Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M10/00—Physical treatment of fibres, threads, yarns, fabrics, or fibrous goods made from such materials, e.g. ultrasonic, corona discharge, irradiation, electric currents, or magnetic fields; Physical treatment combined with treatment with chemical compounds or elements
  • D06M10/005—Laser beam treatment
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/407—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties containing absorbing substances, e.g. activated carbon
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
  • D04H1/541—Composite fibres, e.g. sheath-core, sea-island or side-by-side; Mixed fibres
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
  • D04H1/541—Composite fibres, e.g. sheath-core, sea-island or side-by-side; Mixed fibres
  • D04H1/5412—Composite fibres, e.g. sheath-core, sea-island or side-by-side; Mixed fibres sheath-core
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
  • D06M11/80—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with boron or compounds thereof, e.g. borides

Definitions

• the present disclosure broadly relates to methods for improving the durability of particle coatings on nonwoven fiber webs, and articles preparable thereby.
• Coatings of powders (e.g., graphite) on nonwoven fiber webs are widely known; however, the powders are typically loosely bound to the fibers and are prone to falling off.
• Various methods have been devised to overcome this problem, including: 1) use of a curable resin applied to the fibers prior to powder coating, and that when cured securely binds the powder to the fibers; 2) in those cases where the nonwoven fiber web is durable enough, the powder may be rubbed onto it in a process known as triboadhesion; and 3) the powders can be selected to contain binder components that can fuse to the fibers on heating.
• each of these techniques has disadvantages if a particle coating consisting essentially of inorganic particles is desired.
• the presence of binder components in approaches 1) and 3) would be unacceptable in such a situation, and durability of particle coatings made by approach 2) is generally problematic as particle coatings are typically prone to damage by methods such as abrasion and/or rinsing with solvent.
• the present disclosure provides an easy method to enhance the durability of particle coatings that involves instantaneous heating by exposure to pulsed electromagnetic radiation having at least one wavelength in the range of 200 nm to 1000 nm.
• pulsed electromagnetic radiation having at least one wavelength in the range of 200 nm to 1000 nm.
• the present inventors believe that the modulated electromagnetic radiation hitting the particles in the particle coating is converted to heat that is localized adjacent to the particles thereby softening the adjacent fibers and increasing adhesion between those fibers and the particles.
• the present disclosure provides a method of making a nonwoven article, the method comprising exposing a particle coating disposed on a thermally-softenable nonwoven fiber web to pulsed electromagnetic radiation having at least one wavelength in the range of 200 to 1000 nanometers, wherein the particle coating comprises loosely bound distinct particles that are not chemically bonded to each other and are not retained in a binder material other than the thermally-softenable nonwoven fiber web, and wherein the pulsed electromagnetic radiation has sufficient fluence and pulse width to increase bonding force between at least a portion of the loosely bound distinct particles and the thermally- softenable nonwoven fiber web.
• the present disclosure provides a nonwoven article made according to the foregoing method of the present disclosure.
• the present disclosure provides a nonwoven article comprising a thermally- softenable nonwoven fiber web having a particle coating disposed thereon, wherein the particle coating comprises distinct particles that are not chemically bonded to each other and are not retained in a binder material other than the thermally-softenable nonwoven fiber web, and wherein the particle coating is at least 60 percent retained after a one minute immersion in isopropanol at 22°C.
• visible light refers to electromagnetic radiation having a wavelength of 400 to 700 nanometers (nm).
• powder refers to a free-flowing collection of minute particles.
• pulsed electromagnetic radiation refers to electromagnetic radiation that is modulated to become a series of discrete spikes with increased intensity.
• the spikes may be relative to a background level of electromagnetic radiation that is negligible or zero, or the background level may be at a higher level that is substantially ineffective to increase adhesion of particles in the particle coating to the fiber.
• thermo-softenable means softenable upon heating.
• particle coating refers to a coating of minute particles which may or may not be free- flowing.
• Fig. 1 is an enlarged schematic side view of an exemplary article 100 according to the present disclosure.
• the present disclosure provides an easy method to enhance the durability of particle coatings on nonwoven fiber webs using instantaneous heating by exposure to a modulated source of electromagnetic radiation.
• exemplary article 100 comprises a thermally-softenable nonwoven fiber web 110 having a particle coating 120 disposed thereon.
