Insight once again excelled with its broad coverage of up-to-the-minute marketing and technical issues via mostly original papers presented to a truly international list of over 600 of the great and good of our industry. As noted at other Insight events, the uncrowded program and longer Q&A sessions consistently allow the speakers to present and develop their themes to the full. The result is, perhaps paradoxically, a higher density of what we all attend conferences for: knowledge, information, understanding, and contacts.
30 years of EDANA statistics
Pierre Wiertz of EDANA charted the progress of the European Industry using their uniquely consistent set of industry surveys commencing in 1971. He saw three distinct periods each of a decade:
• ‘71-‘81 being characterised by 11.5% overall growth (from 65,000 tonnes in ‘71 to 190,000 tonnes in ‘81). This was driven by the growth of Spunbond and the arrival of one-piece diapers. The collapse of the once dominant apparel interlining nonwoven sector occurred in this period.
• '82-'91, with 8.5% growth (205,000 to 450,000 tonnes), highlighting the emergence of air-laid, hydroentanglement and the effect of a 1987 Financial Times Supplement on the industry as attracting new investors.
• '92-2001, with 7.5% growth (500,000 to 1,070,000 tonnes), the decade of hydroentanglement and air-laid growth fuelling the demand for wiping products.
Other statistics from the 2001 survey:• Airlaid reached 108,100 tonnes
• Wipes reached 151,000 tonnes compared with 57,400 in 1996. Here, the personal care sector used 81,000 tonnes and the household/industrial sector used 70,200 tonnes - down from 73,900 tonnes in 2000 due to the economic slowdown.
• 2000-2001 market growth was 4.3% in tonnage but 12.7% in area due to the trend to lighter fabrics in hygiene. Industry profitability was however still declining.
• Wet laid production had increased to 68,600 tonnes after a long period of stasis.
• Bonding methods: 182,200 tonnes of thermal (static), 108,200 tonnes of chemical (declining), 66,900 tonnes of needling (growing) and 99,500 tonnes of hydroentangling (growing)
• Compared with the US split of 66/24 short-/long-life, Europe splits 63/27.
• Fibres/polymers used: 120,000 tonnes of viscose up from 92,500 tonnes; 228,500 tonnes of polyester which is growing in staple but declining in spunbond; 491,000 tonnes of PP, declining in staple but growing in spunbond; 129,000 tonnes of woodpulp.
Asked what would follow wipes as the next growth application, Mr Wiertz mentioned cosmetics (more wipes?) and breathable sports clothing based on fabrics such as Miratec®, Evolon® and Neotis®. The organo-tin scare has had no effect on sales of disposables, but was good for the analytical chemists.
Krzysztof Malowaniec , a senior VP with Paul Hartmann AG ( Germany ) and the current Chairman of Edana reviewed the European scene commencing with a patent analysis:
• 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.
Mr Malowaniec went on to reveal “No1” as P&G and “No2” as K-C, and used a Stiftung Warentest consumer survey of diapers to point out that despite their enormous R&D efforts, diapers from these companies were only marginally ahead of the private-label products in consumer perception of quality. (He estimated 92% of the intellectual property required to make a diaper was now in the public domain.) In the 2002 consumer survey, only 54% rated the brands ahead of private label compared with 60% in 1992.
Other changes since a Jan 2000 survey:• The German diaper market has declined by 5% due to the improved diapers being changed less frequently.
• P&G's share has dropped from 39 to 32%.
• Private Label has increased from 20 to 30%
• Training pants had 3% of the market until P&G introduced a better product and since then the market has been growing.
In response to questions, K-C do not have a training pant on the German market, “Swiffer” type wipes are growing rapidly, and the demand for biodegradable materials remains almost non-existent due to lack of composting infrastructure.
Sabine Martini of Smartini ( Germany ) provided an assortment of 2001 market statistics:
• 64% of WE diapers were branded. Some producers sell into both branded and private label sectors.
• Private label diaper share varied from about 50% in Germany and the Netherlands to 15% in the UK and 12% in Italy .
• Europe uses 81,400 tonnes of baby wipes along with 35,900 tonnes of industrial wipes and 34,300 tonnes of household wipes, according to EDANA.
• P&G had the largest share (~30%) followed by private label (~28%), J&J (~20%) Beiersdorf (~5%) and “others” (~13%)
• In the UK in 2001, J&J lead the baby wipe sector with ~40% share, P&G had ~25%, the remainder being private label and others.
