P&G's purchases of nonwovens have increased by 50% since 1996 and should double in the next 3-5 years. By then their expenditure on nonwovens will be three times the 1996 levels. However the nature of the partnership between P&G and its nonwoven suppliers will have to change dramatically. To date P&G has emphasised the need for cost reduction over improvements in functionality and the development of innovative new materials. In future more new nonwovens will be needed, and P&G is likely to have fewer strategic development partners.
The successful ones will be those who can demonstrate:
• A track-record of innovation and speed to market
• Global reach: able to supply consistent materials wherever P&G launch products
• Minimum overlap of core-competences (with P&G?)
• Ability to collaborate with other P&G suppliers
Furthermore P&G would expect to see radical change over the whole of their supply chain. The successful partners would:
• Upgrade their R&D facilities to respond to the new challenge
• Install strong pilot-scale development facilities to speed up the flow of prototype materials for evaluation
• Would be capable of supplying identical materials regardless of source, i.e. nonwoven manufacturing plants had to become more standardised.
P&G for their part would also change:
• They would become more transparent to their suppliers, and provide clear success criteria (and feedback?)
• They would give the lion's share of business to the most innovative, not to the lowest cost producer.
• They would provide specifications based mainly on performance criteria which would be consistent globally
• Cost control, while taking second place to functional requirements would remain important: P&G want to eliminate all cost that does not contribute to a consumer-perceivable benefit.
This message to the nonwovens industry was summarised: If you can deliver breakthough performance advantages, P&G will take your innovation to the global consumer products market on a larger scale and faster than anyone else.
Thermal Conductivity Measurements
Paul Brady of American Nonwovens presented results of measurements of thermal conductivity on a variety of fibrous and feather waddings in a 50 0 C temperature differential. Ignoring everything but insulation value, it was clear that all organic materials of similar diameter performed similarly, as did all inorganic materials. There was no difference between chicken feathers and polyester for instance, down being only marginally better than either. Diameter and wadding density were the key factors, so the most cost-effective approach was to use the cheapest fibre in the lowest density to achieve the desired insulation value. In real consumer products, parameters other than insulation value (e.g. resilience, FR) were often important, and the choice of fibre would be affected by these factors.
OR Fabric Myths
Dr William Rutala of University of North Carolina Health Care System reviewed drapes and gowns from an infection control perspective and the problems arising from Surgical Site Infections (SSI's). The USA carries out 27 million surgical procedures a year. 15 to 18% of patients pick up infections while in hospital, and 66% of these infections are at incisions. Protection of the health care workers from blood-borne pathogens is equally important. 30% of surgeons and their first assistants still get skin contaminated with blood, as do 12% of other assistants and 4% of scrub nurses. The longer operations carry the highest contamination risk. Current drape and gown materials are clearly inadequate, Dr Rutala listing the myths as:
• The best products are chosen scientifically. Not so, one of the problems being the inability of current barrier performance test methods to predict in-use performance. The tests are not dynamic, make no attempt to simulate the wear and tear of a long operation, and take no account of the amount of blood that they have to withstand.
• Plastic reinforced gowns are impermeable. Not so, especially towards the end of a long procedure which could involve abrasion, tearing or puncturing of the gowns.
• Reusables offer better protection than disposables. Not so. A review of studies comparing the infection rates of disposables v durables showed that disposables had significantly reduced SSI's.
• Reusables are better for the environment. Not so. Life cycle analysis had shown that neither product was superior: both had environmental disadvantages, disposables being wasteful of raw materials and reusables having high impacts due to the washing procedures.
Even the economic case for reusables was debateable.
The best disposables from a barrier viewpoint were the laminates or “polypropylene treated” products, but there were many other factors to consider, not least the surgeons comfort (heat stress), the ability to move freely (drape) and to flex without linting.
Tom Ryle of Clopay Plastic Products Company presented a survey of breathable materials patents, focussing on the microporous (continuous vapour pathways) variety rather than the monolithic (which work by sorption onto the wet face and desorption from the dry). Product patents outnumbered process patents by about 2 to 1, and the most patented applications were diapers and electrical. For diaper backsheets the favoured process appeared to be extrusion coating of a PP nonwoven followed by in-line incremental stretching to create the pores. This was now the largest and most active application area, with some 70% of diapers in the US , Europe and Japan using breathable backs. 100% penetration globally could be expected. Other applications listed were Clothing, Medical (drapes, gowns, wound-care, drug-delivery, sterile packaging), packaging (fruit and vegetables, moisture-venting packs e.g microwavable popcorn), printing, especially ink-jet (unique surfaces, ink absorbtion/durability, transparency/opacity) and Building (housewrap, roofing, flooring) Moisture vapour transmission rates of 1500-3000 gms/sq.meter/day were typical.
