Discussion on the Development and Sustainable Development of VCI Plastic Film

Li Yanling Wei Shili(Suzhou Qiyang Antirust Technology Co., Ltd.)

Preface: As one of the main products of VCI packaging materials, VCI plastic film has only been developed in recent years. It is an anti-corrosion packaging material formed by adding VCI to the plastic film in a certain way. It is a special functional film. The production and development history of VCI plastic film is later than VCI paper, but because it can simplify the packaging process, it also has the advantages of transparency, thermoplasticity and airtightness. my country's VCI plastic film has been developed rapidly, which satisfies The market share of the metal protective packaging industry is increasing year by year. This has also brought to society an increasing amount of packaging waste. With the global trend of advocating resource conservation, consumption reduction, and development of a low-carbon economy, my country has also proposed a development strategy for green packaging, namely, vigorously developing reusable, Appropriate packaging that is recycled or degraded, and does not cause pollution to the human body and the environment during the entire life cycle of the product. As a representative of functional metal anti-corrosion packaging materials, VCI plastic film should fully consider the issues of resource utilization, energy consumption, personal safety, recycling and waste disposal. This article introduces the current status of my country’s VCI plastic film , Discuss the sustainable development of VCI plastic film from the aspects of product planning, raw materials, production process, packaging use, waste treatment and utilization.

Keywords: VCI plastic film, rust prevention, green packaging, sustainable development1. The principle of metal vapor phase rust prevention1.1 Corrosion of metalsMetal materials are deteriorated and destroyed due to chemical or electrochemical interaction with the environmental medium in which they are located. This phenomenon is called corrosion. According to the reaction mechanism of metal corrosion, corrosion can be divided into electrochemical corrosion and chemical corrosion. Electrochemical corrosion refers to the damage caused by the electrochemical interaction between the metal surface and the ion-conducting medium; chemical corrosion refers to the damage caused by the pure chemical interaction between the metal surface and the non-electrolyte. Among them, electrochemical corrosion is the most common and common corrosion, because as long as there is condensed water in the medium that composes the environment, metal corrosion will proceed in the form of electrochemical corrosion.1.2 Anti-rust principle of VCI plastic filmThe anti-rust and anti-rust effect of the VCI plastic film is actually the anti-rust effect of the VCI using the plastic film as the carrier. VCI or VPI (VCI or VPI for short) can be directly vaporized (or sublimated) under normal temperature and pressure. Under normal temperature and pressure and relatively closed conditions, VCI uses its own material characteristics and The difference in the molecular structure of the polymer resin plays a sublimation effect, that is, the vapor phase rust inhibitor migrates stably and uniformly inside the plastic film package, and then vaporizes, and the vaporized and diffused gas gradually reaches a saturated state. The vapor phase rust inhibitor will diffusely immerse and adhere to the surface of the metal products and the inside of the components in the plastic film packaging to form a dense and transparent gaseous protective layer to prevent the metal from being corroded. And because the rust inhibitor molecule exists in a gaseous state, it has the function of permeating. No matter how complicated the shape of the inside and outside of the metal product, the rust preventive gas can still effectively adhere to the inner and outer surface of the metal component to prevent the oxidation of the metal product. , So as to obtain the ideal anti-rust effect.

2. Development status of VCI plastic filmVCI plastic film is a kind of anti-rust packaging material formed by adding corrosion inhibitor to plastic film in a certain way.In the early days, the coating type anti-rust film was the main representative. With the innovation of processing technology, the current mature vapor-phase anti-rust plastic film products are processed by extrusion blow molding, that is, VCI is added in the form of micro powder to be compatible with it.Among the high-molecular resins with good properties, the VCI plastic masterbatch is made by extrusion granulation, by which the masterbatch is added to the polyolefin resin, and then extruded and blown into a film.Nowadays, what is commonly used in the market is to blow the anti-rust masterbatch and polyethylene (PE) resin into plastic films of different specifications through a certain process.For example, Suzhou Qiyang Anticorrosion Technology Co., Ltd. adopts its self-developed vapor phase anticorrosion masterbatch and LDPF resin to mix and use the international advanced three-layer co-extrusion blown film production line to blow molding.