• In Germany private label led with ~35%, J&J had ~25%, Hartmann ~5%, leaving the remaining ~30% split equally between P&G, Nestle, and “others”.
In estimating the theoretical baby wipe market demand and the current penetration of disposables, Ms Martini assumed 2 wipes per diaper change, admitting that while this was more than actually used on baby's bottom, it was justified by the other uses to which these wipes were put. On this basis the theoretical German market was 5.7 billion wipes and the 2001 penetration was 56.3%. The figures for Western Europe as a whole were 33.8 billion wipes and 49.4%.
Future hygienic absorbent products would be ultra-thin, body-conforming, cloth-like products which controlled odour, promoted skin health and were environmentally friendly according to Pricie Hanna of John Starr Inc.• Thinness: as exemplified by K-C's new “Huggies Pull-Ups”, would need over 55% of SAP in the core. Other products mentioned were Ontex “Hybatex” technology, K-C's “Poise Pantiliner”, SCA's “DriActive Liners” and “Serenity Slender”, and Hartmann's “Ria Ladycare”.
• Body-conforming: as in P&G's “Pampers Custom Fit Cruisers” and “Pampers Easy-Ups” using an apertured card/thermal-elastic film laminate, or in K-C's “Huggies Supreme” with a Spunbond/elastic filament/spunbond laminate.
• Cloth Like: as in P&G's “Pampers Swaddlers” and “Pampers New Baby”. Fine PP fibres made from Atofina's metallocene resins could make softer coverstocks.
• Healthy: as in Mabesa's hypoallergenic diaper with “ProDerm” or J&J's “Carefree super-thin ventilate” pantiliners on the market in China .
• Odour Control: as in SCA's “Odasorb Plus” in “Serenity” or Ontex's “Active ODS”.
• Environmentally Friendly: P&G's licencing of it's “Nodax” biodegradable polymer process to Kaneka to allow films, fibers and nonwovens to be made available. P&G anticipate a 50,000 tonne/year demand. Cargill-Dow's “NatureWorks” PLA and Eastman's “Eastar Bio” are other contenders. Thong, micro and black pantiliners, youth diapers (for enuresis), swim diapers and K-C's semi-durable beach blanket were examples of new products meeting unmet needs. Advanced leakage protection was exemplified by Tampax “Pearl” tampons and Kao's “Leak-Free” adult diaper with absorbent leg gathers.
Increased links between basic material suppliers and the major converters were noted, e.g. the P&G/Equistar Chemicals collaboration on elastic polypropylene from the metallocene route.
Asked about wet-toilet tissue, Ms Hanna felt K-C must be disappointed with progress to date, unattractive presentation to the consumer being part of the problem. The lack of progress of pre-formed cores, (femcare, light incontinence and swim diapers apart) was felt to be due to the major economic consequences for converters who would have to re-equip to use the preformed product effectively. Apertured films and nonwoven topsheets seem to have reached equilibrium in femcare: women preferring one or the other, and some products now using both.
Lynda Kelly of John R Starr Inc surveyed the wipes market:
• Global growth at 5% to 7.7 billion m2 expected through 2006. This will require an extra 1.5 billion m 2 of fabric (or 90,000 tonnes at 60gsm) mainly hydroentangled.
• Hydroentanglement will grow at the expense of airlaid due to a major converter deciding to switch.
• Airlaced (pulp/cardweb laminate hydroentangled) is not yet accepted in the US wipes market.
• Needlepunched fabrics will grow in the washcloth/bathing towel sector.
• New US HE capacity has been announced but imports from Europe and the Middle East will continue to satisfy growing demand.
• Personal care wipes account for 55% of the 2001 global total, Industrial 32%, the remainder being homecare.
• The key companies in “cleaning”, P&G, Unilever, Colgate Palmolive and Reckitt & Benckiser will grow their wipes businesses by developing the wipe delivery system for brands that do not currently use wipes.
• Companies yet to employ the wipe delivery system to any extent will also become nonwoven customers: e.g. Estee Lauder, Sara Lee, J&J (non-baby-care), Revlon, Dial, Gillette, Church and Dwight, Schering Plough.
In response to questions:• Baby wipes will continue to grow: more will be used per change due to their increasing use in other baby- and adult- cleaning tasks.