• Particle coatings on thermally-softenable nonwoven (e.g., thermoplastic) fiber webs can be carried out by various known methods including, for example, exposure to an aerosolized particle cloud, contact with a powder bed, coating with a solvent-based particle dispersion coating followed by evaporation of solvent, and/or powder-rubbed (rubbing dry particles against a substrate to form a coating of the powder particles). Examples of powder-rubbing methods can be found in U. S. Pat. Nos.
• Useful particle coatings comprise minute loosely bound particles capable of absorbing at least one wavelength of the pulsed electromagnetic radiation, preferably corresponding to a majority of the energy of the pulsed electromagnetic radiation. Suitable particles are preferably at least substantially unaffected by electromagnetic radiation, but are moderate to strong absorbers of it. This is desirable to maximize the light (electromagnetic radiation) to heat conversion yield without altering the chemical nature of the particles .
• Exemplary suitable particles include graphite, clays, hexagonal boron nitride, pigments, inorganic oxides (e.g., alumina, calcia, silica, ceria, zinc oxide, or titania), metal(s), organic polymeric particles (e.g., polytetrafluoroethylene, polyvinylidene difluoride), carbides (e.g., silicon carbide), flame retardants (e.g., aluminum trihydrate, aluminum hydroxide, magnesium hydroxide, sodium hexametaphosphate, organic phosphonates and phosphates and ester thereof), carbonates (e.g., calcium carbonate, magnesium carbonate, sodium carbonate), dry biological powders (e.g., spores, bacteria), and combinations thereof.
• organic polymeric particles e.g., polytetrafluoroethylene, polyvinylidene difluoride
• carbides e.g., silicon carbide
• flame retardants e.g., aluminum trihydrate
• the particles have an average particle size of 0.1 to 100 micrometers, more preferably 1 to 50 micrometers, and more preferably 1 to 25 micrometers, although this is not a requirement.
• Graphite and hexagonal boron nitride are particularly preferred in many applications
• the particle coating Prior to exposure to the electromagnetic radiation the particle coating comprises loosely bound distinct particles that are not chemically bonded to each other, and are not retained in a binder material other than the thermally-softenable nonwoven fiber web itself.
• the thermally-softenable nonwoven fiber web preferably comprises thermoplastic fibers, although non-thermoplastic fibers may be used alone or in combination with thermoplastic fibers, for example.
• the fibers of the thermally-softenable nonwoven fiber web are non- tacky and/or non-thermosetting, although this is not a requirement.
• thermally-softenable nonwoven fiber webs include meltspun fiber webs, blown microfiber webs, needletacked staple fiber webs, thermally bonded airlaid webs, and spunlace webs.
• the thermally-softenable nonwoven fiber web may be made by any suitable nonwoven fiber web making process. Examples include meltspun, blown microfiber (BMF), air-laid processes, wet-laid processes, and spunlace. These and other methods will be known to those of skill in the art.
• thermally-softenable nonwoven fiber web comprising thermally-softenable fibers are commercially available.
• the thermally-softenable nonwoven fiber web may be of any basis weight and may be densely compacted or lofty and open, for example.
• thermoplastic polymers materials that may be used to make nonwoven fiber web comprising thermoplastic fibers are disclosed in U. S. Pat. Nos.
• thermoplastic fiber web have a higher melting core and a lower melting sheath.
• the higher melting core should preferably be at least 25°C.
• the pulsed electromagnetic radiation may come from any source(s) capable of generating sufficient fluence and pulse duration to effect sufficient heating of the nonwoven fiber web to cause the particle coating to bind more tightly to it.
• At least three types of sources may be effective for this purpose: flashlamps, lasers, and shuttered lamps.
• flashlamps lasers
• shuttered lamps The selection of appropriate sources will typically be influenced by desired process conditions such as, for example, line speed, line width, spectral output, and cost.
• the pulsed electromagnetic radiation is generated using a flashlamp.
• a flashlamp xenon and krypton flashlamps are the most common. Both provide a broad continuous output over the wavelength range 200 to 1000 nanometers, however the krypton flashlamps have higher relative output intensity in the 750-900 nm wavelength range as compared to xenon flashlamps which have more relative output in the 300 to 750 nm wavelength range.
• xenon flashlamps are preferred for most applications, and especially those involving graphite particles.
• Many suitable xenon and krypton flashlamps are commercially available from vendors such as Excelitas Technologies Corp. of Waltham, Massachusetts and Heraeus of Hanau, Germany.
