EDANA Outlook Monte Carlo : 19th – 21st September 2001

This new addition to the Conference Circuit provided a late summer break in glorious Mediterranean weather for those who travelled despite the tragic events of the previous week. Understandably, US delegates were in short supply, and for the first time at a nonwoven conference, a live video link was set up to allow a “grounded” speaker to present her paper on the big screen. Another first for Edana: there were significantly fewer papers than normal, but the quality of both presentation and attendance was high and the extra time for questions was put to good use.

The line up for the opening session: Dr Raine Schoene, Prof. Klaus Kernig, Dr Rolf Altdorf (PGI: Moderator), and Jean-Francois Artigue.

Phase-out intensive farming

Prof. Claus Kernig presented a review of the political, economic and social trends that have created two very different worlds: the affluent “North” and the impoverished “South”. He went on to explain his thinking:
• The key equations of demographics are HIGH INCOME=FEW CHILDREN and LOW INCOME=MANY CHILDREN.
• The North's population is getting smaller, older and richer, while that of the South is getting larger, younger and poorer.
• So, by 2025, people in the wealthy North will account for only 12.5% of the world's population compared with 25% in 1975
• The problems started in the 18 th Century when excessive population growth in the North forced urbanisation, and also colonisation of the South (to maintain the North's economic and population growth).
• Attempts to correct the resulting relative impoverishment of the South with Northern “aid” in the form of medicines and chemicals made the situation worse by reducing the death-rate without affecting the birth-rate or improving the food producing capability of the South.
• Migration from South to North is now favoured as a quick route to better living standards for Southerners and serious social problems will result.

Prof. Kernig proposed direct involvement of the Southern rural population in world trade by:
• Allowing the “treasures of the south”; labour with agricultural skills and fertile land, to produce organic food for the North while making a reasonable profit.
• Phasing out intensive Northern agriculture, which is now unable to operate economically. The EU spends 52% of its budget to ensure that 2% of its population can have a reasonable standard of living while growing food. American subsidy levels were said to be higher still.

An incredulous questioner wondered at the strategic folly of becoming dependent on the South for daily sustenance. Prof. Kernig thought that interdependency was the key. As with any other real trading relationship, the South would come to need Northern money just as much as the North would need Southern food.

If only we knew what we know…

Dr Raine Schoene of Procter and Gamble wanted to increase the efficiency of research and development by reducing the estimated 30% of R&D budget spent on developing technology that had already been developed elsewhere.
• P&G employed 8000 people in an R&D department with a $1.7 billion annual budget.
• P&G was becoming more open and transparent to outsiders, but internal, inter-divisional barriers seemed to have strengthened.
• “Siloism” and “Not Invented Here” were continual problems especially in the research groups.
• Mergers had brought in different cultures but these seem to integrate least well in R&D.
• Researchers are judged on innovativeness and are thus driven to innovate rather than trying to discover external solutions to their problems.
• Research management should judge performance against how well existing knowledge is utilised, re-application of technology being valued above re-invention.
• Knowledge engineering – the efficient discovery and extraction of solutions by mining the research literature – would be a key discipline.
• Using an intranet, technology councils, and formal communities of practice with their own budgets (of which there were over 20 in P&G) would be encouraged.
• An external focus through suppliers, universities etc. would be developed.

P&G already have over 100 strategic alliances with suppliers so far, the key to their success being trust, and good lawyers to define the ownership of intellectual property fairly.

Worldwide Mass Marketing

Jean-François Artigue of the French Society of Analysis and Development questioned whether globalisation had really begun. Of the world's top retailers by turnover, the leader, Walmart was in 9 countries, Carrefour (No2) was in 25, Kroger (No3) was in only 1. Even within the six main EU countries only 3% of items sold were identical, and only 14% could be considered as approximately equivalent. Most standardisation occurred in batteries with 40% being equivalent between the countries: beauty care products being next with 22% equivalence. At the other end of the scale, kitchen paper (1% equivalent between the six countries) was the least “global”.

Mr Artigue cited the Walmart effect, internet marketing, and the adoption of the Euro as factors which would further reduce European retail prices and favour the development of more Own Brands. These currently held about 15%-20% of retail sales on average but were expected to reach 25% across the board in the near future. The UK had reached 40-45% Own Brands at retail, and other countries would be expected to level out at this percentage in 5-10 years.

Would “global” products be sold at the same price throughout the Eurozone? Coca-Cola, Gillette, L'Oreal, Playstation and Pampers were brands where this could be expected, but overall the retail trade would adapt pricing to local conditions.

A chart of the benefits of joining the Euro in 2002 showed Belgium and Italy as big gainers whilst the UK and Germany would suffer more disadvantages than benefits.

Finally, we were not to ignore the ecological and humanitarian concerns that were contrary to the main politics and economics of globalisation. “Fair-trade” products (e.g. Coffee Direct) were evidence of a desire to bring in an ethical dimension.

Patentology

Krzysztof Malowaniec, Head of the Patent Department at Paul Hartmann and Chairman of EDANA, reviewed the history of patents and their current status as a legal monopoly and a mine of information. Patent law was national and key differences existed:
• In France you only had to register a patent to get one: there was no examination (for inventiveness) and no opposition.
• In the UK there was a full examination of all applications, but no possibility of opposing the patent once granted. Germany was similar but for the fact that opposition was possible up to 3 months after the grant date.
• In the USA applications were published and subjected to a full examination before grant, and even granted patents could be re-examined. Here “first to invent” (rather than first to patent) took priority.

Surprisingly, an estimated 92% of all inventions were not patented and thus became “royalty-free prior art”, while a quarter of all patents were probably invalid.

An analysis of recent patenting activity in disposable absorbent hygiene products showed:
• In 1999 the leading company published 328 patents, of which 242 were for diapers, 72 for pads and 14 for training pants.
• The No2 published 186 patents, 155 of which were diaper related. (20 pads, 7 training pants, and 4 tampons)
• Over the 3 years (96/98) the leading company's patents named 1400 inventors, while the No2 had 842 inventors on the same basis. If you listed patents by inventor it was easy to find the most creative individuals in a company.
• One person in the leading company had 48 patents on absorbent hygienic disposables.

