AU604888B2 - Non-woven material containing wool - Google Patents

Description

7 I i 'Tr-TT-r+-i -i q 12-/ PCT WORLD INTELLECTAL PPERT-ORGANIZATIO1 INTERNATIONAL APPLICATION PUBLISHEMPAJ R TIE P N'W O ATJON TREATY (PCT) (51) International Patent Classification 4 (11) International Publication Number: WO 88/ 08049 D06M 3/08, D04H 1/54, 1/58 Al (43) International Publication Date: 20 October 1988 (20.10.88) (21) International Application Number: PCT/AU88/00100 (81) Designated States: AT, AT (European patent), AU, BB, BE (European patent), BG, BJ (OAPI patent), BR, (22) International Filing Date: 8 April 1988 (08.04.88) CF (OAPI patent), CG (OAPI patent), CH, CH (European patent), CM (OAPI patent), DE, DE (European patent), DK, FI, FR (European patent), GA (31) Priority Application Number: PI 1370 (OAPI patent), GB, GB (European patent), HU, IT (European patent), JP, KP, KR, LK, LU, LU (Euro- (32) Priority Date: 10 April 1987 (10.04.87) pean patent), MC, MG, ML (OAPI patent), MR (OA- PI patent), MW, NL, NL (European patent), NO, (33) Priority Country: AU RO, SD, SE, SE (European patent), SN (OAPI patent), SU, TD (OAPI patent), TG (OAPI patent), US.

(71) Applicant (for all designated States except US): COM- MONWEALTH SCIENTIFIC AND INDUSTRIAL Published RESEARCH ORGANISATION [AU/AU]; Lime- With international search report.

stone Avenue, Campbell, ACT 2601 (AU).

(72) Inventor; and Inventor/Applicant (for US only) NAYLOR, Geoffrey, Robert, Stewart [AU/AU]; 85 Lake Avenue, Ocean Grove, VIC 3226 (AU).ASTRA

AUSTRALIAN

(74) Agents: NOONAN, Gregory, J. et al.; Davies Collis- NOV 1988 on, 1 Little Collins Street, Melbourne, VIC 3000 4 V 1988 PATENT OFFICE This document contains the n n1, nT- ini n12 r lflO iI fl11T I I I!,Vr (54) Title: NON-WOVEN MATERIAL CONTAINING WOOL (57) Abstract Section 49 and is correct for printing.

A method of forming a non-woven material includes blending both synthetic and wool fibres in a web, and stabilising the web by utilising a bonding medium to form dispersed bonds between the fibres. The wool fibres are subjected before formation of the web to a pretreatment effective to modify the epicuticle of the wool so as to substantially increase the surface energy of the wool fibres without destroying their integrity to an extent sufficient for the wool fibres to accept the bonding medium in the web. The dispersed bonds thereby include bonds with wool fibres substantially effective to hold the wool fibres of the material in the web.

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i WO 88/08049~ P CT!A 88/00100

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"NON-WOVEN MATERIAL CONTAINING WOOL" This invention relates to non-woven material containing wool, especially insulating material for clothing and bedding products, and in a particular aspect provides an insulating material formed predominantly from wool fibres.

Down is presently recognized as the superior lightweight filling for clothing and bedding products due to its excellent loftiness. High quality down has a volume fraction of 0.003, that is it contains only 0.3% fibre and 99.7% air by volume. This large volume of trapped, still air is vital to the excellent insulating properties of down and its high warmth to weight ratio. A second important characteristic of down is its high resilience, that is its ability to maintain excellent loft after repeated compressions and indeed through years of use..

A currently used synthetic substitute for 7 r~r WO 88/08049 PCT/AU88/00100 2 down is a lightweight non-woven open web of polyester fibres. The web may be a conventional card web in which the fibres are partially aligned parallel"to the web direction, or a random web in which there is no preferred orientation of the fibres. The resilience of the random web is considered to be superior to that of the partially aligned web. The open web structure is normally stabilized by some form of bonding. This bonding can be achieved by a variety of methods including chemical bonding methods and thermal bonding. A common form of chemical bonding is the use of either a spray adhesive (spray bonding) or bath immersion of the product in a solution of adhesive. Thermal bonding is a technique that appears to have a promising future and the non-woven industry has shown a trend towards this method. In thermal bonding, effective dispersed bonds are achieved by initially forming the web to N include a portion of thermoplastic fibres of lower melting point than the majority of the polyester fibres. On heating the blend, the low melting point fibres melt to form droplets which on cooling bond and stabilise the structure. In a variation, the bonding is achieved using conjugate thermoplastic fibres, for example bicomponent fibres each in two parts, core and sheath, made from two different polymers of differing melting points. On heating, only one component melts and so the binder fibre maintains its integrity as a fibre rather than forming a droplet.