Skin Health under Diapers
Howard Maibach of the University of California School of Medicine Department of Dermatology described work on the effects of occluding skin with nonwovens used in diapering, femcare, incontinence pads, wound dressings etc. He pointed out that human skin is a micro-porous membrane with an important barrier-to-chemicals function which was suppressed by wetness. He thought the key to future diaper design was an understanding of the “invisible dermatology” of the skin, i.e. changes that occurred before damage became apparent. Instruments were now available to study this and could show that occluded skin was much more likely to be damaged by chemicals, for instance the surfactants used on coverstock. They could even show the onset of maceration caused by pure isotonic water. Breathability was therefore a good thing, but skin wetness was much more important than coverstock dryness. Wet skin absorbed more chemicals and was damaged by the chemicals in urine and faeces much more easily. He thought glove intolerance (contact urticaria, non-allergic contact dermatitis) suffered by surgeons, dentists and other regular glove wearers was a related problem. Here the answer seemed to involve providing gloves with an absorbent interlining. Asked if diapers with a (surfactant-free) absorbent interlining would be better he thought they would, the audience being left to deduce that this would only be the case before urination. The instruments used were a Trans-epidermal water loss meter to assess barrier function, a Laser-Doppler Flowmeter to assess sub-cutaneous blood flow, Capacitance measurement to assess skin wetness, and a Reflectance meter to detect the onset of erythema.
Effects of Humidity on Breakthrough Pressure
Y.K. Kamath of TRI on the effects of condensation on the breakthrough pressure. TRI's method for identifying the largest pore in a hydrophobic PP nonwoven involves forcing liquid up through a nonwoven until the first bubble of liquid appears on the surface. A graph of water pressure v. time indicates the precise breakthough pressure. Experiments to see if the humidity under which the nonwoven was conditioned affected this breakthrough pressure gave the expected result: higher humidity conditioning meant the sample was more easily wettable and breakthough occurred at progressively lower pressure. However on reconditioning back from the highest humidity tested (90%RH) to the lowest (20%RH) the breakthrough pressure remained at the lower level. Moisture regain curves were then plotted and showed an unusual hysteresis effect. PP moisture content rose from 0 to 0.4% between 0 and 90% RH, but remained at 0.4% when redried to 0%RH. The changes in breakthough pressure could be due to this hysteresis; wetted and dried PP being more wettable than the original polymer. A contribution from the audience suggested another possibility: the coverstock suffered a microscopic stretching during each pressurisation and did not relax on drying. The maximum pore size therefore became a little larger with each determination. The PP isotherms are nevertheless intriguing.
Improved Breathables needed
Joseph Palomo of Allegiance Healthcare reviewed the uses of breathable films in surgical fabrics. He concluded that while the films had penetrated the high-barrier gown market, improvements in comfort and cost effectiveness were needed to allow them to dominate. The most obvious way forward was the development of thinner films, simultaneously improving permeability and reducing cost. New breathable polymers could also yield improvements, as would nonwoven carriers specifically designed to support the films or coatings.
Two-Fibre Thermal Bonding Study
Hawthorne Davis (NCSU) described a thermally-bonded nonwoven as a set of bonds held together by bridging fibres. Thermal bonding must create strong bonds without weakening the bridging fibres. Experiments with pairs of fibres bonded at a single cross-over point allowed bond strength, fibre strength and visual appearance of the bond to be determined over a range of temperatures for three structurally different PP fibres.
• Fibervisions T196 – a PP homopolymer fibre with a degraded sheath - known to form strong bonds.
• As 1. but with spin-finish removed.
• A sheath-core PP bicomponent with a 3% ethylene/97% PP random copolymer sheath.
• A “bico” control made with the same PP polymer in both core and sheath with and without finish.
Several interesting observations were made:
• Polymer needs to flow to allow a strong bond, so the temperature at which bonding starts is also the temperature at which fibre strength begins to fall.
• Bonding is localised around the edges of the area of fibre overlap, and tends to be absent in the centre. This suggests bonding occurs where the pressure is low possibly indicating the Clapyron effect coming into play (Melting point increasing with applied pressure)
• Fibres with low birefringence sheaths (1,2 and 3) bond well at lower temperatures and allow the bridging fibres to maintain strength better.
• T196 without finish gives higher bond strengths.
There is an analogy with fibre structure here: point bonds being the equivalent of fibre crystalline regions, and the bridging fibres behaving as amorphous regions.