Petrochemical Trends

Marie-Pierre Chevallier, Totalfinaelf's VP of Corporate planning provided a fascinating insight into oil supply and demand trends and their impact on the polymers used in personal care products.
• Despite continuous rumours that the world is running out of oil, the oil industry has continuously re-estimated upwards world oil reserves, now standing at 40 years of consumption. Recently developed technologies are creating new reserve potential for the future.
• Geographically, Middle East countries dominate world total oil reserves.
• In spite of the increase in energy prices since the first half of 1999, oil and gas remain cheap energy and feedstock sources.
• Oil is an essential raw material for the chemical industry, from polymers to intermediates and specialties. In the US , the role of gas is notably more important, ethane being a major petrochemical feedstock.
• Polymers represent the unprecedented growth story of the last 40 years, growing from a few million tonnes per annum to close to 150 million metric tonnes per annum in 2000.
• The range of polymers used has widened and they now compete with almost all materials used in our day-to-day life.
• Polymers exhibit better economics and benefits all over the product life cycle.
• Petrochemical monomers and polymers still represent a cheap source of materials.

Future trends and R&D programmes are oriented towards :
• the use of cheaper, more abundant and more environmental friendly feedstocks
• more use of gas as a raw material for petrochemicals,
• the development of bio-polymers,
• closer integration of polymerisation with refining operations.
• the development of new products with better processability, intrinsic properties and economics, maybe utilising alloys, polymer blends and grafting.

Another Fibre from Corn?

Ellen Kullman of Dupont presented her paper over an ISDN line from Wilmington having been prevented from travelling in the aftermath of the WTC atrocity. Dupont sees biotechnology as the key to growth and is targeting 25% of revenues from businesses using only sustainable, renewable resources by 2010. The old polymer of 1,3 Propanediol (PDO) and terephthalic acid known as 3GT was now viable thanks to the new process to make low cost PDO developed by Shell/Degussa and acquired by Dupont in 1998. This had become the basis of the Sorona™ polymer, now in production at the rate of 12000tpy at the new Kinston N.C. continuous polymerisation plant. Dupont USA has no plans to make staple fibre from the polymer preferring to licence others to do it. Teijin, Saehan, Toray, Far Eastern and Dupont SA had taken up the option. However a slide did suggest they would make nonwovens, presumably spunbonds, themselves. The new fibre was said to be soft, elastic and easily dyeable. Fabrics (of unspecified construction) were lint-free, sterilisable, flame resistant to class 1 standard and had breathable-barrier properties. It would cost “about 50% more than PET or PE” and should be used in applications where its recoverable elasticity was a key advantage.

The relevance of all this to biotechnology and corn? PDO can be made by bacteria from glycerol, glycerol being a product of the action of yeast on glucose obtained from cornstarch. Dupont has now genetically modified a bacteria to carry out direct conversion of glucose to PDO. This patented organism and process would, by 2003, be making the PDO for Sorona™, presumably as economically as the Degussa process.

China : Is there a market?

Robert Rufli, President of BBA Nonwovens Asia-Pacific provided some statistics and observations related to nonwovens in China :
• As a proportion of Chinese skilled worker income, western-style disposable diapers and femcare appear 10 times as expensive as they do to an American.
• A months supply of western-style femcare requires 2% of a Chinese secretary's income and this market is growing well.
• For diapers, the figure is 11 to 23% and this is too high to allow regular use.
• About 12,000 tonnes per year of spunbond are produced at a quality suitable for high-quality disposables. (Only about 750 tonnes of this are required in locally-made diapers)
• Ditto 10,000 tonnes of carded, through air-bonded staple, but all this is used in locally-produced femcare.
• Ditto 18,000 tonnes of carded, calender-bonded staple of which about 7000 tonnes are surplus to local needs.
• Overall there is more than enough nonwoven produced in China to meet current internal market needs, so a lot is exported at very competitive prices.
• A list of 14 diaper producers and 14 femcare producers was said to be far from complete.
• The biggest Chinese nonwoven companies will be starting up plants in the West within 5-10 years.
• Since BBA announced the 2.7m, 16000 tpa M&J air-laid installation in China , a Chinese machine builder is offering similar lines and has made several installations.
• Spunbond and hydroentanglement lines have also been developed in China at much lower cost than Western machines. These are now available for export to USA and Europe .
• The problem of counterfeiting and patent infringement will diminish as China joins the World Trade Organisation.
• Information, “confidential or not” flows quickly and efficiently around China .

The Opportunities of Ageing

Sabine Martini of Smartini Consulting reviewed the published demographics of several western countries showing that the proportion of those aged 65+ would roughly double by 2050. The problems arising from this trend were regularly discussed, but the marketing opportunities were not:
• About a third of these “best-agers” were master consumers with high levels of disposable income, a love of spending and an inclination to try new things.
• They put quality and safety before price.
• However this growing demographic group appeared to be neglected in most advertising campaigns.
• 85% of the 60+ population read newspapers and 60-70% spend more than 3 hours a day watching TV. They are therefore more reachable than the younger audiences.

Inco-Pad Selection

Dr Konrad Giersdor of Stiffung Warentest Foundation (A consumer protection organisation in Germany , partially government-funded) estimated that there were 50 million incontinence suffers worldwide, 13 million in the USA , two thirds being women. Of the 65+ generation, 12% of women and 7% of men were sufferers.

Dr Giersdorf had organised an all-woman panel test of 23 commercial pads for light to medium incontinence from Germany and Austria . The 100 panelists were “calibrated” for amount of urine lost and all were allowed to use the products at home. The main conclusions:
• All pads performed as expected.
• Consumers could decide between products on price, the cheapest products being one-third the price of the most expensive.
• Instructions for use were inadequate.
• There was no standardisation of descriptions of the size of the products (one mans mini is another mans regular ).
• None of the products advised the user to seek medical advice in case their problem has a medical solution.

