Three overlapping conferences and an exhibition meant that only a selection of the available presentations could be covered. Themes included Natural Fibres and Sustainable Materials, Filtration Opportunities for Nonwovens, Nonwoven Technology Update, Medical and Biotechnology and Technical Textiles R&D. The exhibition was small compared with the Frankfurt version and contained little of interest for disposable hygiene products.
Kim Glas, Deputy Assistant Secretary of Commerce for Textiles and Apparel, USDOC, Washington, D.C., USA and an Obama appointee, listed the top 5 sources of US textiles and apparel in 2009 as China ($32bn) Vietnam ($5.3bn) India ($4.6bn), Mexico ($4.1bn) and Indonesia ($4bn). Total imports amounted to $81bn while total exports were only $13.6bn, mainly to Canada ($3.5bn) and Mexico ($3.2bn). Free Trade Agreements were the key to reducing this textile trade-gap: 17 of were already in place and a further 3 were pending, but none so far were with any of the top 10 countries supplying the USA. The Trans-Pacific Partnership FT Agreement was facilitating exports to the Pacific Rim which now accounts for 40% of global trade, and the first round of talks involving the USA were held in March this year in Australia. The USA, Australia, Peru and Vietnam will be added to the original members, Brunei, Chile, Singapore and New Zealand shortly. In total the Free Trade Agreement countries take 70% of US textile exports but together they only account for 9% of global GDP.
Support for the textile industry included the requirement that the Department of Homeland Security bought...certain clothing and textiles related to national security from domestic producers. Congress had also granted funds amounting to $8.3 million to the National Textile Center, the Textile/Clothing Technology Corp and Philadelphia University. Furthermore the Department of Commerce’s Sustainable Manufacturing Initiative would help the textile industry to “go green”.
Michael Jänecke, Director Techtextil, Messe Frankfurt GmbH, Frankfurt, Germany observed that TT’s have withstood the recession better than apparel, and in the US and Europe have avoided the market share losses to Asian producers experienced by apparel. However Asia and Eastern Europe are now increasingly focussing on TTs with South Korea and China supporting new investments in this segment.
Considering textiles by country since 2008:
· French TTs lost 15% of turnover c.f. 35% losses in basic textiles, but some TT specials grew 60%.
· Italian textiles lost 20-50% of turnover, 5000 jobs and 3000 small companies. Cheapest mass-market textiles performed best. Auto, Building and Sport textiles were now recovering.
· In Germany, TTs account for 50% of total textiles and excluding Auto, suffered only a slight decline. The governments economic stimulus is now increasing demand, especially in construction and geotextiles. For textiles as a whole zero growth is expected in the near future.
· Turkish textiles declined to 2004 levels in the first half of 2009 forcing industry restructuring. There were 30,000 companies with less than 10 empoyees, 150 of these making TTs with a value of $1.5bn, exporting $0.9bn to the EU, Russia and the USA.
· Indian textiles employ 85 million people and account for 4% of GDP (14% of exports). Growth slowed but there was no recession. Government is encouraging demand growth with improved infrastructure projects, new medical facilities and automotive industry growth. They intend to adhere to “global standards of eco-friendliness.”
· Russian textile imports have grown by 2% through the recession and the total textile market is now expected to grow at 30-40% pa with 90% of this being TTs. Currently 70% of TTs are imported with local producers failing to meet the demand. Modernisation of textile production is expected to require €3.3bn.
· Canada has over 400 textile makers employing over 40,000 and producing $6bn worth of goods, about half of which is exported, 82% being to the USA.
· South Korea, now the 6th largest supplier of textiles and clothing is focussing on high value TT’s and their convergence with IT, biotechnology and nanotechnology. They have secure core technology in auto, aerospace, construction and medical fabrics. Government is supporting production of composite fibres, nanotextiles and aramids for use in semiconductors, batteries and precision filters.
· Taiwan is experiencing a prolonged recession in textiles and fibres and is planning reorientation away from mass production towards high value medical, energy storage and ecological textiles. TT’s will grow from 10% of textiles in 2002 to 33% in 2015.
