Nano Packaging Technology Research and Application

The so-called "nano packaging" is the application of nanotechnology, using nano-composite (packaging) materials, so that the packaging has a super-functional or singular characteristics of a kind of packaging summary. The so-called nano packaging material is nano-composite packaging material with nanometer-scale structural unit, which is made of particles or crystals with a disperse phase size of 1 to 100 nm combined with other packaging materials or added. Nanostructures may become the basis for technological improvements. Once the critical dimensions of the material can be controlled, the characteristics of the new material and the functionality of the device can be enhanced, even beyond what we believe may be achieved.

Since the nano-sized grains are finer than those of the conventional materials, the number of atoms on the grain boundary is larger than the number of atoms inside the grains, forming a high-concentration grain boundary, thereby imparting properties of many different conventional materials for nanomaterials, such as high strength. , High hardness, high resistivity, low thermal conductivity, low elastic modulus, low density, etc. These excellent properties determine its wide application prospects in the future.

Green packaging aims to change people's traditional ideas, make full use of the comprehensive characteristics of packaging materials, pay attention to ecological balance, and make it greatly beneficial to the environment and human society. Nano packaging is the use of nanotechnology to change the traditional packaging materials and packaging technology, the most effective use of atoms and molecules, giving the material high-new features, focusing on saving resources, is greatly beneficial to human society.

Add nano-technology bags to enhance barrier properties and extend shelf life

New Progress in Nano Packaging Development in China

The research on nanotechnology in China started earlier. Some of the technologies are at the forefront of the world. Many new results have also been achieved in the field of packaging applications, and they have been partially commercialized.

In May 2004, Beijing Huajing Wufang Company launched its newly developed nano-composite functional film, which greatly improved the performance of the packaging film. The company uses nano-inorganic powder coating technology to modify the functional inorganic nano-powder to improve the compatibility of the nano-particles with the matrix resin and prevent the agglomeration of the nano-particles.

At present, the nanocomposite functional films developed by the company include antibacterial films, anti-UV films and antistatic films. The nano-composite antibacterial film effectively overcomes the problem of discoloration of silver-based antibacterial agents, and has high transparency, good weather resistance, non-toxicity, and low cost, and is common to most common microorganisms such as Escherichia coli, Staphylococcus aureus, and Aspergillus niger. Good antibacterial effect; its nano-composite anti-UV film utilizes a unique nano-powder dispersion process and polymer matrix composite preparation technology, so that the film not only has good UV shielding performance, but also has good transparency, weather resistance and chemical stability. Nano composite anti-static film using inorganic nano-materials and film substrate composite technology, can promote polymer grain refinement, so that the transparency of the film is good, and greatly improved the anti-static properties.

In July 2004, Gansu Province's key investment projects, investment of up to 200 million yuan "nanometer PET" beer bottle manufacturing projects to attract investment. The "nano-PET" beer bottle adopts nano-surface modification technology, which can meet the technical requirements for beer canning. Its barrier properties, acetaldehyde release, and fragrance dissipation are all lower than those of glass bottles. And beer bottled beer can be used for a shelf life of 12 months. The past glass beer packaging has the potential safety hazard of explosion, and the biggest advantage of the "nano-PET" beer bottle is that it will not explode. The project is preparing to install 35 production lines. After production, the annual output will reach 900 million, the output value will be 545 million yuan, the tax will be 127 million yuan, and the profit will be 159 million yuan. The investment can be recovered after 1 year and 3 months of production. This project is an original development project and has a whole set of technologies, including design and manufacture of equipment other than PET raw material production, preform design and production, and blow-molding. The technology combines nano-surface treatment technology with bottle manufacturing on a single production line. The cost is low and there is a good market profit margin. The overall cost of each bottle is only 0.21 yuan, and the cost of glass beer bottles is as high as 0.9 yuan. Once the beer bottle is put into production, the beer price is expected to drop.

China stipulated that during the 2008 Beijing Olympics, the audience could not bring metal and glass bottled drinks into the audience. Therefore, many companies have started to research and develop nano-scale plastic beer bottles to seize the market. Zijiang Enterprise and Zhongfu Industry have purchased equipment from HUSKY and plan to enter the nano-scale plastic beer bottle market. The Taiwan Plastics Technology Development Center is also interested in working with Taiwanese companies to develop nano-scale plastic beer bottles. The gas barrier performance of this kind of beer bottle is close to the level of the glass bottle, its strength and heat resistance are good, the quality is light, and the transportation cost is saved more than the glass bottle.

Other packaging companies in China have also paid increasing attention to the development and application of nanotechnology. Zhejiang Shangfeng Packaging Group Co., Ltd. is a leading company in the packaging industry in China. The company has achieved gratifying success in the development and application of nanotechnology in the packaging field. In order to promote the application of nanotechnology in the packaging field, the company has specially set up a packaging nanotechnology application research center.

