US20100151760A1 - Non-woven sheet containing fibers with sheath/core construction - Google Patents

Non-woven sheet containing fibers with sheath/core construction Download PDF

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Publication number
US20100151760A1
US20100151760A1 US12/334,904 US33490408A US2010151760A1 US 20100151760 A1 US20100151760 A1 US 20100151760A1 US 33490408 A US33490408 A US 33490408A US 2010151760 A1 US2010151760 A1 US 2010151760A1
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United States
Prior art keywords
polymer
fibers
woven
pps
sheath
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Abandoned
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US12/334,904
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English (en)
Inventor
David Matthews Laura, Jr.
Xun Ma
Paul Ellis Rollin, JR.
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EIDP Inc
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EI Du Pont de Nemours and Co
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Application filed by EI Du Pont de Nemours and Co filed Critical EI Du Pont de Nemours and Co
Priority to US12/334,904 priority Critical patent/US20100151760A1/en
Assigned to E. I. DU PONT DE NEMOURS AND COMPANY reassignment E. I. DU PONT DE NEMOURS AND COMPANY ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: LAURA, DAVID MATTHEWS, JR., MA, XUN, ROLLIN, PAUL ELLIS, JR.
Priority to US12/499,328 priority patent/US20100147555A1/en
Priority to EP20090768594 priority patent/EP2358935B1/fr
Priority to CA 2742381 priority patent/CA2742381C/fr
Priority to KR1020117016338A priority patent/KR20110105804A/ko
Priority to JP2011540948A priority patent/JP2012512336A/ja
Priority to PCT/US2009/067833 priority patent/WO2010075024A1/fr
Priority to BRPI0916156A priority patent/BRPI0916156B8/pt
Priority to CN200980150385.7A priority patent/CN102245823B/zh
Publication of US20100151760A1 publication Critical patent/US20100151760A1/en
Abandoned legal-status Critical Current

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    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/12—Layered products comprising a layer of synthetic resin next to a fibrous or filamentary layer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/40—Layered products comprising a layer of synthetic resin comprising polyurethanes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
    • B32B5/022—Non-woven fabric
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
    • B32B5/08—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer the fibres or filaments of a layer being of different substances, e.g. conjugate fibres, mixture of different fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/02—Physical, chemical or physicochemical properties
    • B32B7/025—Electric or magnetic properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/04—Interconnection of layers
    • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
    • 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
    • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
    • D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
    • D04H3/14—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between thermoplastic yarns or filaments produced by welding
    • 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
    • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
    • D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
    • D04H3/16—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
    • B32B2262/02—Synthetic macromolecular fibres
    • B32B2262/0253—Polyolefin fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
    • B32B2262/02—Synthetic macromolecular fibres
    • B32B2262/0261—Polyamide fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
    • B32B2262/02—Synthetic macromolecular fibres
    • B32B2262/0276—Polyester fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
    • B32B2262/02—Synthetic macromolecular fibres
    • B32B2262/0276—Polyester fibres
    • B32B2262/0284—Polyethylene terephthalate [PET] or polybutylene terephthalate [PBT]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
    • B32B2262/12—Conjugate fibres, e.g. core/sheath or side-by-side
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
    • B32B2262/14—Mixture of at least two fibres made of different materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/20—Properties of the layers or laminate having particular electrical or magnetic properties, e.g. piezoelectric
    • B32B2307/206—Insulating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
    • B32B2307/582—Tearability
    • B32B2307/5825—Tear resistant
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/70—Other properties
    • B32B2307/702—Amorphous
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/70—Other properties
    • B32B2307/718—Weight, e.g. weight per square meter
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
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    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/70—Other properties
    • B32B2307/724—Permeability to gases, adsorption
    • B32B2307/7242—Non-permeable
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2457/00—Electrical equipment
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
    • Y10T442/60—Nonwoven fabric [i.e., nonwoven strand or fiber material]
    • Y10T442/637—Including strand or fiber material which is a monofilament composed of two or more polymeric materials in physically distinct relationship [e.g., sheath-core, side-by-side, islands-in-sea, fibrils-in-matrix, etc.] or composed of physical blend of chemically different polymeric materials or a physical blend of a polymeric material and a filler material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
    • Y10T442/60—Nonwoven fabric [i.e., nonwoven strand or fiber material]
    • Y10T442/637—Including strand or fiber material which is a monofilament composed of two or more polymeric materials in physically distinct relationship [e.g., sheath-core, side-by-side, islands-in-sea, fibrils-in-matrix, etc.] or composed of physical blend of chemically different polymeric materials or a physical blend of a polymeric material and a filler material
    • Y10T442/641—Sheath-core multicomponent strand or fiber material

