Crazy Nanofibers

　 　 Nanofibers There are many definitions, but most industry experts define fibers with diameters of less than 1 microns as nanofibers. Experts also believe that these fibers can be smaller according to the production processes of different non-woven industries. At present, the most advanced technology can spin fibers with diameters of nearly 10 nanometers, but the most common ones are fibers between 75 and 100 nanometers in diameter.

　　 So far, the range of application of nanofiber technology in the non-woven industry is largely limited. Filter material And some biomedical, sound insulation materials and energy reserves, but researchers familiar with the technology believe that the application of the technology is limitless.

"We are now working hard to bring the whole industry to new technologies, such as nanofibers, and use them in existing applications," said Mr. ANTHONYFABBRICANTE, President of NONWOVENSTECHNOLOGIES. "This technology can be used in any nonwovens application field. There are too many different areas. We dare not claim to be experts, but we are willing to provide the cornerstone. Once we launch this technology, its development will be unlimited.

Mr. FABBRICANTE has been concentrating on how to use nanofibers for melted spraying for many years. Non-woven fabrics And in recent years, a great breakthrough has been made in how to produce large amounts of melt blown nanofibers through polypropylene and polyester. Last year, NTI and ARTHURG. RUSSELL (AGR) has signed a licensing agreement on the technology of using its patents to produce high-speed melt blown nanofibers. According to Mr. FABRICCANTE, the breakthroughs in NTI's high-speed melt blown nanofiber technology and the combination of AGR's more than 60 years' experience in automatic machine production make them occupy a very unique position in the industry.

This new production technology allows the production of non-woven fabrics per standard commercial spinneret to be about 20% higher. This fiber has a higher number of spinneret per linear inch than other competitive fibers, and these spinneret holes are as small as 0.002 inches. The decision makers hope to create a production line of one to three meters per minute and 500 meters per minute to produce this material, which will be applied to insulation, Geotextiles and hot-melt fields. Other applications will also include biological fibers, two-component fibers, spunbonded technology and hydraulic / air entanglement.

Mr. FABBRICANTE said that recently, University of Tennessee has successfully carried out experiments on melt blown nanofibers, and AGR is currently developing its four row spinneret device, consisting of 15 inches per row. Once completed, the peak device will only be 24 inches long.

NTI's technology is only one of many technologies for the production of microfiber nonwoven fabrics, which are widely used in areas requiring impermeability and efficient surface, including special melt blown, electrostatic spinning, electrostatic blast and bifurcated fiber production. Now microfiber has been in a steady position in melt blown and wet laid micro glass technology, and the next step is to include smaller diameter fibers and even nanofibers.

Czech's ELMARCO is a company that has long been a leader in the nanotechnology industry. The company's industrial grade standard equipment can produce a large number of efficient, reliable and low-cost nanofibers from organic polymers, biopolymers and non organic materials. "Nanofibers are the most developed and most comprehensive nanomaterials that can produce obvious value-added products." "Their best application areas are air filtration products and biomedical materials for wounds, but many other applications have reached the final stage of trial," said Mr. LADISLAVMARES, executive director of the company.

ELMARCO has signed cooperation agreements with the private sector and academia, so that they can promote their technology to the new non-woven industry. "Basically, the nonwoven industry is dominant in our business plan," said Mr. STANISLAVPETRIK, President and chief executive officer of ELMARCO. "The market demand for the equipment we manufacture is enormous."

Performance based

The advantages of nanofibers are numerous. They enable roller material manufacturers to produce lightweight and solid materials, and these materials also have good permeability, humidity core, material with draping and opaque properties. Their limitations are mostly linked to the cost demand and the number of manufacturers with productive capacity, rather than nanofiber nonwoven materials themselves. Thanks to the increasing performance, nanofiber nonwoven materials have been increasingly used to replace traditional textile materials, even though their prices are not necessarily cheap.

In terms of filtration, ultrafine fibers and nanofiber materials are used to ensure the efficient circulation of cloth while capturing benign particles. However, apart from their functional advantages, they did not achieve the best performance requirements in the production process. Although it is one of the earliest non-woven industrial technologies, wet web forming technology can provide the flexibility needed to produce medium materials containing microfiber materials.

A recent example of producing microfiber nonwoven materials by wet process is the DISRUPTO technology of AHLSTROM, which uses micro glass and nano bauxite. The technology is the INDEX08 award winner. The nanofiber based filtration media material combines the two methods of electronic and mechanical capture. Its main advantages include low pressure drop, high loading capacity and high quality filtration efficiency.

Mr. JEROMEBARRILLON, vice president of sales of liquid filtration materials at AHLSTROM, said that nanotechnology has enabled filter media producers to innovate technologies that they have not been able to break through for a long time.

"In the filtration process, one of the strengths of nanofiber materials is to improve simultaneously in three aspects of efficiency, capacity and pressure drop. The efficiency is improved without sacrificing other aspects. "

In addition to DISRUPTOR technology, AHLSTROM has the ability to produce electrospun nanofibers in North America. Mr. BARRILLON thinks that for customers, the key to how to use nanoscale technology well in products is to pay full attention to the intellectual property rights in the industry. "From the perspective of knowledge industry, our company is transparent and free, but to produce such products, many processes are now closely protected by patents. Manufacturers must be careful to maintain freedom and transparency and not infringe on other companies' patents. "

Another interesting nanofiber is the nanofiber network made by HOLLINGSWORTH&VOSE using HVISION platform technology. These media materials are porous materials with unprecedented controllability and durability. With this technology, the diameter and thickness of the fibers can be adjusted to achieve high performance in a wide range of applications. Multifunctional nanoscale media materials can be applied to any non-woven coating, including glass, cellulose, synthetic fibers, and can also be used as substrates alone. In terms of air filtration media materials, nanoscale enhanced the performance of media to remove particles from air steam; in terms of liquid filtration media materials, nanoscale was designed to meet the stringent standards of many liquid applications. In addition to filtration, the porous structure of H&V company's nano mesh technology is very lightweight and has high performance surface. Therefore, it is the best choice for making heat insulation and sound insulation materials, anti allergy bedding, waterproof breathable fabrics and energy reserves.