Finish Film stability
Theory predicts that any liquid film on a curved surface such as a fibre is unstable and is bound to collapse into droplets. Films of finish are no exception, their viscosity slowing down the collapse but having no effect on the maximum stable thickness of the film. On a 10 micron diameter fibre this was about 100 nanometers. Normal concentrations of finish would therefore be expected to form beads on the fibre surface rather than continuous films. Dr Thomas Theyson of Goulston Technologies used high speed photography to observe the finish application/drying process on moving polypropylene monofilament and multifilament yarns. He showed that on monfils, beading of the finish (Lurol NF-6004) only occurred above 0.5% add-on. On multifil yarns, due to the ability of the finish to accumulate in capillaries at fibre contact points, beading did not occur below 20% add-on.
Better Thermal Bonds with Weaker Fibres
Dr Gajanan Bhat's paper (UTK) on the effects of fibre morphology on the properties of thermally bonded PP nonwovens showed that stronger, highly-stretched fibres give the weakest thermal bonds. As-spun fibres (of the same diameter as the fully stretched ones) gave the best bond strengths, and better overall fabric strength. He concluded that the crystallinity of fully-formed fibres interferes with bond formation and their low extensibility prevents efficient load sharing between bonding points in the tensile tests. A significant increase in crystallinity of the as-spun fibres occurred in bonding, but due to the slow laboratory bonding process, this may be more than would be observed commercially.
Plasma for Wettability and Sterilisation
One Atmosphere Uniform Glow Discharge Plasma (OAUGDP) could raise the surface energy of LLDPE film from around 30 dynes/cm (hydrophobic) to around 70 dynes/cm (hydrophilic) in one second. Unfortunately the effect is not durable and the surface energy decays to 50 dynes/cm in a few days. Longer exposure times increase the durability: 15 seconds allowing 70 dynes/cm to be maintained for weeks.
Dr Roth of the UTK's Plasma Sciences Laboratory also showed how diaper film (Linear Low Density PE) exposed for 5 minutes lost a half-micron of thickness, revealing exposed titania particles on the etched surface. Low density polyethylene etched more quickly (3 minutes) but the surface appeared to repair itself, becoming smooth again after 8 days storage. The contact angle of the film dropped from 105 o to 50 o in the first second of treatment. Polyester film contact angle could be reduced from 90 o to 15 o in 5 seconds treatment, but decayed to 40 o over 2 days of storage. Sterilization of surfaces is another consequence of OAUGDP treatment, survival curves for E. coli and Staph. aureus showing treatment times above 25 seconds being effective in completely disintegrating the bacteria. A novel air filter has been developed wherein melt-blown PP filter media can be sterilised by OAUGDP during use. In response to a question, Dr Roth said the effect of plasma treatment on cellulose remains to be studied.
Increasingly aggressive hydroentanglement processes are allowing increasingly novel nonwovens to be produced. Don Gillespie of Fleissner Inc. reported the successful hydroentangling of 17 dtex spunbond PP at 300 gsm but did not say at what speed. Other, presumably much lighter and finer-fibred webs have been entangled at 500m/min. Water pressures of up to 600 bar (8400psi) were being used, and were allowing the production of stable roofing membranes and coating bases, thereby removing the need for overbonding with hard latexes. Energy use in bonding ranged from 0.25 to 0.85 KwH/Kg. Sandwich structures comprising air-laid pulp between two spunbonds were allowing low cost wipes and absorbents to be produced. The most recent practitioners of the HE Spunbond art, Freudenberg, were however targeting conventional textiles with their splittable spunbonds being hydroentangled prior to textile dyeing, finishing and making up into garments. Spunlaced SMMS must be just around the corner.
PLA Development Update
Dr James Lunt's paper on Cargill Dow's PLA fibres was very similar to the Wakefield paper presented in June. The main points of interest were:
• $0.5 to $1.00/lb is still being quoted as the resin price from Blair.
• Concerns over the low melting point (for textile use) are being addressed by the development of a “stereocomplex with a crystalline melting point of 210 o C” This has interlocking D- and L- polylactide chains and is based on Dupont technology.
• Fossil-fuel energy use for the Blair plant was put at 57MJ/Kg (but could be reduced to 34 and then 5 if Blair switched to non fossil energy sources! A cellophane figure of 91, and a polyester figure of 76 MJ/Kg were mentioned, but not the comparable CIRFS figure of 54 MJ/Kg for viscose staple, which could also be reduced to single figures if non-fossil energy was used.)
• Apparel applications were clearly the main focus now, but PLA carpet tiles had been launched by Interface. (Resilience is good, but abrasion resistance is worse than regular polyester)
• Hohenstein comfort studies show PLA/Cotton sportwear laminates to be more comfortable that PET/Cotton laminates. (But PP/Cotton is the best?)
• The higher surface energy of PLA fibres leads to good wicking performance of unfinished fibres. (Could be useful in coverstock/ADL's)
• Lactus bacillus was the current fermentation organism, but others could be used.