Definitions

  • the present invention is directed to a non-woven sheet having improved characteristics due to the selection of specific fibers.
  • U.S. Patent Application Publication No. 2005/0269011 A1 discloses a method for making a spunbonded fabric from a blend of polyarylene sulfide and a crystal enhancer.
  • U.S. Pat. No. 6,949,288 discloses a multicomponent fiber with a polyarylene sulfide component and incorporation of the fibers into various products.
  • the present invention is directed to a non-woven sheet comprising multicomponent polymeric fibers having an average fiber diameter greater than 7 microns, said fibers further comprising:
  • a sheath component of from 10 to 70 weight percent of a first polymer based on the total weight of polymer in the core and sheath (b) a core component of from 30 to 90 weight percent of a second polymer based on the total weight of polymer in the core and sheath, wherein the melting point of the first polymer is at least 15 degrees C. higher than the melting point of the second polymer,
  • the non-woven sheet being further characterized by having a normalized air resistance greater than 0.2 s/(g/m 2 ).
  • the non-woven sheet particularly in combination with a further dielectric sheet is useful as an insulating material.
  • FIG. 1 depicts a typical process for making fiber and forming the fibers into a non-woven web or sheet.
  • FIG. 2 shows the additional calendaring process utilized in this invention.
  • multicomponent fibers it is meant the fiber is comprised of more than one polymer.
  • the fiber is bicomponent, meaning it is melt spun with two thermoplastic polymers in a sheath-core arrangement.
  • more than one polymer is meant to include not only polymers having different chemical structures, but polymers having similar structures but having different melting points.
  • nonwoven an assembly of textile fibers in a random web or mat held together by mechanical interlocking, by fusing of the fibers or by bonding with a cementing medium.
  • a preferred final article of the present invention is a non-woven sheet having a normalized air resistance greater than 0.25/(g/m 2 ) in combination with a dielectric film with the article suitable for use in electrical insulation.
  • the non-woven sheet has superior mechanical strength, initial tear resistance and elongation.
  • the non-woven sheet is made from multicomponent sheath/core polymeric fibers having an average diameter greater than 7 microns.
  • a preferred range of average fiber diameter is in a range from 14 to 21 microns.
  • the multicomponent sheath/core polymeric fibers can be round, trilobal, pentalobal, octalobal, like a Christmas tree, dumbbell-shaped, island-in-the-sea or otherwise star shaped in cross section.
  • the fibers may also be in a side by side arrangement.
  • the polymer component of the sheath is referred to as the first polymer and the polymer component of the core is referred to as the second polymer
  • the core component contains a second polymer present in a range from 30 to 90 weight percent based on the total weight of polymer in the core and sheath. Accordingly, the sheath component contains a first polymer in a range from 10 to 70 weight percent.
  • a preferred range for the second polymer is in a range from 30 to 50 weight percent and accordingly a preferred range for the first polymer is in a range from 50 to 70 weight percent.
  • a further requirement in the sheath/core construction of the fibers is the melting point of the first polymer (the sheath) which is at least 15 degrees centigrade higher than the melting point of the second polymer (the core). Typically, the difference in melting points is at least 20 degrees centigrade. Accordingly, the sheath has a higher thermal stability than the core.
  • One preferred embodiment of the present invention is directed to a non-woven sheet made from sheath/core fibers wherein the core is formed from polymers such as polyolefin, polyester or polyamide (the second polymer) and the sheath is formed from melt processable polymers such as polyarylene sulfide, polyimide, liquid crystalline polyester or polytetrafluoroethylene (the first polymer).
  • the sheath contains polyphenylene sulfide having an estimated zero shear viscosity of from 2300 to 2700 Poise when measured at 300° C. and the core component is polyethyleneterephthalate.
  • the first and second polymers either alone or in combination may include polyolefin, polyester or polyamide in the second polymer and polyarylene sulfide, polyimide, liquid crystalline polyester or polytetrafluoroethylene in the first polymer provided the melting point of the sheath is at least 15° C. higher than the melting point of the core.
  • the polymeric components forming the multicomponent fibers can include conventional additives such as dyes, pigments, antioxidants, ultraviolet stabilizers, spin finishes, and the like.
  • conventional additives such as dyes, pigments, antioxidants, ultraviolet stabilizers, spin finishes, and the like.
  • crystallinity enhancing additives in the polymeric compositions is optional.
  • Prior art processes that form a non-woven sheet having multicomponent fibers can be used, including processes that form the sheet solely from multicomponent fibers in staple form.
  • Such staple fiber non-wovens can be prepared by a number of methods known in the art, including carding or garneting, air-laying, or wet-laying of fibers.
  • the staple fibers preferably have a denier per filament between about 0.5 and 6.0 and a fiber length of between about 0.6 cm and 10 cm.
  • the fibers in the non-woven sheet can be continuous filaments directly spun into the sheet without any intentional cutting of the filaments.
  • the non-woven sheet can be made from processes as outlined in FIG. 1 to spin and consolidate continuous filament thermoplastic webs known in the art as spunbonding or meltblowing. An attenuating force should be provided to the bundle of fibers by a rectangular slot jet. By spinning the fiber at line speeds from 3500 to 5000 m/min, a significant amount of the second polymer is crystallized while the first polymer is not.
  • Multiple component spunbonded webs suitable for preparing laminate parts can be prepared using methods known in the art, for example as described in U.S. Pat. No 6,548,431 to Bansal et al.
  • Multicomponent fibers can be incorporated into a non-woven sheet by melt spinning fibers from spinning beams having a large number of holes onto a moving horizontal belt as disclosed in U.S. Pat. No. 5,885,909 to Rudisill et al.
  • Continuous filament webs suitable for preparing the non-woven fabrics preferably comprise continuous filaments having a denier per filament between 0.5 and 20 with a preferred denier per filament range of 1 and 5.
  • the non-woven sheet must be subjected to a further calendering step as shown in FIG. 2 to give a sheet having the desired level of porosity, degree of crystallinity of the first polymer and basis weight.
  • This calendaring step may be carried out as a separate operation or integrated into the web forming line of FIG. 1 and located after the filament bonding rolls.
  • the sheath polymer which is substantially amorphous, flows, becomes substantially crystalline and forms a continuous phase.
  • a measure of the extent of the continuous phase is sheet porosity or air permeability with a highly continuous phase having a low air permeability. Some increase in crystallinity of the core material is also observed.
  • the core fibers remain as discrete domains of fibrous filaments in a continuous phase of sheath material.
  • Parameters necessary to give good calendered non-woven sheet properties such as roll temperature, roll pressure, line speed and contact time with the rollers vary depending on the polymeric composition of the fiber sheath and, to a lesser extent, to the polymeric composition of the core.
  • Calendering can be carried out in the temperature range of from 90° C. to 240° C. with higher temperatures permitting faster line speeds. Preferable calendering conditions are about 200° C. at a nip pressure of about 3500 N/cm.
  • non-woven sheet or web having a porosity, as measured by normalized air resistance, of at least 0.2 s/gsm and a basis weight in the range from 30 to 350 gsm. More preferably, normalized air resistance is in the range of from 0.2 to 5.0 s/gsm. More preferably, the basis weight range is from 30-300 gsm and most preferably from 50-150 gsm.
  • the calendering process did not cause any deterioration in the tear strength of the calendered non-woven sheet when compared to the tear strength of a non-calendered sheet made in accordance with FIG. 1 .
  • the non-woven sheet can be used with a film to make a composite laminate suitable for use in electrical insulation.
  • the film provides the desired dielectric properties and the low porosity non-woven sheet minimizes loss of those dielectric properties.
  • the film is positioned adjacent to, and attached to at least one non-woven sheet to form the composite. Where two non-woven sheets are used, the film is sandwiched between the two sheets which allow the composite laminate to be impregnated with a matrix resin or varnish either prior to installation in an electrical device, or after installation in the device.
  • the impregnation resin may also include additives.
  • the film is attached to the non-woven sheets by an adhesive which may be a film, liquid, powder or paste.
  • the cure temperature of the adhesive must be lower than the melting point of the polymers of the fiber, preferably by at least ten degrees centigrade.
  • Either a thermoset or thermoplastic adhesive may be used.
  • a urethane adhesive is particularly suitable.
  • thermal lamination may also be possible.
  • Suitable bondable films include PET films that have an amorphous PET layer or layers on the outside of a PET film.
  • Suitable PPS films for thermal lamination include Torelina® PPS from Toray.
  • a multi-layer non-woven could be used as long as the layer of the multi-layer non-woven that is in contact with the film is made from the multicomponent fibers as previously described.
  • Basis weight and thickness of the non-woven sheet is not critical and is dependent upon the end use of the final laminate. In some preferred embodiments the basis weight is 50 to 150 grams per square meter and the final thickness of the non-woven sheets in the laminate structure is 50 to 125 micrometers.
  • thermoplastic film any suitable film can be used.
  • a thermoplastic film useful examples include polyester, polyamide, poly(phenylene sulfide) (PPS), and/or other thermoplastic materials.
  • the thermoplastic film can be a homogeneous material or it can be layered structure with different thermoplastics in different layers.