· China’s economic growth declined to 6.1% for the first quarter of 2009 before returning to the official “feel good” level of 7.9% in the second quarter. Over the same period exports of textiles fell by 11% and many producers are now focussing on domestic demand, where demand for TTs is “tremendous”, increasing by 11.4% in 2008. Masks, protective clothing, hygienic and medical products were in high demand.
Tom Murphy, Executive Vice President, RSM McGladrey, Inc., Minneapolis, MN, USA
Said the US Manufacturing Sector has seen significant challenges over the last two years.
Production levels declined by over twenty percent and capacity utilization fell to the seventy
percent range. Yet, contrary to public opinion, and manufacturing’s loss of over 2.1 million jobs since the recession started in December of 2007, the US manufacturing sector is still the largest in the world:
· Productivity has doubled since 1987
· The US attracts most inward investment (China second and UK third)
· The US was the third largest exporter after the EU and China, and 57% of exports were from manufacturing.
· The US is still the world leader in innovation (patenting evidence)
· The trade deficit is mainly due to trade with China and Japan: NAFTA trade was in surplus in 2009 if energy is excluded.
· The US is falling behind in infrastructure. China committed twice as much of its stimulus pack to infrastructure as the US (US= $300bn on infrastructure)
· 84% of US energy comes from fossil sources and this must be replaced.
· 2007 levels of output won’t be reached again until 2012, and no more than 50% of the jobs lost will be recovered.
What are the implications for the technical textile industry?
· Consolidation will be critical for survival to offset the foreign competition through product differentiation, expanded offerings, increased market share, the ability to enter international markets and being able to supplement forward integration.
· Partnering in both directions in the supply chain with suppliers and customers will be necessary to squeeze out more efficiency.
· More TT manufacturers will follow the apparel companies abroad.
· The demand for polyester is expanding into stretch, microfibers, recycled, antimicrobial and nonwovens.
· New fiber development, military fabrics, global expansion and medical textiles will provide new opportunities for the US.
David Trumbull, NTA Vice President of International Trade, National Textile Association, Boston, MA, USA noted that there were signs of recovery in the textile sector, with March 2010 statistics showing job losses in textiles levelling off at 400,000. Finance was still a big issue and the NTA has been working with government to expand the availability of loan guarantee programs. Despite the title, data specific to TTs was non-existent, largely because there was no trade association covering this market. The only TT’s the NTA dealt with were nonwovens and flock.
William C. Smith, Techtextil North America Symposium Director, Principal, Industrial Textile Associates, Greer, SC, USA estimated that 25% of all US fibre consumption went into TTs, a market worth $31 billion in sales. Globally TTs were worth $121bn and had been growing at an average 3.8% pa until the recession when a 5.5% decline occurred despite a 25% increase in military textile production.
· Automotive fabrics, the largest US TT sector declined by 300 million square yards as car production fell to 10 million from 16 million. The average car requires 21 kgs of TTs. China now makes more cars than the USA. 2010 should see a US recovery to about 12 million cars, but it will be 2013 before the 16 million mark is reached again and this assumes that ageing baby-boomers will not make do with one car, and a smaller one at that.
· Geotextiles, flat in 2009 were expected to grow by 5% this year.
· Outdoor textiles (awnings, marine etc) declined by 18% in 2009 – flat this year.
Dr. Martin Jacobs, Executive Director, National Textile Center, Spring House, PA, USA described the National Textile Center as a Federally-funded 8 university consortium supporting the US textile industry through basic research and technology transfer aimed at improving the global competitiveness of US textiles. It also trains graduates and provides the industry with 90% of its needs – 2000 graduates to date, 6 of whom provided the following short talks.
Bogdan Zdyrko, Ph.D., Research Assistant Professor, Clemson University, Clemson, SC, USA is trying to prepare artificial antibodies by grafting. Here an alginate fibre is coated with an epoxy surface such as PGMA (poly glycidalmethylacrylate) which has the right functional groups to bind to an antigen. An antigen (e.g. fibrinogen) is then attached to this surface and surrounded by PEG polymer chains which encapsulate the antigen molecules and “mould” to their shape. The antigen is dissolved using protease leaving the empty moulds which are then able to selectively absorb more fibrinogen. That’s the idea: checking how well it works remains to be done.