It is known that the properties of synthetic fibres may be enhanced in certain respects, by blending in a selected proportion of a staple natural fibre, such as wool. In particular, wool provides WO 88/08049 PCT/AU88/00100 3 good moisture absorption capacity and therefore enhanced comfort for the user. A blended synthetic and wool insulating batt has been proposed in a paper by Hoffmeyer and Watt in WRONZ Report R128, January 1986, published by the Wool Research Organization of New Zealand (WRONZ). Various different lofty batts were formed as non-woven webs stablised by thermal bonding using a blend with mono or bicomponent bondable fibres and wool. Hoffmeyer and Watt reported that none of the fibres assessed gave a measurable bond to wool fibres, even when the latter had been pretreated by either scouring, solvent extraction, chlorination with 2.8% Basolan DC or chlorine-Hercosett treated with 2.8% Basolan DC followed by 2.8% Hercosett 57. Some of the webs at least mechanically trapped the wool fibres. The products were, however, observed to be poorly stabilised insofar as the wool fibres were concerned and to exhibit poor resilience and generally inferior properties relative to down.

A non-woven fabric comprised of thermoplastic fibres and wool fibres is disclosed in Australian patent 459539, wherein the wool fibres are said not to be interbonded to each other at their crossing points and only lightly bonded if at all at the points at which they cross the thermoplastic fibres, being held in the structure by mechanical constraint.

It is an object of the present invention to provide a non-woven material formed from synthetic and wool fibres, which is capable of substantially improving on the polyester/wool product of the Hoffmeyer and Watt paper and the product of patent 459539, and also to provide a viable alternative to jr -4down. The inventors have unexpectedly found that it is possible to bond the wool fibres into the web structure.

The invention accordingly provides a method of forming a non-woven material comprising blending both synthetic and wool fibres in a web, and stabilising the web by utilising a bonding medium to form dispersed bonds between the fibres, wherein the wool fibres have been subjected before formation of the web to a pretreatment effective to modify the epicuticle of the wool so as to substantially increase the surface energy of the wool fibres without destroying their integrity to an extent sufficient for the wool fibres to accept the bonding medium in the web, whereby said dispersed bonds include bonds with wool fibres substantially effective to hold the wool fibres of the material in the web.

,The invention still further provides a non-woven material comprising a web of both synthetic and wool fibres stabilised by dispersed bonds between the fibres provided by a bonding medium, wherein said wool fibres S. 20 have been subjected to a pretreatment effective to' modify the epicuticle of the wool whereby said dispersed bonds include bonds with wool fibres of the web substantially effective to hold the wool fibres of the material in i o. oi o oo; l,phhspe.008,15912-8.spe,4 WO 88/08049 PCT/AU88/00100 the web.

The pretreatment for the wool fibres is advantageously a treatment which proceeds at such rate that it is effective at the surface but preferably has substantially not penetrated the interior of the wool fibres. The wool fibres may preferably be sprayed with fluid for effecting said pretreatment, but also may be immersed in a bath of the treatment fluid. The resultant modification of the epicuticle of the wool may be by way of etching or removal, or other modification.

It has been surprisingly found that convenient treatments to achieve the required bonding susceptibility include adaptations of treatments previously employed to shrinkproof wool fibres. In general, the treatments required for the purposes of the present invention are more severe than those used for the purposes of shrinkproofing but, contrary to expectations, do achieve a sufficiently higher Isurface energy without destroying the integrity of the fibres.

The pretreatment therefore preferably comprises a degradative chemical treatment in which the critical parameter is set so that the modification of the epicuticle of the wool is greater than required to shrinkproof the wool fibres.

Alternatively, a physical pretreatment such as a plasma treatment or mechanical abrasion may be employed. The degradative chemical treatment may be an acid etching or permanganate treatment but most preferably comprises acid chlorination of the fibres, Acid chlorination can be done with either sodium hypochlorite in hydrochloric acid solution, or a solution of chlorine gas or other reagents designed

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i SWO 88/08049 PCT/AU88/00100 to liberate chlorine in solution, e.g.

dichloroisocyanuric acid and its salts (DCCA). The preferred level of treatment is exhaustion of at least 3% of chlorine on the weight of wool and most preferred is a 4-8% treatment. The preferred pH is lower than 5.5 and most preferred is the range 2.0 to This treatment is then followed by neutralization e.g. with bisulphite or sulphite, and rinsing of the wool. The wool may be dyed before or after chlorination if required. These treatments may be suitably carried out using the commercially available KROY machinery, available from Kroy Corporation of Canada, that is normally used as a shrinkproofing process.