  • the preferred polyesters include poly(ethylene terephthalate), poly(ethylene naphthalate), and liquid crystalline polyesters.
  • Poly(ethylene terephthalate) can include a variety of comonomers, including diethylene glycol, cyclohexanedimethanol, poly(ethylene glycol), glutaric acid, azelaic acid, sebacic acid, isophthalic acid, and the like.
  • branching agents like trimesic acid, pyromellitic acid, trimethylolpropane and trimethyloloethane, and pentaerythritol may be used.
  • the poly(ethylene terephthalate) can be obtained by known polymerization techniques from either terephthalic acid or its lower alkyl esters (e.g.
  • PEN Poly(ethylene napthalate)
  • PET and PEN films are MYLAR® and TEONEX® films respectively, sold by DuPont-Teijin Films.
  • liquid crystalline polyester herein is meant polyester that is anisotropic when tested using the TOT test or any reasonable variation thereof, as described in U.S. Pat. No. 4,118,372.
  • One preferred form of liquid crystalline polyesters is fully aromatic.
  • Possible LCP compositions for films and film types are described, for example, in U.S. Pat. No. 5,248,530 to Jester et al.
  • PPS film is TORELINA® film sold by Toray Company.
  • thermoplastic compositions may also be present in the film. These materials should preferably be chemically inert and reasonably thermally stable under the operating environment of the part in service. Such materials may include, for example, one or more of fillers, reinforcing agents, dyes, pigments, antioxidants, stabilizers and nucleating agents. Other polymers may also be present, thus forming polymer blends. In some embodiments, the composition can contain about 1 to about 55 weight percent of fillers and/or reinforcing agents, more preferably about 5 to about 40 weight percent of these materials.
  • thermoplastic film can also contain an internal layer of thermoset material.
  • thermoset material for example, KAPTON® EKJ film, sold by DuPont, has thermoplastic polyimide outside layers with a thermoset polyimide layer inside the structure.
  • Thermal lamination processes to make the composite are well known in the art and include batch processes such as a platen press or vacuum bag or a continuous process such as a double belt press.
  • the thickness of non-woven sheets was measured in accordance with ASTM D374-99 Method E.
  • the basis weight of the non-woven sheets was taken according to ASTM D 646-96.
  • the air resistances of the non-woven sheets were measured in accordance with TAPPI T 460 om-02 as the amount of time to pass 100 ml of air through the sheets at a pressure differential of 1.22 kPA. The data is reported in seconds.
  • Normalized air resistance was calculated by dividing the air resistance in seconds (determined by TAPPI 460 om-02) by the basis weight in grams per square meter (determined by ASTM D 646-96). In some instances as noted in Table 2, the air resistance measured according to TAPPI T 460 was below the recommended minimum of 5 seconds. For these samples, the time to pass 300 ml of air through the sheets at a pressure differential of 1.22 kPA was taken. This time was divided by a factor of 3 in order to provide a basis of comparison of samples that complied with the recommended minimum time of 5 seconds for 100 ml of air with those that required a larger volume of air to obtain a meaningful result. Also where noted, the air resistance of the sheet was too low to be measured using either 100 ml or 300 ml of air. In these cases, the air resistance is assumed to be near zero.
  • Average fiber diameter was determined as follows. A bundle of fibers was carefully collected just below the attenuating jet. The fiber bundle was then prepared for viewing under an optical microscope. A digital image of the fiber bundle was then captured with the aid of computer. The diameter of at least thirty (30) clearly distinguishable fine fibers were measured from the photographs and recorded. Defects were not included (i.e., lumps of fine fibers, polymer drops, intersections of fine fibers). The average (mean) fiber diameter for each sample was calculated.
  • X-ray diffraction samples were run on a PANalytical X'Pert MPD diffractometer using copper radiation. The analysis was run in reflection mode using fixed 1 ⁇ 2 deg. slits for the incident and diffracted beam optics and a 0.3 mm receiving slit. This unit had a proportional detector with a curved graphite monochromator. Scan parameters were 5-40 degrees two-theta with a step size of 0.15 degree at 20 seconds per point. The instrument was calibrated using a sample of silicon provided by PANalytical.
  • SEM Scanning Electron Microscope Imaging samples were cut from the appropriate examples and placed on aluminum SEM stubs.
  • the stubs were placed in a sputter coater and coated for 80-100 seconds with a thin layer (1-2 angstroms) of gold/palladium. This coating serves as the necessary conductor for the SEM.
  • the stubs were inserted in a mount and placed in the SEM chamber. After pumping down to vacuum, each sample is imaged at different magnifications, at working distances of 8-11 mm in secondary emission (SE) mode. All images were captured and saved electronically.
  • SE secondary emission
  • HFIP hexaflouro isoproponol
  • a bicomponent spunbond fabric was made from a poly(ethylene terephthalate) (PET) component and a poly(phenylene sulfide) (PPS) component.
  • PET poly(ethylene terephthalate)
  • PPS poly(phenylene sulfide)
  • the PET component had an intrinsic viscosity of 0.63 dl/g and is available from E. I. duPont de Nemours, Wilmington, Del. under the tradename Crystar® polyester (Merge 4415).
  • the PPS component available from Ticona Engineering Polymers, Florence, Ky. under the tradename Fortron® PPS was a mixture of 70 wt % grade 0309 C1 and 30 wt % grade 0317 C1.
  • the PPS component had an estimated zero shear viscosity of approximately 2500 Poise measured at 300° C.
  • the PET resin was dried in a through air dryer at a temperature of 120° C. to a moisture content of less than 50 parts per million.
  • the PPS resins were dried in a through air dryer at a temperature of 115° C. to a moisture content of less than 150 parts per million.
  • the PET polymers were heated in an extruder at 290° C. and the PPS resins heated in a separate extruder at 295° C.
  • the two polymers were metered to a spin-pack assembly where the two melt streams were separately filtered and then combined through a stack of distribution plates to provide multiple rows of spunbond fibers having sheath-core cross sections. Such processing is well known to those skilled in the art.
  • the PET component comprised the core and the PPS component comprised the sheath.
  • a spin pack assembly consisting of 4316 round capillary openings was heated to 295° C. and the PPS and PET polymers spun through each capillary at a polymer throughput rate of 0.8 g/hole/min.
  • the PET component consisted of 70% by weight of the total weight of the spun bond fibers.
  • the fibers were cooled in a cross flow quench extending over a length of 122 cm.
  • An attenuating force was provided to the bundle of fibers by a rectangular slot jet.
  • the distance between the spin-pack to the entrance of the jet was 92.5 cm.
  • the fibers exiting the jet were collected on a forming belt traveling at 50.1 m/min. A vacuum was applied underneath the belt to help pin the fibers to the belt.
  • the fibers had an average diameter of 14.5 microns.
  • the spunbond layer was then passed between an embosser roll and an anvil roll as shown in FIG. 1 to achieve filament to filament bonding.
  • the bonding conditions were 135° C. roll temperature and 875 N/cm nip pressure. After thermal bonding, the spunbond sheet was formed into a roll using a winder.
  • the non-woven web was then smooth-calendered to achieve further densification of the already bonded non-woven web.
  • Line speed was 18.3 m/min.
  • Calender rolls 1 and 4 were smooth unheated rolls with a nylon composite shell having an outside diameter of 50 cm.
  • Calender rolls 2 and 3 were heated stainless steel rolls having an outside diameter of 46 cm. The steel rolls were heated to a surface temperature of 200° C.
  • the sheet was passed through a nip between calender rolls 1 and 2 under a nip pressure of 3100 N/cm. The sheet then traveled around Calender roll 2 and passed through the open nip between calender rolls 2 and 3 .
  • the sheet then wrapped around Calender roll 3 and through the nip between calender rolls 3 and 4 .
  • the nip pressure between calender rolls 3 and 4 was 3500 N/cm.
  • the spunbond sheet had a basis weight of 90 g/m 2 .
  • a bicomponent spunbond fabric was made from a poly(ethylene terephthalate) (PET) component and a poly(phenylene sulfide) (PPS) component.
  • PET poly(ethylene terephthalate)
  • PPS poly(phenylene sulfide)
  • the PET component had an intrinsic viscosity of 0.63 dl/g and is available from E. I. duPont de Nemours under the tradename Crystar® polyester (Merge 4415).
  • the PPS component available from Ticona Engineering Polymers under the tradename Fortron® PPS was a mixture of 70 wt % grade 0309 C1 and 30 wt % grade 0317 C1.
  • the PPS component had an estimated zero shear viscosity of approximately 2500 Poise measured at 300° C.
  • the PET resin was dried in a through air dryer at a temperature of 120° C. to a moisture content of less than 50 parts per million.
  • the PPS resins were dried in a through air dryer at a temperature of 115° C. to a moisture content of less than 150 parts per million.
  • the PET polymers were heated in an extruder at 290° C. and the PPS resins heated in a separate extruder at 295° C.
  • the two polymers were metered to a spin-pack assembly where the two melt streams were separately filtered and then combined through a stack of distribution plates to provide multiple rows of spunbond fibers having sheath-core cross sections.
  • the PET component comprised the core and the PPS component comprised the sheath.
  • a spin pack assembly consisting of 2158 round capillary openings was heated to 295° C. and the PPS and PET polymers spun through each capillary at a polymer throughput rate of 1.4 g/hole/min.
  • the PET component consisted of 50% by weight of the total weight of the spun bond fibers.
  • the fibers were cooled in a cross flow quench extending over a length of 122 cm.
  • An attenuating force was provided to the bundle of fibers by a rectangular slot jet.
  • the distance between the spin-pack to the entrance of the jet was 92.5 cm.
  • the fibers exiting the jet were collected on a forming belt traveling at 43.8 m/min.
  • the fibers had an average diameter of 17.5 microns.
  • a vacuum was applied underneath the belt to help pin the fibers to the belt.
