EP2898128A2

EP2898128A2 - Yarn having flame-retardant effect and textile fabric formed therefrom

Info

Publication number: EP2898128A2
Application number: EP13766897.6A
Authority: EP
Inventors: Albrecht LABSCH; Martin GEBERT-GERM; Bernhard Müller; Axel Russler
Original assignee: Glanzstoff Bohemia sro
Current assignee: Glanzstoff Bohemia sro
Priority date: 2012-09-24
Filing date: 2013-09-20
Publication date: 2015-07-29
Also published as: US20150252500A1; WO2014044401A3; DE102012018814A1; WO2014044401A2

Abstract

The invention relates to a yarn having regenerated cellulose fibers produced by a spinning process, in particular a wet-spinning process and in particular consisting thereof, and having flame-retardant characteristics brought about by a flame retardant means spun into at least one portion of the regenerated cellulose fibers, wherein the yarn as seen across the cross-section thereof has an inhomogeneous distribution of the flame retardant mean and has a weight displaced towards the outside in relation to the yarn center.

Description

ZIMMERMANN

PATENT OFFICES EUROPEAN PATENT ATTORNEYS EUROPEAN TRADEMARK ATTORNEYS EUROPEAN DESIGN ATTORNEYS

Dipl.-Ing. H. Leinweber (1930-1976)

Dipl.-Ing. H. Zimmermann (1962-2002) Dipl.-Phys. Dr. Jürgen Kraus

Dipl.-Ing. Thomas Busch

Dipl.-Phys. Dr. Klaus Seransky

Dipl.-Phys. Dr. Patrick Werner

Rosental 7

D-80331 Munich

TEL. + 49-89-23 11 24-0

FAX + 49-89-23 11 24-11

the

vemvmk

Our sign

Glanzstoff Bohemia s.r.o.

Terezinskä 60,

CZ-41017 Lovosice

Yarn with flame retardancy and textile fabrics formed therefrom

The invention relates to a yarn which has and in particular consists of a spinning process, in particular wet-spinning of viscose eellulosic regenerated fibers, and which has a flame retardant co-spun at least in part of its cellulosic regenerated fibers flame retardant properties as well as textile structures made of such yarns, in particular textile fabrics.

Such yarns have been known in the art for about 30 years. They are suitable for use in protective fabrics (PPE (Personal Protection Equipment) area) for a number of reasons. This is on the one hand in a higher wearing comfort of the cellulosic fibers over synthetic fibers, which can be seen in particular in a higher moisture absorption. Furthermore, as a non-thermoplastic material, cellulose does not tend to deform, melt or increase in adhesion, even at elevated temperatures. Due to the flame retardant properties, such yarns, with a sufficiently high proportion of flame retardant, also achieve sufficient resistance to the effects of fire, and in particular also passed the firing test in accordance with EN ISO 15025. If these flame retardancy properties are achieved by a co-spun flame retardant, this remains permanent and such regenerated cellulosic fibers are also referred to below as permanently flame retardant. The term "flame-retardant" in flame-retardant properties generally includes resistance to flame exposure in the first place, and more particularly includes resistance to flame exposure in that combustion is not promoted after removal of the applied flame, which corresponds to an LOI of about 25 or higher.

In many cases, the commercially used regenerated fibers are currently staple fibers sold under the trade name ^Lenzing® FR. Other fibers of wool and / or high-temperature resistant synthetic fibers in the form of intimate mixtures can also be combined with these staple fibers, for example in order to reduce the costs of high-temperature-resistant synthetic fiber yarns alone.

Despite having achieved with the yarns of the type described advantages of flame resistance has been found that, especially in the fire department still no satisfactory wearing properties are achieved, especially when the firefighters are exposed to very high temperatures over several minutes.

Because of these problems, the invention has for its object to provide a yarn from which textile fabrics can be produced, in particular in the field of protective clothing, whose usefulness is improved under high loads.

This object is achieved by providing the yarn of the aforementioned type, which is characterized essentially in that it has a nonhomogeneous over its cross-section distribution of the spun flame retardant with respect to the yarn center outwardly shifted weight.