• In extrusion, like PET, the polymer must be dry. It loses 10% inherent viscosity if processed with 100ppm water content.
Jeff Dugan (Fibre Innovation Technology) followed on to give the first nonwoven conference paper by one of CDP's development allies:
• PLA's key feature is that it is melt-spinnable while conferring some of the advantages of cellulosic fibres.
• Current prices are high but will fall into the “polyester-nylon” range when Blair is at capacity.
• The inherent wettability of PLA gives improved wet-laying and hydroentanglement.
• Its low refractive index means deeper and brighter dyeing than regular polyester.
• FIT has made a wide range of bicomponent fibres (skin-core, concentric and asymmetric, segmented pie, multi-core) and the multilimbed “4DG” shape using PLA. (USP 5,525,282 - June 11 th 1996 quoted)
• Carpet applications benefit from the resilience of PLA, but “tests are incomplete at the time of writing”.
• PLA burns but releases less heat and smoke than PET. It also shrinks very powerfully above its heat set temperature and so pulls away from flame.
• Its very good UV stability makes it good for window fabrics.
Jeff listed the main drawbacks of PLA as:
• Relatively poor abrasion resistance (but presumably better than cotton).
• Low melt temperature will limit it's use in higher temperature environments.
• Easy hydrolysis at conditions close to those used in commercial laundries and fabric finishing processes. It was being turned to advantage in the composting claims (hydrolyses wet at >60 o C). PLA could also be used as the “sea” in an islands in the sea bicomponent, and could be dissolved in 3 minutes in a commercial finishing process using hot 3% caustic.
• A “scroopy” handle. Unless corrected by surface finish this restricts resilience in wadding applications.
Meltblowing Biodegradable Polymers
Dieter Müller of the University of Bremen has attempted making meltblown nonwovens from polylactic acid, polyesteramide, polyvinyl alcohol, cellulose diacetate and a polycaprolactam/thermoplastic starch alloy. Polypropylene was the control. Only PLA and PEA (after adding 3% glycerol) gave fibrous webs like PP, but only PEA gave a nonwoven with usable strength. (PP meltblown was 40 times the strength, with 5 times the extensibility of the PLA and twice the strength, with one fifth of the extensibility of the PEA.) Neither PVOH, PC/TS nor cellulose diacetate, even with 10% glycerol added, would form fibres. Relative prices of the biodegradable polymers, with an appropriate health warning, were given as (c/lb) PP=0.35, PEA=1.4, PLA=0.75, CA=1.7, and PC/TS=1.9.
Donald Schiffler of NC State has tested webs of PTT, PET, Nylon, 50/50 PET/Nylon, 50/50 PET/PTT and also 90/10 PTT/PET in hydroentanglement and thermal bonding. Poly trimethylene terephthalate's inherent low bending rigidity enables it to form HE fabrics at lower bonding energy (<50kj/kg) than the others, and gives softer fabrics with comparable strengths at high energies. Calender bonding on the other hand gave poorer fabric strengths, the speaker concluding further development was needed to allow PTT to realise it's promise in this bonding system. Asked about potential applications for PTT in nonwovens Mr Schiffler thought it was probably premature to speculate, but woven and knitted applications were commercial. In latex bonding he would expect the fibre to behave like PET.
Several papers covered the use of image processing to characterise nonwovens, the most compelling being from Andrew Kallmes of MK Systems who is commercialising a procedure developed by Dr. Scharcanski at the Federal University of Rio Grande do Sol ( Brazil ) and C. Dodson at UMIST ( England ). Grey-scale images of any material could, in principle, be captured by any method e.g radiography or light microscopes. These were then scanned and digitised into some 65,000 pixels. The intensity of each pixel was compared with that of each of the nine surrounding pixels and computer analysis allowed the position and size of fibres and voids to be plotted. Polar diagrams appeared to give an accurate and quantitative representation of the structure of the nonwoven.
To Bead or not To Bead
Hollow sphere pigments made by Rohm and Haas for use in paints and papers could have applications in nonwovens. Michele Mlynar reviewed their production, uses and benefits. The production process was described as follows. An emulsion of acrylic acid and styrene is polymerised. A polystyrene shell forms around an acrylic acid core which on treatment with alkali swells and orients the shell radially. The resulting rigid beads are dried, air diffuses in, and the PS skin becomes completely impermeable, trapping a small amount of solid superabsorbent inside. One micron diameter beads have a core diameter of 0.82, their unique feature being that their 2 light-scattering surfaces yield a total refractive index equivalent to titanium dioxide while being effectively weightless. Even through paper industry super-calenders these beads stay spherical except at the surface where they flatten due to melting.
