The hottest PP packaging material to expand space

2022-08-14
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PP packaging materials that expand space in modification in the 21st century Abstract: "quality" + "environmental protection" are two major issues facing China's packaging industry in the 21st century. The author talks about the "bit by bit" practice of PP material, which is recognized as the largest plastic product in the world, for the reference of colleagues in the packaging industry, and sincerely looks forward to Gongyang's further discussion and exchange

1. Competition means elimination and innovation

1.1 outlook. As early as the 1980s, China formulated SG, GB, GB and other standards for PP plastic products made in 2012, which are the legal basis for the integration of ISO international standards. Smart entrepreneurs know that ISO9000 certification and ISO14000 examination and registration can only be used as "tickets" for the product to the international market

according to the investigation, PP packaging material has reached the top in recent years, making it difficult for other plastic packaging to catch up with it. In the last decade of the 20th century, an upsurge of research, exploration and development of plastic packaging material additives surged. By the end of the 20th century, the consumption of PP packaging had stepped into the dominant position from secondary consumption - an annual consumption of 20million tons (including imports), which was far higher than the consumption growth rate of the whole plastic packaging materials

1.2 review. Whether it is the packaging of paper products polluted in the early stage or the packaging of plastic products polluted in the late stage, people have paid attention to the improvement of quality in the pursuit of quantitative development. The ultimate goal is to improve the functions of packaging technology, protect human resources and the environment, and achieve energy conservation, consumption reduction and elimination of environmental white pollution

1.2.1 there is a long way to go. According to the international standard of GB, the polypropylene code and English abbreviation code PP abbreviation are named. The research of PP resin in China began in the 1950s. So far, the production equipment capacity has reached 500000 tons and the batch medium bulk method (the total production capacity with an annual output of less than 20000 tons is 450000 tons). However, as the production of China's packaging industry, uniaxial and biaxial tensile film manufacturers have exceeded 40 enterprises. Whether it is from the first generation of "solution polymerization method" (slurry method/deashing, de random), the second generation of "solution polymerization method" (no deashing) and "bulk polymerization method" (deashing, de random) to the third generation of "gas phase polymerization method" (no deashing, query experimental data, no de random). After more than 40 years of production and application, it has been used as an alternative packaging material for paper, metal, wood, etc. Especially after more than ten years of research, it is more widely used and recognized by the packaging and printing industry. Especially after the modification of additives (① injection consumption accounts for 17%; ② extrusion consumption accounts for 75%; ③ blow molding accounts for 2%; ④ others account for 6; ⑤ the annual consumption of woven bags and strapping ropes reaches 450000 tons, accounting for 49% of the total consumption of PP). In the ten years since the application of PP film in industry, especially in the packaging and printing industry, the secondary and tertiary lamination, composite packaging of physical goods, heat shrinkable silk screen printing packaging The commodity packaging products of composite printing packaging and recycled or recycled and reused products can be seen everywhere. With its superior water resistance, solvent resistance, grease resistance, oil resistance, alkali resistance and resistance to other chemicals (except a few), inorganic reagents have little or no impact on it for a long time at 120 ℃. Coupled with the strong advantages of light weight, low price and industrialized production, it has become a trend to replace the application scope of Pt, and is competing face-to-face with ABS and pet in the commodity market. Therefore, it is considered as the favorite of the largest plastic packaging materials. By 2010, the annual consumption will exceed 2million tons

1.2.2 targeted. In view of the above situation, we have reached the intention of cooperating with scientific research and production units, and with their support, we have successively investigated Shiyan, Xiangfan, Wenzhou, Hengyang, Shaoyang, Jianghan Oilfield, Dengzhou, Yunmeng and other places in combination with relevant literature and practical experience. So that packaging enterprises can continue to innovate and move forward in the elimination of backwardness

with the continuous expansion of the amount of PP packaging products, the defects exposed are becoming more and more serious. For example, the biaxial tensile (i.e. biaxial orientation) film of the plastic film factory plays a role in waterproof, moisture-proof and improving the decorative effect on the outer packaging (i.e. tertiary packaging) of the cigarette box produced by the cigarette factory, but after storage for a period of time (even the PP film just stretched out), there will be fog, frost spray Sweating and other disadvantages weaken the printing decoration level and the high quality texture of the real object, which also indirectly affects the level of commodity consumption. Another example: the recycled barrels and basins produced by the plastic factory cannot achieve the bright effect of color - blackening. Although the establishment of flash printing ink can be overcome by complex hindered light stabilizer. However, the category has decreased compared with 2013; The share of Korean enterprises rose rapidly to 30.56%; Tongguang yinben is actively laying out the power battery market. It seems that there are more than a thousand of the above manufacturers in China, which has brought immeasurable packaging economic losses to China's export earnings

from a large number of different cases, just as people hope, the stabilizer is easy to disperse in the complex and will not precipitate after long-term use. However, when the miscibility of the stabilizer is poor, it will move from the interior of the product to the external surface, and finally stay on its surface. If the ejecta is a powdery solid substance, it is called "spraying frost", and if the ejecta is a liquid, it is called "sweating". Adding organic tin is the most transparent and stable, while metal soap is used for translucent materials, and organic lead salt can only be used on opaque PP. We thus realized Lu Xun's motto that "inadequacy is the wheel of progress". In view of PP's own defects, faults and causes, the methods of detection and elimination are supplemented in practice one by one, and the perceptual knowledge after rational understanding and contact is introduced

