Classifications

• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/02—Yarns or threads characterised by the material or by the materials from which they are made
  • D02G3/04—Blended or other yarns or threads containing components made from different materials
• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D15/00—Woven fabrics characterised by the material, structure or properties of the fibres, filaments, yarns, threads or other warp or weft elements used
  • D03D15/50—Woven fabrics characterised by the material, structure or properties of the fibres, filaments, yarns, threads or other warp or weft elements used characterised by the properties of the yarns or threads
  • D03D15/513—Woven fabrics characterised by the material, structure or properties of the fibres, filaments, yarns, threads or other warp or weft elements used characterised by the properties of the yarns or threads heat-resistant or fireproof
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/44—Yarns or threads characterised by the purpose for which they are designed
  • D02G3/443—Heat-resistant, fireproof or flame-retardant yarns or threads
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2331/00—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products
  • D10B2331/02—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products polyamides
  • D10B2331/021—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products polyamides aromatic polyamides, e.g. aramides

Definitions

• This invention relates to methods of producing flame resistant materials which are particularly suitable for withstanding the effects of relatively high temperatures.
• protective clothing for the purposes of protecting people who are inadvertently or otherwise exposed to conditions of extreme heat flux and very high temperature flames.
• a prime function of protective clothing is to protect the user from the effects of extreme heat and flames for as long as possible or, in the case of an emergency, at least as long a * s may be necessary, to be able to escape from the region at which extreme temperatures occur to a location at a lesser and more acceptable temperature level.
• any protective clothing is intended to shield the body of the user for as long as may be necessary for the enabling survival of the person being exposed to the extreme temperatures.
• a protective clothing material may be formed from more than one layer of fabric of which a first layer, the outer layer, has to be able to provide the shielding or screening capability against the heat and flames, whilst a second layer serves to provide a layer of Insulation which retards the penetration of heat through the clothing to the user.
• the heat insulation afforded can be regarded as not only comprising the outer garments ⁇ i.e., those more conventionally regarded as protective clothing) but also the underwear of the user since this too gives a degree of heat insulation.
• the outermost layer of a protective clothing system can be regarded as being the most important part of the protective clothing since it is this layer which has to withstand the major part of the effect of extreme heat conditions, and since this layer as mentioned has to act as the shielding layer not only with respect to the user's body i.e., skin but also as a means of protection for the insulation providing layer or layers of the clothing.
• the fabric used for forming a shielding layer must be able to satisfy or fulfil very special conditions.
• the material must be flame resistant. That is the material has to be able to exhibit a limiting oxygen index (L.O.I.) of at least 26.5 when in fabric form. In other words the material needs to be self ext inqui shing when the ignation source is removed. (This criteria has been considered by L. Bebisek in Textile Chemist & Colorist Vol 6, No 2, 1974 pages 25-29).
• L. Bebisek in Textile Chemist & Colorist Vol 6, No 2, 1974 pages 25-29 it is necessary that when the material is exposed to an intense heat flux the material must remain as an uninterrupted surface for as long as poss lble.
• flame resistant fibres in general will be called FR-FIbres.
• This group of materials will hereinafter be called R-Fibres.
• FR-Fibres when spun into yarns and woven into fabrics have been found to deteriorate substantially or show high thermal shrinkage and 'rapid 'burst open 1 on exposure to flames and intense heat.
• R-FIbres have been found when in fabric form to be able to withstand intense thermal fluxes for a worthwhile time period with far less heat shrinkage and without 'burst-open' or with a delayed 'burst-open' together with retention of their flexibility accompanied by a certain amount of strength for time periods far longer than those afforded by FR-Fibres under the same conditions.
• R-Fibres Some of the reluctance to use R-Fibres has been based, for example, on the adverse properties of poor dyeability and in some instances inherent bright colouring and poor light fastness. Also some mechanical properties like the abrasion resistance are not optimal for fabrics in dai ly wear uses.
• 'In flame condition' 2 during a ten seconds exposure to a heat flux of 8.4J/cm. s (i.e., 2 cal/cm s.) and hereinafter identified as 'In flame condition'.
• the term 'synergistic' is used in the United States Patent in the sense that the strength when in the 'in flame condition' of a fabric formed from the blend is significantly higher than the sum of the strength contributions from the individual components of the fabric when in the 'in flame condition'.
• a method of forming a flame resistant combination of at least two staple fibre components, in a sliver, roving, single or plied yarn or woven or knitted fabric form and characterised by the step of keeping one of the components deliberately, positively or otherwise intentionally segregated with respect to the remaining component or components of the combinat ion.