• Geographic growth to be expected in South America first.
• Air-lace will grow as wipes enter the cost-reduction phase.
• Wet toilet tissue is still a growth opportunity, but not in the form of the recent K-C product.
Real Nanofibers at low cost
Evan Koslow of KX Industries has refined short-cut lyocell using a purpose-built refiner designed to avoid shortening the fibre too much. The resulting 100-250 nm fibrils have sufficient strength and length to be wet-processed into filters. Such filters can intercept bacteria whilst maintaining much higher permeability than comparable membranes.
He currently operates a pilot system making 10-15 lbs/hour of the nanofiber, but will have a 250lb/hr capability in 6 months and a 2000 lb/hr unit a year from now.
The highly self-bonding fibrils form much thinner HEPA filter paper at higher strength and with equivalent particle removal efficiency to conventional epoxy glass products. (The test used 0.18 micron dioctyl phthalate droplets at 32 liters/min through a 100 cm 2 flat sheet). Being 0.16mm thick c.f. the equivalent epoxy-glass at ~0.4mm, the nanofiber paper can be pleated to pack more area into a filter frame yielding 25% lower pressure drop and higher dirt holding capacity.
For water filters, the nanofibers are blended with a few percent of bico which is melted without calendering to give a relatively permeable wet-strength paper. (1 litre/sec/cc at 40 psi differential pressure: high c.f. membranes of similar pore-size)
When used in conjunction with an active carbon “protective adsorbent”, a 50 cm 2 piece of an antimicrobial-treated nanofiber paper can process 90 litres of contaminated water (over 6 days, gravity fed with a small hydrostatic head) before its viral reduction performance declines below 4-log. The cost of such a filter was put at 3-4 cents. Dr Koslow believes a few percent of low-cost nanofiber based on lyocell would, when added to diaper-pulp, greatly modify the wicking properties. It would also cause dramatic changes in the capabilities of precoats such as diatomaceous earth.
In response to questions:
• Nanofibres in fluff pulp would reduce odour by reducing bacteria.
• A paper machine has to be extensively modified to cope with the <50 CSF slurries.
• The electrospinning route to nanofibers will be unable to reach the productivity of the refining approach.
• Nanofiber air-filters fail when dirt capacity is reached.
• Nanofiber water-filters fail when the active-carbon protective layer breaks down.
• The bubble point for the 0.35-micron mean flow pore size is due to a 1.8 micron pore. Nevertheless the paper would intercept 99.9% of 0.35-micron particles.
Even Cheaper Lyocell Nanofibers
Calvin Woodings (consultant) described how to make a highly fibrillating version of lyocell and pointed out that it would be cheaper than the current textile versions. Furthermore the fibrillation would not be a problem in most products:
Mr Woodings described highly fibrillating lyocell as the ultimate islands-in-sea bicomponent fibre, with millions of crystalline nanofibres floating in a sea of potentially-dissolvable amorphous cellulose.
He suggested that current lyocell was proving to be a niche fibre, unlikely ever to reach the scales predicted by the pioneers because of it's relatively high price. The key to further growth was to think nonwovens rather than textiles. He suggested future investment should be in a “2 nd Generation” lyocell process using lower-capital, larger-scale plants to make a basic fibrillating fibre that would be fine for mainstream nonwovens and could be cross-linked for the lower-volume critical textile uses.
Evan Koslow said his KX Industries company makes an active carbon filter element (PLEKX™) by bonding the carbon particles with “microdots” of hot melt adhesive at a level that hardly reduces the active surface area. KXI has now done the same with superabsorbent powder and can make a highly porous 100% SAP sheet that does not gel block. The hot-melt particles are 1/20 th the size of the SAP particles.
When sandwiched between a suitable cover (tissue or porous spunbond mentioned) and backsheet (tissue or non-porous sheet) the composite swells with minimal X-Y spreading on wetting. One particular grade of SAP surprised Dr Koslow's researchers by spontaneously forming a 3 dimensional array of tubes which filled with fluid prior to its total absorbtion, leaving air-spaces in the swollen pad. This allowed the 100% SAP layer to capture large insults in a few seconds prior to the usual slow absorbtion by the polymer.
The hollow tubes in the SAP are 4-8mm in diameter and appear to form as one side of the laminate swells causing curls and twists. They have minimal integrity and are easily crushed.