  • the spunbond layer was then passed between an embosser roll and an anvil roll as shown in FIG. 1 to achieve filament to filament bonding.
  • the bonding conditions were 135° C. roll temperature and 875 N/cm nip pressure. After thermal bonding, the spunbond sheet was formed into a roll using a winder.
  • the non-woven web was then smooth-calendered as in Example 1. After calendering, the spunbond sheet had a basis weight of 78 g/m 2 .
  • a bicomponent spunbond fabric was made from a poly(ethylene terephthalate) (PET) component and a poly(phenylene sulfide) (PPS) component.
  • PET poly(ethylene terephthalate)
  • PPS poly(phenylene sulfide)
  • the PET component had an intrinsic viscosity of 0.63 dl/g and is available from E. I. duPont de Nemours under the tradename Crystar® polyester (Merge 4415).
  • the PPS component available from Ticona Engineering Polymers under the tradename Fortron® PPS was a mixture of 70 wt % grade 0309 C1 and 30 wt % grade 0317 C1.
  • the PPS component had an estimated zero shear viscosity of approximately 2500 Poise measured at 300° C.
  • the PET resin was dried in a through air dryer at a temperature of 120° C. to a moisture content of less than 50 parts per million.
  • the PPS resins were dried in a through air dryer at a temperature of 115° C. to a moisture content of less than 150 parts per million.
  • the PET polymers were heated in an extruder at 290° C. and the PPS resins heated in a separate extruder at 295° C.
  • the two polymers were metered to a spin-pack assembly where the two melt streams were separately filtered and then combined through a stack of distribution plates to provide multiple rows of spunbond fibers having sheath-core cross sections.
  • the PET component comprised the core and the PPS component comprised the sheath.
  • a spin pack assembly consisting of 4316 round capillary openings was heated to 295° C. and the PPS and PET polymers spun through each capillary at a polymer throughput rate of 1.0 g/hole/min.
  • the PET component consisted of 60% by weight of the total weight of the spun bond fibers.
  • the fibers were cooled in a cross flow quench extending over a length of 122 cm.
  • An attenuating force was provided to the bundle of fibers by a rectangular slot jet.
  • the distance between the spin-pack to the entrance of the jet was 92.5 cm.
  • the fibers exiting the jet were collected on a forming belt traveling at 65.9 m/min. A vacuum was applied underneath the belt to help pin the fibers to the belt.
  • the spunbond layer was then passed between an embosser roll and an anvil roll as shown in FIG. 1 to achieve filament to filament bonding.
  • the bonding conditions were 135° C. roll temperature and 1050 N/cm nip pressure. After thermal bonding, the spunbond sheet was formed into a roll using a winder.
  • the non-woven web was then smooth-calendered as in Example 1. After calendering, the spunbond sheet had a basis weight of 76 g/m 2 .
  • a bicomponent spunbond fabric was made from poly(ethylene terephthalate) (PET) component and a poly(phenylene sulfide) (PPS) component.
  • PET poly(ethylene terephthalate)
  • PPS poly(phenylene sulfide)
  • the PET component had an intrinsic viscosity of 0.67 dl/g and is available from E. I. DuPont de Nemours under the tradename Crystar® polyester (Merge 4434).
  • the PPS component available from Ticona Engineering Polymers under the tradename Fortron® PPS, was a mixture of 70 wt % grade 0309 C1 and 30 wt % grade 0317 C1.
  • the PPS component had an estimated zero shear viscosity of approximately 2500 Poise measured at 300° C.
  • the PET resin was dried in a through air dryer at a temperature of 120° C. to a moisture content of less than 50 parts per million.
  • the PPS resins were dried in a through air dryer at a temperature of 115° C. to a moisture content of less than 150 parts per million.
  • the PET polymers were heated in an extruder at 290° C. and the PPS resins heated in a separate extruder at 295° C.
  • the two polymers were metered to a spin-pack assembly where the two melt streams were separately filtered and then combined through a stack of distribution plates to provide multiple rows of spunbond fibers having sheath-core cross sections.
  • the PET component comprised the core and the PPS component comprised the sheath.
  • a spin pack assembly consisting of 4316 round capillary openings was heated to 295° C. and the PPS and PET polymers spun through each capillary at a polymer throughput rate of 0.8 g/hole/min.
  • the PET component consisted of 70% by weight of the total weight of the spun bond fibers.
  • the fibers were cooled in a cross flow quench extending over a length of 122 cm.
  • An attenuating force was provided to the bundle of fibers by a rectangular slot jet.
  • the distance between the spin-pack to the entrance of the jet was 92.5 cm.
  • the fibers exiting the jet were collected on a forming belt traveling at 52.7 m/min. A vacuum was applied underneath the belt to help pin the fibers to the belt.
  • the spunbond layer was then passed between an embosser roll and an anvil roll as shown in FIG. 1 to achieve filament to filament bonding.
  • the bonding conditions were 135° C. roll temperature and 1050 N/cm nip pressure. After thermal bonding, the spunbond sheet was formed into a roll using a winder.
  • the non-woven web was then smooth-calendered as in Example 1. After calendering, the spunbond sheet had a basis weight of 78 g/m 2 .
  • a bicomponent spunbond fabric was made from poly(ethylene terephthalate) (PET) component and a poly(phenylene sulfide) (PPS) component.
  • PET poly(ethylene terephthalate)
  • PPS poly(phenylene sulfide)
  • the PET component had an intrinsic viscosity of 0.63 dl/g and is available from E.I. DuPont de Nemours under the tradename Crystar® polyester (Merge 4415).
  • the PPS component had a melt flow index of 101 g/10 min at 316° C. under a load of 2.16 kg and is available from Ticona Engineering Polymers under the tradename Fortron PPS 0309 C1.
  • the PET resin was dried in a through air dryer at a temperature of 120° C. to a moisture content of less than 50 parts per million.
  • the PPS resins were dried in a through air dryer at a temperature of 115° C. to a moisture content of less than 150 parts per million.
  • the PET polymers were heated in an extruder at 290° C. and the PPS resins heated in a separate extruder at 295° C.
  • the two polymers were metered to a spin-pack assembly where the two melt streams were separately filtered and then combined through a stack of distribution plates to provide multiple rows of spunbond fibers having sheath-core cross sections.
  • the PET component comprised the core and the PPS component comprised the sheath.
  • a spin pack assembly consisting of 4316 round capillary openings was heated to 295° C. and the PPS and PET polymers spun through each capillary at a polymer throughput rate of 0.8 g/hole/min.
  • the PET component consisted of 50% by weight of the total weight of the spun bond fibers.
  • the fibers were cooled in a cross flow quench extending over a length of 122 cm.
  • An attenuating force was provided to the bundle of fibers by a rectangular slot jet.
  • the distance between the spin-pack to the entrance of the jet was 92.5 cm.
  • the fibers exiting the jet were collected on a forming belt traveling at 50.1.
  • the fibers had an average diameter of 14.5 microns.
  • a vacuum was applied underneath the belt to help pin the fibers to the belt.
  • the spunbond layer was then passed between an embosser roll and an anvil roll as shown in FIG. 1 to achieve filament to filament bonding.
  • the bonding conditions were 120° C. roll temperature and 350 N/cm nip pressure. After thermal bonding, the spunbond sheet was formed into a roll using a winder.
  • the non-woven web was then smooth-calendered as in Example 1. After calendering, the spunbond sheet had a basis weight of 83 g/m 2 .
  • a bicomponent spunbond fabric was made from poly(ethylene terephthalate) (PET) component and a poly(phenylene sulfide) (PPS) component.
  • PET poly(ethylene terephthalate)
  • PPS poly(phenylene sulfide)
  • the PET component had an intrinsic viscosity of 0.63 dl/g and is available from E. I. DuPont de Nemours under the tradename Crystar® polyester (Merge 4415).
  • the PPS component available from Ticona Engineering Polymers under the tradename Fortron® PPS, was a mixture of 70 wt % grade 0309 C1 and 30 wt % grade 0317 C1.
  • the PPS component had an estimated zero shear viscosity of approximately 2500 Poise measured at 300° C.
  • the PET resin was dried in a through air dryer at a temperature of 120° C. to a moisture content of less than 50 parts per million.
  • the PPS resins were dried in a through air dryer at a temperature of 115° C. to a moisture content of less than 150 parts per million.
  • the PET polymers were heated in an extruder at 290° C. and the PPS resins heated in a separate extruder at 295° C.
  • the two polymers were metered to a spin-pack assembly where the two melt streams were separately filtered and then combined through a stack of distribution plates to provide multiple rows of spunbond fibers having sheath-core cross sections.
  • the PET component comprised the core and the PPS component comprised the sheath.
  • a spin pack assembly consisting of 4316 round capillary openings was heated to 295° C. and the PPS and PET polymers spun through each capillary at a polymer throughput rate of 1.0 g/hole/min.
  • the PET component consisted of 50% by weight of the total weight of the spun bond fibers.
  • the fibers were cooled in a cross flow quench extending over a length of 122 cm.
  • An attenuating force was provided to the bundle of fibers by a rectangular slot jet.
  • the distance between the spin-pack to the entrance of the jet was 92.5 cm.
  • the fibers exiting the jet were collected on a forming belt traveling at 83.4 m/min. A vacuum was applied underneath the belt to help pin the fibers to the belt.
  • the spunbond layer was then passed between an embosser roll and an anvil roll as shown in FIG. 1 to achieve filament to filament bonding.
  • the bonding conditions were 135° C. roll temperature and 875 N/cm nip pressure. After thermal bonding, the spunbond sheet was formed into a roll using a winder.
  • the non-woven web was then smooth-calendered as in Example 1. After calendering, the spunbond sheet had a basis weight of 53 g/m 2 .
  • a bicomponent spunbond fabric was made from poly(ethylene terephthalate) (PET) component and a poly(phenylene sulfide) (PPS) component.
  • PET poly(ethylene terephthalate)
  • PPS poly(phenylene sulfide)
  • the PET component had an intrinsic viscosity of 0.63 dl/g and is available from E. I. DuPont de Nemours under the tradename Crystar® polyester (Merge 4415).
