Packaging Tracks Nanotechnology

I. Nanotechnology Overview

Nanotechnology (Nano-st) is a concept proposed by scientists in the 1950s. It was born in the late 1980s and is a rising new technology.

Nanotechnology refers to technologies and methods for recognizing and transforming nature within the microscopic range of the nanometer range (10-9 to -7 m), that is, one billionth of a meter, through the direct manipulation and arrangement of atoms and molecules to create new substances. .

Nanotechnology is a means and weapon for mankind to explore the mysteries of the world from a microscopic level. The area it studies is the micro-domain that humans rarely covered in the past, thus opening up a new level of human understanding of the world. Nanotechnology reveals a visible atom and molecular world to human beings with unprecedented resolution. Its ultimate goal is to directly manufacture atoms and molecules with products with specific functions. The microcosmic world of nanotechnology exploration and research is limited to the macroscopic and microscopic levels that humans have explored, that is, it is limited to atoms and molecules, not to microscopic microscopic particles in elementary science, such as elementary particles. Sons, mesons, protons, superons, etc. In the microscopic space-time, the upper limit is generally defined atoms and molecules, but the lower limit is endless. The intermediate field between atoms, molecules, and macroscopic objects is a “virgin land” that people have yet to recognize and develop. The current nanotechnology is how to “open up” this “virgin land”.

We can say that the spatial domain of nanotechnology research is microscopic atoms and molecules in space and time. With nanotechnology, one can freely arrange atoms within a substance and freely manipulate atoms.

Second, nanotechnology is a new technological revolution

Nanotechnology has become a high-tech "century battle."

At present, many countries in the world formulate relevant strategies and plans one after another, and they have invested huge amounts of money to fight the highest point of the nanotechnology strategy. The United States has considered nanotechnology research as the core of the next industrial revolution. The US government’s investment in basic research in nanotechnology has increased from more than 100 million U.S. dollars in 1977 to 500 million U.S. dollars in 2001. Frontiers have become overlords. Other well-known companies, corporations, and consortia are also closely following the progress of nanotechnology research. Major companies such as DuPont, Kodak, Hewlett-Packard and IBM have also set up their own nanotechnology research teams. At present, the nanotechnology research boom has spread all over the world.

The reason why nanotechnology has become a hot spot for comprehensive research is because nanotechnology will create miracles for humans. Its application value in the future will surpass today's computers, which means that nanotechnology has given birth to tremendous opportunities.

Look at the predictions of nanotechnology by scientists in the following areas.

The nanotechnology research work will probably allow the entire collection of the Library of Congress to be stored on a silicon wafer with a diameter of only 0.3 meters.

Nanoelectronics allows quantum components to replace microelectronic devices, and supercomputers can be carried around in pockets.

Nano-organism "components" are combined with nano-inorganic compounds and their crystal structure "components", and nano-electronics are used to control the formation of nano-robots. Doctors can use nanobots to get through brain thrombosis and clear up fat deposits in the heart arteries. They can also perform whole body examinations and treatments by injecting a variety of functional nano-micro-machines into blood vessels.

Nano-scale drugs provide new ways and means for drug delivery and injection. They can directly inject drugs to treat diseased bodies to greatly improve medical efficacy and reduce side effects.

Nanotechnology makes fragile ceramic materials tough, exhibits good toughness near room temperature, and undergoes bending without breaking at 180°C. Nanotechnology has become a strategic approach to brittleness of ceramics.

Nanotechnology can turn good conductor metal materials into non-metal materials; nanotechnology can significantly reduce typical insulator resistance and lose insulator properties; nanotechnology can demagnetize magnetic materials. As a result, new concepts of nanomaterials have been created.