A 1mm thick layer of the bonded SAP under two acquisition layers has been compared with a branded diaper and a conventional incontinence pad in MTS-TEFO testing. Under compression in the test machinery, the KX-SAP was 0.065” thick compared with the ~0.2” pad/diaper thicknesses. 100ml fluid was applied in 7 seconds and the overflow levels measured.
The KX-SAP composite outperformed the inco-pad (12 mls versus 31 mls leaked) but was slightly worse than the diaper (13 mls versus 9 mls.)
In response to questions:
• Do we buy or make the SAP composite? It would be best made in-house next to the diaper line.
• The hot-melt is evenly applied to the SAP “stochastically due to electrostatic charging”.
• The process is heavily patented.
• Multilayers of the SAP would be better than one.
• The laminate is not stiff. The flexibility of the outer “tissues” defines stiffness.
• Rewet and multiple insult results will depend on the coverstock used. 2 nd and 3 rd insults are excellent because the tubes are still open.
• The tubes will certainly collapse under baby's weight.
• KXI's PLEKX™ process can convert 10,000 tonnes/year of SAP into laminate.
• Surface cross-linking was “special” for the first product.
Henning Skov-Jensen of M&J Fibretech described trials to entangle 100% pulp, both with and without a tissue carrier.
• 60-1200 gsm pulp can be entangled without a carrier; down to 8gsm can be entangled with a carrier.
• Untreated pulps give the best wicking: 25-30 cms after about 10 minutes.
• Absorbent capacity drops from 9 to 6 gms/gm as entanglement pressure increases.
• Treated pulps give the best tensiles: at 200 gsm MD tensiles ranged from 10-15 N/5cm, and CD's from 6-14N/5cm. MD Wet ranged from 2-4 N/5cm.
• 150 gsm pulp could be entangled at higher energy to get 25-33 N/5cm in the machine direction.
Latex bonding would triple/quadruple these figures and addition of synthetic fibres, even without thermal bonding, would also give a useful strength boost. Here 20% of 6mm lyocell gave the best tenacities at 80N/5cm, and also enhanced the final absorbency. However the best strengths of all came when 20% bico fibres were melted.
Mr Skov-Jensen introduced 100% synthetic air-laid high-loft, high resilience nonwovens of a wide range of basis weights for use in waddings and acquisition layers.
In response to questions, up to 25% of the pulp could be lost through the wire in hydroentanglement, but 15% was more typical. Even at this level, 100% pulp HE was said to be commercially viable. The use of a carrier could reduce pulp loss to about 4%. He claimed to have hydroentangled 400 gsm webs - but did not comment on the commercial viability of this.
Hydroentanglement of Thermal Bonded Spunbonds
Daniel Feroe of Rieter-Perfojet described work reminiscent of the BBA approach to bulking fully formed textiles by passing them through a hydroentanglement machine. Taking advantage of the fact that their new spunbond pilot line can feed directly into their hydroentanglement line, R-P has explored the effects of water jets on a fully calendered spunbond. Point bonded PP nonwovens in basis weights from 17 to 60 gsm were processed under undisclosed conditions. The hydroentanglement process, as expected:-
• Doubled the thickness of the 60 gsm product and added 30% to the thickness of the 17 gsm.fabric.
• Bending lengths were halved at 60gsm, the effect diminishing with basis weight similarly to thickness.
• Tensile strength was 30% down at 17 gsm and 15% down at 60gsm. However this was on the basis of MD+CD results.
• CD tensiles were increased (from 26 to 33 N/5cms at 20 gsm)
• The HE'd fabrics looked more even and felt better than the controls (no jet-lining, presumably due to the fact that the point bonds survived the treatment)
Just as air-jet texturising can make a filament yarn feel more like a spun yarn, spun-lacing a spunbond makes it more like a carded thermal bond. Despite the strength losses, the HE'd spunbond remains stronger than the equivalent carded product despite being at least 50% thicker. It also emerges with higher CD strengths and higher elongations than other spunbonds.
Mr Feroe estimated the spunlacing could be done on a spunbond line for an additional $0.05/kg. The process was not yet commercial, he had not yet tried spunlacing SMS structures, and while hydrophilic spunbonds could be treated, we guessed they would emerge hydrophobic, and need refinishing afterwards.