Ms Mlynar saw potential application in binders for nonwovens and presented the results of trials with 1 and 0.5 micron beads added to acrylic binders, one (non-ionic, Tg -11 o C) chosen to bond viscose webs and the other (Anionic, Tg +34 o C) chosen to bond polyester webs. HSP additions of up to 50% on binder solids were used. The expected significant opacity improvements were seen, tensiles were largely unaffected, but handle stiffened above the 20% add-on level especially on the viscose fabrics. At 20% add-on, the opacity of the 1oz/yd 2 nonwovens was around 5 percentage points higher with the 1 micron beads and 10 percentage points higher with the 0.5 micron beads (control fabrics had 43-45% opacity). In private conversation, Michele could not say whether the bead forming technology was capable of modification to allow the trapped SAP to be rewetted, or whether different polymers could be used.
Food Service Wipes
Bill Vogel of Atlantic Mills provided data on the US market for food-service wipes. 45.3% of the US spending on food goes to commercial, institutional or military establishments serving food. There are 831,000 of them, employing 11 million people and together they turnover $376 billion per year. Some details were available: $34billion was spent by institutional or military canteens, £35 billion by fast food outlets and $39 billion by full-service restaurants. About half of the adult population of the US eats out on a typical day. 80% of the wipes used are still textile, and of the 20% nonwoven, spunlace technology has the largest share. Nonwovens need to be robust enough to be used all-day in a wet, detergent and bleach laden environment with sanitizers containing chlorine and ammonia. Reducing the incidence of food-borne illnesses - e.g. E. coli, salmonella - has become a major driving force in wipe selection, the provision of sanitised nonwovens and the development of standardised cleaning procedures being appropriate responses to the problem. For instance, avoiding cross contamination between pre-cooked and cooked food areas requires the use of two different wipes, colour coded to allow them to remain separate. Combining nonwovens and bactericides is complex. The EPA's pesticides regulations can come into play and users must have a full appreciation of EPA requirements before selling a product or making claims. How long does it take to get EPA approval for a product? There is no set time, the process being continuous as the science and knowledge of sanitising surfaces evolves.
Developments in Carding
William Oxenham's (NC State) paper covered flat top cards for sliver production in some detail. They can now do 120 kg/hour/metre and the Reiter C51 is fitted with automatic card-wire grinding to reduce down-time and variability of web-quality between grinds. Roller cards achieve 600kgs/hr/metre and can reach speeds of 500 m/min on 0.9 dtex PP, but only 250 m/min on PET and 100 m/min on nylon. Suction transfers are needed to keep the webs on rolls and conveyors. Various manufacturers brochures were used to illustrate other systems.
Full List of Papers with Abstracts
“See above” indicates the paper is covered in the main body of this report
KEYNOTE SPEECH: NONWOVENS INNOVATION AND DEVELOPMENT FOR A GLOBAL CONSUMER PRODUCTS COMPANY:
Karl Michael Schumann: Director of New Platform Technologies – P&G. See Above
• IMPERFECTIONS OF COMMON NONWOVEN'S THERMAL RESISTANCE TEST METHODS
Lubes Hes - Technical University of Liberec
A series of nonwovens and wovens were compared for thermal conductivity using high and low emissivity contact plates. Nonwovens (low density fabrics) give lower results on more reflective contact plates. Thermal conductivity measurements should therefore include information about the optical properties of the measuring plates.
• MODEL DEVELOPMENT FOR COST AND EFFICIENCY COMPARISON OF NONWOVEN, THERMAL INSULATION MATERIALS
Paul Brady - American Nonwovens - See main report
• ROLL PRODUCT MANUFACTURERS COST OF QUALITY
Paul Frost - PJ Associates
The use of control charts, statistical process control and experimental design (Taguchi) to control quality
• TWO-PARAMETER CHARACTERIZATION OF GLASS VEILS AND WIRES BY AIR PERMEABILITY TESTS
C. Heil - Owens Coming Veil Netherlands BV
Air-porosity measurements on standard wire-mesh test sieves allowed comparisons between predicted porosity (Ergun equation) and actual. Interesting graphs of porosity versus pore-diameter for the wires and various porous sheets.
• DESIGN OF EXPERIMENT FOR PHYSICAL PROPERTY IMPROVEMENTS OF FIBERGLASS MAT
Toni Aldridge - Franklin International
The value of factorial experimentation rediscovered in the course of investigating the effects of binder level on the strength of glass mat.
614 445 1230
• ENGINEERED COMPOSITE PRODUCTS USED IN ADVANCED FILTRATION
Frank Cousant - Ahlstrom Technical Specialties, LLC
Data on filtration efficiency for different paper/nonwoven/fabric combinations. “The only limitation is the designers imagination”.