In the second half of this presentation Frank Courtray of Courtray Consulting described how his mannequin testing system for pads had been used to evaluate 19 of the panel-test products. Comparison with the panel results yielded 16 matches and 3 deviations, the deviations all having credible special explanations.

At Risk from the Precautionary Principle

Dr Roger Bate's paper was not presented, but from the CD ROM of the conference, his theme was as follows:
• Health scares such as alar, saccharine, breast implants, passive smoking, nuclear power, pesticide residues, mobile phones and GM crops are in some cases without foundation and in others blown up out of all proportion.
• The less developed countries are encouraged to react to these scares in the same way as the developed countries.

This inappropriate “exporting” of the precautionary principle has dire consequences exemplified by:
• Thousands of Peruvian deaths from cholera resulting from reduced use of chlorine in drinking water.
• Thousands of Indian jobs lost because the trade in recycling batteries was destroyed by concerns over cadmium, zinc and nickel handling.
• Modern nuclear reactors, which could transform the lives of millions of Africans, are ignored because of concerns over problems with old reactors.
• The banning of DDT use in agriculture by the EPA prevented its use in much lower and safer quantities to control the malaria mosquito in less developed countries.

Dr Bate, a Fellow of the Institute of Economic Affairs in London concluded that the precautionary principle must be interpreted locally, i.e. by the people who will be most affected by any action arising from it. Otherwise the principle will be responsible for more deaths than the malaria mosquito.

Coffee Break at the Meridian Beach Plaza .

Cocktails at the Hotel de Paris, but still working!

INTC Baltimore: 5-7th September 2001

Seventy-seven full presentations, twenty sessions, a suppliers new technology showcase with a further fifteen short papers, table-top displays, award ceremonies, and for TAPPI members numerous committee meetings, had all been squeezed into two and a half days at a delightfully sunny Baltimore harbourside loacation. The attendance, at around 350, was down on last years Dallas meeting (~500) and well below the combined attendance of the lNDA and TAPPI technical conferences that this blockbuster has replaced. With the delegates having to choose between three papers at any one time, some of the speakers were certainly addressing smaller groups than the quality of their presentations merited. But overall it worked, and INDA/TAPPI are to be congratulated on cramming so much technical information into such a short time. For all but those interested in the broad scope of the industry, choosing between sessions should not have been difficult.

Key Points

• Wellman has developed a permanently hydrophilic polyester fibre from polyethylene glycol and terephtalic acid using branching agents to correct the spinnablity problems.
• Antimicrobials that release chlorine when challenged by microorganisms are now being commercialised. They can be permanently bonded to cellulose or synthetics and are activated by mild chlorine bleaching.
• Reiter Perfojet claimed that an improved “Swiffer” could be made by “Jetlace” hydroentangling of polyester to a “Perfobond” spunbonded PP. Cheaper, bulkier, stronger dusters resulted.
• Samples from a simple air-forming process making chef’s hats direct from a card were remarkably good and the process was now being commercialised. Many other shapes were possible
• Optimisation of thermal-bond fabric strength involves balancing failure of the bond itself with failure of the fibres within two fibre diameters of the bond.

Microdenier Spunbonds Fumin Lu of Ason Engineering Inc defined microdenier as 1 denier and below and pointed out that the high-speed spinning needed to achieve these deniers economically inevitably meant higher filament orientation and stronger fibres and fabrics. Ason's short-tube draw system allowed the filaments to flap around in turbulence at the tube exit giving more “form drag” and hence a higher drawing force. At 400m/sec air speed this was said to be five times that achieved with a conventional long laminar flow draw tube. Data from experiments with a range of resin melt flow rates processed under identical spinning conditions showed that increasing the MFR from 35 to 350 increased a15gsm fabric hydrostatic head from 100 to 140 cms. However MD tensiles dropped from 2.3kgs to 1.7, CD tensiles fell from 1kg to 0.7kgs, % Crystallinity fell from 65 to 54, crystal size fell from 23 to 20 angstroms and the pure monoclinic structure obtained at 35 MFR was contaminated with smectic at 350MFR.

If the spinning conditions were optimised for each resin so that they could be run at the same throughput , the denier reduction (to 0.5 at the 6000m/min spin speed achieved with the 350MFR resin) allowed the fabric hydrostatic head to increase from 150 to 207 cms. This enabled the 350 MFR resin to be converted at 11gsm to give the same HH as a 15gsm made from the 35 MFR resin. MD Tensiles fell from 2.8 kgs at 35 MFR to 2.2 kgs at 350 MFR. Overall the 350 MFR resin (EOD39-60 from Atofina) gave the finest fibres and the best hydrostatic heads with acceptable tensiles when converted on the Ason machine.

Increasing Melt Flow Rates

Kimberly McLoughlan of Sunoco had also examined the relationship between increasing MFR and reducing tensiles having ensured that changes in MFR did not affect the Molecular Weight Distribution in the resin. Resins with MFR's from 19 to 188 with similar MWD's were converted on a Reicofil II system to give 2.5 denier fibres and 17 and 30 gsm fabrics. Over the MFR range, 30 gsm fabric tensiles fell by 70% despite filament strengths declining by only 13%. The optimum bonding temperature was significantly lower at the high MFI, and this lower crystallinity polymer appeared to form better bonds with flatter fibres. So why were the fabric tensiles so low? Dr Mc Loughlan postulated that as the bonds were stressed, the flatter filaments rupture more easily at the edge of the bonded areas.

Metallocene PP Spunbonds

Gajanan S Bhat of UTK compared PP spunbonds made from the conventional Ziegler-Natta resins and the newer metallocene catalysed isotactic varieties. Fabrics and filaments made from each type three different production rates were tested for tensiles, and structural properties.

• Both polymer types ran well on the Tandec Reicofil (“somewhere between I and II”) system.
• Metallocene PP (mPP) gave higher filament strengths (67g/tex versus 25g/tex at the highest throughput) and lower filament elongations (120% v. 296%), but also lower crystallinity and birefringence.
• The mPP fabrics had maintained these higher tensiles over a wider range of bonding temperatures.
• This strength advantage was due to the stronger filaments, the better-formed thermal bonds, and an apparently reduced degradation of filaments at the bond edges.