Nanotechnology applied in packaging

Nanotechnology that can be applied in the field of packaging: nano ink, nano paper, polymer based nano composite (PNMC), nano antibacterial packaging, nano plastic packaging, nano adhesive, nano security printing, nano military protective packaging, nano green Packaging, nano-magnetic printing and so on.

Nano ink

Nanotechnology brings a huge change to the ink manufacturing industry in terms of pigments, so that the ink is no longer dependent on chemical pigments, but can choose the appropriate volume of nanoparticles to present different colors, such as TiO2, SiO2 nanoparticles are white, Cr2O3 Green, Fe2O3 is brown.

Inorganic nanomaterials such as A12O3 have good fluidity, and if added to the ink, the abrasion resistance of the ink film can be greatly improved.

Nano-scale carbon ink is conductive and has a good shielding effect against static electricity. It can prevent electric signals from being disturbed by external static electricity. If it is added to ink, it can be made into conductive ink, such as large-capacity integrated circuits, modern contact panel switches. Wait. If Ag is made into nano-scale instead of micro-sized Ag in conductive ink, 50% of Ag powder can be saved. This conductive ink can be directly printed on ceramic and metal, and the ink film is thin and even and smooth. If the Cu, Ni material is made of nano-scale ultrafine particles, it can replace palladium and silver and other precious metals conductive.

Because the nanoparticles have good surface wettability, they are adsorbed on the surface of the ink pigment particles, can greatly improve the ink's lipophilicity and wettability, and can ensure the stability of the entire ink dispersion system, so the nanoparticles added with nanoparticles The ink has been greatly improved in printability. In electrostatic copying, the use of magnetic nanopowders instead of non-magnetic toners, which are widely used today, can eliminate the need to add ferromagnetic particles as a carrier in the latter, thereby producing a single-component copying developer, which can save raw materials. , And can improve copy quality.

Because of the poor lightfastness of fluorescent anti-counterfeiting inks and the fact that the anti-counterfeiting mechanism has been deciphered and the anti-counterfeiting function has been lost, the nano-anti-counterfeiting inks that have been successfully researched by Guangzhou University for near-infrared absorption have demonstrated reliability, safety, stability, and aging resistance in small-scale test samples. Both have reached a satisfactory level. At present, this product has been used in high-tech fields such as packaging, ticket security and infrared sensors.

Nano plastic

The so-called "nanoplastic" refers to an organic/inorganic nanocomposite material in which an inorganic filler is dispersed in a nanometer size in an organic polymer body. The raw material used for nano-plastics is "montmorillonite", a type of natural clay mineral produced in China and a layered silicate. Filling and modifying plastics can improve the mechanical properties of plastics, and can also develop various functional plastics, such as conductive plastics, magnetic plastics, anti-degradable plastics, anti-ultraviolet and anti-aging plastics. The nano-plastics made of inorganic nano-materials uniformly dispersed in plastic have excellent physical and mechanical properties, high strength, good heat resistance, low density, good transparency, and high gloss.

Although the use performance of nano-plastics has been greatly improved, in appearance, nano-plastics are no different from ordinary plastics. Because nanometers are dispersed, its size is similar to the wavelength of visible light, so nano plastics are usually colorless and transparent, and a small amount shows milky white, but it does not affect its use. In addition, the amount of nano inorganic particles is very small, generally 2% to 5%, only about 1/10 of the amount of common inorganic filler, so the density of nano plastics is almost constant or increase is very small, will not increase due to density increase The cost of plastics processing will not cause other performance degradation due to too much filler. Due to the small size of the nano-particles, almost no breakage breakage occurs during molding and recycling, and it has good recyclability. The preparation process of nano plastics is not complicated, and the production process of common plastics can be slightly improved, so the nano plastics have a better performance-cost ratio than ordinary plastics.

Polyester PET nanoplastics, with excellent barrier properties, rapid crystallization properties, and excellent melt strength and stability, can replace the expensive polyethylenformate (PEN) resin. And in line with food packaging requirements, can be directly used to blow beer, cosmetics bottles. PET bottles are often used for filling liquid items (such as cola, juices, sodas, etc.). Common PET has poor heat resistance, cannot be hot-filled, and has poor barrier properties against oxygen and carbon dioxide gas. Nano-PET bottles overcome these shortcomings and can be used to directly fill hotter edible liquids, as well as beer, pesticides and other items. Nano-PET is much lighter than glass, and it is not easy to break. Even if it is explosive, it is less dangerous and it is convenient for transportation and storage. It can also be reused after high-temperature pasteurization, avoiding the production of glass bottles and the environment during waste disposal. Pollution. At present, three-layer composite materials of nano-PET and nano-nylon have been used to prepare beer and juice packaging bottles with high heat-resistance and gas sealing performance requirements. (to be continued)