Dr. Anil Netravali, Cornell University, Ithaca, NY, USA is trying to make biodegradable composites from sugar cane waste and soy protein. The bagasse is dissolved in phosphoric acid to make liquid crystal cellulose fibres (Enka’s old Bocel Process). These are fibrillated and embedded in a soy protein matrix to give composites to compare with Kevlar embedded in the same soy protein. The cellulosic composite tensile strengths are about 60% of the aramid composite but the extensions are 3 times greater. Dr Netravali is also trying bacterial cellulose as a reinforcement for soy protein. Applications in ballistics are envisaged.
Yong K. Kim, Ph.D., Chancellor Professor, University of Massachusetts, Dartmouth, MA, USA is air-laying short cut fibres through two rectangular boxes arranged in line, one containing electrodes which orient the fibres in the machine direction and the other containing electrodes which orient the fibre in the cross direction. Field strengths of 20-40kV/m work well with fibres of 10-25mm length. Nylon and Polyester fibres appear to work well to give a unique cross-laid structure with fibre layers preferentially arranged at right angles.
Xiangwu Zhang, Ph.D., Assistant Professor, North Carolina State University, Raleigh, NC, USA made LiFePO4/C composite nanofibers using a combination of electrospinning and sol-gel techniques. Polyvinyl alcohol (PVA) was used as polymeric matrix of the LiFePO4/C composite system, and was converted to carbon in a calcination/carbonization step to improve the conductivity. These were intended for the cathode of the battery. The anode was made by electrospinning silicon nanoparticles in PVA and then carbonising to get a silica/carbon composite. Batteries with these electrodes should exhibit higher power densities, longer life and a wider operating temperature range.
Marian G. McCord, Ph.D., Associate Professor, Textile Engineering, Biomedical Engineering, North Carolina State University, Raleigh, NC, USA observed that modern high performance wound dressings using hydrocolloids, gels, gel fibres etc tend to be costly so she is exploring coating conventional cotton dressings with nanofibres. While this is possible using electrospinning, the nanofibres adhere badly, and are not very durable. So she has tried using APPT (Atmospheric pressure plasma treatment) on both the substrate and the nanoweb to improve bonding. In fact the APPT and electrospinning have been carried out on the same roller. Peel tests and Gelboflex durability testing proved the benefits of using APPT.
Jeffrey A. Joines, Ph.D., Assistant Professor, North Carolina State University, Raleigh, NC, USA has modelled carpet recycling to nylon polymer within the Carpets of America Recycling scheme logistical framework. He concluded that unless virgin nylon polymer prices increased substantially, any such scheme would be uneconomic. He is now studying polyester and mattress recycling.
Dave Healey, Director, Synthetic Technology, Hollingsworth & Vose Company, East Walpole, MA, USA reviewed the problems of improving the performance of HVAC bag filters which generally have to fit in 24” square ducts. Adding more pockets, lengthening the pockets and tapering the pockets have diminishing returns: the extra surface area failing to yield the expected reduced pressure drop because the pockets interfere with their neighbours and the duct walls. Electretting the fabrics helps, but EU regulations now mandate discharging the filters with IPA before testing, and in Sweden, continuous testing over 6 months is required for filters carrying an electric charge. Moving to finer fibres with meltblowing or electrospinning improves the mechanical efficiency of the filters but gives face-loading problems and shorter filter lives. H&V have therefore developed meltblown with a wavy surface - “Nanowave” – which increases surface area and mechanical efficiency without face loading, and increases the dust-holding capacity by 2-3 times. The benefits can be translated into reduced pressure drop and hence energy savings. In a 6 month comparison with a similarly rated electretted filter, the Nanowave showed constant filtration efficiency around 40% compared with a 60% efficiency for the new electrets which declined to 20% by the end of their life.
