 kg, and there should be a safety valve for automatic venting, which can automatically vent when a certain gas pressure is reached in the bucket
7. special packaging technology
(1) inflatable packaging. Inflatable packaging is a packaging technology that uses inert gases such as carbon dioxide or nitrogen to replace the air in the packaging container, so it is also called gas replacement packaging. According to the aerobic metabolism characteristics of aerobic microorganisms, this packaging method changes the composition of gas in sealed packaging containers, reduces the concentration of oxygen, inhibits the physiological activities of microorganisms, enzyme activities and the respiratory intensity of fresh goods, and achieves the purposes of mold prevention, corrosion prevention and freshness preservation
(2) vacuum packaging. Vacuum packaging is a kind of packaging method that after the articles are put into the airtight container and vacuumized before the container is sealed, so that there is basically no air in the sealed container
general meat commodities, grain processing commodities and some commodities prone to oxidation and deterioration can be packaged in vacuum. Vacuum packaging can not only avoid or reduce fat oxidation, but also inhibit the growth of some molds and bacteria. At the same time, when it is heated and sterilized, the heat conduction is accelerated because the gas inside the container has been eliminated. The high-temperature sterilization efficiency is improved, and the cracking of the packaging container due to the expansion of gas during heating sterilization is avoided
(3) shrink wrap. Shrink packaging is a packaging technology that wraps articles (or inner packages) with shrink film, and then heats the film appropriately to shrink the film and stick to the articles (or inner packages)
shrink film is a kind of polyethylene film that has been specially stretched and cooled. Due to the residual shrinkage stress generated by the film during directional stretching, Huigong will have to consider whether it is a failure in the refrigeration system after receiving a certain amount of heat. The company has successively signed contracts in the fields of clean energy, high-end equipment, smart electricity, intelligent transportation, etc., with a total amount of more than 800million yuan, so that it shrinks sharply both horizontally and vertically, At the same time, the thickness of the film is increased, and the shrinkage is usually 30-70%. The shrinkage force reaches the maximum in the cooling stage, and can be maintained for a long time
(4) stretch packaging. Stretch packaging is a new packaging technology adopted in the 1970s. It is developed from shrink packaging. Stretch packaging is a packaging method that relies on mechanical devices to stretch and tightly wrap the elastic film around the package at room temperature, and seal the end of it. Since stretch packaging does not need to be heated, the energy consumption is only one twentieth of that of shrink packaging. Stretch packaging can be used to pack single items, and it can also be used for collective packaging such as pallet packaging
(5) deoxygenation packaging. Deoxygenation packaging is a new method of deoxygenation packaging after vacuum packaging and inflatable packaging. Deoxidation packaging is to use deoxidizer that can react with oxygen in a sealed packaging container, so as to remove the oxygen in the packaging container, so as to achieve the purpose of protecting the contents. Deoxygenation packaging method is applicable to some items that are particularly sensitive to oxygen, and is used in food packaging where even a small amount of oxygen will cause the quality to deteriorate
information source: Industry Information Service
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