• a method of forming a flame resistant combination of at least two flame resistant staple fibre components in woven or knitted fabric form and characterised in that one of the components is deliberately, positively or otherwise intentionally segregated with respect to the remaining component or components of the combination in such manner that the 'heat performance' properties, as hereinafter defined, are synergi st ical ly related with respect to the corresponding properties of the individual components.
• the components are assembled in such manner that said combination when in woven fabric form includes in the warp and weft directions of the fabric flame resistant yarns which comprise said one component, said flame resistant yarns being spaced apart by a distance having a maximum value of 20 times the thickness of the fabric.
• a flame resistant fabric including threads incorporating a flame resistant combination of at least two staple fibre components, in single or piled yarn form of which at least some of the thread forming yarns are characterised by having at least one of the components thereof deliberately, positively or otherwise intentionally segregated wi th respect to the remaining component or components of the combination.
• Figure 1 is a very schematic oblique representation of apparatus for carrying out a proposed test for assessing the properties of heat resistant materials particularly those produced by the proposals of the invent ion;
• Figure 2 is a schematic side view of the apparatus of Figure 1;
• Figures 3 and 4 are graphs representing inter-relationships of defined factors of materials of the invention and prior art.
• the radiant heat of a quartz infrared tube 1 of 500 Watts is used.
• the current supplied to this quartz tube can be changed by a transformer (not shown) to
• a test fabric strip 2 of 20 millimetres wide is suspended from a metal strip 3 positioned above the quartz tube 1 by means schematically indicated at and is held out of the region of the tube 1 until the test commences.
• the fabric strip 2 supports at i s lower end 6 by way of an attachment means 7 a reference weight 8 which in the proposals under considera ion weighs 20 grammes.
• the means 7 can be engaged by the means 5 to hold the fabric away from the tube 1.
• the fabric strip 2 wraps around a portion only of the tube. t In practice, it Is required that the chordal length 9 of the wrap, which latter is the length of contact between the fabric and the tube, should be 7 millimetres. This is indicated in Figure 2.
• the 'flame strength' is measured by applying a fixed flame-time of ten seconds and by having the fabric strips support different weights. (Column 3 lines 21-27). It is proposed by using the quartz tube 1 and the fixed weight 8 to measure the time that the fabric has to be subjected to the heat flux before the fabric can no longer support the fixed weight. ( e.g., it will be understood that the time required is effectively a characteristic of the amount of heat flux in Joules) Hence the means (aperture) 5 which shields and holds the fabric strip out of the quartz tube region can be retracted.
• the fabric strip 2 wi 11 swing against the quartz tube and an area of 1.4 square centimetres will be in contact with the quartz tube 1 this being the area related to the above mentioned chordal length 9. As a result the fabric strip 2 will be exposed to a heat flux of 4.5 J/s.
• a timer is arranged to measure the time required for the weight 8, supported by the fabric strip 2 to fall down.
• the amount of heat flux that the fabric can withstand can be calculated as being the 'heat performance' of the fabric.
• This amount of heat flux in Joules can be divided by the total tex (denier) of all of the yarns running in the vertical (test) direction in order to compute the 'heat performance' in millijoules (mj) per decitex (dtex) of the test fabric.
• the proposed Heat Performance Test measures time. The time which is so important while escaping the effects of extreme heat and flame. As every second is important in terms of distance a person can move from the heat and flame location each second and each additional second increases the possibility of survival.
• a fabric formed from the fibre may be subjected to the above mentioned test. If the 'heat performance' per decitex is at least 15mJ the fibre can be considered to be a R-fibre.
• the FR component is meta-aramlde
• the R-fibre component is para-aramide
• polyparaphenyleneterephtalamide fibre made by Du PONT, U.S.A. and sold under the trade name 'KEVLAR'.
• the fibre length is 38 millimetre (1.5 inches) and the fibre fineness Is 1.7 decitex (1.5 dpf). Different amounts of these fibres are mixed in fibre form and spun into single yarns of 49 tex (12 c.c).
• the yarns are woven into plain weave fabrics of approximately 21 x 21 threads per centimetre after removing sizing components and dirt (desizlng).
• the basis weights of these fabrics have ranges of 227-241 grammes/square metre (6,7-7.1 oz/square yard) .
• the synergistic effect as used in the sense of the present invention, can be seen from Table 1 as the relation of the 'heat performance' of the intimate blended fabrics compared with 'the heat performance' of the fabric of 100% R-fibres, i.e., the fabric made out of 100% of the best of the two components.
• the 'heat performance' of all of the fabrics of intimate blended fibres are higher than that of the 100% para-aramide fabric. It can be seen that the synergistic effect increases with a decreasing amount of para-aramide.
