Classifications

• • 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
  • D04H1/42—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 characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
  • D04H1/4209—Inorganic 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
  • D04H1/42—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 characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
  • D04H1/4209—Inorganic fibres
  • D04H1/4218—Glass 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
  • D04H1/44—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 the fleeces or layers being consolidated by mechanical means, e.g. by rolling
  • D04H1/46—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 the fleeces or layers being consolidated by mechanical means, e.g. by rolling by needling or like operations to cause entanglement of fibres
• • 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
  • D06M15/00—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment
  • D06M15/19—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment with synthetic macromolecular compounds
  • D06M15/37—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D06M15/53—Polyethers

Definitions

• the present invention relates to an aqueous dispersion, comprising emulsions and microemulsions of perfluoropolyethers carboxylic salts, and its use as needling-aid for producing needle felts of mineral fiber glass wool.
• Inorganic mineral fibers are manufactured by pulling, centrifugal, blowing or centrifugal/blowing processes of molten mineral masses in the form of interlocked fibers. Because of the brittleness of the fibers the resulting felt lacks structural strength compromising the possibility of use in application such as acoustic and thermal insulation, filter media, fireproofing material. To overcame this deficiency inorganic fiber felts are impregnated with an organic binder (usually a phenol-formaldehyde-urea or other organic resin) locking fibers together assuring optimal mechanical prope0rties when placed in use.
• organic binder usually a phenol-formaldehyde-urea or other organic resin
• Fiber needle felts are a combination of mineral fibers mechanically intertwined to form a non-woven fabric which do not contain any organic binder. They give excellent high thermal insulation and thermal protection and they can be safely used at the following temperatures without changing properties: C fiber as high as 500 °C, E fiber 650 °C, rockwool fiber 700 °C, silica fiber 800 °C, ceramic fiber 1000°C.
• the purpose of the needling-aid is to favor the sliding of the barbed needles into the fibers reducing thus friction.
• part of the needling-aid moves from fibers onto the surface of the barbed needle facilitating its subsequent release from the mat. Furthermore, a certain reduction of mutual friction between fibers promotes mechanical interlocking.
• An inevitable consequence of mechanical stresses induced by needling is the rupture of some fibers with consequent production of fine materials and powders.
• An additional advantageous effect of the needling-aid is to bound dusts thus avoiding their release during use.
• the needling-aid is applied on the chute of the spinning machine by means of a sprayer.
• the needling-aid should have low viscosity and low surface tension in order to facilitate spraying, wetting and spreading onto the fibers.
• the needling-aid should possess a high viscosity in order to consolidate the felt promoting fiber interlocking and dust binding.
• perfluoroplastics such as polytetrafluoroethylene (PTFE), fluorinated ethylene-propylene polymers (FEP), polyvinylidene fluoride (PVDF) or fluoroelastomers such as copolymers of vinylidene fluoride and hexafluoropropylene, terpolymers of vinylidene fluoride, hexafluoropropylene and tetrafluoroethylene are applied as aqueous dispersions to substrates to obtain composites which are flexible and not brittle and which exhibit a low coefficient of friction.
• PTFE polytetrafluoroethylene
• FEP fluorinated ethylene-propylene polymers
• PVDF polyvinylidene fluoride
• fluoroelastomers such as copolymers of vinylidene fluoride and hexafluoropropylene, terpolymers of vinylidene fluoride, hexafluoropropylene and
• PFOA perfluorooctanoic acid
• APIFA ammonium perfluorooctanoate
• EP 0819788 teaches the use of aqueous dispersions of halogenated and preferably perfluorated polyethers and polyesters and alcohols as needling-aid additives.
• An important advantage of the method proposed in the reference is the production of a fiber glass felt which does not release formaldehyde even if heated at approx. 500 °C.
• perfluoropolyethers used do not contain PFOA and related compounds.
• PFOA PFOA and related compounds.
• MIC methylisocianate
• Methylisocianate is a highly toxic and irritating chemical extremely hazardous to human health.
• EP 1022260 teaches the use of water emulsions of methyl phenyl silicone oils as useful needling-aids for mineral wool. These emulsions are claimed to release less than 50 mg of formaldehyde per kg of fibers when exposed to temperatures as high as 350 °C. Although this result represents a considerable improvement over the use of mineral oil emulsions it does not comply with the requirements for the emission of aldehydes according to the LGA certificate "LGA-schadstoffger certified" which prescribe, in the same conditions, a maximum concentration of 10 mg of formaldehyde per kg of fiber felt.
• a common drawback of the needling-aids for needle felts described in the prior art is the release of toxic or irritating decomposition compounds when exposed to temperatures typical of ovens, cookers and other household and industrial applications.
• the aim of the invention is to prepare a needling-aid for producing a needle felt which does not release any toxic or irritating decomposition product, notably formaldehyde, methylisocianate, perfluorooctanoic acid and salts thereof at temperatures up to 350 °C.
• any toxic or irritating decomposition product notably formaldehyde, methylisocianate, perfluorooctanoic acid and salts thereof at temperatures up to 350 °C.
• the present invention is further clarified in three embodiment.
• water dispersible perfluoropolyethers and optionally polyether modified polydimethyl siloxanes allows the elimination of non ionic, anionic, cationic or amphoteric hydrocarbon based surfactants which are recognized of being precursors of formaldehyde. Further the absence of ammonia, organic amines, urea and derivatives thereof as neutralizing agents of the carboxylic group or contaminants excludes the presence of any nitrogen source which can be a precursor for high-temperature formation of methylisocianate.
