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
  • D04H1/492—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 by fluid jet
• • 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
• • 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
• • 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
  • D04H1/70—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres
  • D04H1/72—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being randomly arranged
  • D04H1/732—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being randomly arranged by fluid current, e.g. air-lay
• • 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
  • D04H18/00—Needling machines
  • D04H18/04—Needling machines with water jets

Definitions

• This invention relates to a method presented in the introductory part of the accompanying claim 1 for making a nonwoven.
• the invention also relates to a nonwoven presented in the introductory part of the accompanying claim 9.
• a product is formed from raw materials on a moving support with the help of an air stream.
• the raw material is mixed with bonding fibres which help keep the formed nonwoven from falling to pieces.
• Heating directed to the fibrous web moving on top of the support brings the bonding fibres to a state where they bind the fibres to each other.
• An alternative method is to use liquid bonding agents sprayed on the web and activated by heating.
• An alternative for the use of a specific bonding fibre or other bonding agent is mechanical bonding.
• One advanced technique is spunlacing, i.e. hydroentangling carried out with fine liquid jets.
• the jets are directed to a fibrous layer moving at a certain speed on a support.
• the jets take the fibres along with them and make them entangled, and since the support is one with holes, for example a wire, the liquid of the jets is allowed to flow through the support to the other side.
• This is advantageous in that no specific heat-activated bonding fibres are needed as long as the fibres used as raw material are long enough. Bonding fibres and other bonding agents with reasonable prices are conventionally ones which do not decompose naturally which is an obvious defect considering the handling of the products made from nonwovens as waste.
• the European application publication 491383 introduces a wet laying method in which polyester fibres (PET) are formed into a sheet on a so-called wet former and, with the help of a bonding fibre mixed with the fibres, thermal bonding is carried out prior to the spunlacing.
• PET polyester fibres
• thermal bonding is carried out prior to the spunlacing.
• a pre-web is formed where the fibres are bonded by thermal bonding after which several pre-webs are arranged on top of each other and this combination is spunlaced.
• a previously known fibrous material which can be used as the basic raw material for making nonwovens is a fibre produced with a so-called solvent-spinning method.
• the fibre in question is a cellulosic fibre which is produced by dissolving cellulose into a specific solvent without preparing a derivative of it, after which a spinning into a water-based precipitation bath is carried out.
• the solvent used is an amine oxide solution which is spun into water or water solution to form the fibres.
• This technique is described particularly in the English application publication 2001320 and in the international publication W095/35399, the latter including statement about the fibrillation tendency of the fibres produced. This tendency makes these fibres particularly suitable for use in connection to spunlacing.
• the fibres also exhibit good absorption properties, making them attractive also as material for absorbent products.
• the fibres are also known as "Lyocell fibres".
• cellulose-based raw material to as great extent as possible is beneficial in that the product can be made perfectly biodegradable when it does not contain conventional bonding fibres or agents.
• problems may arise despite the spunlacing in the coherence, i.e. the strength of the product.
• the purpose of the invention is to remove the aforesaid defects and to present a method for making a product with good strength without using separate bonding agents.
• the purpose of the invention is also to present a product with the aforesaid good properties.
• the method according to the invention is primarily characterized in what is presented in the characteristic part of the accompanying claim 1.
• the product according to the invention is characterized in what is presented in the characteristic part of the accompanying claim 9.
• the fibrous web is formed by dry laying from cellulosic fibres manufactured with the sol vent- spinning method through an amine oxide solution, and furthermore before spunlacing the fibrous web is prebonded by raising the temperature of the fibrous web and by bringing it to contact with a surface causing mechanical shaping.
• This way excess flushing of fibres during the spunlacing can be prevented since the fibres are lightly prebonded to each other.
• other cellulosic fibres can also be used in the fibre blend. Prebonding can be carried out with heated calenders placed before the point of spunlacing in the machine direction.
• a product characterized in that the aforesaid prebonding prior to the spunlacing has been carried out is superior in its strength values and acquisition to a product produced with conventional methods.
• the product can be used for manufacturing various absorbent products, it is applicable for different types of disposable wipes, such as wet wipes, or for the surface layers of thicker absorbent disposables, such as baby diapers, ferninine pads, incontinence products and so on. Because the parts of the product are both prebonded and spunlaced, no particles come easily off which would be particularly harmful with hygiene and hospital products.
• a web w is formed from the fibres used as raw material on a continuous support 1 which is permeable to air.
• a suction box into which the air is lead is placed on the opposite side of the support 1 from the point of view of the air stream delivering the fibres.