  • the PPS component available from Ticona Engineering Polymers under the tradename Fortron® PPS, was a mixture of 70 wt % grade 0309 C1 and 30 wt % grade 0317 C1.
  • the PPS component has an estimated zero shear viscosity of approximately 2500 Poise measured at 300° C.
  • the PET resin was dried in a through air dryer at a temperature of 120° C. to a moisture content of less than 50 parts per million.
  • the PPS resins were dried in a through air dryer at a temperature of 115° C. to a moisture content of less than 150 parts per million.
  • the PET polymers were heated in an extruder at 290° C. and the PPS resins heated in a separate extruder at 295° C.
  • the two polymers were metered to a spin-pack assembly where the two melt streams were separately filtered and then combined through a stack of distribution plates to provide multiple rows of spunbond fibers having sheath-core cross sections.
  • the PET component comprised the core and the PPS component comprised the sheath.
  • a spin pack assembly consisting of 4316 round capillary openings was heated to 295° C. and the PPS and PET polymers spun through each capillary at a polymer throughput rate of 1.0 g/hole/min.
  • the PET component consisted of 50% by weight of the total weight of the spun bond fibers.
  • the fibers were cooled in a cross flow quench extending over a length of 122 cm.
  • An attenuating force was provided to the bundle of fibers by a rectangular slot jet.
  • the distance between the spin-pack to the entrance of the jet was 92.5 cm.
  • the fibers exiting the jet were collected on a forming belt traveling at 71.5 m/min. A vacuum was applied underneath the belt to help pin the fibers to the belt.
  • the spunbond layer was then passed between an embosser roll and an anvil roll as shown in FIG. 1 to achieve filament to filament bonding.
  • the bonding conditions were 145° C. roll temperature and 875 N/cm nip pressure.
  • the spunbond sheet was formed into a roll using a winder.
  • a DSC spectrum of this non-woven web material had an exothermic peak or cold crystallization peak of 11.63 J/g at 119° C. associated with the enthalpy of crystallization of one or both components, and endothermic peaks of 24.08 J/g at 258° C. and 12.37 J/g at 281° C., associated with the melting points of the PET and the PPS components respectively.
  • a wide angle X-ray diffraction pattern was taken of this spunbond sheet and showed no evidence of PPS crystallinity in the spectrum. Some PET crystallinity was evident.
  • the non-woven web was then smooth-calendered as in Example 1.
  • the spunbond sheet had a basis weight of 68 g/m 2 .
  • a DSC spectrum of the material after this smooth calendering step had no exothermic peak at 119° C. but the endothermic peaks at 258° C. and 281° C., associated with the enthalpy of fusion of the PET and PPS components remained.
  • the mass of PPS which comprised 50 wt % of this example, the difference in magnitude between the enthalpy of crystallization before calendering and the PPS enthalpy of fusion after calendering was 1.42 J/g.
  • Example 7 The difference between the two DSC spectra of Example 7 indicates that the additional smooth calendering process step significantly increases the degree of crystallinity of the components of the fiber. They are now substantially crystalline.
  • a wide angle X-ray diffraction pattern was taken of the calendered spunbond sheet and showed peaks associated with PPS crystallinity.
  • the peaks associated with PET crystallinity increased in intensity. This again confirms that the calendering step converts amorphous PPS into a crystalline phase and further enhances PET crystallinity.
  • the reference document for identifying crystalline PPS in both the uncalendered and calendered sheets is “X-Ray Diffraction Analysis Technique for Determining the Polymer Crystallinity in a Polyphenylene Sulfide Composite by Lee et al, Polymer Composites, December 1995, Vol 16, No 6, pages 481 to 488.
  • a single component spunbond fabric was made from poly(phenylene sulfide) (PPS).
  • PPS poly(phenylene sulfide)
  • the PPS had a melt flow index of 101 g/10 min at 316° C. under a load of 2.16 kg and is available from Ticona Engineering Polymers under the tradename Fortron PPS 0309 C1.
  • the PPS resin was dried in a through air dryer at a temperature of 105° C. to a moisture content of less than 150 parts per million.
  • the polymer was heated in an extruder to 295° C.
  • the polymer was metered to a spin-pack assembly where the melt stream was filtered and then distributed through a stack of distribution plates to provide multiple rows of spunbond fibers.
  • the spin pack assembly consisted of 4316 round capillary openings.
  • the spin-pack assembly was heated to 290° C. and the polymer was spun through each capillary at a polymer throughput rate of 1.2 g/hole/min.
  • the fibers were cooled in a cross flow quench extending over a length of 122 cm.
  • An attenuating force was provided to the bundle of fibers by a rectangular slot jet.
  • the distance between the spin-pack to the entrance of the jet was 127 cm.
  • the fibers exiting the jet were collected on a forming belt traveling at 108 m/min.
  • a vacuum was applied underneath the belt to help pin the fibers to the belt.
  • the spunbond layer was then passed between an embosser roll and an anvil roll as shown in FIG. 1 to achieve filament to filament bonding.
  • the bonding conditions were 145° C. roll temperature and 700 N/cm nip pressure. After thermal bonding, the spunbond sheet was formed into a roll using a winder
  • the non-woven web was then smooth-calendered as in Example 1. After calendering, the spunbond sheet had a basis weight of 66 g/m 2 .
  • a single component carded non-woven web made from discontinuous poly(phenylene sulfide) (PPS) staple fibers was obtained from Bondex, Inc., Trenton, S.C.
  • the grade of material was R073G008.
  • a DSC spectrum of this material had an exothermic peak of 0.5733 J/g at 122.5° C., associated with the enthalpy of crystallization of the PPS, and endothermic peak of 58.35 J/g at 281.2° C., associated with the enthalpy of fusion of the PPS.
  • This non-woven web was then smooth-calendered as in Example 1. After smooth calendering, the spunbond sheet had a basis weight of 86 g/m 2 .
  • a DSC spectrum of this post calendered material had an exothermic peak of 1.064 J/g at 123.0° C., associated with the enthalpy of crystallization of the PPS, and endothermic peak of 57.59 J/g at 281.2° C., associated with the enthalpy of fusion of the PPS. Based on the mass of the PPS, the difference in magnitude between the enthalpy of crystallization before calendering and the PPS enthalpy of fusion after calendering was 57.02 J/g. A comparison between the two DSC spectra of this example indicates that the material, as received, was already highly crystalline and calendering did not further increase crystallinity
  • a bicomponent spunbond fabric was made from poly(ethylene terephthalate) (PET) component and a co-polyester (coPET) component.
  • PET poly(ethylene terephthalate)
  • coPET co-polyester
  • the PET component had an intrinsic viscosity of 0.63 dl/g and is available from E.I. du Pont de Nemours under the tradename Crystar® polyester (Merge 4415).
  • the coPET component is a 17 weight percent modified di-methyl isophthalate PET copolymer also available from DuPont as Crystar® Merge 4446.
  • the PET resin was dried in a through air dryer at a temperature of 120° C. to a moisture content of less than 50 parts per million.
  • the coPET resin was dried in a through air dryer at a temperature of 100° C., to a moisture content of less than 50 parts per million.
  • the polymers were heated in separate extruders with the PET resin heated to 290° C. and the coPET resin heated to 275° C.
  • the two polymers were metered to a spin-pack assembly where the two melt streams were separately filtered and then combined through a stack of distribution plates to provide multiple rows of spunbond fibers having sheath-core cross sections.
  • the PET component comprised the core and the coPET component comprised the sheath.
  • the spin pack assembly consisted of 4316 round capillary openings.
  • the spin-pack assembly was heated to 295° C. and the polymers were spun through each capillary at a polymer throughput rate of 0.8 g/hole/min.
  • the PET component consisted of 70% by weight of the total weight of the spun bond fibers.
  • the fibers were cooled in a cross flow quench extending over a length of 122 cm.
  • An attenuating force was provided to the bundle of fibers by a rectangular slot jet.
  • the distance between the spin-pack to the entrance of the jet was 127 cm.
  • the fibers exiting the jet were collected on a forming belt. A vacuum was applied underneath the belt to help pin the fibers to the belt.
  • the spunbond layer was then lightly bonded between an embosser roll and an anvil roll.
  • the bonding conditions were 160° C. roll temperature and 700 N/cm nip pressure. After thermal bonding, the spunbond sheet was formed into a roll using a winder.
  • the non-woven web was then further calendered as in Example 1 except that the line speed was 15.2 m/min, the steel roll temperatures were 110° C. and the nip pressures were 1400 N/cm. After calendering, the spunbond sheet had a basis weight of 70 g/m 2 .
  • a commercially available non-woven web was obtained from Innovative Paper Technologies, Tilton, N.H.
  • the web marketed under the tradename ThermalShield comprised a blend of poly(phenylene sulfide) (PPS) and poly(ethylene terephthalate) (PET) fibers.
  • PPS poly(phenylene sulfide)
  • PET poly(ethylene terephthalate)
  • the sheet had a thickness of 0.5 mm and a basis weight of 44 g/m 2 .
  • This non-woven was evaluated as received without any additional smooth calendering.
  • Table 1 is a summary of the key parameters relating to fiber production of the above examples and Table 2 lists the principal non-woven web features including mechanical test results of the webs made from these fibers.
  • test results show that a calendered non-woven of PPS sheath/PET core fibers provides an extremely low porosity web, as measured by normalized air resistance, when compared with comparative examples of a non sheath/core construction or a sheath/core construction but of different polymeric components.
  • the mechanical properties show a similar trend.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Nonwoven Fabrics (AREA)
  • Multicomponent Fibers (AREA)
  • Laminated Bodies (AREA)
  • Insulating Bodies (AREA)
US12/334,904 2008-12-15 2008-12-15 Non-woven sheet containing fibers with sheath/core construction Abandoned US20100151760A1 (en)