• the pulsed electromagnetic radiation can be generated using a pulsed laser.
• Suitable lasers may include, for example, excimer lasers (e.g., XeF (351 nm), XeCl (308 nm), and KrF (248 nm)), solid state lasers (e.g., ruby 694 nm)), and nitrogen lasers (337.1 nm).
• the pulsed electromagnetic radiation is generated using a continuous light source and a shutter (preferably a rotating aperture/shutter to reduce overheating of the shutter).
• Suitable light sources may include high-pressure mercury lamps, xenon lamps, and metal-halide lamps.
• the electromagnetic radiation spectrum is preferably most intense at wavelength(s) that are strongly absorbed by the particles, although this is not a requirement.
• the electromagnetic radiation spectrum is preferably most intense in spectral regions in which the particles are least reflective, although this is not a requirement.
• the source of pulsed electromagnetic radiation is capable of generating a high fluence (energy density) with high intensity (high power per unit area), although this is not a requirement.
• high fluence energy density
• intensity high power per unit area
• the pulse duration is preferably short; e.g., less than 10 milliseconds, less than 1 millisecond, less than 100 microseconds, less than 10 microseconds, or even less than 1 microsecond, although this is not a requirement.
• the pulsed electromagnetic radiation preferably be powerful, but the exposure area is preferably large and the pulse repetition rate is preferably fast (e.g., 100 to 500 Hz).
• the resultant exposed particle-coated nonwoven fiber web may be immersed in a solvent such as, e.g., isopropanol for a fixed interval (e.g., 1, 2, 3, 4, or even 5 minutes, or longer) at about 22°C (e.g., room temperature), and then removed, dried, and weighed. Weight loss of powder can then be determined by subtraction.
• the solvent should be selected such that it does not dissolve the nonwoven fiber web.
• the particulate coating of the nonwoven article is sufficiently bonded to the nonwoven fiber web so that after one minute of immersion in isopropanol at 22°C at least 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or even at least 90 percent of the particulate coating remains bonded to the nonwoven fiber web.
• the present disclosure provides a method of making a nonwoven article, the method comprising exposing a particle coating disposed on a thermally-softenable nonwoven fiber web to pulsed electromagnetic radiation having at least one wavelength in the range of 200 to 1000 nanometers, wherein the particle coating comprises loosely bound distinct particles that are not chemically bonded to each other and are not retained in a binder material other than the thermally- softenable nonwoven fiber web, and wherein the pulsed electromagnetic radiation has sufficient fluence and pulse width to increase bonding force between at least a portion of the loosely bound distinct particles and the thermally-softenable nonwoven fiber web.
• the present disclosure provides a method according to the first embodiment, wherein the particle coating comprises at least one of graphite or hexagonal boron nitride.
• the present disclosure provides a method according to the first or second embodiment, wherein the particle coating consists essentially of graphite.
• the present disclosure provides a method according to any one of the first to third embodiments, wherein the pulsed electromagnetic radiation is generated using a flashlamp.
• the present disclosure provides a method according to any one of the first to third embodiments, wherein the pulsed electromagnetic radiation is generated using a pulsed laser.
• the present disclosure provides a method according to any one of the first to third embodiments, wherein the pulsed electromagnetic radiation is generated using a continuous light source and a shutter.
• the present disclosure provides a method according to any one of the first to sixth embodiments, wherein the thermally-softenable nonwoven fiber web comprises fibers having a higher melting core and a lower melting sheath.
• the present disclosure provides a nonwoven article made according to any one of the first to seventh embodiments of the present disclosure.
• the present disclosure provides a nonwoven article comprising a thermally-softenable nonwoven fiber web having a particle coating disposed thereon, wherein the particle coating comprises distinct particles that are not chemically bonded to each other and are not retained in a binder material other than the thermally-softenable nonwoven fiber web, and wherein the particle coating is at least 60 percent retained after a one minute immersion in isopropanol at 22°C.
• the present disclosure provides a nonwoven article according to the ninth embodiment, wherein the particle coating comprises at least one of graphite or hexagonal boron nitride.
• the present disclosure provides a nonwoven article according to the ninth or tenth embodiment, wherein the particle coating consists essentially of graphite.
• the present disclosure provides a nonwoven article according to any one of the ninth to eleventh embodiments, wherein the particle coating is at least 90 percent retained after the one minute immersion in isopropanol at 22°C.