Dr Bhat thought the benefits arose from the better control of molecular weight distribution in PP manufacture by the metallocene route.

Thermal Bond Failure

Stephen Michielsen of Georgia Tech has investigated how the properties of PP fibres change in thermal bonding. If fibres are to bond, the molecular chains must have the mobility and the time to flow from one fibre into another at the bonding point. In theory, the chains are mobile above the glass transition temperature so PP fibres should bond on contact at room temperature. In fact the PP chains are immobilised by crystallinity and heat input is required to melt the crystals before true mobility can arise. When crystals melt, the birefringence and the density of the fibre should change, so there will be a morphology gradient from unbonded fibres, through the bridging region and into the bond point. These changes have now been observed using polarised laser Raman microspectroscopy. This technique allows 1 micron resolution and has been used to make multiple measurements in the region of two fibre diameters outside the bond edge. It has shown that the birefringence (and hence the fibre strength) decreases by half in this region, and this loss of strength diminishes as the speed through the calender increases. With polypropylene the polymer density increases into the bond itself, whereas with polyester, which is reluctant to recrystallise, it decreases. Dr Michielsen concluded that there is a trade off between bond strength and fibre strength at the bond edge, and that the optimum results would be obtained when half of the bonds failed internally and half failed due to fibre breakage at the bond edge. Asked about the effects of denier he felt that heat diffusion rate into the fibre was the key. Thicker fibres would be slower to heat up, but the bond edge region - defined as 2 fibre diameters from the bond edge - would still be important.

Bicomponent Technology

Hans Georg Geus of Reifenhauser GmbH reminded us that bicomponent fibre production required careful adaptation of resin rheology to prevent the two polymers having widely differing stabilities at the extrusion temperature, and to prevent dissolution of one polymer in the other. The technology was nevertheless established and the markets were expected to grow although the magnitude of the growth was difficult to estimate.
• Geotextiles and hygiene would be the main growth areas.
• PLA bico fibres would allow biodegradable spunbond and meltblown fabrics
• Unspinnable polymers could form the sheath on a spinnable core polymer.
• Meltblown bico's were more difficult because the air jets modify the fibre shape uncontrollably.
• The Reicofil system used a stack of apertured plates in the spinneret, their selection defining the type of bico produced (sheath/core, side-by-side, segment-pie etc).

Biodegradable polyester

Bill Haile of Eastman Chemical Co. provided an update on the development of the Eastar Bio biodegradable polyester.
• The relatively soft and elastic fibre was proving difficult to crimp and card and this was restricting its use as a staple fibre.
• The polymer was however useful in spunbond or meltblown or as a skin on PP or PET core bicomponent bonding fibres.
• It was being developed as a bonding fibre for hemp-based biocomposites.
• 10% of short-cut Eastar Bio in papermaking bonds the paper during normal drying and doubles the wet strength.
• Films based on the polymer have much better moisture vapour transmission rates than PE, so Eastman are trying to improve this property further.
• The polymer is more prone to hydrolysis in fibre spinning than PET, but careful attention to pre-drying the polymer can control this problem.
• The fibre has proved stable in normal use in textiles for over 3.5 years now.
• The fibre is not degraded by water per se, but the presence of water can allow bacteria to attach to the surface and these can commence the degradation process.

Durably hydrophilic synthetics?

Mark Nehra of Uniquema reviewed the issues in making synthetics durably hydrophilic. Additives in the dope failed because the concentration had to be too high to be cost effective. Surface treatments were generally too easily lost to be described as durable, the exception being silicones which often caused problems in subsequent processing or use. He felt their Cirrasol PP842 and PP843 finishes were the answer, providing silicone performance in a silicone-free product. PP842 at 0.5% gave strikethrough results below 7 seconds for at least 10 insults.

Hydrophilic Polyester

Keith Carnes of Wellman Inc. introduced a new hydrophilic polyester (Sensura Ô ) which gave permanently enhanced wicking along with enhanced thermal bond strengths, lower pilling, higher softness and better dyeing without affecting sterilisability, stability, crimp, carding or bulk. The new polymer was made by polymerising polyethylene glycol with terephthalic acid, the problems of low melt viscosity and poor fibre spinning inherent in this approach being solved by the use of branching agents. Varieties of the new fibre for use in nonwoven, spun-yarn and filament-yarn fabrics had been evaluated, the nonwoven versions (T870 and T289) by thermal bonding 50gsm webs of 100% and 50/50 rayon blends on a 25% bonded-area calender.
• T289 gives similar strengths to PET but achieves them at 200 o C where PET requires 230 o C. Elongations of the T289 fabrics were however nearly double those of the PET.
• Tested as an acquistion distribution layer for multiple insult overflow, the T289 fabric gave a quarter of the overflow of the PET control at the first insult, but only 75% of the overflow at the third insult. (Wellman is now looking at air-laid routes to ADL's)
• 50/50 T289/rayon blends were more than 50% stronger than PET/rayon blends and had double the elongation.
• Demand wettability testing showed that the T289/rayon blend had three-times the capacity of PET/Rayon with the acquisition rate (measured after 20 seconds absorbtion) also being three times that of the control.

T870 generally gave values half-way between the T289 and PET in nonwovens. In knitted fabrics the T870 gave home-launder pilling levels comparable to 100% cotton with a 14% improvement in drying time, a 34% improvement in moisture vapour transmission, a 60% reduction in shrinkage and a 75% increase in perceived comfort!

The T801 filament yarn at 1.5 dpf was said to give the same handle as a 0.6-0.75dpf PET yarn, along with a better dye uptake (20%) shorter dyeing time (1.75hrs cf 2.75 hrs for PET) while maintaining better wash fastness. Knitted fabrics dried 35% faster than PET, had 65% better stain resistance, 70% better wicking and 270% better static dissipation.

Infuriatingly, the moderator did not allow questioning of these remarkable claims and Mr Carnes disappeared before the end of the session.