• the web w is lead forward to the moisturizing point where it is moisturized with a water jet device 2.
• the amount of water sprayed by the device is adjusted so that the web is evenly moisturized but its water content is not noticeably increased.
• the moisturized surface i.e. the upper surface of the web is calendered with a hot roll 3 against which an unheated roll 4 on the other side of the support 1 presses the web.
• the web After the web has passed through the calender formed by rolls 3 and 4, it is transferred to another support 5 supporting it from the upper side. After this the unmoisturized lower surface is moisturized with a water jet device 6 which is similar to the device 2 in the first moisturizing point. Then the support 5 and the web w are lead through a calender formed by rolls 7 and 8 of which the lower roll 7 which is in contact with the lower surface of the web w is a heated roll. After this the web w is transferred to yet another new support 9 supporting it from beneath.
• the web w is transferred to a spunlacing station 10 where the web w is spunlaced according to the known method by directing the water jets from above so that the combined effect of heat and moisture make the prebonded fibres totally tangled with each other.
• the fine water jets are fed with a suitable nozzle device from above through the web w, and the water that passes through the support 9 is collected in the other side.
• the support 9 together with the web w are lead through a dryer 11 after which the finished web, i.e. the nonwoven can be removed from the support 9, for example, by reeling it to a roll 12.
• the manufacture of a fibrous web is hence carried out in the same line where after the forming point the web w is constantly lead forward through various stages so that in the end a continuous product ready to be reeled or otherwise collected is provided.
• the supports 1, 5 and 9 can be known forming supports permeable to water and air, such as wires equipped with the suitable mesh.
• Optimum values are for the temperature approx. 100° C, for the rule pressure approx. 21 kg/cm and for the moisture approx. 10 %.
• the aforesaid values are given to the web run rate of 5 rn/min. As the run rate increases, the calender temperature can be increased, for example.
• the temperature of the moisturizing water can also be utilized so that if hot water or vapour is used, the surface following the moisturizing point does not necessarily have to be hot, the required heat being provided through the moisturizing water, and the shaping is carried out with an unheated surface.
• the rolls 3, 4 and 7, 8 of the calenders in the drawing can all be unheated.
• fibres made with the solvent spinning method Such fibres are made by diluting cellulosic fibres, usually some wood fibre, into an amine oxide solution, usually some water soluble N-oxide of tertiary amine.
• a substance generally used for this purpose is the water solution of the N-oxide of N-methylmorpholine.
• Other equivalent substances include N-oxide of N,N-dimethylcyclohexoic amine, N-oxide of N,N- dimethyletanol amine and N-oxide of N,N-dimethylbenzoic amine.
• the method for making the fibres as well as their tendency to fibrillate is described in the international publication WO 95/35399.
• the fibrillation tendency can be defined by measuring the freeness according to the Canadian standard, C.S.F, from the fibre suspension.
• the fibrillation tendency is good if the fibres (6 g 5 mm long fibres in 2 l. of water) achieve a certain C.S.F value after a specific amount of rounds in a laboratory spreader according to the T- 205 om-88 of the TAPPI standard.
• the fibrillation tendency is good if the C.S.F value measured according to the T-227 om-94 of the TAPPI standard is 400 ml or less after a maximum of 270 000 spreader rounds.
• the aforesaid fibres can form a majority of the basis weight of a finished nonwoven, the nonwoven can, for example, be made completely from these fibres. However, mixtures of fibres can also be used, in which case all the fibres are brought well-mixed along an air stream to the forming point.
• Mixture fibres are preferably natural fibres and/or cellulosic converted fibres, such as viscose fibre, that is generally fibres with polymer structures derived from nature which are biodegradable.
• Suitable natural fibres include, for example, wood fibres, such as mechanical or chemical pulp with relatively long fibres generally used in paper making.
• Viscose fibre is a cut fibre made from regenerated cellulose.
• the proportion of fibres made with the solvent spinning method can be very small, for example in the range 2 - 50 %, in which case their significance is in their good entangling and bonding abilities during hydroentangling, that is, they act in a way as bonding fibres.
• the line can be provided with types of conveyance of the web w different from the one shown in the drawing.
• the web w can be treated only on one side with the prebonding method described, even though to accomplish an even effect it is preferable to treat both sides of the web before spunlacing.
• the basis weight of the fibrous web w and the finished nonwoven may naturally vary within the known limits and depending on the intended use of the nonwoven, usually within 30 - 300 g/m 2 .

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Nonwoven Fabrics (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8546513

Family Applications (1)

Country Status (5)

Cited By (5)

Families Citing this family (1)

Citations (5)

• 1996
  • 1996-08-21 FI FI963259A patent/FI112803B/fi not_active IP Right Cessation
• 1997
  • 1997-08-13 EP EP97935586A patent/EP0920549B1/de not_active Expired - Lifetime
  • 1997-08-13 DE DE69719997T patent/DE69719997T2/de not_active Expired - Lifetime
  • 1997-08-13 ES ES97935586T patent/ES2195161T3/es not_active Expired - Lifetime
  • 1997-08-13 WO PCT/FI1997/000475 patent/WO1998007914A1/en active IP Right Grant

Patent Citations (5)

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