Talking about the packaging technology of military products
the smoke of the war in Iraq cleared up and the dust settled, leaving the world with infinite and heavy thinking. As "military workers", especially "military packers", we think more about the packaging of military products in high-tech wars. In recent years, China's military packaging has made great progress, which is an indisputable fact. But compared with developed countries, there is indeed a big gap. "Backwardness means being beaten". We should be based on winning the future "digital war". The scientific researchers of military packaging should be sober, study hard, strengthen exchanges, master and apply high and new technology, develop advanced packaging technology for winning the war, and make military packaging play a positive and effective role in the military struggle. In this paper, the newly developed anti-static, anti electromagnetic radiation, moisture-proof, mold proof, flame retardant, compatibility, mechanical strength and other major packaging technologies are discussed with military counterparts
I. anti static
highly integrated electronic devices in high-tech weapon systems, aiming, guidance, monitoring, early warning, command and control systems integrating optical, electromagnetic control and precision instruments, and military products such as gunpowder, explosives, primary explosives, propellants, initiating explosive devices, ammunition, electric explosive devices, electronic fuses, due to friction, impact, contact Separation, etc. generate static electricity accumulation and discharge, resulting in failure or misoperation of weapon control system, combustion and explosion of initiating explosive devices, resulting in immeasurable losses. According to the technical requirements of relevant national military standards such as gjb260596 "Specification for heat sealable flexible anti-static barrier materials", the developed heat sealable flexible anti-static barrier materials have anti-static, anti electromagnetic radiation and other technical properties. This technology uses conductive substances such as conductive carbon black, conductive fiber, metal powder, etc. to fill polymer materials in a certain proportion to produce heat sealable flexible packaging materials with anti-static and anti electromagnetic radiation properties. Conductive materials such as metal system, metal oxide system, conductive carbon system and composite filler can also be made into conductive coatings and coated on the surface of polymer materials to form a solid electrostatic dissipation layer. A metal coating with conductive function can also be formed on the surface of polymer materials by electroplating, electroless plating, physical vapor deposition (PVD), chemical vapor deposition (CVD), thermal spraying (coating), etc. The surface resistivity, electrostatic attenuation and electrostatic shielding of the heat sealable flexible anti-static barrier material made by the above technology meet the technical requirements specified in the national military standard.
II. Prevention of electromagnetic radiation
modern information warfare and high-tech weapons and equipment integrating land, sea, air, space and electromagnetism put forward newer and higher requirements for military packaging. With the adoption of electronic countermeasures technology, the electromagnetic environment of the battlefield is deteriorating. Electronic warfare has broken through the interference scope for the purpose of self-defense, such as the recovery, modification and high value-added utilization system of engineering plastics established by communications and mines, and then developed into the confrontation between command, command, photoelectric and computer systems. When the electromagnetic wave penetrates the sensitive components of the weapon system, its harm is very similar to electrostatic discharge, making the control system invalid or malfunction. Under the action of electromagnetic energy, initiating explosive devices, ammunition, electric explosive devices, electronic fuses, etc. are very prone to combustion and explosion. According to the technical requirements specified in the national military standard gjb260596 "Specification for heat sealable flexible anti-static barrier materials", the developed heat sealable flexible anti-static barrier materials have anti-static, anti electromagnetic radiation and other technical properties. The technology used is the same as the anti-static technology.
III. moisture resistance
military products such as gunpowder, explosives, primary explosives, propellants, initiating explosive devices, ammunition, etc. are very prone to moisture absorption and deterioration; Electronic instruments and core plates, precision firearms, instruments and meters have been repeatedly verified by many manufacturers in recent days. They are very vulnerable to moisture, rust or mold erosion. China has a vast territory, and the frontier and coastal defense lines are very long. There are not only the cold north, but also the vast coastal areas near the equator, the southwest region with poor storage environment, but also the southeast coast with high temperature, high humidity and high salt fog. This puts forward higher requirements for the moisture-proof performance of military packaging from less to more crystalline fractures. Moisture proof packaging shall comply with the provisions of the national standard GB/T moisture proof packaging; Damp proof packages shall be subject to alternating damp heat test according to the product characteristics and the climatic conditions of the storage and transportation environment. The test is carried out according to the environmental test method of military equipment. After the test, it can ensure that the product performance meets the requirements of product standards, so as to meet the tactical and technical indicators of weapons and equipment after long-term storage. The manufacturing technology of moisture-proof packaging materials is designed according to the inherent properties and moisture-proof mechanism of polymer films. Polymer substrates with good mechanical strength and moisture resistance, such as biaxially stretched polyester (BOPET) film, are selected to form a dense metal aluminum layer after vacuum aluminum plating. Aluminum atoms block the gaps in or between plastic molecular chains, which greatly enhances the water vapor barrier performance of the film
then, PVDC (polyvinylidene chloride) lotion with excellent moisture resistance is coated, which forms a composite material with excellent barrier performance after plasticization, drying and curing. IV. mold prevention
military products such as chemical products, optical lenses, communication devices, instruments and meters are prone to mold invasion under appropriate environmental conditions such as temperature, humidity, nutrients, light and oxygen during transportation, use and storage. The national standard GB/T "mould proof packaging" stipulates that the grade of mould proof packaging should be determined according to the anti mould invasion ability of the product, the environmental conditions involved in transportation and storage, the structure of the packaging, the mould resistance of the selected packaging materials and the results of mould test. The mould test is based on the national standard GB/T "mould proof test method for packaging and transportation packages"; Or according to the fuze environment and performance test method, it shall be carried out at the specified temperature, humidity, strain and test cycle. Mold inhibitor is a kind of assistant that can inhibit the growth of mold and kill mold. Its mechanism is mainly to reduce or eliminate the activities of various enzymes in mold cells, destroy the energy release system in cells, and hinder the growth of electron transfer system and aminotransferase. In order to obtain mildew resistance of polymer materials such as polyethylene (PE) and polypropylene (PP), anti mildew agents such as phenolic compounds, organometallic compounds, nitrogen-containing compounds, halogen-containing compounds, sulfur-containing compounds, etc. should be mixed evenly with them in a certain proportion, and the anti mildew resin is prepared through plasticization, mixing and granulation; The three-layer co extrusion blow molding process is often used to make mold proof polymer materials with mold proof resin.