Hats off to UMIST

Hugh Gong of UMIST has developed a pilot process to air-form chefs hats directly on moulds positioned after the doffer of a card. He used bicomponent fibres and this paper reviewed the conditions required to get the optimum through-air bonding. Samples of the hats shown after the talk proved remarkably even and strong and were about to be commercialised by the only chef's hat producer in the UK , who had sponsored the work. He was dismissive about the achieving such good-looking products in such a short and simple process, referring questioners to a recent International Nonwovens Journal for a description of the details of the air-forming. He thought the method could be used for a variety of other products, especially filters and moulded garment interlinings (e.g bra cups) Marks and Spencers were said to be taking an interest.

Antimicrobials I

Thomas Theyson of Goulston Technologies reminded us that the Aegis Microprobe Shield silane-quat antimicrobial is unconventional in that it is durably fixed to the fibre surface, not consumed by microorganisms, does not encourage resistance to develop, gives no zone of inhibition in the standard plate test, but kills a variety of bacteria and fungi by “stabbing” its long alkyl chain through the cell wall. Furthermore it can be mixed with the spin finish and a simple bromo-phenol blue stain test can show whether or not it is still active.

Antimicrobials II

Robert Monticello of Aegis Environments compared antimicrobial additives, making the following points:
• 61% of women now actively seek antimicrobial versions of products.
• Developing resistance to antimicrobials can “teach” bacteria how to resist antibiotics.
• A “pump action” mechanism of resisting antimicrobials is apparent: the bacteria simply recognises an invading substance and pushes it back out through its cell wall.
• Unconventional antimicrobials which do not leach and kill bacteria by a mechanical action were best. The silane quaternary ammonium compounds with a silanol group allowing permanent covalent bonding to the fibre and a quaternary ammonium group with a long alkyl chain (-Si-C 3 H 6 -N + -C 18 H 37 ) that could stab through the bacterial membrane were best.
• Antimicrobials with a long history of safe use such as their (originally Dow Corning technology) silane quats were to be preferred.
• ASTME 2149-01 was the preferred evaluation procedure for bacteria, and ASTM G21 was best for fungi.
• Being cationic, the silane quats react with bromophenol blue to give a blue color and are thus easily detected on surfaces.

Antimicrobials III

Roy Broughton of Auburn University provided a comprehensive update of his INTC 1999 paper on the methods of making textiles antimicrobial and introduced some newer approaches involving halogens. Chlorine for instance is a very broad spectrum, fast acting biocide with an advantage over the more specific antimicrobials in that organisms cannot develop a resistance to it. Despite the fact that it kills most life-forms and is capable of reacting in nature to form some highly toxic compounds, the Auburn group has funding from the National Textile Council to develop compounds that retain chlorine, releasing it only when challenged by a micro organism. The group has now published and patented approaches based on halamine chemistry, more specifically chloramines such as hydantoin which provide kill ratios in excess of 99% in a few minutes.

The first approach to getting these compounds into products involved synthesising polymers specifically to support the chloramine functionality. For instance hydantoin was attached to polystyrene in an elastomer to make a drinking straw which purified water. Subsequently they reacted the halamine with formaldehyde to provide a finish (methylol hydantoin) which bonded to cellulosics as part of the permanent press finishing (DHDMEU) chemistry. Mild (0.01%active chlorine) bleaching of the finished fabric converted the hydantoin group into a chloramine thus activating the textile.

This approach has been used on cotton hospital sheets, and here any loss of activity due to soiling is regenerated each time the sheets are washed and bleached.

For synthetics, the fibre surface has to be activated before the hydantoin can be attached: nylon needed formaldehyde pre-treatment and polyester requires ammonia. Again, once the hydantoin is attached a mild bleaching activates it. After applying a 9 log innoculum of staph. aureus to the polyester a 5 log kill was observed in 10 minutes and a 7 log kill in 20 minutes.

Halosource (Seattle) were said to be among a number of companies commercialising this halamine technology. In an aside on the use of chitosans as absorbable antimicrobials, Dr Broughton stressed the need for extreme levels of purity in the crab shell extract to avoid proteins known to cause allergic reactions contaminating the dressings.

Faster Carding

Sigfried Bernhardt of Spinnbau reviewed the developments in high speed carding in order to identify further bottlenecks. Carding, widely assumed to be incapable of further development when 50kg/hr/metre was reached in 1980, was now providing 300kg/hr/metre on commercial systems thanks to increasing roller speeds, more precision in settings, better clothing, better drives and the use of suction transfers and turbulence control. A quality/productivity compromise arises because improving web quality needs more working points and more compaction between cylinders and doffers both of which means the fibre has to stay longer in the card.

Better quality and hence higher potential output could for instance be obtained by carding, cross-folding, and then feeding the output of the cross-folder to yet another card. For high speed coverstock production the current state of the art was a double doffer system with belts and vacuum transfers on each doffer giving a potential 400kgs/hour/metre, or 400 metre/min operation at 15gsm. Air-layers, giving full dispersion of staple fibres in an airstream prior to laydown with a 1:1 MD/CD ratio could be added to a line after carding, but these were currently unable to work at lightweights without web drafting which still tended to spoil the quality as well as the MD/CD ratio. The more voluminous webs from these systems were more difficult to handle at higher speed. This type of airlay was currently restricted to 80 m/min.

Staple Fibre Air-Laying

Michel Collotte of NSC Nonwoven System Thibeau gave the first presentation of their new Air-web Ô staple fibre air-lay system. This would produce MD/CD ratios of less than 1:1.5 from 10-40mm fibres at up to 260 kg/hr/m in basis weights from 35 to 200gsm. Like the Fehrer, Hergerth and Chicopee air-lay systems also described, it needed to be fed by a card and appeared limited to about 80m/min web speed at 40 gsm. Its main application currently was make-up removal pads.