Stuart Smith of American Nonwovens Corporation described their experiences since the 1997 decision to install their first fine-denier spunbond line. This system accelerates the filaments to higher velocities at laydown, and hence allows more orientation to be developed and, if required, finer filaments to be produced at higher productivity than on conventional machines. In principle, the technology should, from a single beam produce something with a cover factor equivalent to an SMS. Furthermore, it's ability to accelerate filaments up to 8000 m/min should allow it to run a wide range of polymers, including nylon, polyesters and polylactic acids. The higher orientation leads to improved fibre properties and hence nonwovens with higher strength, lower extensibility and reduced heat shrinkage.
In practise the American Nonwovens line has successfully produced 24-50 gsm nonwovens at an MD/CD of 2:1 from PP, PET or CoPET (Eastar Bio) polymers with filament deniers from 0.9 to 1.5, giving a basis weight uniformity of +/- 7.5% across the width. These have been successfully tested and accepted in various markets but not released for sale because American Nonwovens feel this range is too limited for their purposes.
A major machinery upgrade is now underway in collaboration with the machine supplier, who will redesign and re-engineer to achieve:
• 10-120 gsm fabrics
• at 0.5 to 4 denier
• with an MD/CD of 1.2-1
• using a wider range of polymers
• to give a uniformity better than +/-5%
The line is now expected to be competed in mid-2003, 6 years after commencement of project.
American Nonwovens want the line to make speciality, high performance products for niche markets, and clearly the first iteration could not do this. In particular they are targeting barrier materials with higher air permeability and hydrostatic heads at lower basis weights than SMS, and filtration products.
In response to a question, they have not run PLA on the line.
Detlef Frey of Reifenhauser promoted the latest version of their spunbond machinery. The main improvement over Reicofil 3 relates to it's ability to process polymers other than polypropylene, especially polyester into fully crystallised polyester filaments (i.e. laydown at >5000m/min). These would have a tenacity of up to 33 cN/dtex (sic) with a boiling water shrinkage of less than 5%. For polypropylene the main advantage would be higher potential throughput or the ability to make finer deniers
Asked if a Reicofil 3 line could be fitted with the improved Reicofil 4 cooling, stretching and laydown system, Mr Frey thought not because the new system required 5m depth per beam compared with 4.4m available on the “3” system. No “4” lines were yet running commercially but two were scheduled for start-up in mid 2003. He did however claim to have installed a total of 125 lines (270 beams) of the earlier systems, in 30 different countries. Reicofil 4 worked well with polybutylene terephthalate.
Tom Daugherty of P&G positioned the stretch-apertured nonwoven (“SAN”) technology, now available for licence, as a spin-off from years of studying the failures around point-bond sites when producing stretchable diaper components. They had learned how to make bonds fail on demand by designing them to be the weakest link. So, if a thermal bonded nonwoven was embossed with intermittent lines and then stretched by passing through interdigitating grooved rollers (ring-rolling) the lines became apertures in a regular pattern defined by the embossing pattern, while the original thermal bonding pattern, and hence the fabric strength, survived.
Fabric widths could be doubled (basis weights halved) in the process and the resulting nonwoven would be considerably softer, more porous and more flexible than the original. Apertures of the highest clarity (no fibres crossing the hole) and with lint-free edges could be up to 30mm in diameter, and total open area could be as much as 70%. The process also allowed lamination of multiple layers of nonwoven. Patent protection is of course available: USP's 5628097, 5658639 and 5916661 being listed.
In response to questions:
• Most nonwovens can be apertured: there are few limitations.
• The pilot line at P&G is 355mm wide.
• Two nonwoven producers are already operating the process on a commercial scale.
• Wipes are among several areas where this technology will allow unique products to be produced.
• The line will operate at speeds to allow on-line use in any current nonwoven production process.
Carsten Andersen of Formfiber Denmark ApS positioned his Spike airlaid nonwoven former as a high productivity waste recycling machine capable of making a wide range of bulky waddings from a wider range of raw materials. Inputs could be trim-waste, scrap, cut-outs etc from the hygiene, medical, textile, carpet, paper and automotive industries. The machine would handle any fibre length from dust to 75mm. Outputs could be 10-5000 gsm in thicknesses up to 40cms. At 1000 gsm a 1 meter wide former would consume tonne per hour of raw material.