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Win win cooperation

Another vision that looks beyond nanotechnology in the application of filtration materials is OERLIKON. Two years ago, the mechanical equipment supplier's comber division reached a cooperation agreement with ELMARCO company, which combined the non-woven fabric and the nanofibers manufacturing sound insulation materials. The new product is an online production of five layers of structure, namely, combed nano-carding nano-carding material.

"This material can not be produced off-line because of the need of some adhesive material for the woven nonwoven fabric, so ELMARCO decided to cooperate with our OERLIKON to combine its textile with our existing combed production line." Mr. STEFANSCHLICHTER, division director of OERLIKON's carding machine, said, "the material layer must be surrounded by nanomaterials because the nano layer is very sticky and easy to break. The carding material layer has played a very good protective role.

ELMARCO has also developed electrospinning technology for the production of high quality nanofibers, and has cooperated with AVGOL, a melt spinning nonwovens manufacturer, to develop media for filtering media. In spunbonded applications, ELMARCO's production principles need to be merged offline for reasons of production speed. He produced spunbonded nonwovens and then covered with nanofibers. Conversely, in the process of weaving, nanofibers require on-line production because of the steps of adhesion. OERLIKON is a good partner for ELMARCO to develop this technology because they have a three layer doffing production line, and a layer of nanofibers is added to the fabric layer to create a total of five layers of material.

Mr. SCHLICHTER said that the five layer structure is the best choice for making sound insulation materials, because it has better barrier effect than the similar products, and it also has higher frequency and lower weight when blocking bass. "If other products are used, the thickness of the mat must be very thick, and using this synthetic material can save materials. Secondly, the material can be applied to some applications which are limited to the weight and size of the material, such as the dishwasher. At present, there is a widespread demand for noise reduction in the market, but the design of dishwasher is relatively standard, so only a certain number of noise insulation materials can be added inside.

A good academic attempt.

At present, many research projects involving nanofibers are being carried out in the academic circles at least in the field of non-woven industry. Researchers at the university are studying how they can be better applied to the nonwoven industry, where University of Tennessee is the leader. A few years ago, labs there focused on nanotechnology. At present, they are testing a fusion test line using NTI and HILLS nanofiber technology. According to Professor GAJANANBHAT, director of the Department of materials science and engineering of the school and director of the Nonwovens Materials Research Laboratory (UTNRL), laboratory researchers, apart from conducting independent research, also help cooperative companies learn more about this technology.

"At present, our production line is the only place where we have two competitive nanofiber modules at the same time," he said. These two models are all in place, and we are already engaged in the production of nanofibers. Unlike traditional electrostatic spinning, this is a way of speeding up and continuous networking.

While helping small and medium-sized manufacturers develop more efficient filtration products, biomedical applications are also very important. In fact, Dr. BHAT is currently working with other researchers to develop a small module for biomedical materials.

In addition, AKRON university is also working with ELMARCO to expand its scope of nanotechnology research. As one of the new members of the CFNC, ELMARCO's first contribution is to provide a unique experimental device for nanofiber production -- nano spider experimental machinery. ELAMRCO's private technology is easily upgraded to industrial level, thus bringing huge opportunities for putting the results of the Federation's experimental projects into commercial use. ELMARCO is also the chief supplier of machinery capable of providing nanofiber materials for industrial production.

AKRON university has a long and successful research tradition in this kind of research, and has also developed the electrospinning process for producing nanofibers and applications. Professor DARRELLRENEKER and Professor GEORGECHASE are experts in this field. They have long recognized the great potential of nanofibers in the practical field. In 1998, CFNC was set up to carry out academic exchanges with members of the Federation of innovative industries in order to better promote creativity.

The tasks of CFNC include the basic research and design of filtration media for integrated function filtration, the development and application of nanofibers. The research covers the theoretical stage, mold making, and how to capture and combine micro and nano sized particles and particulates in non-woven fabric filtration products made of micron and nanofibers. The formation methods of nanofibers and the structure of non-woven fabric materials containing nanofibers, the combination of liquids and liquids and gases and liquids, etc.

The application of nanofibers in nonwoven industry is developing continuously. Whether it is based on slow speed, low cost electrospinning, or high melt blown technology, the technology will surely bring interesting new products to the nonwoven industry. "This is a new and exciting new technology that will bring a whole range of new products." Mr. FABBRICANTE predicts.

ELMARCO has just launched a new organic nanotechnology production line and has contributed to protecting the environment. ELMARCO's policymakers agree and predict that the current "green wave" will sweep nanotechnology.

　　 Nanoscale technology, nanofiber, contributes to the protection of the environment in almost every aspect of its application, "said Mr. MARES of ELMARCO." its highly efficient and highly permeable filtration reduces pollution, and its characteristics of forced air passing through the liquid form greatly reduce energy consumption. Catalysts, particulate filters, automotive fuels and oil filters improve fuel efficiency while reducing radiation rates. In conclusion, the advantages of using nanofiber materials to produce greener products are numerous.