Carol Clemens, President, Allasso Industries Inc., Raleigh, NC, USA has used sheath-core bicomponent fibre technology to make multilimbed fibres with very high surface areas. Sections shown had 32 lobes where the earlier 4DG fibres had 6 lobes obtained from shaped spinneret holes. The 32 lobe shape is the core of the fibre, the skin being sacrificial and dissolved the fibres have been processed into fabric.
This configuration gives:
· High absorbency and wicking characteristics
· Deep channel filtering effective for bacteria
· Exceptionally high surface area that can be functionalised for biomedical applications
· A 20 micron diameter winged fibre gives the same surface area as a 0.3 micron meltblown.
· The large fibres resist compression (unlike meltblown of similar surface area) and the channels can take dust particles without affecting the pressure drop.
Actually the winged fibre is oval with an aspect ratio of 0.54 (width 17 microns, thickness 9 microns). It is available as PET, PP, PBT, PA, and PLA and can be produced as spunbond, staple or short-cut. Applications envisaged include air and water filtration, biomedical filters and adsorbers, battery separators, artificial leather, wipes and absorbents.
Mike Budai, Coating and Laminating Manager, Dynatec, Inc., Hendersonville, TN, USA explained how their hot-melt laydown equipment could do everything from lay uniform 100gsm webs 16ft wide to coating a single elastomeric yarn on a diaper production line. Fibre deposition could be random or in controlled waves, and if exceptional web weight uniformity was needed, melt flow could be provided by using a metering pump for every nozzle. The adhesives could also be applied in horizontal or vertical stripes of varying width or in box shapes or just on the edges of a nonwoven or film. Laminates could therefore be made with various levels of porosity, and the hot melt could also fix powders such as superabsorbent, active carbon powder, silica gel or calcium carbonate between the layers.
Nagendra Anantharamaiah, The Nonwovens Institute, North Carolina State University, Raleigh, NC, USA is developing nonwovens for performance apparel and observes that the hydroentangled spunlaid microfiber nonwovens made from segment-pie bicomponent fibres suffer from the “Velcro Effect” where the microfibers snag on rough skin to spoil the tactile property of a very smooth surface. Furthermore they tend to be hard to dye and show poor pilling and abrasion properties.
Fibrillating Islands in a Sea fibres which have a polyethylene sea which fractures to liberate the nylon core fibres during hydroentanglement looked interesting because the fibrils from the sea enhanced the bonding and gave better cover and strength. However these fibres need very high pressure water jets and give suede-like fabrics – which was felt to be a disadvantage for performance apparel.
Tipped trilobal bicomponents fracture with ease and if made with 75% nylon tip and 25% polyethylene core yield four fibres of equal denier and a tendency to crimp on hydroentanglement. The resulting fabrics were easily stabilised by thermal bonding, soft and durable and free of the Velcro effect.
Further extensions to tricomponency become possible if the core of the trilobal is hollow or has another core polymer within. The elastomers of the title were mentioned but briefly: if used as cores, the fibres were hard to spin.
Bong-Yeol Yeom, The Nonwovens Institute, North Carolina State University, Raleigh, NC, USA has made nanofibre webs by electrospinning 12% nylon 6 dissolved in 3 parts of formic acid mixed with 7 parts of acetic acid. Up to 5% of boehmite nanoparticles (7nm average diameter) were added to the solution and electospinning used the Elmarco system to coat a 20gsm PP meltblown nonwoven. Fibre diameters were pretty consistent averaging around 80nm regardless of the boehmite concentration.
Filtration performance was assessed by dioctyl phthalate penetration as-spun, after discharging and after electretting. The effects of charge dominated the results. The boehmite nanoparticles did slightly improve the aerosol filtration performance, but this appeared due to the higher electrostatic charge held by the fibres containing it.
Everette Scarboro, Jr. Regional Sales Director – North America, Oerlikon Textiles, Charlotte, NC, USA showed how crosslapped web weight varies considerably from side to center to side. Crosslappers have been modified to minimize this “smile” effect but it was not until additional sophisticated controls were employed that true leveling was accomplished.