The application of nanotechnology in the military is even more unpredictable. The most typical is the stealth material of military weapons. This stealth material is made using nanotechnology. In the Gulf War of 1991, for example, the fighter aircraft deployed on the first day of the United States escaped Iraq’s stringent military radar surveillance network and quickly reached the Iraqi capital Baghdad. It quickly destroyed the Telegraph Building and other military targets of Pakistan, which lasted for 40 years. During the day's battle, the U.S. aircraft flight reached 1,270 sorties, which resulted in the destruction of 95% of the Iraqi military’s important military targets. None of the U.S. military planes were damaged. At that time, they were shocked by the world. The Iraqi military radar surveillance system is incapable of handling US military aircraft. It is that the US military plane is coated with a layer of nano stealth material.

Third , the application of nanotechnology in the field of packaging technology

The application of nanotechnology in the packaging field has not been paid attention to by people. In fact, nanotechnology has a broad application prospect in the packaging field. In the packaging materials and packaging technology, the value of nanotechnology will be inestimable. The magical functions and characteristics of nanotechnology can be analyzed from the following aspects.

1. Elimination of static electricity improves packaging and printing speed and effectiveness

Metal nanoparticles have the special function of eliminating static electricity. We can use this feature of nanotechnology to apply nanoparticles to the surface of packaging and printed materials to eliminate static electricity generated when packaging and printing materials are transported on high-speed full-automatic packaging machines or printing machines, thereby greatly improving packaging and printing. speed. In addition, due to the elimination of static electricity, the surface of the packaging and printing material no longer attracts dust, and the surface of the material is no longer covered with dust and friction increases, resulting in scratches. At the same time, the printed surface is free of electrostatic dust to improve the printing effect. Therefore, nanotechnology can greatly improve packaging and printing effects through its static elimination characteristics.

2. Sterilization improves packaging quality and increases shelf life

The addition of nano-particles to packaging materials (such as plastics and composites) produces odor-elimination and sterilization. Now some of our companies are using this technical feature to add nanoparticles to refrigerator materials (plastics) to produce antibacterial refrigerators, which greatly extend the shelf life of foods stored in refrigerators so that users do not have to worry too much about foods. corruption. Nanoparticles can also be added to paper, plastic and composite materials for packaging foods, which can increase the shelf life of packaged foods.

3. Replace traditional chemical pigments to produce advanced printing inks

As early as in 1994, XM X of Massachusetts, USA applied for and obtained a patent for the production of uniform ink nanoparticles for printing inks. The company is preparing to design and manufacture a commercial production system that will no longer rely on chemical pigments, but rather select the right nanoparticles to obtain a variety of pigments to produce advanced printing inks. Nanotechnology has created conditions for the production of high-grade printing inks.

4. Makes fragile and non-toxic packaging containers tough

Ceramic containers and glass containers are two traditional packaging containers. Because they have the advantages of non-toxicity, sealing, and smooth surface, they have occupied an important position in the packaging industry because they have the disadvantages of being brittle and inconvenient to handle. Now it has been Some metal packaging replaced. In recent years, countries such as Western Europe, the United States, and Japan have developed nanotechnology and added nanoparticles to ceramics or glass to obtain tough ceramics or glass materials. For example, the United Kingdom mixes nano-alumina with zirconium dioxide and has obtained high-toughness ceramic materials in the laboratory. As another example, Japan added aluminum oxide nanoparticles to ordinary glass, significantly changing the brittleness of the glass. The breakthrough of these technologies has brought hope to scientists who have struggled for toughening ceramics and glass for nearly a century, and has brought new hope to our revitalization of the ceramic packaging and glass packaging industry.

5. Make anti-counterfeit packaging into a new stage

Nanomaterials have superior sensitivity and have broad application prospects in terms of temperature sensitivity, gas sensitivity, moisture sensitivity, etc. The use and development of anti-counterfeit packaging will make anti-counterfeit packaging technology enter a new stage.

The sensitivity of the nanoparticles can be used to prepare temperature (heat) sensitive materials, gas sensitive materials and moisture sensitive materials, respectively, and then used as anti-counterfeit packaging.