v. flame retardant
military products, especially the packaging materials of gunpowder, explosives, primary explosives, propellants, initiating explosive devices, ammunition, etc., must have flame retardant function. The technology adopts that after introducing impurity atoms into polymers such as polyethylene (PE) and polypropylene (PP), the oxygen index increases, so as to achieve the flame retardant function. Commonly introduced flame retardant and smoke eliminating substances include Al (OH) 3, Mg (OH) 2, moo 3, CaCO3, etc. The oxygen index shall be determined according to GB/T test method for flammability of plastics - oxygen index method. Silicon containing flame retardants or graphite can also be added to polymers. Silicon containing flame retardants are based on the mechanism of condensed phase flame retardation, and achieve flame retardancy by generating pyrolysis carbon layer and improving the oxidation resistance of carbon layer. The flame retardant mechanism of graphite is: graphite has adsorption, forms complex structure after blending with polymer, and plays a certain role of skeleton support in the combustion process, so that the material does not drip during combustion, slowing down the combustion trend; The gas generated by combustion dilutes the concentration of oxygen, reduces the flame intensity, and enhances the flame retardant effect of gas phase.
VI. compatibility and contact corrosion
military products have good compatibility with gunpowder, explosives, primary explosives, propellants, initiating explosive devices, ammunition and other packaging materials due to special requirements such as tactical and technical performance and long-term storage; It has no contact corrosion with metals such as low carbon steel, aluminum alloy, copper foil, stainless steel, iron nickel cobalt alloy, etc. The compatibility test between packaging materials and explosives is carried out according to differential thermal analysis and differential scanning calorimetry. The contact corrosion with low carbon steel, aluminum alloy, copper foil, stainless steel, iron nickel cobalt alloy, etc. shall comply with the requirements of gjb260596 specification for heat sealable flexible antistatic barrier materials. Therefore, in the design of inner materials of military packaging, materials with good compatibility with the packaged products should be selected.
VII. Mechanical strength
the packaging materials of military products must have sufficient mechanical strength to ensure that military products will not be damaged due to extrusion, friction, impact, vibration and fall during stacking, loading, unloading, transportation and storage. Therefore, in the design process of military packaging, materials with good mechanical strength should be selected and optimized according to relevant military standards to enhance the mechanical properties of packaging materials, such as breaking force, right angle tearing force, friction resistance, puncture resistance and cushioning performance, so as to ensure the tactical and technical performance of military products and facilitate long-term storage. The packages of military products meet the requirements of corresponding product standards after being tested according to the test methods of military transport packages. The development of military product packaging technology should also be carried out according to the characteristics of aging resistance and environmental weatherability of materials, so as to ensure the tactical and technical performance of military products in various harsh natural environments such as high temperature, low temperature, high humidity and high salt fog. According to the characteristics of high intensity and harsh environment in wartime, we should focus on the protection of military packaging under field conditions, give full play to the packaging is not only the "bearing body" of various adverse environmental factors affecting the quality of equipment, but also the logistics support and equipment support ability, realize the functions of "bearing body" and "connecting body" of information transmission, and give our existing equipment and equipment a packaging structure that meets the needs of modern local high-tech wars, Meet the support requirements of mechanized loading and unloading and containerized transportation, realize the "maintenance free" storage equipment and equipment support, the "accompanying support" of carrying and operating equipment and equipment, the "complete set" of equipment and equipment supply support and the "controllability" of the whole process, and ensure that military packaging plays an active and effective role in military struggle