The bonding medium conveniently comprises low melting point thermoplastic fibres or conjugate e.g. bicomponent, thermoplastic fibres initially included with or comprising the synthetic fibres during formation of the web. The web is preferably a random web, for example in the form of a batt of the material, or may be compressed to form a thin paper-like structure. The invention is especially useful, however, in the formation of an open lofty web.

An appropriate synthetic fibre, also providing the bonding medium, comprises polyester based conjugate fibre. It is advantageous to use a synthetic fibre of similar diameter to that of the wool fibres. A suitable such conjugate fibre is the Melty 4080 bicomponent fibre manufactured by Unitika of Japan. Other conjugate fibres which may be employed are the polyolefin based fibres produced by the Chisso Corporation of Japan and the Daiwabo Corporation (Japan). Some other suitable synthetic WO 88/08049 PCT/AU88/00100 7 binder fibres include copolyester binder fibres, for example from Eastman Chemical Company, Mini Fibers Inc., or EMS Grilon SA, and vinyl acetate/vinyl chloride copolymer fibres from Wacker-Chemie GmbH.

Conjugate nylon fibres although possible are less satisfactory due to their higher softening/melting point range.

Where the synthetic fibre is a polyester based conjugate thermoplastic fibre the non-woven material formed preferably contains at least 20% by weight of synthetic fibre. After formation of the unbonded web the structure is advantageously heated under suitable conditions of temperature and time, appropriate to the specific fibres in use, to melt the lower melting point thermoplastic component of the blend of fibres. This melted component then flows over and is accepted by adjacent fibres. On cooling, a network of bonds is formed, thereby stabilizing the structure. The pretreatment of the wool ensures that satisfactory bonds are formed between the wool and the synthetic fibres and not just between the synthetic fibres themselves. This is vital particularly in low density applications where the total number of crossover points between fibres, that is potential bonding sites, is very small.

The pretreated wool fibres and the synthetic fibres are preferably blended together to give an intimate blend. This process is well known and, for example, can be the output of a carding machine or an airlaid carding machine. Other blending mechanisms may be equally adequate providing uniform blending is achieved. This blend of fibres is in the form of a batt of fibres which can, if necessary, be compressed

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WO 88/08049 PCT/AU88/00100 to produce products of higher densities.

There are many possible end uses of this invention. Some applications include continental quilts and quilted products, pillows, mattresses, cushions, clothing, inner soles for shoes, insulation materials, and as a substitute for polyurethane foam.

Example Various insulating materials in accordance with the invention were formed by blending conjugate thermoplastic polyester fibres, specifically Melty 4080 bicomponent fibres, with wool fibres of diameter um. These had been pre-treated by acid chlorination, as described above, entailing exhaustion of 6% of chlorine on the weight of the wool from a solution having a pH in the range 2.0 to The synthetic to wool blend ratio was 20% to by weight. The fibres were blended together as described above to produce a low density web.

After formation of the open lofty web the structure was heated for 10 mins in an oven preheated to 150 0 C, to melt the lower melting point component of the bicomponent fibres. The melted polyester flowed over and was accepted by the wool fibres. On cooling of the structure, observation of the batt under the microscope revealed dispersed localized bonds formed not only between the synthetic fibres but also between the synthetic and wool fibres.

These experimental non-woven materials were formed as batts which were found to have highly satisfactory properties. They had a packing fraction of 0.003, i.e. similar to down, and in a test of resilience where each batt was compressed cyclically a large number of times, loss of thickness of the WO 88/08049 PCT/AU88/00100 batt was much less than that noticed with batts formed in accordance with the aforementioned WRONZ disclosure. In the latter, the wool fibres, not being bound into the web structure, do not help prevent the collapse of the structure. The resilience of the batts formed according to the invention was found to be similar to that of polyester batts of the prior art. Sample quilts were also formed from the experimental batts of non-woven material and their thermal properties measured. The warmth to weight ratio was found in each case to at least equal those of similar quilts formed from down. Down is of course relatively more expensive than wool.