For needlepunch nonwovens, the tensions created by needles stopping web motion with every punch add to the problem and elliptical needling (where the needles move with the web) provides a solution albeit at high expense. Profi-line CV1 from Dilo, and ProDyn from NSC provide further solutions by varying the card web basis weight periodically so that after cross-laying a “frown” profile enters the needleloom to allow a level final product.
Oerlikon’s WebMax solution can be retrofitted to existing lines. It goes “in the crosslapper or between the card and the crosslapper” to contol card web basis weight to achieve the same effect at lower cost, probably by web-drafting, although Mr Scarboro was deliberately vague about mechanisms. Because most needlepunched nonwoven buyers specify a minimum thickness, reducing thickness variability allows the basis weight to be reduced and the material savings from WebMax give payback in less than a year.
Timothy Robson, Business Development Manager, Hills, Inc., W. Melbourne, FL, USA described a new method of making meltblowing dies by photochemical etching semi-circular channels on the insides of the die tip plates so that when conjoined they form capilliaries. These capilliaries can have diameters of <.1mm and L/D’s of >100:1 where traditional drilled holes are limited to ~0.2mm in diameter and ~10:1 L/D. High L/D capilliaries allow running at the low throughputs required for nanofibre production while maintaining the high die-tip pressures needed for good polymer distribution, and hence good web and filament diameter uniformity. Furthermore the etching process allows higher hole densities and so greatly improves throughput of ultra-fine fibres. Because the new dies can withstand higher pressures, polymers such as PA and PBT can now be processed into nanofibres.
One filtration example was given. Here a 2 gsm nano PP Meltblown on a 17 gsm PP spunbond gave almost the same filtration efficiency as a commercial HEPA filter (30 gsm standard PP Meltblown on a 70 gsm PP Spunbond) but with half the pressure drop.
Bill Lynch, Key Account Manager, Hermann Ultrasonics, Bartlett, IL, USA provided the traditional paper on sonic bonding noting that it is a reliable and efficient bonding process which meets sustainability targets by eliminating the need for adhesive materials and high thermal heat bonding processes. Ultrasonic processing is still used for bonding and laminating multi layers of nonwoven materials and films improving the strength, performance, appearance and feel of the lamination. Other uses include embossing, perforation, slitting, cutting and splicing for Hygiene, Medical, Filtration, Wipes, Construction, Automotive and Home markets.
More interesting was a brief mention of the Ultraspin rotary sonotrode systems that help feed thicker or fluffier type materials at high speed, and a question regarding the glue-free diaper target which indicated that Hermann is working on laminating 12-13gsm PP backsheets to PE film, and this is proving tricky. Bico PP/PE spunbond could however be laminated to PE film without difficulty.
Needlepunch: Competition for spunlacing?
Terry Purdy, Sales Manager, Dilo, Inc., Charlotte, NC, USA also provided a traditional paper - on needlepunching. Among descriptions of the multitude of combinations of machinery needed to make all types of nonwovens, with or without needling, one slide covered a new concept: Hyperlacing. This looked like an artificial leather production line but here the 8 needlooms were set up to produce nonwovens in the 30-60 gsm range for wiping applications. Needles with a single barb intended to carry a single fibre through the web were used, and the line was said to be capable of running at 100m/min. Symbols on the diagram suggested the first loom was downstroke, the second upstroke and the remaining 6 were needling from both sides with elliptical board motion. Data on capital cost and nonwoven properties compared with hydroentanglement systems was not forthcoming.
Larry McAmish, Technical Services Manager, IMERYS Performance Minerals, Marietta, GA, USA presented the results of trials conducted at several universities. In all cases the spunbonds maintained most of their physical properties up to 20% calcium carbonate in the fibre, but the tenacity dropped by 50% at 50% loading. With spunlaced staple fibres, nonwoven strengths were increased by the calcium carbonate loading presumably due to surface friction increases. There were also some novel effects associated with suspending high density, inorganic particles within a lower density polyolefin matrix such as the improved stability of an electrostatic charge on this composite material due to triboelectric effects. In staple fiber applications, there were additional benefits of improved web formation both in carding and spunlacing. There were also some aesthetic benefits, and sustainability advantages resulting from the considerably lower carbon footprint of the mineral phase.