Scrim Reinforcement I

Ed Hovis of AET Speciality Nets and Nonwovens promoted the range of apertured nets made by melt-embossing and counter-rotating dye processes now available for filtration, healthcare and textile applications. Melt-embossed nets were made by calendaring a film then stretching it to open up perforations between oriented film “filaments” connecting the embossed areas. Many different geometries are possible from a variety of polymers (mainly PP, PE and copolymers) with hole sizes varying from about 50 to about 800 microns and with open areas between 15 and 65% comprising up to 1600 holes/square inch. Thicknesses vary from 2 to 17mils, with bicomponency achievable by coextruding a two-layer film from two different polymers. MD-only stretching gives low open area but well-defined flow channelling. Pattern definition is best with HDPE, worse with PP, and a perforated film without obvious filament interconnections is obtained with soft polymers like polyurethane. Counter-rotating dye technology gives tubular diamond-pattern nets from a variety of polymers that are used to reinforce filters and other fabrics.

Scrim Reinforcement II

Keith Misukanis of Conwed Plastics described an experiment using their extruded PP scrims to reinforce hydroentangled polyester. Three net types and three weights of 1.6dpf Dacron PET were combined by HE and compared with hydroentanglement of the PET alone. The nets were all 4 threads per inch in both directions and varied in basis weight. (20, 40 and 80 gsm). Measurements of tensile, tear and air permeability showed that the composites tensile and tear properties were dominated by the scrim properties, whereas the air-permeability was unaffected by the scrim.

Replacing Scrim with Spunbond

Daniel Feroe of Rieter-Perfojet made a case for replacing the apertured net reinforcement of a Swiffer Ô - like dry duster with a spunbond reinforcement. Perfojet Jetlace could be used to hydroentangle polyester staple to a Perfobond spunlaid PP fabric. At 2.2 dpf the output of a single-beam Perfobond spunlaid line would be 300 kg/hr/m and therefore well matched to the output of a Jetlace line. With the PP spunbond reinforcement, the wipe is twice as strong as the net-reinforced products now on the market, with 20% better bulk and a 45% better ability to take a static charge. Wiping tests suggest the dust capture capability of the spunbond-reinforced product is between 40 and 100% up on the current commercial products. Cost calculations showed that the Perfojet approach would require a production line costing 30million Euro (50% more than the current process) but would produce 16722 tonnes/year of saleable product compared with 12602 tonnes/year from the present process. On a per kilo basis, the spunbond reinforced product would cost 1.69 Euros compared with 2.89 Euros for the net-reinforced version.

Latex and thermal bonding revisited

Alfred Watzl of Fleissner Gmbh reviewed their chemical and thermal bonding equipment in the context of using it to upgrade fabrics made on their hydroentanglement systems. Points of interest:
• 250,000 tonnes of HE fabrics were made in 2000.
• Lightweight webs were best bonded with foamed latex, on-line.
• Heavyweight webs were best bonded off-line with foam or liquid binders.
• The biggest Fleissner HE line for card webs was 5m wide running at 250-300m/min.
• The biggest Fleissner HE line for spunbond was 5.5m wide running at 500 m/min.

Stretching Spunlaced PTT

Donald Schiffler of the Nonwovens Cooperative Research Centre, NCSU compared the stretch, recovery and compressive behaviour of plain and apertured HE fabrics made from polytrimethylene terephthalate (PTT) fibres and conventional PET. Being a soft fibre, PTT is easier to entangle and gives a microdenier handle at normal filament deniers. It recovers better from 10% strain, especially in apertured fabric form, but shows little difference in recovery from compression. The apertured PTT fabrics were also perceived as the softest. 50/50 PTT/PET fabrics showed a large and currently inexplicable increase in fabric thickness.

Specialty Resins and Additives

Julian Jensen of Eastman Chemicals Co. described their reinvolvement with fibres as a supplier of specialty resins to the fibre industry. They would never again produce fibres themselves but felt their history in the field enabled them to serve their fibre-producing customers better than most. He listed the specialities as:
• Eastar Bio, the biodegradable polyester resin (see later)
• The low IV homopolymer for spunbond and meltblow processes
• PCT (poly-cyclohexane terephthalate) high melting point fibres
• PCTA – acid modified for filament production
• Various additives and concentrates.

New VAE Binders

Ronald Pangrazi of Air Products Polymers introduced three new experimental binders:
• Airflex HTP, a Vinyl Acetate Ethylene copolymer with high temperature resistance allowing it to perform like an epoxy up to 120 o C. It was free of formaldehyde and alkyl phenylethoxylate and could be applied by all techniques. The target application was mould release.
• Airflex LTC, a VAE copolymer which cured fully at 65 o C. This was also APE free and could be made formaldehyde free if required. It could be used to bond low-melt fibres or save energy or increase line speeds.
• Airflex IAS, a VAE copolymer with increased adhesion to synthetics to give higher wetstrength nonwovens. Compared with the standard Airflex 105 binder this increased wet strength from 500 to 840 gms/5cms. It was intended for use on multi-bond airlay lines or for reinforcing PET/Rayon blends.

Disruptive technology?

D K Smith of Smith, Johnson Associates reviewed methods of using the US Patent database to spot disruptive and innovative technologies. 3D patent maps, patent genealogy trees, and patent citation analysis could provide worthwhile insights into the direction of development in an industry. However companies recognised this and some took steps to obscure their lines of interest by assigning to remote subsidiaries, covering non-critical aspects, or taking out many narrow patents. Others didn't patent at all preferring total secrecy.

The US patent office currently issued around 3000 patents a week; 700,000 from 1996 through 2000. Of these 6657 dealt with nonwovens, and 403 with nonwoven manufacturing processes.
• 52 US companies had filed nonwoven process patents in the 5 year period compared with 1 British company and 9 German companies. There were no patents from the world's biggest nonwoven producer, Freudenberg .
• Kimberly Clark led the table with 122 patents, followed by P&G (41), 3M (24), Dupont (21), Fiberweb Group (15) and J&J (7)

Dr Smith had chosen 10 process types and assigned each patent to one of these types:
• Lamination (23.3%) emerged as the biggest category, with Spunbond next (21.8%) and then Meltblown (15.6%)
• There were surprisingly few hydroentangling (8.9%) and pulp air-lay (2.8%) patents, and perhaps more than expected on the old dry-lay process (12.8%).
• Analysis of numbers by year showed that hydroentangling patents were steadily increasing (11 in 2000), while lamination patents had peaked at 31 in 1998 and had fallen to 15 in 2000.
• Total nonwoven process patents were down from 96 in 1998 to 67 in 2000.
• Other than combining nonwoven processes to make new materials the other significant trends involved making nonwovens more elastic, more biodegradable and more flushable.