The invention is based on the finding that the above-described not completely satisfactory usability is due to an insufficient dimensional stability of the textile fabric under prolonged exposure to heat. Due to the inhomogeneous distribution of the spun-on flame retardant a garnmittennaher area is created with relatively lower or vanishing flame retardant, which improves the dimensional stability of the total yarn. In that regard, it is surprising that a higher quality of textile fabrics against extreme heat effects is not achieved by an increased flame retardant addition, but by a reduction in flame retardants based on the total weight of the textile fabrics. In the case of the preferred phosphorus-containing flame retardants, there are economic as well as ecological advantages.

In this way, it is possible that a fabric made only from such a yarn under ten-minute heat exposure of 260 ° C a maximum dimensional change subject to less than 10%. For example, the criteria set out in NFPA 1971 may be used as a test criterion.

The inventively achieved high dimensional stability, in other words, this specific resistance to hot air shrinkage has quite considerable practical effects. Imagine what would happen if, for example, gloves shrink so much under thermal impact that they can not be taken off after use, or a jacket shrinks in the course of a fire so that breathing becomes difficult or even impossible.

The co-spun flame retardant could be added in the form of a particulate solid to the dope as a dispersion. Preferably, a phosphorus-containing flame retardant is used, in particular 2,2'-oxybis [5,5-dimethyl-1, 3,2-dioxaphosphorinane] 2,2 'disulphide, also known under the trade name Exolit or Sandoflam. In this case, a phosphorus content based on the cellulose in the range of 2.5% or higher, preferably 2.8% or higher, more preferably 3.2% or higher, or even higher than 3.5% is desired.

Preferably, the yarn has a core-shell structure, wherein the shell has a higher flame retardant content than the core. In particular, in the case of a flameproof core, a ratio core: shell of 4: 5 or smaller, preferably 3: 4 or smaller, in particular 2: 3 or smaller could be provided. Thus, the jacket itself could have a homogeneous flame retardant distribution, as well as the core. In the case of a flameproof core, the stated proportions are favorable in order to achieve sufficient resistance to burning (for example according to burning tests from EN ISO 11612 and EN ISO 469 with respect to EN ISO 15025), in particular if a textile fabric to be produced from the yarn is no further component having. If, in addition, blending-inhibiting fiber types are used as blending partners for the production of such a fabric, which in themselves fulfill high requirements for thermal resistance tests (for example according to ISO 17493), the specified ratio could also be 1: 1 or greater.

In a practical embodiment of the invention, the yarn is a hybrid yarn. In this case, the core of the hybrid yarn should furthermore preferably have or consist of a cellulosic multifilament. The soul can be free of flame retardants with an LOI of 17. It is particularly preferred that the cellulosic multifilament used for the soul is spun according to the modal method known per se, that is the modified classical viscose method with which increased strength properties can be achieved. In particular, it is preferred if this cellulosic multifilament, when manufactured, has parameter values for the quotient of the percent measured draft and the final take-off speed defined in meters per minute Process parameter is less than 2.5 or less than 2.0, preferably less than 1, 67, or less than 1, 5, in particular less than 1, 3 or even 1, 25, but preferably greater than 0.75 and in particular preferably greater than 1.0. Furthermore, it is preferred that the product of these two quantities is on the one hand preferably greater than 3,200, in particular greater than 3,600 or in particular even 4,000, on the other hand preferably less than 8,000, in particular less than 7,500 or even 7,000, corresponding to the parameter values of the claims 14 to 17 of the not yet published application PCT / EP2012 / 002069 of the same applicant.

In principle, the sheath of the hybrid yarn could be formed by a simple ply and twist of another regenerated cellulosic fiber. However, it has been further recognized that the above-explained very high dimensional stability is particularly well achieved, especially when the yarn is a Umwindungsgarn. The production of twisting yarns per se is known to the person skilled in the art. It can be carried out on suitable commercially available machines. In the context of the invention, it has been recognized that in the case of the spun yarns, a higher hot air shrinkage due to the co-spun flame retardant in the fiber direction of the cellulosic regenerated fiber of the wrap no longer runs in the fiber direction of the core of the hybrid yarn, but transversely thereto, so that a lower hot air shrinkage in the yarn direction is achieved becomes.

Thus, the invention also discloses a hybrid yarn with a cellulosic regenerated fiber core and a wrap comprising a regenerated cellulosic regenerated fiber flame retardant, wherein a textile fabric produced only from the hybrid yarn undergoes a dimensional change at a temperature of 260 ° C. for ten minutes of a maximum of 10%, in particular a maximum of 8% learns. The soul of this wrapping yarn could in this case even have a flame retardant itself, in particular in the overall Flammschutzmittelverteilung shifting manner. However, the distribution described above with outwardly shifted weight is particularly preferred.