Hammermilled wipes production waste has been processed into 250 gsm white boards. Mixed textile and carpet waste including foam has been processed into thermoformable sound absorbing boards for use in automobiles. Cleaner fibres could be made into 5000 gsm webs and through air bonded if 10% bico fibre was added. Cotton and cotton waste had also been processed.
Diapers for the Third World ?
Rich Chapas (Consultant) argued the case for really low-cost disposables made locally to allow the world's “base of pyramid” consumers to enjoy their benefits. The target market would be those on incomes of under $1500/year, most of whom were without power or clean water. Successful examples of “base of pyramid” marketing were nutritional products and the provision of mobile phones (one per village) to allow commerce to start. Nonwoven sales were admittedly a few years away but water-purifiers, femcare and constructional composites were possible starting points. An in-country entrepreneur and a multi-national company prepared to take the long-view were necessary to get going.
Diapers for the Third World – Part 2
Bill Ouellette of Chlorox Services Company, formerly with Procter and Gamble, emphasised that Chlorox was not interested in the diaper market, and gave the paper originally intended for May 2002's NTC conference in Ottawa. In a nutshell he argues that if 1960's style (and performance) diapers were made with current advanced materials and conversion machinery, they would be so cheap they could be sold in markets where diapering does not yet exist. This, he thought, was the only way to grow the diaper sector at any reasonable rate in the next few years.
The target price to open up this market, defined as the population of the third world on $3300/year or more, must be less than 4 cents per diaper, c.f. the 21 cents for today's economy diapers in the USA.
Other points of interest:
• The billions spent on making near-perfect diapers a little better is now reducing revenue. Diaper usage is declining as they are worn longer.
• A Z-fold diaper made of tissue paper with plastic back could meet the price target.
• Cover/core/backsheet composites formed on an air-lay line would come close.
In response to questions:
• Small companies producing such diapers locally would do better than the multi-nationals.
• The new diapers would not replace cloth diapers: diapering would be a cultural change for the target population.
Ruth Zielinski of Childbirth and Womens Services PLC thought women would soon be electing to reduce the frequency and/or intensity of their menstruation, or even to eliminate it altogether. Options include:
• Taking oral or non-oral contraceptive hormones continuously until it is convenient to have a period.
• The new Seasonale™ pill will be marketed on the basis of a period every 3 months.
• Patches (e.g. Ortho Evra™) or vaginal rings (e.g NuvaRing™) containing hormones are normally omitted once a month to allow menstruation, but can be used more or less continuously.
• An intrauterine device (Minera™) can be left in for up to 5 years. While using this total flow reduces and after one year, 20% of women have no period at all.
• Removal of the endometrium altogether causes 62-74% of women to stop having periods and causes flow reduction in the remainder. The “ablation” procedure takes 10 minutes as an out-patient procedure, and most women can be “back to work” in 3-4 days.
• Extreme exercise suppresses menstruation, apparently without any harmful side effects – assuming pregnancy is not required.
John Poccia gave a personal view of femcare materials having pointed out that his views were not necessarily those of his employer, Johnson and Johnson . During an overview of the female anatomy, menstruation and markets, the following points were notable:
• Peak pressure on a tampon would be 100mbar
• Highest “normal” recorded fluid loss was 42 g/24 hours (day one). Typical values for the first two days were 10-20g/day.
• The fluid is shear-thinning and does not clot.
• A lot of fluid remains in a pad's acquisition layer: better cores are needed.
• Additives to pads (protein cleavers) can reduce the fluids viscosity to aid its absorbtion by the core.
With regard to the market:
• The US market (2001) uses 26% thickpads, 14% thin pads, 30% liners and 30% tampons by volume.
• Nonwoven and apertured film covers have equal shares of the pad market.
• Winged pads have 45% of the pad market.
• 45% of liners are used only between periods, and 15% are used only during periods. The remainder is classed as “dual usage”, which seems to mean that 40% of pantiliner users use them all the time.
• Thong, black and micro products were growing most rapidly.
• J&J is marketing Carefree™ in China with a spun-laced cover and core to get maximum “textile-like” quality.
• P&G and J&J together make 75% of the world's tampons.
• 9% of US tampons are digital, the remainder being equally split between plastic and paper applicators.
• Only 10% of German tampons use applicators whereas in the UK , 45% are digital.
• The fastest growing tampon sku is the multipack system.