• PAPER AND MELTBLOWN COMPOSITES - A REVIEW
Rowland Griffin - Monadock Nonwovens
Useful list of references (if you really want to try and replace paper with meltblown nonwoven.)
• NEW FILTRATION MATERIALS FOR THE NEW MILLENNIUM
Ed Homonoff- Edward C. Homonoff & Associates
Aerogels (for use in active filters), splittable fibres, and superabsorbent fibre filters reviewed (again).
• FILTRATION PROCESS IN ELECTROSTATICALLY CHARGED FILTER MEDIA
T. J. Ptak - Purolator Products. Inc.
An overview with theoretical treatment of particle capture mechanisms. No mention of the effects of the loss of charge in use though.
• DESIGN OF COMPOSITE FILTRATION MEDIA USING FLOW POROMETRY
Krishna Gupta - PMI. Inc.
Six filter materials combined to make four composites: capilliary flow porometry helps the design process.
• 902 GLASS: A BIOSOLUBLE FIBER GLASS FOR AIR FILTRATION MEDIA
Foster Harding. Ph. D. - Johns Manville
A review of the problems and legislation related to inhaling glass fibre. 902 glass clears from the lungs faster than other glass fibres and has passed EU standards for low biopersistence.
• REVIEW OF ASHRAE TEST RESULTS VERSUS REAL LIFE PERFORMANCE
Charles Kern - Johns Manville
Comparisons of glass and synthetic fibre filter media. Synthetics look good in the lab. but work less well in real-air where the electrostatic charge on the synthetic decays too quickly.
• LARGE EDDY SIMULATION (LES) APPROACH FOR SOLVING FLUID DYNAMICAL PROBLEMS IN THE NONWOVEN FABRIC INDUSTRY
Ravi O.S. Prasad. Ph.D. - Fluent, Inc.
Computer modelling of fluid flow could help design of fibre distribution systems in air-lay, wet-lay and spun-lay processes.
• USE OF GOWNS AND DRAPES IN HEALTHCARE
William A. Rutala, Ph.D., M.P.H, - University of North Carolina - See Above
919 966 1635
• APPLICATIONS AND REQUIREMENTS OF BREATHABLE MATERIALS
Tom Ryle - Clopay Plastic Products Co, - See Above
• NONWOVEN FABRIC OCCLUDED TO SKIN: EFFECT ON SKIN BARRIER-FUNCTION
Howard Maibach, M.D. - University of California Medical Center - See above
• EFFECT OF CAPILLARY CONDENSATION ON BREAKTHROUGH PRESSURE OF NONWOVEN BARRIER FABRICS
Y. K. Kamath - TRI/Princeton - See above
• BREATHABLE COMPOSITES FOR SURGICAL FABRICS
Joseph Palomo - Allegiance Healthcare -See above
• STRENGTH LOSS IN THERMALLY BONDED POLYPROPYLENE FIBERS
Hawthorne Davis - North Carolina State University - see above
919 515 6578
• SPINNING OF SUBMICRON STRUCTURE FIBERS
John Hagewood, Ph.D. - Hills, Inc.
Splittable and islands-in-the-sea fibre technology reviewed again. “Any size can now be produced at reasonable cost”
321 724 2370
• PRODUCTION OPTIMIZATION & CHARACTERIZATION OF SM & SMS NONWOVEN COMPOSITE CONTAINING BI-COMPONENT PP/PE MICRO-FIBER MELT BLOWN WEBS
Larry Wadsworth, Ph.D. - The University of Tennessee
When you increase the percentage of PP in a meltblown PP/PE bico, higher bonding temperatures and pressures are needed to make the SMS laminate. If it overbonds, increase the calender speed.
• OPTIMIZATION OF PROCESSING CONDITIONS FOR A PP HOMOPOLYMER IN A REICOFIL SPUNBONDING PROCESS
Rammohan Nanjundappa - Colbond Nonwovens
4 hole sizes, 4 basis weights and 4 bonding temperatures analysed to give a strength response surface for a 35 MFR PP.
828 665 5039
• SPUNBONDING & SPUNLACING: TWO LEADING TECHNOLOGIES COMING TOGETHER
Alfred Watzl - Fleissner GmbH & Co. - See above
+49 06103 401 265
• DEVELOPMENT OF FINISHES FOR COTTON-SURFACED NONWOVENS FOR USE AS HOSPITAL OPERATING ROOM APPAREL
Christine Sun, Ph.D. - The University of Tennessee
Flurocarbon finishes improve repellency, soften the handle and reduce the abrasion resistance. Latex finish just improves the abrasion. FC on top of latex is a good compromise.