The quotient of the titre of the core and the denier of the covering yarn (the turn-around) is preferably 0.75 or less, more preferably 0.6 or less, in particular 0.5 or less.

Furthermore, it is preferred that a sheath yarn of the hybrid yarn comprises or consists of a cellulosic multifilament, in particular using the same viscose as the core, thereby achieving as similar mechanical and textile properties as possible. Such cellulosic multifilaments are described in particular in the above-mentioned unpublished patent application PCT / EP2012 / 002069. It is a high-strength, permanently flame retardant yarn based on regenerated cellulose. This yarn is also marketed under the brand name Viskont ^® FR and is in particular, due to its very smooth surface, high abrasion resistance and high specific dry tensile strength in the range of 28 to 30 cN / tex good for use as lining material, for example, in firefighting clothing.

Although the sheath yarn of the hybrid yarn is particularly preferred in view of these properties, it would be quite conceivable to form the sheathing yarn of the hybrid yarn based on staple fiber yarns, even if somewhat lower strength properties, especially in abrasion behavior (Martindale, pilling tests) are achieved.

With respect to the previously sold Viskont ^® FR should also be noted that this yarn alone does not cause a sought very high dimensional stability at very high temperatures despite decent resistance.

Furthermore, it is preferred that the wrap yarn has a twist of 800 TPM or less, preferably 600 TPM or less, more preferably 400 TPM or less, but more preferably 200 TPM or more, preferably 250 TPM or more, on the one hand low basis weights and on the other hand to obtain sufficient fire protection and good structural integrity of the yarn.

Not only for the core (the soul) as already mentioned above but also for the sheath (the sheath yarn / the wrap), it is preferred that its cellulosic regenerated fibers are spun according to the modal process. Thus, in spite of the co-spun flame retardant, the single yarn serving as a wrap also has better overall performance characteristics, for example a higher wet modulus correlating with higher dimensional stability to washing.

With regard to the titres of the individual yarns for core and / or winding, it is preferred that these be 220 dtex or less, preferably 190 dtex or less, in particular 167 dtex or less.

In addition to the yarn according to the invention itself, a textile fabric is also protected by the invention itself, which comprises such a yarn, consists predominantly thereof or is formed purely from this yarn. Thus, mixtures with other types of yarn can be used, such as aramid. This textile fabric should have a hot air shrinkage of less than 10%, preferably less than 8%, in particular less than 6%, at a temperature load of 260 ° C. for 10 minutes exposure time.

It may be a fabric, wherein the yarn of the invention is used at least as a warp yarn. On the other hand, the textile fabric could also be a knitwear. The textile fabric preferably has a weight per unit area of 300 g / m ² or less, preferably 250 g / m ² or less, and in particular of 200 g / m ² or less. As a result, a good wearing comfort can be achieved with satisfactory performance properties.

Further constituents of the textile fabric are conceivable, in particular as long as the above hot air shrinkage and the flame resistance are not significantly reduced. For example, in the case of a woven fabric, aramid could be used as the weft yarn.

When the fabric is a fabric, it is not limited in the nature of its construction. For example, twill weaves of different types, but also plain weaves, satin ribs, or jacquard weaves could be used.

With regard to the usability, it is further preferred if the textile fabrics have a rub resistance of at least 80,000 turns, preferably at least 90,000 turns, in particular at least 100,000 turns under load of 12 kPa (measured according to Martindale EN IS012947-1, 2).

With regard to possible applications, for example knits made of the yarn according to the invention can be used for flameproof gloves. The fabrics according to the invention can, as already explained, be used for clothing in the PPE range, for example for clothing for persons in the fire and military, in clean rooms, foundries, blast furnaces and other occupational groups with a high risk of thermal exposure.

Other possible uses of the textile fabrics according to the invention are also to be seen in technical applications in which heat resistance is required, for example, for trim and cover fabrics in interiors, cars, aircraft or ships, for filter materials, covers, etc.

In addition to textile fabrics, the applications of the yarn according to the invention also include cords, ropes and ropes as well as the use as a monofilament.