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Claims (12)

1. 2. A method according to claim 1 wherein said f pretreatment comprises a degradative chemical treatment in which the critical parameter is set so that the modification of the epicuticle of the wool i is greater than required to shrinkproof the wool fibres.
2. 3. A method according to claim 1 or 2 wherein the pretreatment is a treatment which proceeds at such a rate that it is effective at the surface of the wool fibres but has substantially not penetrated the interior of the fibres.
3. 4. A method according to any preceding claim wherein said pretreatment comprises acid etching or permanganate treatment of the wool fibres. r, WO 88/08049 PCT/AU88/00100 12 A method according to any preceding claim wherein said pretreatment comprises acid chlorination of the wool fibres.
4. 6. A method according to claim 5 wherein said acid chlorination comprises exhaustion of at least about 3% of chlorine, on the weight of wool, from a solution having, a pH lower than about 5.5, followed by neutralization and rinsing of the wool fibres. ii
5. 7. A method according to claim 6 wherein said acid chlorination comprises exhaustion of chlorine, in the range 4 to 8% on the weight of wool, from a solution having a pH in the range 2.0 to
6. 8. A method according to any preceding claim wherein the web is an open lofty web. S91 A method according to any preceding claim wherein the bonding medium comprises low melting point thermoplastic fibres or conjugate thermoplastic fibres initially included with or comprising said synthetic fibres during blending of the web. A method according to claim 8 and 9 wherein the bonding medium and said synthetic fibres comprises conjugate thermoplastic fibres, and the non-woven material comprises at least 20% by weight of such conjugate themoplastic fibres. -12-
7. 11. A non-woven material formed by a method according to any one of claims 1 to
8. 12. A non-woven material according to claim 11 comprising an open lofty web of both synthetic and wool fibres.
9. 13. A non-woven material comprising a web of both synthetic and wool fibres stabilised by dispersed bonds between the fibres provided by a bonding medium, wherein said wool fibres have been subjected to a pretreatment effective to modify the epicuticle of the wool whereby said dispersed bonds include bonds with wool fibres of the web substantially effective to hold the wool fibres of the material in the web.
10. 14. A non-woven material according to claim 13 wherein S* said web is an open lofty web. i
11. 15. A method of forming a non-woven material according to claim 1 and substantially as hereinbefore described with reference to the Example.
12. 16. A non-woven material according to claim 13 and substantially as hereinbefore described with reference to the Example. I e 0 Dated this llth day of September, 1990 COMMONWEALTH SCIENTIFIC AND INDUSTRIAL RESEARCH ORGANISATION By its Patent Attorneys DAVIES COLLISON 913,phhspe.008,15912-88.spe,12 _T 0 C I INTERHATIONAL SEARCH REPORT NPCT/AU88/oc010o ft j~1 H' .2' 1. CLASSIFICATION OF SU UitCT MATTRA 'ort.sI' lsi5CIlNOn UnmO01 Ollu. I'll5 ,1 Accetl~i~t itlltnitgni I P las iaecation O(IC) OftoIi Galn NatoealClaseicatior and PC nt.C~l. 00GOM 3/08, D04H 1/54, 1/58 1I 11.0 ILO 1SARCH10 MI~M lumOoCUmcn~tittGASearched-' CIA a lcallon 5 1SVI imClassricallon Symooll IPC ~D04H 1/54, 1/58, D06M 3/02, 3/08, 3/10 .l10/-0, 11/00, 11/02 IPCand Keyword: wool us 428/296 0ouroitlhiiionSared other thian Mnmum OccumeIntaliOn to the Etoent thi! suchl Documents are included in the Fields SlitChed AU IPC as above Ill. DOCUMINTS COMNSIDERED 10TO 131 RELEVATO Category I Citation ofDoacumret' i, 1 llIrdil ti*er*s aooraorsts, ofIntsrelevant 