Deborah K. Lickfield, Ph.D., President, Lickfield Consulting, LLC, Easley, SC, USA provided assorted data on the market:
· World speciality textiles market had increased from 21 million tonnes worth $115bn in 2007 to 22 million tonnes worth $120bn in 2009
· The Medical subsegment was worth $8bn in 2007.
· In 2008, USA, EU and Japan the leading medical market segments by revenue were Wound care (32%), Incontinence care (19%), Patient Care linens (17%), Drapes (15%), Gowns (7%), Masks (5%) and Sterile Wrap (5%)
· K-C, J&J, SCA, Molnlycke, Cardinal and P&G were listed as the main global competitors in primary medical textiles – P&G for Incontinence product and wipes.
Almost any new polymer and fibre technology would attract interest from medical product developers. There is huge interest in cross-sectional shapes and anything else which gives high surface area, or incorporates active ingredients or novel surface treatment.
Advanced wound care is particularly active. Globally $5.6bn was spent on chronic wounds in 2007, and there are over 4 million in the US where a care of a single chronic wound can cost up to $80,000. Current products include:
· Moist products: Alginate, films, foams and hydrocolloids
· Active products: the above with haemostats or components to accelerate healing or antimicrobials such as silver.
· Quikclot® - gauze with an aluminosilicate nanoparticle haemostat.
· Gauze with negatively charged phosphoric acid to extract proteases from healing wounds.
· Coolmax® FreshFX medical hosiery with silver ions.
· Celliant® fabrics from fibres containing ingredients to oxygenate the skin and increase blood circulation.
Gadi Borkow, Ph.D., Chief Medical Scientist, Cupron Inc., Gibton, Israel described how copper oxide is spun into fibers endowing them, and fabrics made from them, with potent broad-spectrum anti-bacterial, anti-viral, anti-fungal and anti-mite properties. The risk of any adverse reactions to dermal exposure to copper is known to be extremely low, and now animal studies have shown the fabrics to be free of irritation or allergenicity issues. The EPA has approved the use of copper (metal) as an antimicrobial worksurface.
Applications under development include:
· Athletes foot prevention socks
· Diabetic ulcer healing socks
· Bed linen to reduce MRSA contamination in hospitals.
· Anti dust-mite bed linen (Now approved by the EPA)
· Anti-viral face masks
· Anti-viral filters to remove HIV from breast milk (with funding from the Bill Gates Foundation)
· Tissue regeneration dressings: (Copper works through angiogenesis whereas silver is inactive)
· Wrinkle-reducing pillowcases (make skin look younger).
Davis Khan, Research Scientist, Kimberly-Clark, Dallas, TX, USA explained that he was at TechTextil because K-C had developed a great new raw material for applications outside K-C’s usual domain and was therefore available to licence. Why had they developed it? Because there was a need for low cost conductors in consumer products and they had 135 years of experience in papermaking. The new material in question was not a nonwoven but a conductive paper made from 10%-30% 3mm carbon fibres and 90% pulp along with wet-strength enhancers and colorants as necessary. This could be used as-is, or hydroentangled into other nonwovens, or fed into air-laying Co-Form style. At 40 gsm with 10% carbon it would cost ~$0.37/m2 and at 75 gsm with 25% carbon fibre it would cost $0.97/ m2. The resistance can be tailored, and the positioning of the paper in a product can be arranged to give targeted, effective heating at low cost. For instance a paper with 30% carbon fibre carrying a 130mA current from a 7.5v power supply would heat at 840W/m2.
In addition to semi-disposable heating pads giving a 97oF surface for 8 hours from a 3v Li-ion battery, the paper could provide 115oF to release scent from gels, liquids or waxes, and allow “easier cleaning of grease and oil” when used in a mop-head. It could also be used as radiating elements in RFID tags or smart textiles.
Ultrasonic bonding and laminating has been shown to shatter the carbon fibres and break the conductivity of the cellulose paper. With the right pattern roll, ultrasonics can create circuit patterns. This technique has been used to make simple membrane switches and a disposable keypad.