• ROLE OF FIBER FINISH IN THE CONVERSION OF FIBER TO NONWOVENS:FINISH PERFORMANCE AS A MECHANICAL PROCESSING AID IN CARDING
Abdelfattah Seyam. Ph.D. - North Carolina State University
Finish levels from 0.36 to 1.36% were obtained by blending PP bales with 2%, 0.6% and 0.1% finish. 0.6% was also made by blending the high and low levels to achieve non-uniformity. 0.36% appeared to be the best level for web uniformity. Finish-on-fibre uniformity appeared irrelevant .
• THE STABILITY OF LIQUID FILMS ON HIGHLY CURVED SURFACES
Thomas Theyson, Ph.D. - Goulston Tech.. Inc. See above
• INFLUENCE OF SELECTED PROCESS PARAMETERS ON THE SOFTNESS OF LIGHTWEIGHT NONWOVEN FABRICS
Krishna Parachuru, Ph.D. - Georgia Institute of Technology
Data from panel, strength and Kawabata testing on 17 fabrics was correlated with production conditions. Regression equations were computed. Shear stiffness and fabric weight correlated best with panel assessment.
• INCREASING THE SURFACE ENERGY & STERILIZATION OF NONWOVEN FABRICS BY EXPOSURE TO A ONE ATMOSPHERE UNIFORM GLOW DISCHARGE PLASMA (OAUGDP)
J. Reece Roth - The University of Tennessee - See above
865 974 4446
• ENHANCING THE SPREADING PERFORMANCE OF FINISHES
Mark Nehra - Uniquema
Their new ESC technology allows more even application of lower levels of finish on fibre by “expert formulation of the spin-finish component chemistry available”
• LOW-BORON FIBERGLASS FORMULA FOR HIGH EFFICIENCY MICROGLASS FILTER MEDIA
Jack Xu - Johns Manville
For use in semi-conductor clean room air-filters to avoid boron contamination of the silicon wafers.
• USE OF INFRARED THERMOGRAPHY TO IMPROVE THE MELT SPINNING AND PROCESSING OF POLYESTER FIBERS
Glenn Gibson - Eastman Chemical Co.
Being able to see temperature differences helps eliminate them. Views of the filaments in the quench zone show the variability (45-70 o C) we always suspected.
• NONWOVENS FROM POLY (TRIMETHYLENE TEREPHTHALATE) STAPLES
Don Shiffler - North Carolina State University - See above
• MELTBLOWN FABRICS OUT OF BIODEGRADABLE POLYMERS
Dieter H. Mueller. Ph.D. - BIK/Universitv of Bremen - See above
• IMPLICATIONS OF FIBER MORPHOLOGY ON THE: STRUCTURE & PROPERTIES OF THERMALLY BONDED POLYPROPYLENE NONWOVENS
Gajanan Bhat - The University of Tennessee - See above
423 974 0967
• CHARACTERIZATION OF COTTON/CELLULOSE ACETATE NONWOVENS OF UNTREATED & AQUEOUS PRETREATED WEBS PRIOR TO THERMAL BONDING
K. E. Duckett - The University of Tennessee
More on the calendering of wet- acetate (as at INDA-TEC 99). Water acts a plasticiser and lowers the bonding pressure. Some internally plasticised fibres are beginning to appear.
• EFFECT OF BIAS ANGLE ON THE MECHANICAL PROPERTIES OF STITCH-BONDED FABRIC
Vladimir Lasic - University of Zagreb
MD testing gives the highest results, CD the lowest. Strength and extension variations are inversely related. Honestly.
• THEORETICAL DESIGN OF NONWOVEN FABRICS
Peter P. Tsai. Ph.D. - TANDEC
Calculated and actual values of pore-size and permeability are in agreement for meltblown but not for needlefelts (because pore size could not be measured). Filtration efficiency of multilayer structures can be deduced from measurements of the components. Strength can be calculated from the fibre orientation distribution function.
• CHARACTERIZATION OF STRUCTURAL CHANGES IN NONWOVEN FABRICS DURING LOAD-DEFORMATION EXPERIMENTS
Behnam Pourdeyhimi,. Ph.D. - North Carolina State University
Image capture and analysis during a tensile test. MD/CD orientation increases under load, and bond points get narrower. This has nothing to do with bonding temperature in calendering, and everything to do with the original MD/CD orientation.
• NONWOVENS IN BATTERY SEPARATORS
John G. McCulloch,Ph.D. - Nonwoven/MB Ind.
A useful history of battery and fuel cell development with 39 references and 100+ patent numbers.