• While innovation in tampons has been minimal over the last 60 years, P&G's Rely™ was truly innovative and the best performing product. But for TSS all tampons would now be made like this. It had high capacity, freedom from leakage and was very comfortable to use.
• Innovation was clearly still possible in this category: target – the properties of Rely™ without any TSS connotations.
• Materials used in external protection would “spill over” into tampon designs.
• Tampon patenting has been rising over the last five years.
In response to questions:
• Interlabial products avoid the TSS issue but still have design problems. Superabsorbents were not required: product design was the key issue.
• P&G's Pearl™ tampon is “incremental” rather than revolutionary.
• Would 2 different ADL's help in absorbing the 2 phases of the fluid? No.
• The driving forces in pad and liner design will be ultrathin and textile-like.
100gsm cores with acquisitive coverstock
Jim Hanson of MTS continued his crusade for pre-formed diaper cores with part three of the series:Testing Food Pads
• 400ml absorbent core capacity is unnecessary: 100ml would do.
• 100 gsm bico/SAP core with cover and back would be adequate c.f. 600gsm now.
• 90% SAP would be possible in these lighter structures. 50-70% would be used in practice.
• Waterproofed wet-strength tissue paper could be the backsheet. This could also be air-laid.
• Multiple layers of lightweight cores would be a better way of reaching higher absorbency
• SAP's would not have to be surface cross-linked for high retention under pressure. The resilient bico-structure would provide this.
• The ability to use really different superabsorbents would allow newcomers to avoid existing patents.
• Diapers would need redesigning to get the best out of the new cores.
Wicking tests, and diaper testing on live consumers remained to be done.
Genevieve Beland of Lysac Technologies (Canada) pointed out that the absorbency test methods used in the food industry are a) not standardised and b) do not reflect the performance-in-use of food-pads. In particular:
• The use of 0.2% saline or even tap water to test absorbency gives very different results to the exudates e.g. from chicken.
• Pads have to work at lower temperatures than testing temperatures.
• Pads are often in use at a 45 degree angle on supermarket shelves.
• Stacking during transport increases the pressure on the pad to at least 0.3psi.
Lysac therefore developed a synthetic exudate to simulate the high viscosity, protein and salts content of real exudates. They also standardised on a 30 min dunk followed by a 10 minute horizontal drain, for the TFA test, and a 24 hour soak under 0.1 psi at 4 0 C for the AUL test. For retention they applied 0.3 psi in a centrifuge. These methods showed their Safe and Natural Absorbent Polymer (SNAP) performs just as well as the cheaper “synthetic” SAP's .
Ms Beland would not reveal the chemistry of SNAP beyond saying it was a polysaccharide.
The Jewel in the Crown?
Andrew Urban – Consultant listed the problems facing the start-up hygienic product producer:
• Higher materials cost due to less powerful purchasers.
• Minimal R&D expenditure.
• Minimal “infrastructure of engineers and technical personnel”.
• One plant can't supply nationwide.
The solutions to these problems were said to be:
• Sole sourcing – admittedly with the disadvantage that this would prevent the buyer from staying in touch with the changes in market price.
• Patent analysis: using a patent professional is expensive, so read the magazines, ask suppliers to share their surveys, and maybe use a consultant.
• Patent licencing: expensive, but so is defending an infringement suit.
• Having a quality control system: “simply the logic of production put on paper”.
• Having a process control system such as that used at Pope and Talbot before it was sold to Paragon Trade Brands.
Mr Urban felt this last point was the “jewel in the crown” in attempts to succeed against P&G and K-C.
Down to the wire?
Tom Israel of Albany International has studied the effects of forming-wire weave-pattern on the properties of air-laid nonwovens. Four wires, (two warp- and two weft- faced, each at two different permeabilities) were tested by making 50, 100 and 200 gsm webs from Weyerhaeuser NB416 pulp at 300 inches/min on one DanWeb former. The conclusions:
• Web thickness is affected by the wire pattern (and by the basis weight).
• Warp-faced wires increased the MD/CD orientation slightly, weft-faced wires had the opposite effect.
• The wire pattern is visible on the underside of the webs.
• Latex bonding masked the effects.
Mr Israel explained that the data would probably not be applicable to a large machine working at higher speeds. He proposed checking the effects of thermal bonding next.