• the yarn has been woven in a plain weave to provide a piece of fabric of 21x21 threads per centimetre comparable with the 90/10 fabric of intimate blended yarns mentioned In Table 1.
• the 'heat performance' of the fabric of the I-yarns with a 10% R-fibre shows a synergisitc effect of 38% compared with a 'heat performance' of 17mJ/dtex of 100% R-fibre. If the R-flbres are positively, deliberately or otherwise intentionally segregated in the core of the S-yarn a synergistic effect of 92% is. found which Is about two and one half times more than that of, I-yarn.
• a yarn of 49 tex (12 c.c) yarn count is spun incorporating 63% APYEIL meta-aramide (FR) fibres of UNITIKA, JAPAN; 27% flame retardent viscose non-meltable FR-fibres of LENZING AG, AUSTRIA, and segregated in the core of the yarn 10% KEVLAR para-aramide (R) fibres of Du PONT, U.S.A.
• the yarns are again woven into a plain weave fabric of 21x21 threads per centimetre ( thr/cm) after desizi ⁇ g
• Another method to segregate the R-fibres In the core of a yarn is to pre-spin a v.ery fine spun yarn.of R-fibres only or to use a filament yarn of R-fibres.
• the R-fibre pre-spun or filament yarn can be segregated in the core of the yarn.
• the pre-spinning can be done with any spinning machine capable of spinning very fine yarns.
• the core spinning can be done by known core-spinning techniques, i.e., ring; open-end; friction-spinning machines etc.
• a very fine spun yarn of 100% KEVLAR para-aramide (R-fibres) has been pre-spun into a yarn count of 12 tex (50.c.c.)
• R-fibres KEVLAR para-aramide
• FR APYEIL meta-aramide
• the yarns have been woven again into a 21x21 (thr/cm) fabric of a plain weave, washed and tested.
• a fabric can be made of the above mentioned S-yarn of 24% R-fibres in combination with a yarn of 0% R-fibres and the yarns can be used one after the other. In other words if one out of two yarns in the fabric contains 24% R-fibres the aggregate amount of R-fibres in the fabric is 12%.
• the fabric thicknesses of the fabrics mentioned in Table 3 range between 0.51 and 0.52 millimetres.
• the distance between two S-yarns is 2.38 millimetres.
• the S-yarn spacing distance can be defined as the ratio of 4.6 times the fabric thickness. If this distance is increased the danger of a small piece of fabric, bordered by the S-yarns in the warp and weft direction, breaking open will also increase.
• the distance between two R-fibre containing yarns is limited and is not allowed to exceed 20 times the fabric thickness.
• single yarns can be plied or twinned.
• two or more yarns can be plied, of which at least one yarn (which will be only a very fine yarn compared with the other yarn components with which It is to be plied) comprises R-fibres.
• the above mentioned 100% KEVLAR para-aramide (R-fibre) yarn of yarn count 12 tex (50 c.c.) can be plied with a 100% APYEIL meta-aramide (FR-fibre) of yarn count 37 tex (16 c.c.) resulting in a plied yarn combination of yarn count 49 tex (12 c.c.) in which again the amount of deliberately segregated R-fibres is 24%.
• yarns of FR-fibres can be plied with at least one yarn of a combination of FR and R-fibres in which the R-fibres are deliberately segregated. This is preferred to decreasing the amount of R-fibres and avoids the pre-spinning of very fine yarns of R-fibres.
• the (S) yarn containing 24% R-fibres mentioned above is a yarn containing the R-fibres in (pre-spun) yarn form. As is shown above the 'heat performance' increases depending on a decreasing of the amount of R-fibres. If the pre-spinning system is used the low percentage " of R-fibres can only be -achieved .for rather coarse yarns (thick yarns) because there are limits to the fineness of the pre-spun yarn.
• the segregation of the R-fibres can also be achieved In fibre-form as in the S-yarn Example of Table 2, and thus not in a pre-spun form.
• a 10% segregated R-fibre containing S-yarn has been spun on a DREF friction spinning machine.
• the R-fibres are not pre-spun but Incorporated In the yarn in fibre form.
• the fibre input into the drafting part of the machine has been a sliver of FR-fibres and a roving of R-fibres. In the drafting zone the fibre-input, i.e., the sliver and the roving, will be drafted but will keep their relative placement.
• this sliver/roving pairing system can be used to obtain the segregated R-fibres in the ring spun yarn.
• R-fibres is obtained which, after spinning on the ring spinning frame, will result in a ring spun yarn with segregated R-fibres.
• Example 1 of the United States Patent the Intimate blending was achieved on these machines (column 5 line 30).