Priority Applications (9)

Application Number Priority Date Filing Date Title
US12/334,904 US20100151760A1 (en) 2008-12-15 2008-12-15 Non-woven sheet containing fibers with sheath/core construction
US12/499,328 US20100147555A1 (en) 2008-12-15 2009-07-08 Non-woven sheet containing fibers with sheath/core construction
CN200980150385.7A CN102245823B (zh) 2008-12-15 2009-12-14 包含具有皮/芯型构造的纤维的非织造片材
KR1020117016338A KR20110105804A (ko) 2008-12-15 2009-12-14 심초형 구성을 가진 섬유를 포함하는 부직포 시트
CA 2742381 CA2742381C (fr) 2008-12-15 2009-12-14 Feuille non tissee contenant des fibres avec une construction gaine/coeur
EP20090768594 EP2358935B1 (fr) 2008-12-15 2009-12-14 Feuillle non-tissee contenant des fibres de type âme/gaine
JP2011540948A JP2012512336A (ja) 2008-12-15 2009-12-14 鞘／芯構造を有する繊維を含有する不織シート
PCT/US2009/067833 WO2010075024A1 (fr) 2008-12-15 2009-12-14 Feuille non tissée contenant des fibres avec une construction gaine/coeur
BRPI0916156A BRPI0916156B8 (pt) 2008-12-15 2009-12-14 Folha de não tecido, componente de isolamento elétrico, isolamento, dispositivo elétrico e método para produzir uma folha de não tecido