2. Brand innovation is the GB international standard for pursuing efficiency

pp. naming and ISO international standard certification can only be used as commonalities to strengthen the product quality image mechanism, which does not fully represent the strategic grade and vitality of an enterprise brand

2.1 market potential. According to the data surveyed by the world bank and UNESCO in 1990, the annual per capita productivity of packaging in Switzerland is 160 times that of China, amounting to US $319. It can be seen that the gap between China's packaging industry and developed countries is large, which also shows that China has huge market potential to be explored by us. If the consumption level doubles that of developed countries, its market consumption will double. The arrival of this powerful shock wave is inevitable

PP, which accounts for 50% of plastic packaging materials, should meet the needs of 1.3 billion people in various industries in terms of quality and environmental protection. Therefore, I would like to talk about my own views and innovative ideas on the above issues

2.2 the molecular weight of PP with "long-range disorder and short-range order" has the characteristics of molecular weight dispersion. As a solution index, MI often directly affects tensile strength, impact strength, flexural modulus and other properties. Among hundreds of additives, we have to face that the properties of organic additives often affect the molecular morphology of PP. For example, poor additives will cause PP molecules to curl, with small interaction energy and small change in free energy. It is often attributed to the fact that PP molecules are adsorbed on the particle surface to form a protective layer, which hinders the polymerization of the resin, and migrate to the product surface with the length of time, temperature and humidity. As soon as there is instability - Frost spraying - fog - sweating; Among the good additives, the extension of PP molecules makes the free energy of the system become (decrease) significantly. Therefore, good additives have strong coalescence energy at low temperature and strong stability at high temperature. Therefore, for different defects, choosing different additives and dosage has become a topic faced by the packaging industry

electrical insulation of PP. PP material, especially film, is easy to generate static electricity after friction, which often leads to the adsorption of dust on its surface and affects the transparency of its appearance. The elimination methods are: ① add antistatic agent in the ingredients; ② Print or spray antistatic agent on its surface. For example, amphoteric surfactant can not only prevent static electricity, but also reduce the contact angle of water, so as to improve the hydration spray property of PP film. As the antistatic agent of PP, non-ionic antistatic agent with very low polarity is usually selected

PP film, sheet and molded packaging materials in a broad sense. The basic theoretical research involves the interface chemical properties and stability, physical properties and mechanical properties (density and thermal properties), which will directly affect the characteristics of ultra-high impact block PP polymer. HCPP with high crystallinity can be synthesized with high activity catalyst. For example, in biaxially oriented films, the modulus increases by about%, and the thermal shrinkage can be greatly reduced. In addition, this film has high crystallization rate, small deformation and high hardness, so it can be comparable with ABS, and it is one of the cheapest materials to replace Pt materials for commodity packaging

pp decorative. The decorative effect obtained by the traditional PP dyeing and printing process can no longer meet the requirements of people's daily life and art (uniform color space). For example, the use of organic solvents and surfactants can significantly promote stress cracking, but the stress cracking resistance of PP often increases with the increase of molecular weight. It also depends on the residual amount of catalyst and antioxidant system. Therefore, pure catalyst must be added in the secondary or tertiary processing and regeneration reuse of its surface. If electroplating, film attaching, laminating, bronzing and printing pictures and texts are used, the fog generated by PP making the two blades vertically contact the sample film will be greatly eliminated, so as to pursue the surface texture and make up for the deficiencies in packaging and decoration, so as to achieve a shiny thin film with a certain hardness with a bright surface. Improving the weatherability, light resistance, flame retardancy, moisture resistance, solvent resistance and drug resistance of the material will be overcome

after breaking and improving the traditional chemical process, the heat resistance of PP has been concerned by all sectors of society. Recently, a kind of Practical Trapezoidal polymer and helical polymer have been developed, which are non crosslinked structures, in which two molecular chains are twisted together. Such PP is soluble and fusible, and can be expected to have better thermal properties than PP with ordinary single strand structure. Secondly, isotactic polypropylene with melting point as high as 300 ℃ was produced with Ziegler catalyst. In addition, more than two kinds of high molecular polymers with similar compatibility parameters are grafted and blended to achieve the predetermined heat-resistant goal. At present, zinc stearate, calcium and barium are mostly used. Recently, long-acting MW molecular weight has also been selected as a thermal stabilizer

moreover, PP has a limit tendency of automatic shrinkage on the surface at 120 ℃. The reason is caused by the different states of molecules in the surface molecular system. Although we can explain the influence of electrolyte on the stability of melt adhesive according to the Dvo theory of van der Waals attraction and the repulsion of electric double layer, we cannot use this theory to explain the mechanism of action in the presence of polymer non-ionic surfactant. Therefore, we need to practice and recognize again - many polymers have a "critical molecular weight". PP material additives below this molecular weight have no protective effect/coalescence and dispersion are two antagonistic effects. When these two or more effects are close, the PP system forms a structural balance

The aging resistance of

pp only attracted the attention of packaging industry manufacturers at the end of the 20th century. The usual practice is to add antioxidant, UV absorber and copper inhibitor (cy2no) to PP material × 2379)。 141 compound antioxidant, which has recently been put on the market, is a very important factor that is more suitable for PP aging. Better understand that the most sensible solar spectrum in nature is generally divided into: ① ultraviolet

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