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
  • D04H1/44—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
  • D04H1/48—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 in combination with at least one other method of consolidation
  • D04H1/49—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 in combination with at least one other method of consolidation entanglement by fluid jet in combination with another consolidation means

Definitions

• the invention relates to a process for the production of a nonwoven fabric, in which the fibers used are gathered together flatly to form a mat, interwoven by jets of a fluidic medium directed against the surface and then glued.
• the invention has for its object to show a method for producing a dimensionally stable nonwoven that ensures the achievement of a high modulus. This is to be understood as the force required for a 5% stretch.
• This object is achieved according to the invention in a method of the type mentioned at the outset by impregnating the fiber mat consisting of interwoven fibers with a binder, linearly stretching it at least 20% linearly at least in the transverse direction and drying it while solidifying the binder.
• the proposed method is particularly suitable for the manufacture of dimensionally stable nonwovens with a weight per unit area of 20 to 80 g / m 2 , and in addition to good tensile stability, they are notable for particularly low elongation in the width direction.
• the high dimensional stability enables the nonwovens to be mechanically bonded to a synthetic material by means of a needling process.
• they can serve as stiffening materials in this case, but when using chemically activatable fibers they can also be used as binding materials for the subsequent laminating of the laminate onto a carrier.
• An embodiment which has been found to be particularly suitable for this purpose can be obtained if the interwoven fiber mat is produced from hot water-soluble polyvinyl alcohol fibers, if it is impregnated with the aqueous solution of a water-soluble resin and linearly stretched at least 20% at least in the transverse direction, and if below the softening temperature of the fibers is dried.
• the softening temperature of the aforementioned fibers in hot water is approximately in the range between 40 and 90 ° C. The drying must therefore be carried out in such a way that the said temperature interval is not reached.
• the solubility in water can be increased by adding alkali-saponified polyvinyl acetate. This can be mixed with other resins to further increase solubility.
• the hot-water-soluble polyvinyl alcohol fibers are flatly assembled into a mat by known methods, for example using a carding machine or an air layer.
• the thus formed, uncompressed and relatively unstable mat is exposed to the action of liquid or gas jets directed against the surface.
• the fiber mat thus obtained is then sprayed or impregnated with the aqueous solution of a water-soluble resin or the like. It is then stretched by at least 20% at least in the transverse direction, preferably by 40% or more.
• the forces exerted on the fiber mat by the stretching process result in a particularly large elongation of the fibers in the loosened surface areas and thus a strong increase in tensile strength and elongation stability in these areas.
• the other areas in which significantly more fibers are gathered together in a very small space, are characterized by the greater effectiveness of capillary forces a strong accumulation of binding agent, overall seen through a strong material agglomeration, which is stabilized by the drying process and also results in high stretch stability.
• the binder content be at least 60% by weight, preferably at least 70%.
• the fibers contained in the surface areas of a high fiber density are not significantly stretched by the at least transverse stretching of the fiber mat used. They have a large residual elongation and are able to withstand the mechanical stress caused by the needles penetrating during a subsequent needling process without damage and breakage. Even a needling process is therefore not able to significantly alter the nonwovens obtainable by the proposed method with regard to their elongation modulus.
• the binders used in the proposed process are preferably water-soluble resins such as polyvinyl alcohol, polyethylene oxide, hydroxyalkyl cellulose, carboxymethyl cellulose, polyacrylamide, polyvinyl pyrrolidone, polyacrylate, starch and the like.
• Polyvinyl alcohol is considered with regard to the film-forming properties, the dissolution time, the treatability of the solution and preferred because of similar advantages, particularly in relation to the treatment of fiber mats made of polyvinyl alcohol fibers.
• the nonwovens obtainable by the proposed method achieve an elongation of 10% only when loaded with 1 kg / cm or more. They are undesirably stretched or changed in shape and are less suitable as binding materials if a corresponding stretch already occurs at a lower load.
• the resulting mat was transferred to a 30 mesh wire screen and exposed to water jets to intertwine the fibers.
• the water had a pressure of 40 kg / cm 2 . It was directed through nozzles against the surface of the mat, which was 0.3 mm in diameter.
• the self-stable fiber mat thus obtained was then impregnated with a 1.5% strength aqueous solution of water-soluble polyvinyl alcohol resin, stretched 50% in the transverse direction and dried in this form.
• the nonwoven fabric obtained is excellently suitable as a binding material and shows a 10% elongation only when loaded with 1.5 kg / cm. The elongation at break was 15%.
• the needles inserted during the needling process are not significantly deflected laterally, which results in a precise needling pattern while avoiding frequent needle breaks.
• the nonwoven fabric is distinguished by a high modulus of elasticity and can be dissolved in a remarkably short time by activating its adhesive forces, which is advantageous in relation to the lamination of substrates with a laminate needled with the nonwoven fabric.
• the nonwovens obtainable by the proposed method are therefore extremely suitable for such chemical bonding purposes.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Nonwoven Fabrics (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
• Decoration Of Textiles (AREA)
• Automatic Embroidering For Embroidered Or Tufted Products (AREA)

Applications Claiming Priority (2)

Publications (3)

Family

ID=16374881

Family Applications (1)

Country Status (4)

Cited By (5)

Families Citing this family (14)

Citations (1)

Family Cites Families (6)

• 1981
  • 1981-12-07 JP JP56197461A patent/JPS5898464A/ja active Granted
• 1982
  • 1982-12-02 US US06/446,335 patent/US4570311A/en not_active Expired - Fee Related
  • 1982-12-04 DE DE8282111235T patent/DE3262715D1/de not_active Expired
  • 1982-12-04 EP EP82111235A patent/EP0081218B1/fr not_active Expired

Patent Citations (1)

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