Speed trap

Brian Osmondson of TSI Inc . promoted their laser-doppler velocimeter which could measure the speed of anything to within 0.1% without touching it. In addition to the obvious uses in law enforcement and nonwovens production the machine had been successfully used to measure the velocity profile of a filament between its emergance from a spinnerette and stretching.

Worthless images

Norman Lifschutz of Hollingsworth and Vose, along with other TAPPI menbers, had been trying to use a digital imaging technique to measure the length and diameter of glass microfibres simultaneously. The different labs were failing to get the same answers from the same fibres and Dr Lifshutz had concluded that the results were a function of the pixel size used in digital imaging. The technique has been declared valueless and no further work is planned.

Winding-up

Alessandro Celli of A.Celli SpA pointed out that in the now fiercely competitive environment of a mature nonwovens industry high speed was an essential component of all business activities, not just production. Current commercial production speeds were said to be:
• 150-200 m/m for carded spun lace lines
• 200-250 m/m for airlaid pulp lines
• 400 m/m for carded PP thermal bond lines
• 700-800m/m for spunbond lines.

His super winders could run at 1000m/min and cope with all these, collecting jumbo rolls from the production line and automatically transferring them for off-line high speed inspection, slitting and rewinding.

Points from other Papers

S S Ramkumar of Texas Tech had been using the Instron and sledge method of measuring fabric surface friction and was promoting this as a simple way of quantifying the handle of nonwoven fabrics. Correlation of the technique with real handle assessments however remains to be made.

Michael Thomason of BBA reviewed INDA, EDANA, ISO and ASTM methods and pointed out that ASTM D5035 gave consistently higher values for tensile strength than ISO 9073-3.

Austin Robinson of Maier America LLC had developed cooled bearings for thermal-bonding calenders which allowed hot-oil machines to work reliably at 300 to 400 o C.

LarryWadsworth of TANDEC was hoping to acquire new Reicofil spunbond equipment and a new 12” meltblown line.

Andrey Troshko of Fluent Inc. presented a computer analysis of air flow and fibre accumulation in a fluff-pad machine. While the graphics were interesting, as yet no attempt had been made to correlate it with any data from a practical machine.

Footnote: This report covers only the papers attended. Summaries of those simultaneously presented papers reprinted on the CD-ROM of the conference will be prepared shortly (see below). Attendance (~350) was down on last years meeting and below the levels of the last combined INDA and TAPPI technical conferences that it has replaced.

