Technical requirements for flexible packaging of t

Technical requirements for flexible packaging of military products

in recent years, the packaging technology of military products in China has made considerable progress, which is an indisputable fact. But compared with developed countries, there is indeed a big gap. Scientific researchers in the packaging of military supplies products should have a clear head, work hard to learn 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 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 flexible packaging technologies are discussed as follows

1. Anti static

the electronic devices in high-tech weapon systems are mostly highly integrated aiming, guidance, monitoring, early warning, command and control systems that integrate light, electromagnetic control and precision instruments, as well as munitions products such as gunpowder, explosives, primary explosives, propellants, initiating explosive devices, ammunition, electric explosive devices, electronic fuses, etc. 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, and the loss is immeasurable. According to the exposure draft of the catalogue of packaging, transportation and storage of initiating explosive devices, it includes two parts: 1. The safety requirements of the national catalogue of industries encouraging foreign investment and the general technical conditions for the packaging, transportation and storage of aerospace initiating explosive devices, as well as the technical requirements specified in gjb2605-96 "Specification for heat sealable flexible anti-static barrier materials", the developed heat sealable flexible anti-static barrier materials have anti-static Anti electricity sometimes adopts cast structure (cast steel, cast aluminum, etc.) magnetic radiation and other technical properties. In this technology, conductive substances such as conductive carbon black, conductive fiber, metal powder, etc. are filled with polymer materials in a certain proportion to produce flexible materials with anti-static and anti electromagnetic radiation properties. Conductive materials such as metal series, metal oxide series, conductive carbon series and composite fillers can also be made into conductive coatings and coated on the surface of polymer materials to form a solidified 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 sealing flexible anti-static barrier material made by these technologies meet the technical requirements of the national military standard

2. Anti electromagnetic radiation

the modern information war and high-tech weapons and equipment integrating land, sea, air, space and electromagnetism put forward newer and higher requirements for the packaging of munitions products. With the adoption of electronic countermeasures technology, the electromagnetic environment of the battlefield is deteriorating. Electronic warfare has broken through the interference category for self-defense such as communication and radar, and then developed into the confrontation between many systems such as command, command and control, photoelectric and computer. When the electromagnetic wave penetrates the sensitive devices of the weapon system, its harm is like electrostatic discharge, which makes 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 general requirements for preventing the harm of electromagnetic fields to ordnance, the safety requirements for the packaging, transportation and storage of initiating explosive devices, the general technical conditions for the packaging, transportation and storage of aerospace initiating explosive devices, and the technical requirements specified in gjb2605-96 "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

3. Moisture proof

munitions 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 are very susceptible 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, which puts forward higher requirements for the moisture-proof performance of military packaging. Moisture proof packaging shall comply with the provisions of the national standard GB/t5048-1999 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 (damp heat test). After the test, it can ensure that the product performance meets the requirements of product standards. In particular, it is necessary to strictly implement the relevant standards of the general specifications for ammunition packaging to meet the tactical and technical requirements of ammunition 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

select polymer substrate with good mechanical strength and moisture resistance, and 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 barrier of the film and extends its shelf life by twice the water vapor performance. Then, PVDC lotion with excellent moisture resistance is coated, and the composite material with excellent barrier performance is formed after plasticization, drying and curing

4. Mold proof

chemical products, optical lenses, communication devices, instruments and meters and other military products are prone to mold invasion under appropriate environmental conditions such as temperature, humidity, nutrients, light, oxygen and so on during transportation, use and storage. The national standard GB/t4768-95 "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 mold test shall be carried out at the specified temperature, humidity, strain and test cycle according to the national standard GB/t4857.21-95 mold proof test method for packaging and transportation packages, or according to the fuze environment and performance test method mold test. 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 anti mildew properties of polymer materials, anti mildew agents such as phenolic compounds, organometallic compounds, nitrogen-containing compounds, halogen-containing compounds, sulfur-containing compounds, etc. need to be filled with them in a certain proportion to prepare anti mildew materials

5. Flame retardant

munitions 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 the polymer, 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, MoO3, CaCO3, etc. The oxygen index shall be determined in accordance with GB/t2406-1993 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, based on the mechanism of condensed phase flame retardation, achieve flame retardancy by generating cracked carbon layers and improving the oxidation resistance of carbon layers, mainly cartons. 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

6. Compatibility and contact corrosion

due to the special requirements of tactical and technical performance and long-term storage, the packaging materials of Quartermaster products have good compatibility with gunpowder, explosives, primary explosives, propellants, initiating explosive devices, ammunition, etc; 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 of packaging materials is carried out according to the differential thermal analysis and differential scanning calorimetry of explosive compatibility test. The contact corrosion with low carbon steel, aluminum alloy, copper foil, stainless steel, iron nickel cobalt alloy, etc. shall meet the requirements of gjb2605-96 "Specification for heat sealable flexible antistatic barrier materials". In the design of inner materials of military packaging, materials with good compatibility with the packaged products should be selected

7. 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 product packaging, according to the general specification for ammunition packaging and other relevant military standards, materials with good mechanical strength are selected to optimize the combination, so as to enhance the mechanical properties of packaging materials, such as breaking force, right angle tearing force, friction resistance, puncture resistance and cushioning performance, ensure the tactical and technical performance of military products, and facilitate long-term storage. After the packaging of military supplies products is tested according to gjb2711-96 "test methods for military transport packaging", the internal military supplies products meet the requirements of the corresponding product standards

the development of packaging technology for Quartermaster products 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 Quartermaster products in various harsh natural environments such as high temperature, low temperature, high humidity and high salt fog. The sealing methods of Quartermaster product packaging have been diversified, such as vacuum sealing, inert gas filling sealing, mechanical sealing, etc., which are not only convenient for repeated opening for service treatment, but also can play its reliable protective function. According to the characteristics of high intensity and harsh environment in wartime, we should focus on the military packaging under field conditions, give full play to the packaging as the "bearing body" of various harsh environmental factors, and realize the functions of "bearing body" and "connecting body" of logistics equipment support capacity, give our army a packaging structure that meets the needs of modern local high-tech war, and meet the support requirements of mechanized loading and unloading and containerized transportation, Ensure that military packaging plays an active and effective role in military struggle

source: China packaging business