The general metal particles are black and have the characteristics of absorbing infrared rays, and have large surface area, high surface activity and sensitivity to the surrounding environment (temperature, heat, light, humidity, etc.). Therefore, when the nano-particles with these characteristics are added into the packaging material, or made into a coating or a polishing agent, they are applied to the surface of the material and used for product packaging. When people select a product, they can be identified by heat, light, or humidity to achieve anti-counterfeiting. This means that the use of nanotechnology can achieve color anti-counterfeiting, physicochemical effects anti-counterfeiting and other purposes.

6. Make fresh-keeping packaging more effective and simpler

At present, the research and development of fresh-keeping packaging are not effective and the process is very complicated. The relative cost is high during the packaging operation and storage. With nanotechnology, these problems will be solved.

When we researched the fresh-keeping packaging of fresh fruits and vegetables, we discovered that there is a gas substance that accelerates deterioration of fruits and vegetables. This gas substance is ethylene. In fresh-keeping packaging, fruits and vegetables release ethylene. When the concentration of ethylene reaches a certain concentration, the fruits and vegetables will accelerate rot. Therefore, ethylene absorbers should be added to the fresh-keeping packaging to reduce the ethylene content in the package to improve the preservation effect and extend the shelf life. . However, tests have shown that the effect of the ethylene absorbents found so far is not ideal, which has led to difficulties in the research of fresh-keeping packaging. And just nano-sized Ag powder has a catalytic effect on ethylene oxidation, that is, nano-A g powder can be used as a catalyst for ethylene oxidation. Adding nano-A g powder to the fresh-keeping packaging material can accelerate the oxidation of ethylene released from fruits and vegetables and reduce the ethylene content, so as to achieve a good preservation effect. The nanoparticles used as oxidation catalysts mainly include Fe3O4, Fe2O3, Co3O4, NiO, and Pt, Rh, Ag, Pd, and the like.

The use of nano-technology packaging containers with clean sterilization and preservation. For example, nano-TiO2 catalyzes hydrocarbons under the irradiation of visible light. This effect can be applied to the surface of glass, ceramics, and other materials coated with a layer of nano-TiO2, which can produce a very good cleaning and sterilization effect. Japan in this regard A successful experiment has been done. As long as the surface of glass and ceramic materials is coated with a thin layer of nano-Tio2, any substance that adheres to its surface, such as oil, bacteria, etc. under the irradiation of light, is catalyzed by Ti02, making these hydrocarbon substances qualitative. It is further oxidized to become a gas or a substance that can be easily wiped off, and at the same time has a significant bactericidal effect.

7. Nanotechnology can greatly improve the performance of plastic packaging materials

Nanoparticles absorb UV light. Plastic packaging products are susceptible to ageing and brittleness under ultraviolet light irradiation. If a transparent coating containing nanoparticles is coated on the surface of the plastic packaging material, the coating has a strong UV absorption capability in the range of 300 to 400 nm. Can prevent the aging of plastic packaging, and greatly increase the use of plastic packaging (such as packaging, large equipment, wrapping, etc.) and life.

There are two types of packaging materials that are good for UV absorption. One is a resin film of 30 to 40 nm of TiO2 nanoparticles; the other is an alcohol-containing resin film of Fe2O3 nanoparticles. The former has a strong absorption capability for ultraviolet rays within a wavelength of 400 nm, and the latter has a good absorption ability for ultraviolet rays within a wavelength of 600 nm. The nano-technology light-absorbing material will become a good alternative to traditional packaging materials, creating technical conditions for the modification and functional protection of packaging materials.

8. Make the packaging container processing performance greatly improved

China's various types of beverage and food packaging metal cans, domestic materials have always been poor toughness and poor ductility, processing is easy to produce cracks and other technical problems, making us a lot of metal packaging containers (cans, boxes, barrels, cans, etc.) used raw materials need import. If nanotechnology is used, the addition of nano-particles to can-making metal materials can greatly increase the toughness and ductility, greatly reduce the forming process of packaging containers, and increase their reliability and yield.

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