High Wet Strength EVA's for Wipes
John Parsons of Vinamul Polymers explained that the family of self-crosslinking EVA binders typically used in airlaid latex-bonded wipes gave excellent absorbency and colour but would not give usable structures with wet CD tensiles above 500 g/inch. They were also low in solvent resistance, a point which became important as household cleaning wipes used increasing aggressive lotions. This strength could be improved with external cross-linkers, or bico fibres or, if cost and stiffness were not a problem by using more binder. Vinamul had however decided to try to make a better EVA, targeting a 50% improvement in wet strength. The result was their new 25-135A, ready-for-use, 50% solids emulsion which featured a 0 0 C Tg polymer.
First trials with 25-135A at M&J Fibertech demonstrated the required 50% strength increase, or strength equivalence to the old binder at 20% lower add-on (16%). Methyl Ethyl Ketone strength was up by 60% but the fabrics were stiffer and the absorbency rate (5 down to 37secs) and capacity (16.4 to 15 g/gm) had deteriorated. Reformulation to improve this had restored the absorbency to acceptable levels while maintaining a 45% strength benefit over the old latex.
The new latex can now be used like the old to yield the required improved strength in industrial wipes, or at a 16% binder level to reduce the cost of baby wipe products. If lighter products could be marketed, then at 20% binder add-on, strength equivalence was obtained at 47gsm c.f. the 60 gsm standard.
The binder is now in commercial trials in the USA with issues such as wet caliper, loft, extractibles, machine speeds, and wire fouling still to be investigated. The brand name will be Elite ULTRA.
In response to questions:
• The binder is FDA compliant.
• It does tend to neutralise antimicrobials.
• There is no wicking data yet.
• Vinyl acetate monomer levels are below 1000ppm
• It can be foam-applied.
• 150 0 C for 2 seconds is needed for full cure.
• There is 80-90ppm of formaldehyde in the emulsion.
• It costs less than bico fibre to achieve the target strength.
• EVA itself is not absorbent.
Lamination combining winding
Allessandro Celli of A.Celli spa ( Italy ) promoted Celli winders and once again included some details of the hot-melt lamination stage being added, thanks to a collaboration with Nordson, to a full speed slitter/rewinder. This time the possibility of multiple lamination steps leading to the ability to, for instance, stick backsheet to core to ADL was discussed. He thought this was a better way of making absorbent pads on roll than trying to form several different layers on an air-lay machine.
Michael Toal described how Caligen Foam Ltd (UK) has adapted their elastic foam to provide an alternative to conventional elastics in leg-cuffs. The new SoftSeal® product:
• Will give a better seal over a larger area, eliminating red marks on baby's legs. This is due to a higher retraction load at 2/3rds stretch giving a better seal over a larger area.
• Has >300% elongation at break with <10% creep over 1 hour or <30% creep over 4 hours.
• Is available in a wide range of colours, co-ordinated with waist-bands.
• Is ultrasonically weldable.
• Looks good to mothers.
Diaper producers would need a new unwind stand to take the 1metre diameter, 0.8 metre wide spools of 14-50mm wide, ~1.5mm thick foam. The width is typically slit into two on-line to feed each cuff, and this width will be halved at 100% extension.
In response to questions:
• 16mm foam, stretched to 8mm was used in the Joa trial
• Unicharm diapers did indeed use a similar foam in the 1980's “Moony”. The patents have expired.
• Spools run for 4-8 hours between splices.
• The foam is stable up to 160- 180 0 C so an elastomeric adhesive or sonic bonding can be used.
• Caligen's successes to date are not in diapers.
• Price? “We feel we can compete”.
Greg Hearn of Hyosung (America) Inc., a newcomer to the US diaper scene, reviewed the evolution of diapers from the dawn of time through Victor Mills' invention of Pampers in 1961 to the introduction of leg elastic in the 1970's. Leg elasticity was initially provided by a 0.25 inch low-modulus rubber band about .007 inch thick: the success criteria being containment through even pressure at a level which did not leave red marks on the baby. Multi-strand rubber thread, spreading the pressure over a greater area, did this better than the band, and multi-strand spandex yarns followed. Hyosung produce these and are now trying to offer innovative solutions to the containment problem. Asked if spandex could be available in ribbon form, Mr Hearn thought not. Their spandex shelf life was about a year.
Friday 1 November 2002
Source: Insight Tampa October 2002