• Formaldehyde and methylisocianate are detected in concentration lower than 8 mg and 0.02 mg per kg of fiber respectively in the final needle felts treated with needling-aid solutions prepared according to the present invention and exposed to temperatures up to 350 °C. Further, the same needle-felts when exposed to the aforementioned working conditions do not emit any PFOA or derivatives and precursors thereof.
• Needling-aid solutions prepared according to the present invention have the additional advantage of using a solvent having a boiling point less than 150 °C, preferably less than 80 °C and more preferably less than 60 °C which instantaneously evaporates as soon as the needling-aid solution is sprayed onto the glass fibers in the chute of the spinning machine. This is a crux to exclude the presence of traces of solvent on the finished product which can act as potential precursor for toxic or irritating thermal decomposition compounds during use.
• Viscous aqueous dispersions disclosed in the present invention have the additional advantage that they are obtained in a homogeneous and translucent form only by gentle mixing of ingredients without requiring particular mixing devices such as high pressure homogenizers, turbo mixers or emulsifiers.
• Viscous aqueous dispersions disclosed in the present invention have long shelf-life. They are physically stable for at least 6 months, and do not produce precipitation or flocculation in the temperature range from 5 °C to 50 °C.
• the pH of the aqueous dispersions of the present invention is generally between 5 and 12, preferably between 6 and 11, most preferably between 7 and 10.
• the dynamic viscosity of aqueous viscous dispersions disclosed in the present invention is generally between 1 mPa ⁇ s and 10000 mPa ⁇ s, preferably between 100 mPa ⁇ s and 5000 mPa ⁇ s, most preferably between 400 mPa ⁇ s and 2500 mPa ⁇ s.
• a further object of the present invention is the preparation of a practically applicable needling-aid solution starting from the aforementioned viscous aqueous dispersions which are diluted with water to a final concentration of approx. 0.01% to 10% (weight percentage of perfluoropolyether) preferably from 0.05% to 2% (wt.) and most preferably from 0.1% to 1% (wt.) and then sprayed onto the mineral fibers coming out from the chute of the spinning machine.
• the surface tension of needling-aid solutions prepared according to the present invention ranges from 12 mN ⁇ m -1 to 30 mN ⁇ m -1 depending on the perfluoropolyether formula and concentration.
• Low surface tension positively affects spreading and capillarity favoring the rapid and uniform coating of fibers with the perfluoropolyether solution.
• the mutual friction between fibers and between fibers and barbed needles in the subsequent needling process is extremely reduced favoring mechanical interlocking of fibers without any appreciable fracture or breakage.
• the cost of the finishing treatment is comparable or even lower than other traditional needling-aids.
• a needling-aid composition was prepared in that 0,038 kg of potassium carbonate were dissolved into a mixture of 7,6 kg of demineralized or softened water and 1,824 kg of acetone where after 1,52 kg of a perfluoropolyether based on hexafluoropropylene commercially available under the designation Krytox 157 FS were added.
• the mixture was vigorously stirred until the achievement of a clear gel which was diluted with demineralized or softened water obtaining a translucent and stable solution having a perfluoropolyether content of approx. 4,25% (wt.).
• the diluted perfluoropolyether solution was then sprayed onto the glass fibers in the chute of the spinning machine. Fibers were then conveyed in a tunnel heated at 130 °C in order to facilitate the evaporation of water and acetone. The fiber mat thus formed was conveyed to the needle-punching process.
• the mineral wool felt obtained had a bulk density of 78 kg/m 3 and a thickness of 25 mm and it was tested by TUV Rheinland LGA Products at 350 °C for the release of aldheydes and methylisocyanate using the ceramic tube furnace method.
• a needling-aid composition was prepared in that 0,041 kg of potassium carbonate were dissolved into a mixture of 7,4 kg of demineralized water and 1,81 kg of acetone where after 1,5 kg of a perfluoropolyether marketed under the designation Cheminox® PO-7M-CA having an average molecular weight of ca. 1250 and purchased from Unimatec Co. were added. The mixture was vigorously stirred until the achievement of a clear gel which was diluted with softened water obtaining a stable solution having a perfluoropolyether content of approx. 4,21% (wt.).
• the mineral wool felt obtained had a bulk density of 78/m 3 and a thickness of 20 mm and it was tested by TUV Rheinland LGA Products at 350 °C for the release of aldheydes and methylisocyanate using the ceramic tube furnace method.
• a needling-aid composition was prepared in that 0,05 kg of potassium carbonate were dissolved into a mixture of 4,95 kg of softened water and 1,5 kg of acetone. 0,025 Kg of a polyether modified polydimethyl siloxane marketed under the trade name Strucksilon 8005 where than added together with 1,5 kg of a Krytox 157 FS. The mixture was vigorously stirred until the achievement of a clear gel which was diluted with softened water obtaining a stable solution having a perfluoropolyether content of approx. 3,0% (wt.).
• the mineral wool felt obtained had bulk density and thickness similar to those reported in previous examples and it was tested by TUV Rheinland LGA Products at 350 °C for the release of aldheydes and methylisocyanate using the ceramic tube furnace method.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Mechanical Engineering (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Colloid Chemistry (AREA)
• Paper (AREA)

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Cited By (3)

Citations (5)

• 2013
  • 2013-03-18 IT IT000008A patent/ITVE20130008A1/it unknown
• 2014
  • 2014-03-03 PL PL14157479T patent/PL2781635T3/pl unknown
  • 2014-03-03 SI SI201430014T patent/SI2781635T1/sl unknown
  • 2014-03-03 EP EP14157479.8A patent/EP2781635B1/fr active Active

Patent Citations (5)

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