• the sliver/roving pairing system is used on the last draw frame no blending or mixing will occur if one R-fibre roving is fed (in the middle of the other slivers fed) into the machine.
• the output of this last drawing frame and the input of the next machine, the roving frame will be a sliver with segregated R-fibres.
• a ring spun yarn is achieved incorporating segregated R-fibres.
• a process for incorporating segregated R-fibres in a yarn of flame resistant fibres by means of a sliver/roving pairing system If the sliver/roving system is used on the last draw frame as mentioned above, the amount of R-fibres can be very small as the feeding of the machine is six or more slivers of FR-fibres and one roving of R-fibres. A percentage of 2 or, if a twistless roving, as explained hereinafter, is used even less than one percent can be achieved.
• the sliver/roving pairing system has to be used on a machine of which the input is a single sliver only, i.e., a roving frame, a DREF friction spinning machine etc., the lower limit of the percentage R-fibre cannot be too low as there are practical limits to the fineness of the roving.
• the twistless 'yarn' spun according to these systems can be used as a roving in the sliver/roving pairing systems if the amount of glue used in these systems is decreased to such an amount that the drafting of the fibre bundle in the drafting zone is not afffected.
• a 49 tex (12 c.c.) single ringspun yarn is made and woven into a plain woven fabric of 21 x 21 yarns per cm.
• the sliver/roving pairing system on the last draw frame is used to obtain yarns containing 1,2, 10 and 33% segregated R-fibres. After desizing the 'heat performance' is measured and the synergistic effect computed.
• modacryl ic fibres show a L.O.I, value greater than 26,5, and thus will not continue to burn when the ignation source is removed, the protective effect as a shielding or screening outer layer in flame protective clothing is rather low as the fabric deteriorates rather rapidly.
• a S-yarn according to the present invention is prepared from 98% modacrylic fibres of 40 millimetres (1.6 inch) fibrelength and 1.7 dtex (1.5dpf) (VELICREN FRS modacryllc fibres of SNIA SA, Italy) and deliberately segregated in the core of the yarn 2% para-aramide
• R-fibres polyparaphenyleneteraphtalamide of 40 millimetre (1.6 inches) fibrelength and 2.2 dtex (2.0 dpf)
• the 2% deliberately segregated R-fibres in combination with a non-organic FR-fibre is too low to achieve a sufficiently improved synergistic effect as compared with the 'heat performance' of 100% R-fibre, even though the improvement of the 'heat performance' from 4.5 mj/dtex to 13.1 mj/dtex shows a synergistic effect as compared with the sum of the 'heat performance' contributions from the individual components (4.6 mj/dtex) .
• the percentage weight of the deliberately, positively or otherwise intentionally segregated R-fibres, if used in combination with non-organic FR-fibres only, should not be lower than 3%.
• Table 7 shows the break open tests of the imtimate blended fabrics mentioned in Table 1.
• COMPOSITION T.P.P. TEST (%FR/%r) (Break-Open) 100/0 3S 95/5 above 10S 90/10 above 10S 80/20 above 10S 67/33 above 10S 0/100 above 10S
• All fabrics comprise 49 x 49 tex yarns (12 x 12 c.c.) and approximately 21 x 21 thr/cm (53x53 thr/inch)

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Woven Fabrics (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)

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• 1985
  • 1985-08-13 GB GB858520318A patent/GB8520318D0/en active Pending
• 1986
  • 1986-08-05 GR GR862067A patent/GR862067B/el unknown
  • 1986-08-06 WO PCT/GB1986/000476 patent/WO1987001140A1/en not_active Ceased
  • 1986-08-06 AU AU61921/86A patent/AU6192186A/en not_active Abandoned
  • 1986-08-06 EP EP86904875A patent/EP0268586A1/en not_active Withdrawn
  • 1986-08-06 JP JP61504260A patent/JPS63500392A/ja active Pending
  • 1986-08-07 ZA ZA865935A patent/ZA865935B/xx unknown
  • 1986-08-12 IL IL79689A patent/IL79689A0/xx unknown
  • 1986-08-12 ES ES8601020A patent/ES2000391A6/es not_active Expired
  • 1986-08-12 DD DD86293598A patent/DD251579A5/de unknown
  • 1986-08-13 PT PT83189A patent/PT83189A/pt not_active Application Discontinuation
  • 1986-09-12 CN CN198686106246A patent/CN86106246A/zh active Pending
• 1987
  • 1987-04-07 DK DK177487A patent/DK177487A/da not_active Application Discontinuation
  • 1987-04-13 KR KR870700319A patent/KR880700117A/ko not_active Withdrawn

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