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US12/334,904 US20100151760A1 (en) 2008-12-15 2008-12-15 Non-woven sheet containing fibers with sheath/core construction

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US12/499,328 Continuation-In-Part US20100147555A1 (en) 2008-12-15 2009-07-08 Non-woven sheet containing fibers with sheath/core construction

Publications (1)

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US20100151760A1 true US20100151760A1 (en) 2010-06-17

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US12/334,904 Abandoned US20100151760A1 (en) 2008-12-15 2008-12-15 Non-woven sheet containing fibers with sheath/core construction

Country Status (8)

Country Link
US (1) US20100151760A1 (fr)
EP (1) EP2358935B1 (fr)
JP (1) JP2012512336A (fr)
KR (1) KR20110105804A (fr)
CN (1) CN102245823B (fr)
BR (1) BRPI0916156B8 (fr)
CA (1) CA2742381C (fr)
WO (1) WO2010075024A1 (fr)

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US20130011544A1 (en) * 2010-03-22 2013-01-10 E I Du Pont De Nemours And Company Stabilization of polymeric structures
GB2495622A (en) * 2011-10-13 2013-04-17 Don & Low Ltd Non-woven fabric
CN103890256A (zh) * 2011-08-26 2014-06-25 纳幕尔杜邦公司 包含非织造纤维网的绝缘材料
US20140234598A1 (en) * 2012-09-06 2014-08-21 Xamax Industries, Inc. Composite sheet material and method for forming the same
WO2014134020A1 (fr) * 2013-02-27 2014-09-04 Bha Altair, Llc Fibre à deux composants et milieux filtrants contenant des fibres à deux composants
US20140265019A1 (en) * 2013-03-15 2014-09-18 I-Chung Liao Manufacturing method of an activated-carbon Filter Element
US9138943B2 (en) 2012-09-06 2015-09-22 Xamax Industries, Inc. Composite sheet material and method for forming the same
US20180002838A1 (en) * 2016-05-11 2018-01-04 Sason Kamer Synthetic Threads and Materials and Garments Produced Therewith
KR101848761B1 (ko) * 2017-09-19 2018-04-17 손제영 배열회수보일러의 철산화물 집진필터 및 그 제조방법
US10026522B1 (en) * 2014-08-19 2018-07-17 Superior Essex International LP Flame retardant insulation material for use in a plenum cable
US20190025953A1 (en) * 2017-07-24 2019-01-24 Microsoft Technology Licensing, Llc Forming touch sensor on fabric
US10252200B2 (en) 2016-02-17 2019-04-09 Hollingsworth & Vose Company Filter media including a filtration layer comprising synthetic fibers
US20190184318A1 (en) * 2013-08-06 2019-06-20 Amogreentech Co., Ltd. Filter medium for liquid filter and method for manufacturing same
KR102024505B1 (ko) * 2019-02-14 2019-09-23 한국남부발전 주식회사 배열회수보일러용 고성능 철산화물 집진필터 및 그 제조방법
US11014030B2 (en) 2016-02-17 2021-05-25 Hollingsworth & Vose Company Filter media including flame retardant fibers

