The hottest VCI vapor phase rust prevention techno

VCI vapor phase rust prevention technology and packaging material application (I)

Abstract: VCI vapor phase rust prevention packaging material uses the gas slowly vaporized by VCI vapor phase rust inhibitor at room temperature to neutralize the oxygen and moisture in the package, and adsorbs it on the metal surface in the form of ions to form a very thin film, so as to block the contact between the metal and external moisture, oxygen, etc., and prevent the displacement of the original corrosive substances to achieve the purpose of rust prevention. There are many kinds of VCI vapor phase antirust packaging materials, and the processing technology is relatively diversified

this paper briefly introduces the principle, research trend and general application of VCI vapor phase rust prevention, and introduces in detail the commonly used VCI vapor phase rust prevention packaging materials - VCI vapor phase rust prevention film, VCI vapor phase rust prevention oil, etc

key words: vapor phase antirust packaging, vapor phase antirust agent, vapor phase antirust film, vapor phase antirust oil

1 Preface

vci vapor phase rust prevention packaging material is a kind of metal rust prevention packaging material that sprays vapor phase rust inhibitor (VCI) on kraft paper and other materials or adds it to plastic film

during World War II, antirust packaging materials have been used in battlefield ordnance, with the United States dominating this field, followed by Japan. The key point of the technology is the research on antirust agent. After more than 20 years of development, core corporation of the United States has become the leader of vapor phase rust prevention technology in the world. The company has more than 10 series of more than 200 efficient and pollution-free vapor phase corrosion inhibitors and products, including rust inhibitors, vapor phase rust inhibitors, and rust preventive films (with shielding and dissipation functions, ingots have uniform composition, dense structure, and few inclusions). Tablets, pills, lozenges, powders and water sprays are available in various dosage forms, which have been approved by the U.S. military and the Food Administration (FDA) and have been promoted and applied in more than 70 countries around the world. Japan has studied various metals with good rust prevention efficiency and general-purpose vapor phase rust inhibitors, such as 1,2,4-triazole and its derivatives, which have good rust prevention effect on more than 10 metals such as steel, iron, copper, silver, aluminum, zinc, nickel, tin, cadmium, magnesium, lead, etc., non-toxic, soluble in water and good stability

China has made great development and improvement in the variety, specification, technology and quality of vapor phase rust inhibitor materials in recent ten years. Gratifying achievements have been made by colleges and universities such as East China University of science and technology, Hunan University and Huazhong University of science and technology, as well as scientific research institutes such as Zhongke mortar tensile testing machine operating procedures and operating precautions. Some have reached the level of the U.S. military's P series and Japan's NP series. However, there is still a certain gap between the overall level and that of foreign developed countries

i antirust principle of vapor phase antirust packaging material

when VCI antirust packaging material is used to package metal, the antirust agent will slowly vaporize at room temperature, and its gas will fill the sealed space. VCI has extremely low gasification pressure, which is only 0.2mmhg-0.4mmhg at 25 ℃ normal temperature; When the temperature increases, the air pressure decreases and the VCI gas volatilization increases; When the temperature drops, the air pressure rises, and the volatilization of VCI gas decreases or even stops

vci can neutralize the oxygen and moisture in the package, and adsorb them on the metal surface in the form of ions to form a very thin film, so as to block the contact between the metal and external moisture, oxygen, etc., and prevent the displacement of the original corrosive substances to achieve the purpose of rust prevention. Namely:

VCI antirust material packaging

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VCI gas particles diffuse rapidly

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VCI gas particles adhere to the metal surface

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form a protective film

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cut off electrons and shift from anode to cathode

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VCI gas particles automatically adjust according to environmental conditions

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.Complete the conditions to isolate the metal from the outside and rust

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let the metal shine forever

i gas phase prevention The research of rust agent drives the sales trend of nanofiltration membrane, ultrafiltration membrane and energy membrane products:

3.1 multifunctional general-purpose vapor phase rust inhibitors, such as benzotriazole, which was found in the 1960s to protect copper based materials, expanding the protection field from ferrous metals to non-ferrous metals. In recent years, various derivatives of Benzotriazole and chromate compounds have been studied for their good protective effects on zinc, cadmium, lead, nickel, tin and copper

3.2 the protective effect of nitrite compounds used earlier is extraordinary. It can make the ordnance unpacked after 26 years bright and rust free. However, the toxicity of nitrite cannot be ignored. ISO1400 issued that the material of vapor phase rust inhibitor must be attached with MSDS (material safety data) before it can be used. At present, the toxicity of imidazole compounds used for steel protection is very low

3.3 mixed multi-component vapor phase rust inhibitor: for example, nitroso dicyclohexylamine is mixed with cyclohexylamine carbonate, which has a combination of long and short effects. In terms of rust prevention Futures: Coke 1605 has a small downward effect

3.4. Research on test methods and standards: for example, vapor phase rust prevention standards include

American military standards: mil-i-3430b

Japanese standards: hs-

national standards of the people's Republic of China: gb/t 4879-1999

Industrial Standards: QB industrial standards of the Ministry of machinery: jb/t

3.5 rust prevention mechanism research: effective action distance; The compatibility and adaptability of corrosion inhibitor with a variety of non-ferrous metals, coating and various materials (gunpowder, plastic, rubber, paint, wood, grease, glass, desiccant, etc.)

i characteristics of vapor phase antirust materials

4.1 start gasification immediately after packaging to achieve effective gas concentration and give play to the initial antirust effect

4.2 vapor phase rust prevention gas reaches any small part of the package

4.3 the persistent components of vapor phase rust inhibitor exert long-term rust prevention effect

4.4 even if there is water on the surface of the package and there is moisture in the outside air, the effective components of the rust inhibitor will dissolve in the moisture to prevent rust

4.5 the antirust packaging material has extremely low gas transmission rate and humidity, so it has the characteristics of waterproof, moisture-proof, oil resistance and drug resistance. It can prevent the outside water, moisture, oil and drugs from soaking, prevent the loss of effective gas of internal antirust agent, and make the antirust effect more effective

4.6 when packaging metal, steel and machinery, when using VCI vapor phase rust preventive materials, it is not necessary to apply rust preventive oil, butter, etc., and it is not necessary to deal with it separately. Metal parts can be unpacked and used at any time. After use, it can still be reused in the package. It is an ideal packaging material with simplicity, high efficiency and high performance price ratio