INTC 2001 CD-ROM Contents

(Provided by INDA)
Process Technology I
Advances in Microdenier Spunbond Technology Fumin Lu, Ason Engineering, Inc.
Effect of Polypropylene Melt Flow Index on Spunbond Fabric Strength Kimberly McLoughlin, Ph.D., Sunoco Chemicals
New Developments in Bicomponent Spunbond and Bicomponent Melt Blown Hans GeorgGeus, Reifenhäuser GmbH & Co.
Spunbonding Studies with Propylene Polymers Gajanan Bhat, Ph.D., The University of Tennessee
“Terminal Velocity” Is This All About Nonwovens? Alessandro Celli, Ph.D., A. Celli S.p.A.
Filtration
Activated Carbon Felt Implementation for Indoor Air Quality Improvement Valérie Héquet, Ph.D., Ecole des Mines de Nantes
Nonwoven Material Performance in Air Filtration Applications B. Dean Arnold, Kimberly-Clark Corp. USA
Gradient Density Filter Media for Liquid Applications Ganesh Deka, Kimberly-Clark Corp, USA
Low Emission Phenolic for Oil Filter Paper Wayne R. Walisser, Borden Chemical
Fast Evaluation of Average Fiber Diameters of Nonwovens Akshaya Jena, Ph.D. PMI, Inc.
Process Technology II
The Development of, and Opportunities for, Bi-component Melt Blowing Technology John Hagewood, Hills, Inc.
Understanding the Melt Blowing Process Randall R. Bresee, Ph.D., The University of Tennessee
Development and Characterization of Poly(Trimethylene Terephthalate) Based
Bicomponent Meltblown Nonwovens Dong Zhang, Ph.D., TANDEC
Applications of Melt-spun Hollow Fibers in Nonwoven Structures Robert Shambaugh, Ph.D., University of Oklahoma
Performance Analysis of Meltblown Dies Using Computational Fluid Dynamics Aniruddha Mukhopadhyay, Fluent, Inc.
Process-Properties Study of Melt Blowing Polyurethane for Elastic Military Protective
Apparel Garments Larry C. Wadsworth, Ph.D., TANDEC
Finishes & Surfaces
Effect of Finish Uniformity on Friction and Antistatic Protection of Polypropylene Yarn Thomas Theyson, Ph.D., Goulston Technologies, Inc.
Role of Fiber Finish in the Conversion of Fiber to Nonwovens: Finish Performance as a
Mechanical Processing Aid in Needlepunching Abdelfattah M. Seyam, Ph.D., NCRC
Surface Modification of Wool Fibers with Enzymes Gisela Buschle-Diller, Ph.D., Auburn University
Rayleigh Instability Development in Fiber Finishing Eunkyoung Shim, Ph.D., NCRC
Interaction of Liquid Sprays with Nonwovens Yashavanth Kamath, Ph.D., TRI/Princeton
Barriers
Transport Properties of Electrospun Nonwoven Membranes Heidi Schreuder-Gibson, Ph.D., US Army Natick Soldier Center
Novel Linear Low Density Polyethylene Resins for Improved Breathable Microporous
Films Wes. R. Hale, Eastman Chemical Co.
Surgical Drape and Gown Performance Standards Joseph Palomo, Allegiance Healthcare Corp.
Development of Antimicrobial Nonwoven Fabrics--A Study Sabita Baruah, Ph.D., SNDT-Women's University, Mumbai
A Comparison of Antimicrobials for the Nonwovens Industry Robert Monticello, Ph.D., AEGIS Environments
Process Technology III
Where is the “bottle neck” at High Speed Lines? (Comparison of High Speed Lines) Dipl.-Ing. Siegfried Bernhardt, Spinnbau GmbH
Calender Processes in the Nonwoven Industry Ralf Quack, KTM Kleinewefers
An Investigation on Needling Parameters of Moldable Nonwoven Fabrics Produced From
Blended Thermoplastic Fibers Subhas Ghosh, Ph.D., Institute of Textile Technology
The Future of Cards & Airlay and the Future of Batt Forming Michel Collotte, NSC Nonwoven Systems Thibeau
Polymers & Fibers
Polyester Fibre Additives in Paper Making B.E. van Issum, Ph.D., DuPont (ret.)
A Hydrophilic Fiber with the Performance of Polyester Keith J. Carnes, Wellman, Inc.
Stretch, Recovery, Compressive Behavior and Property Tradeoffs for Hydroentangled
Fabrics of Poly(Trimethylene Terephthalate) Staple Donald Shiffler, Ph.D., NCSU
Fibers with “Potential” Glen Reese, KoSa
Effect of Preneedling on the Properties of Hydroentangled Fabrics Idris Ahmed, Ph.D., University of Leeds
Engineering Polymers in Nonwovens, Fibers & Other Extruded Substrates—Processing
and Applications for Polyphenylene Sulfide and Thermoplastic Polyesters Ramesh Srinivasan, Ticon
On-Line Measurements
On-Line Measurement of Nonwoven Weight Evenness Using Optical Methods Hung-Jen Chen, Ph.D., China Textile Institute
Determining Basis Weight Uniformity in Nonwovens: Part 1---Off-Line Methods Behnam Pourdeyhimi, Ph.D., NCRC
Process Technology IV
Apertured Nets—Overview of Non-Fiber Based Non-wovens Ed Hovis, AET Specialty Nets & Nonwovens
Computer Analysis of Air Flow and Fiber Accumulation in a Fluff Pad Machine Andrey Troshko, Fluent, Inc.
Manufacturing a Better Wiping Fabric Daniel Feroe, Rieter Perfojet
Investigation of Flow Characteristics & Geometrical Effects in Hydroentangling Jets E. Ghassemieh, Ph.D., Loughborough University -Speaker Cancelled
Spunlace Nonwovens - Upgrading by Binder Bonding and Thermofusion Alfred Watzl, Fleissner GmbH & Co.
Pneumatic Waste Material Conveying Systems for Nonwoven Applications Gordon Cole, Quickdraft
Mats & Insulation The Effect of Polymer Types and Fibrous Structure on the Thermal Insulation Properties
of Nonwoven Mats Peter P. Tsai, Ph.D., TANDEC
Nonwoven Fabrics in Roofing, in North America Nicholas S. Newman, Ph.D., N. Newman Associations
Advances in Latex Modification of Urea Formaldehyde Resins Wayne Miller , H.B. Fuller Co.
Reducing Variability in a Shingle Mimic Process to Aid in the Development of Better
Materials for the Roofing Market Dennis R. Brown, Owens Corning
Determining Latent Formaldehyde in Fiberglass Mat Stacy Wertz, Georgia-Pacific Resins, Inc.
Absorbents
SNAPs: A Safe and Natural Alternative to SAPs—The New Generation of Superabsorbents Serge Huppé, Lysac Technologies, Inc.
Needlepunched Nonwovens from Cotton Fibers for Absorbent Products Maria Zamfir, Ph.D., Technical University of Iasi
Development of Highly Absorbent Cotton-Core Nonwovens Edward (Mac) McLean, Cotton, Inc.
Sustainability
New Biodegradable Copolyester for Fibers and Nonwovens W.A. Haile, Eastman Chemical Co.
Biodegradable Nonwovens—Natural and Polymer Fibers, Technology, Properties Dieter H. Mueller, Ph.D., BIK-University of Bremen
Sustainability Through 100% Resin Usage Bob Hawkins, Munchy Ltd.
Renewable Nonwoven Composites for a Sustainable Future Matthew W. Dunn, Philadelphia University
Biosoluble Glass Fiber For Use in Ultrafine Diameter Filtration Products Jon F. Bauer, Johns Manville Co.
Properties & Performances
Compressibility of Perpendicular-Laid Fabrics Containing Cotton D.V. Parikh, Ph.D., SCRC/USDA
Introduction of Plastic Net Scrim to Alter the Properties of a Hydroentangled Nonwoven Keith Misukanis, Conwed Plastics
Rapid Morphology (Property) Changes at Bond Edge in Thermal Point-bonded
Nonwovens Stephen Michielsen, Ph.D., Georgia Institute of Technology
Predication of Performance in Thermally Pointed Bonded Nonwovens H. S. Kim, Ph.D., NCRC
INDA Standard Test Methods Update and Comparison to EDANA, ISO & ASTM Michael Thomason, Ph.D., BBA Nonwovens
The Simultaneous Measurement of the Diameter and Length of Glass Microfiber Norman Lifshutz, Ph.D., Hollingsworth & Vose
Evaluation of Hand Characteristics of Nonwoven Fabrics Using Simple Methods S. S. Ramkumar, Ph.D., Texas Technical University
3D Shell Nonwovens: Properties and Characteristics Hugh Gong, Ph.D., UMIST
Binders & Additives
Incorporation of Antimicrobial Materials in Fabric Roy M. Broughton, Jr., Ph.D., Auburn University
Faster and Better - How Radio Frequency Drying Can Improve Both the Speed and
Quality of Your Nonwoven Process Ben Wilson, PSC, Inc.
Development of Halogen-Free Flame Retardant Melt Spinning Nonwovens Christine (Qin) Sun, Ph.D., TANDEC
Advances in Nonwoven Highloft Binders Represented By New Acrylic/Vinyl Chloride
Emulsion Polymers Martin A. Cohen, Ph.D., BF Goodrich Performance Materials

Calvin Woodings 12/Sept/01