Further features, details and advantages of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying figures, wherein

Fig. 1 shows a binding cartridge for an example fabric of the invention and

Fig. 2 shows a comparison of multifilament regenerate fibers versus staple fiber intakes as the chain of fabric achievable strength properties. A first example of a yarn according to the invention is a hybrid yarn whose core is formed by the yarn Viskont HT dtex 67f 38 S90, which is made of the viscose rayon HTFR dtex 167 f60 S90 in S600 and has a denier of 234 dtex. The soul is here flame retardant-free, so that the flame retardant distribution is in the form of a step function with level between soul and zero turn on the flame retardant concentration of the viscose rayon HTFR.

This yarn is used as a warp yarn for a fabric construction formed from a heterogeneous mixture. The shot consists of a 20 tex / 1 aramid. As a construction, a twill weave 2/1 with a warp density of 30 Fd / cm and a weft density of 22 Fd / cm is used, see the weave in Fig. 1.

The fabric produced was washed at 60 ° C for 15 minutes and dried in a tumbler at 90 ° C for 40 minutes. The resulting basis weight was 187 g / m ² . For the intended use (lining for firefighter jackets), the material was not dyed. However, such coloring would have no effect on the test results presented below. First of all, the dimensional change in percent was determined for the fabric under heat of 260 ° C. over 10 minutes in the longitudinal and transverse directions. These were -5% in the longitudinal direction and -0.5% in the transverse direction, as shown in Table 1 below. Furthermore, the tissue was also examined for possible ignition or melting at this temperature, with a negative result (measuring specifications from NFPA 1971, EN ISO 11612 (with respect to the thermal resistance according to ISO 17493 at 260 ° C.)).

Table 1 Heat behavior of the example fabric according to the invention at 260 ° C.

Furthermore, the burning behavior of the fabric was investigated (burn test according to ISO 15025, relevant to the requirements of EN ISO 11612 and EN ISO 469 (protective clothing for fire fighting)). The results are shown in Table 2 and also confirm the quality of the fabric according to the invention in this regard.

Table 2 Burning behavior of the sample fabric.

Flame particles

According to After-Particle, the hole formation ignites

Long / cross burning time glowing glow time detachment OK [y / n]

Top edge: [j / n] filter paper

[s] _Ü7n]: [s]: [Y / N]

Li '"] D / n]

L n 0 n 0 n n n j

Q n 0 n 0 nnnj With regard to strength properties, a tensile test (according to EN ISO 13934-1) was carried out, the result of which is given in Table 3.

Table 3 Strength of the sample fabric.

strength

orientation

[N]

Chain 810.2

Shot 483.4

Finally, the Martinsdale scouring behavior of the example fabric is reproduced in Table 4 (scouring test according to Martindaie EN ISO 12947-1, 2). Values of> 100,000 tours with a load of 12 kPa were achieved. This extremely high abrasion resistance is quite surprising, considering that comparable Viskont ^® materials alone are approximately in the order of 40,000 to 70,000 turns. The good result is largely attributed to the construction of the yarn according to the invention.

Table 4 Martindaie scouring behavior of the sample tissue.

Overall rating

cycles

Sample 1 Sample 2 Sample 3 Result

5000 few pimples roughened few pimples

10000 roughened rough roughened

15000 roughened rough roughened

20000 reminder, whole I. thin F. anger., Whole I. thin F. anger., Whole I. thin F.

30000 anvils, whole I. thin F. anger., Whole I. thin F. anger., Whole I. thin F.

40000 anger., Whole I. thin F. anger., Whole I. thin F. anger., Whole I. thin F.

50000 anger. , whole I. thin F. anger. , whole I. thin F. anger., whole I. thin F.

60000 reminder, whole I. thin F. anger., Whole I. thin F. anger., Whole I. thin F.

70000 anvils, whole I. thin F. anger., Whole I. thin F. anger., Whole I. thin F.

80000 anger., Thin F. anger., Thin F. anger., Thin F.

90000 anger. , thin F. anger., thin F. anger., thin F.

100000 anger., Thin F. anger., Thin F. anger., Thin F.

110000 several F. cracked several F. cracked 2 F. cracked

105000 105000 105000 105000

Another embodiment is a hybrid yarn which is also formed in the form of a rewinding yarn. The soul forms a non-permanently flame-retardant filament yarn dtex 1 10 f 60 S90, the wrapping yarn or the wrap of a permanently flame-retardant yarn dtex 110 f46 S90.