VCI plastic masterbatch

VCI plastic film extrusion blow molding processing

At the end of the 1990s, my country had independent intellectual property rights for the manufacture of VCI plastic film, which broke the international technology monopoly, realized the localization of VCI plastic film, and quickly popularized the material. With the continuous expansion of the application field, the performance requirements of the vapor phase anti-corrosion plastic film are also multi-functional.According to function and structure, it can be divided into the following main types:VCI plastic film for common multi-metal: a product formed by uniformly dispersing the micropowder of vapor phase corrosion inhibitor in the plastic film, with simple structure and maximum dosage;Antistatic type: a plastic film with antistatic function formed by adding an antistatic agent to an ordinary antirust film, which is mainly used for anti-rust packaging of electronic, electrical products and equipment with antistatic requirements;Stretching type: It has ultra-high elongation, puncture resistance, self-adhesive, and can be used for tightly wound packaging of metal parts;Shrinkable type: Anti-rust film that shrinks when exposed to heat, mainly used for fastening and packaging of metal parts;Reinforced type: composite materials with high strength (such as tensile strength, puncture strength, tear strength, etc.) made by compounding high-strength materials, which are widely used in anti-rust packaging of heavy metal products;High barrier type: films with high barrier properties made by multi-layer co-extrusion or compounding, such as aluminum-plastic composite anti-rust film, etc. This type of material has the characteristics of low moisture permeability and low air permeability, especially suitable for high Long-term sealing and rust prevention of precision and high value-added products.VCI plastic film has many characteristics that paper products do not have, such as transparency, beauty, water resistance, oil resistance, good airtightness, recyclability, environmental protection, etc., and are widely used in electromechanical, auto parts, weaponry and other fields.3. The sustainable development of VCI plastic film3.1 Product planning, adhere to sustainable developmentSafety, environmental protection, and sustainable development products have been reflected in various fields such as production and life. The implementation of green packaging and green design of products are the direction and focus of the efforts of all countries in the world. As a representative of advanced anti-corrosion packaging technology, the green design of vapor-phase anti-corrosion plastic film should focus on choosing safe, efficient, and multi-functional vapor-phase corrosion inhibitors, choosing recyclable or degradable carrier materials, and adopting innovative manufacturing processes , Effectively recycle and reuse waste, and achieve the design goal of green vapor phase anti-corrosion plastic film packaging.3.2 Choose safe and efficient raw materials to create a green source3.2.1 Selection of vapor phase corrosion inhibitors, adhere to diversification, high performance, and environmental protectionThere are many types of vapor phase corrosion inhibitors, each of the following types is listed below to illustrate:

A kind of vapor phase corrosion inhibitor alone is not very effective, and the effect is single. It will be better to use different vapor phase corrosion inhibitors in combination. For example, the combined use of urotropine, sodium benzoate and sodium nitrite can be integrated The advantages of these three have a wide range of applications to metals, a more ideal corrosion inhibition effect, and a longer action time. According to national environmental protection requirements, the following substances in packaging materials are restricted substances: Cd cadmium, Pb lead, Hg mercury, Cr hexavalent chromium, polybrominated biphenyls, polybrominated diphenyl ethers, phthalates, polycyclic aromatic hydrocarbons, halogens, perfluorooctanoates And lipids, polyvinyl chloride and other substances.Based on the needs of environmental protection and sustainable development strategies, industrial corrosion inhibitors require not only good corrosion inhibition performance, but also safety and environmental protection, and no harm or adverse effects on the environment and humans. The research and development of environmentally friendly corrosion inhibitors are proposed . Cinnamaldehyde, benzoate, fatty acid, fatty amine, carboxylate, gluconic acid and its salts, amino acid derivatives, silicate, phosphate, etc. are all environmentally friendly vapor phase corrosion inhibitors.3.2.2 Plastic raw material resin, insist on selecting functional and environmentally friendly materialsThe commonly used plastic materials and functions are shown in the following table:

3.3 Treatment of packaging waste, adhere to recycling and sustainable developmentDevelop degradable plastic carriers. Degradable resin material is used as the carrier of vapor phase corrosion inhibitor to produce degradable vapor phase rust preventive plastic film to prevent packaging waste pollution from the source.The recycling of packaging waste is currently the most important aspect of the world's green packaging and circular economy. The recycling of anti-rust packaging has good economic and ecological benefits. In view of the many types of vapor phase anti-corrosion plastic films, the recycling process should be collected and processed separately to facilitate reuse. It is necessary to increase investment in technology and capital in the recycling and reuse of waste gas phase anti-corrosion plastic films.4. Prospects for the sustainable development of VCI plastic filmAs an emerging product and technology, VCI plastic film plays an increasingly important role in the field of metal anticorrosion. Under the requirements of environmental protection and sustainable development, VCI plastic film will have the following development trends: Corrosion inhibitors for rust films are developing towards general-purpose, high-efficiency, non-toxic and environmental protection. Suitable for multi-metal anti-rust protection, general-purpose vapor-phase anti-rust film products that do not contain harmful substances such as nitrite; develop toward the direction of diversified product structure, diversified forms, and diversified substrate resins, such as vapor-phase anti-rust biodegradable film , Polyvinyl acetate anti-rust film, etc.references:[1] Zhang Daquan. Vapor phase corrosion inhibitor and its application [M]. Beijing: Chemical Industry Press. 2007.5.[2] Jiang Wei, Gong Min, Zhao Jinping. Research progress of natural plant green corrosion inhibitors[J]. Corrosion Science and Protection Technology, 2007, 19(4): 278-281.[3]Sun Kai. The development trend and improvement direction of vapor phase anti-corrosion plastic film [Journal Paper]. Plastic Packaging. 2014(3).[4]Liu Hong, Tang Yanqiu, Shen Ping, Bai Fang, Zhou Xianliang, Zhao Baidong. Green design of VCI packaging materials [Journal Paper]. 2010.07.002.[5] Wu Yinshun, Zheng Jiashen. Electrochemical protection and corrosion inhibitor application technology [M]. Beijing: Chemical Industry Press. 2005.6.