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CN102908827B (zh) * 2012-10-30 2014-06-18 厦门柏润氟材料科技有限公司 一种具有皮芯结构的复合过滤材料及其制备方法与应用
CN106048779A (zh) * 2016-06-27 2016-10-26 马海燕 大直径聚苯硫醚复合单丝及其生产方法
DE102017004481A1 (de) * 2017-05-11 2018-11-15 Carl Freudenberg Kg Textiles Flächengebilde für die Elektroisolation
CN110682638A (zh) * 2018-07-04 2020-01-14 康利源科技（天津）股份有限公司 一种dmd绝缘纸的配方
KR20220048879A (ko) 2020-10-13 2022-04-20 서무경 열방성 액정 폴리머를 이용한 모노 필라멘트 제조 장치
WO2022145874A1 (fr) * 2020-12-29 2022-07-07 코오롱인더스트리 주식회사 Tissus non-tissés filés-liés ayant une structure âme-gaine et procédé de fabrication de ceux-ci

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US20130011544A1 (en) * 2010-03-22 2013-01-10 E I Du Pont De Nemours And Company Stabilization of polymeric structures
CN103890256A (zh) * 2011-08-26 2014-06-25 纳幕尔杜邦公司 包含非织造纤维网的绝缘材料
GB2495622A (en) * 2011-10-13 2013-04-17 Don & Low Ltd Non-woven fabric
GB2543434A (en) * 2011-10-13 2017-04-19 Don & Low Ltd Improved fabric
US9566769B2 (en) 2012-09-06 2017-02-14 Xamax Industries, Inc. Composite sheet material and method for forming the same
US9889637B2 (en) 2012-09-06 2018-02-13 Xamax Industries, Inc. Composite sheet material and method for forming the same
US10682833B2 (en) 2012-09-06 2020-06-16 Xamax Industries, Inc. Composite sheet material and method for forming the same
US9138975B2 (en) 2012-09-06 2015-09-22 Xamax Industries, Inc. Composite sheet material and method for forming the same
US9138974B2 (en) 2012-09-06 2015-09-22 Xamax Industries, Inc. Composite sheet material and method for forming the same
US9138943B2 (en) 2012-09-06 2015-09-22 Xamax Industries, Inc. Composite sheet material and method for forming the same
US20140234598A1 (en) * 2012-09-06 2014-08-21 Xamax Industries, Inc. Composite sheet material and method for forming the same
US9199440B2 (en) * 2012-09-06 2015-12-01 Xamax Industries, Inc. Composite sheet material and method for forming the same
US9205635B2 (en) 2012-09-06 2015-12-08 Xamax Industries, Inc. Composite sheet material and method for forming the same
US9339987B2 (en) 2012-09-06 2016-05-17 Xamax Industries, Inc. Composite sheet material and method for forming the same
WO2014134020A1 (fr) * 2013-02-27 2014-09-04 Bha Altair, Llc Fibre à deux composants et milieux filtrants contenant des fibres à deux composants
US8951325B2 (en) * 2013-02-27 2015-02-10 Bha Altair, Llc Bi-component fiber and filter media including bi-component fibers
US9168704B2 (en) * 2013-03-15 2015-10-27 I-Chung Liao Manufacturing method of an activated-carbon filter element
US20140265019A1 (en) * 2013-03-15 2014-09-18 I-Chung Liao Manufacturing method of an activated-carbon Filter Element
US10682599B2 (en) * 2013-08-06 2020-06-16 Amogreentech Co., Ltd. Filter medium for liquid filter and method for manufacturing same
US20190184318A1 (en) * 2013-08-06 2019-06-20 Amogreentech Co., Ltd. Filter medium for liquid filter and method for manufacturing same
US10026522B1 (en) * 2014-08-19 2018-07-17 Superior Essex International LP Flame retardant insulation material for use in a plenum cable
US11738295B2 (en) 2016-02-17 2023-08-29 Hollingsworth & Vose Company Filter media including flame retardant fibers
US11123668B2 (en) 2016-02-17 2021-09-21 Hollingsworth & Vose Company Filter media including a filtration layer comprising synthetic fibers
US11014030B2 (en) 2016-02-17 2021-05-25 Hollingsworth & Vose Company Filter media including flame retardant fibers
US10252200B2 (en) 2016-02-17 2019-04-09 Hollingsworth & Vose Company Filter media including a filtration layer comprising synthetic fibers
US10988865B2 (en) * 2016-05-11 2021-04-27 Sason Kamer Synthetic threads and materials and garments produced therewith
US20180002838A1 (en) * 2016-05-11 2018-01-04 Sason Kamer Synthetic Threads and Materials and Garments Produced Therewith
US20190025953A1 (en) * 2017-07-24 2019-01-24 Microsoft Technology Licensing, Llc Forming touch sensor on fabric
KR101848761B1 (ko) * 2017-09-19 2018-04-17 손제영 배열회수보일러의 철산화물 집진필터 및 그 제조방법
KR102024505B1 (ko) * 2019-02-14 2019-09-23 한국남부발전 주식회사 배열회수보일러용 고성능 철산화물 집진필터 및 그 제조방법

Also Published As

Publication number Publication date
CN102245823A (zh) 2011-11-16
EP2358935A1 (fr) 2011-08-24
BRPI0916156B1 (pt) 2019-05-07
BRPI0916156A2 (pt) 2015-11-10
EP2358935B1 (fr) 2013-08-28
BRPI0916156B8 (pt) 2023-02-28
CN102245823B (zh) 2014-05-07
WO2010075024A1 (fr) 2010-07-01
KR20110105804A (ko) 2011-09-27
CA2742381C (fr) 2014-08-12
CA2742381A1 (fr) 2010-07-01
JP2012512336A (ja) 2012-05-31

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