• POLYLACTIDE POLYMERS: TECHNOLOGY AND APPLICATIONS
James Lunt, Ph.D. - Cargill Dow LLC - See above
• NOVEL PROPERTIES OF PLA FIBERS
Jeff Dugan - Fiber Innovation Tech., Inc. - See above
MICROSTRUCTURAL ANALYSIS OF FIBER SEGMENTS IN NONWOVEN FABRICS USING SEM & IMAGE PROCESSING
HK Versteeg - Loughborough University
More on image analysis to get the fibre orientation distribution of HE nonwovens. Much testing but no correlations drawn. The joy must be in the travelling.
• DETERMINING FIBER ORIENTATION DISTRIBUTIONS IN NONWOVENS WITH HOUGH TRANSFORM TECHNIQUES
Bugao Xu - University of Texas @ Austin
As for 42, with less travelling and more mathematics.
• DEVELOPMENTS IN ABSORBENT PRODUCTS AND THEIR IMPACT ON THE NONWOVENS INDUSTRY
Colin White - MCW Technologies
The history of baby diaper development. “Future development will have a major impact on the nonwovens business as a whole. It is to be hoped that this impact will prove to be generally beneficial…)
• FOOD SERVICE WIPES
William Vogel - Atlantic Mills. Inc. - See above
732 363 9281
• SPREADING & COALESCENCE OF LIQUID DROPLETS ON NONWOVENS
Xuemin Chen - TRI/Princeton
More high-speed photography of finish droplets on single and paired filaments. Films tend to coalesce into droplets and droplets tend to migrate to cross-over points. If crossing angles are small the liquid stays as 4 triangular films, but if large, one large droplet forms. The critical angle increases with increasing fibre surface energy.
• UNIFORMITY & ANISOTROPY IN NONWOVEN FIBROUS MATERIALS
Andrew Kallmes - MK Systems - See above
• FLAME RETARDANT CHEMICAL TREATMENTS FOR NONWOVENS
James R. Johnson, Ph.D. - Olympic Laboratories, Inc.
FR additive choices for different nonwoven applications in composites. (Short paper with no conclusions.)
• CHEMICAL APPLICATION BY FOAM: ONE PRACTICAL AVENUE TO NEW PRODUCTS
Christoph Aurich - Gaston Systems, Inc.
The advantages listed: mainly more uniform add-on, low wet pickup and easier drying, less migration to fibre cross-over points, all contributing to lower costs, higher speeds and less pollution.
• HOLLOW SPHERE PIGMENTS: DO THEY HAVE A PLACE IN THE NONWOVEN INDUSTRY?
Micbele Mlynar - Rohm & Haas Co. - See above
• CROSS-FLOW DRYING & CURING OF WET-LAID GLASS FIBER VEILS
C. Heil, Ph.D. - Owens Coming Veil Netherlands BV
Mathematical modelling of the drying process compared to actual performance. Deeper insights into drying were obtained.
• DEVELOPMENTS IN CARDING
William Oxenham - North Carolina State University - See above
919 515 4552
OPTIMISATION OF ENERGY TRANSFER IN HYDROENTANGLEMENT PROCESS
M. Acar - Loughborough University
Effects of water pressure on the strength properties of Viscose/PET, PET and Twaron fabrics. 32 graphs but nothing new, except the following conclusion seen in print for the first time: “Parallel webs gave higher strength in the MD than cross-laid webs. Moreover, the ratio of MD/CD strength was larger for the fabrics made from the parallel laid webs than from cross-laid webs”
• PRODUCTION OF SUB-MICRON MELTBLOWN FIBERS FOR FILTRATION PRODUCTS
Gregory F. Ward - Nonwoven Technologies, Inc.
A new melt-blowing head using 9 thou orifices, 0.1 gms/hole/min polymer flow rate and 4 adjacent air jets operating at 5-25psi to produce continuous filaments with a diameter of 0.8 to 0.95 microns. The die is part of their recently patented Spunblown™ system which also features twin orifice rows, ultra-high operating pressure, and, with three double-row beams, an output of 190 kgs/hr at 2.2 metres wide. Estimated cost of the line is $4.5-$5.5million. 25 gsm submicron fabric production has an estimated operating cost of 1.6 cents/sq.metre.
• DEVELOPMENT & MODELING OF MONO- & BI-COMPONENT FIBER MELTBLOWN NONWOVEN PROCESS
Dong Zhang, Ph.D. - The University of Tennessee
PP,PE, PET, Co-PET, PBT, PA-6, PA6,6 polymers were used. Surface response methodology was used to analyse the results. The main conclusion was that the methodology “was an efficient and effective method for melt-blown process optimisation.” They await your call.
METHODS OF MANUFACTURING TO IMPROVE QUALITY OF NONWOVEN ROLL GOODS
Michael Maguire - National Wire Fabric
No text provided
©CRW Oct 2000.