A fabric formed solely from this hybrid yarn 220 dtex undergoes a shrinkage at 260 ° C. under 10 minutes exposure time of less than 6% at a ratio of non-permanently flame-retardant to permanently flame-retardant yarn from here 40:60, for example. for both warp and weft (construction twill 3/1, fabric density warp 34 FD / cm, weft 23 FD / cm).

An even lower hot air shrinkage was achieved from the same hybrid yarn in a canvas construction with fabric density 24 FD / cm and weft 18 FD / cm. Here a shrinkage of less than 5% (shot) and less than 2% (warp) was achieved. In addition, in this second embodiment, the same burning behavior as indicated in Table 2 for the first embodiment was achieved.

But even such hybrid game with a ratio of not permanently flame retardant to permanently flame retardant yarn greater than 40:60 are still quite able to show a very low even at 260 ° C shrinkage. If the ratio is significantly higher, however, further flame-retardant or flame-resistant fibers should be used for the production of textile fabrics, since the flame retardancy of the hybrid yarn alone then no longer reliably ensures a non-zero afterburning time (ISO 15025).

As a comparative example, a fabric is still presented that is made of 100% FR filament, dtex 290, construction chain and shot 225 g / m ² . Table 5 shows the heat shrink process of this assembly for several samples at two temperatures. It can be seen that at 180 ° C only a very small percentage of shrinkage takes place, which also meets the standard EN ISO 11612. At even higher temperatures, however, these low levels can not be maintained.

TABLE 5 Shrinkage behavior of a fabric of 100% FR filament, dtex 290, build-up warp and weft, 225 g / m ² at

180 "C and 260" C.

As already explained above, the use of multifilament regenerate fibers in preference to staple fibers or staple fiber intakes is preferred. Comparing the basis weight strengths, higher strength values of 20% to 30% are achieved in the warp if these consist of multifilament regenerate fibers rather than staple fiber intakes. This is illustrated in FIG. 2, which insofar does not relate to the fabrics according to the invention themselves, but serves to explain the background for specific preferred embodiments of the invention.

Claims

claims

Yarn having regenerated cellulosic fibers produced by a spinning process, in particular a wet spinning process of viscose, and in particular consisting thereof, which has flame-retardant properties caused by a flame retardant co-spun in at least part of its cellulosic regenerating fibers, characterized in that the yarn Having seen over its cross-section inhomogeneous distribution of the spun flame retardant with respect to the yarn center outwardly shifted weight.

2. Yarn according to claim 1, having a core-shell structure, wherein the shell has a higher flame retardant content than the core, and in particular in the case of a flame-resistant core, a ratio core: sheath of 4: 5 or smaller, preferably 3: 4 or smaller, in particular 2: 3 or smaller is provided.

A yarn according to claim 2, which is a hybrid yarn.

4. Yarn according to claim 3, wherein the core of the hybrid yarn comprises or consists of a cellulosic multifilament.

5. The method of claim 4, wherein the core does not contain a flame retardant.

6. The method according to any one of claims 3 to 5, wherein the hybrid yarn is a Umwindungs- yarn.

A yarn according to claim 6, wherein the quotient of the denier of the core and the denier of the covering yarn is 0.75 or less, preferably 0.6 or less, in particular 0.5 or less.

8. A yarn according to claim 6 or 7, wherein a Hüllgarn the hybrid yarn comprises a cellulosic multifilament or consists thereof.

The yarn of claim 8, wherein the wrap yarn has a twist of 800 TPM or less, preferably 600 TPM or less, more preferably 400 TPM or less.

10. A yarn according to any one of claims 3 to 9, wherein the core and / or sheath made of cellulosic regenerated fibers spun by the modal process or consist thereof.

11. Yarn according to one of claims 1 to 10, wherein the titer of the individual yarns for core and / or winding 220 dtex or less, preferably 190 dtex or less, in particular 167 dtex or less.

12. A textile fabric comprising a yarn according to any one of claims 1 to 11 or consisting thereof.

13. Textile fabric according to claim 12, the hot air shrinkage at a temperature load of 260 ° for 10 minutes exposure time in the range of 10% or less, preferably 8% or less, in particular 6% or less.

14. A fabric according to claim 13, which is a fabric containing the yarn according to any one of claims 1 to 11 at least as warp yarn.

15. Textile fabric according to claim 13, which is a knit fabric.