• the present disclosure provides a nonwoven article according to any one of the ninth to twelfth embodiments, wherein the thermally-softenable nonwoven fiber web comprises fibers having a higher melting core and a lower melting sheath.
• graphite coatings were applied on PE nonwoven substrates by placing a strip of nonwoven approximately 1.5 inches (3.8 cm) by 10 inches (25.4 cm) in dimension and a small amount of MICRO850 in a sealable plastic bag. The bag was then sealed and shaken, until the PE nonwoven was visibly covered in graphite. The nonwoven was then removed, and excess graphite particles were removed by blowing with compressed nitrogen at a pressure of 40 pounds per square inch.
• the relative amount of graphite coating deposited on the PE nonwoven film was determined by measuring the weight of the sample before and after the process.
• Nonwoven samples were completely immersed (i.e., submerged) in a bath of IP A at room temperature (22°C) and stirred by hand for 1 minute. The samples were then removed and spread onto a clean surface in a chemical hood and allowed to dry completely.
• CEX-A and EX-1 to EX- 12 were graphite coated PE nonwoven substrates prepared as described above.
• the substrate was not subjected to IPL and was a control sample.
• EX-1 to EX-11 were prepared by subjecting the samples to an intense pulsed light irradiation (IPL).
• the source used was a Xe flashlamp, commercially obtained from Xenon Corporation, Wilmington, Massachusetts, as a SINTERON S-2100 Xe flashlamp equipped with Type C bulb. Samples were placed beneath a quartz plate for the irradiation process.
• the substrate was treated 1 time at a pulse rate of 1 Hz and an energy density of 0.1 J/cm 2 .
• the substrate was then removed and flipped over, and the treatment was repeated on the backside of the substrate.
• the substrate was treated 3 times at a pulse rate of 1 Hz and an energy density of 0.1 J/cm 2 .
• the substrate was then removed and flipped over, and the treatment was repeated on the backside of the substrate.
• the substrate was treated 5 times at a pulse rate of 1 Hz and an energy density of 0.1 J/cm 2 .
• the substrate was then removed and flipped over, and the treatment was repeated on the backside of the substrate.
• the substrate was treated 1 time at a pulse rate of 1 Hz and an energy density of 0.2 J/cm 2 .
• the substrate was then removed and flipped over, and the treatment was repeated on the backside of the substrate.
• the substrate was treated 3 times at a pulse rate of 1 Hz and an energy density of 0.2 J/cm 2 .
• the substrate was then removed and flipped over, and the treatment was repeated on the backside of the substrate.
• the substrate was treated 5 times at a pulse rate of 1 Hz and an energy density of 0.2 J/cm 2 .
• the substrate was then removed and flipped over, and the treatment was repeated on the backside of the substrate.
• the substrate was treated 1 time at a pulse rate of 1 Hz and an energy density of 0.3 J/cm 2 .
• the substrate was then removed and flipped over, and the treatment was repeated on the backside of the substrate.
• the substrate was treated 3 times at a pulse rate of 1 Hz and an energy density of 0.3 J/cm 2 .
• the substrate was then removed and flipped over, and the treatment was repeated on the backside of the substrate.
• the substrate was treated 5 times at a pulse rate of 1 Hz and an energy density of 0.3 J/cm 2 .
• the substrate was then removed and flipped over, and the treatment was repeated on the backside of the substrate.
• the substrate was treated 1 time at a pulse rate of 1 Hz and an energy density of 0.4 J/cm 2 . The substrate was then removed and flipped over, and the treatment was repeated on the backside of the substrate.
• the substrate was treated 3 times at a pulse rate of 1 Hz and an energy density of 0.4 J/cm 2 . The substrate was then removed and flipped over, and the treatment was repeated on the backside of the substrate.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Chemical Or Physical Treatment Of Fibers (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

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• 2018
  • 2018-06-26 US US16/626,244 patent/US20200157734A1/en not_active Abandoned
  • 2018-06-26 WO PCT/IB2018/054716 patent/WO2019003115A1/en unknown
  • 2018-06-26 KR KR1020197038394A patent/KR102492536B1/ko active IP Right Grant
  • 2018-06-26 CN CN201880042693.7A patent/CN110799687B/zh active Active
  • 2018-06-26 EP EP18749509.8A patent/EP3645776B1/en active Active

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