0965298 It I Rleverit to ClA- No. X AU,A,32605/71 (BAYER AKTIENGESELL SCHAFT) (20-21) 22 February 1973 (22.02.7.3).See Example 3. US.A,2,500,282 (FRANCIS) 14 M'arch 1950 (14.03-50) See claim US,A, 3,837,995 (FLODEN) 2,1 September 1974 (20) (24.09.74). See Column 3 lines 54-60 and claim 7. US,A,2,277,049 (REED) 24 March 1942' (20) (24.03.42). See Column 4 lines 2-10 XAU,B,32505/78 (511,888) (AUSTRALIAN ATOMIC (11) ENERGY COMMISSION) 26 July 1979 (26.07.79) See page 6 lines 9-20. XAU,B,34815/78 (514, 542) (UNITED STATES (1 DEPARTMENT OF COMMERCE) 11 October 1979 (11.10.79). See page 6 lines 8-10 (continued *Soocial categories of cited documnts;:11 T- later docunmnt ualli~sd .afterltheinlofnitiomil ASlm; '&to "A d~umnt elnn; he eneal til oltheOil.il~h s nt oor rrr dails &Md not In conlit. 0.icalori Out ocu-em deMg te grioal tat 01In*AM Mic -0A~tcited to unaorit&in s tleorincilsot ater y uitinoolin; l~ c GIMS41d 1 Do to s Ii iCilar l(l*.giCI mnomnlioM E.earlier document but iuOlento on of &hot finstsrnattonal -X-docun'enI it est2ICular rolecinCse: thre Cllamod nio r, ilng adaltocannot be COni1dorad Moral at cannot 0s Condost,4 to doculment 1Crr, y mstone doubltsOhOn Ot, yclsitn(il Of 1neile ain ieintg. also .n.chn .6Cited 1 toSliolin~s col-cail ial- of another -y-documfenlt iOfi'tiCular releance: thesClarned tverihion C tattaft atOtther soeciai rlagon lt o 0ciriedl cannotltie considered 1toennl.* in Inventive alscon"Mom tne -0'doCu 'en@t referring IQ in oVat diSilOcijr. Y69se. billon or doCuffent t iiCOrnOn-Ae 111One ot More Otmer SUChSOoC-i. other egns rint:. Such cominsson big Oloaito a otson ilic "Is document Oubish 0 d olior to the interniatonal filing daitoout AIn M.5li ltler %eth IsWIIy dails Chimed &0documinmt member at the aim. olant hemilly IV. CERTIFICATION Diat fIhe Acual Comnoation at inc.nltiSlonil crih Ilita LWtling of thils International Seitcm RVOOit July 1988 (25.07.88) O.Sq. ItrainlS11ii~ina AlWlhOWTll .gneluft Of Aulhitsild Ofticer Australian Patent Office R.E. GRANT Form FCTIISAII10 1 iCand eeel o n.1 1 IW)Oi i I I U 'I II I Intiernational Aotilication No, PCT/AU88/OO100 Ill. DOCUMENTS CONSIDERED TO BE RELEVANT (CONTINUED FROM THE SECOND SHEET) Cateor~y Citaton of Document, with indication, whwe appropriate, of the relevant passages Relevant to Claim No Xi AU,A,14046/70 (COMMONWEALTH SCIENTIFIC AND INDUSTRIAL RESEARCH ORGANISATION) 21 October 1971 (21.10.71). See claim AU,B.79780/75 (487825) (SOUTH AFRICAN WOOL BOARD) 7 October 1976 (07.10.76) US,A,2900291 (O'CONNELL) 18 August 1959 (18.08.59). See Column 5 lines 30-37. US,A,4 483 897 (FUJIMARA) 20 November 1984 (20.11.84) iJS,A,3 010 858 (SEX SMITH) 28 November 1961 '28.11.61) GB,A, 1 307 500 (MONSANTO COMPANY) 21 February 1973 (21.02.73) (11,15-16) (11,15) (11,20) A I f 4, II I I' Form PCT ISA 210 (extra shoot) (January ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTERNATIONAL APPLICATION NO. PCT/AU 88/00100 This Annex lists the known publication level patent family members relating to the patent documents cited in the above-mentioned international search report. The Australian Patent Office is in no way liable for these particulars which are merely given for the purpose of information. Patent Document Cited in Search Patent Family Members Report AU 32605/71 AT 317150 BE 773087 DE 2047014 ES 395404 FR 2107955 GB 1339489 IT 943619 NL 7112972 US 3801428 AU 32505/78 DE 2804983 FR 2379642 GB 1593123 JP 53126400 US 4277242 AU 34815/78 DE 2814179 FR 2386580 GB 1577009 JP 53134999 US 4210415 AU 79780/75 BE 827717 DE 2515434 ES 436443 FR 2267413 GB 1488722 IT 1032631 NL 7504161 US 3994681 ZA 7402248 GB 1307500 CA 958632 DE 2132024 GB 1307500 NL 7108787 US 3676244 END OF ANNEX R r; :f a 4~ 23@/149/5