Adhesive tape with a long-fiber stitch-bonded fleece

Abstract

An adhesive tape (1), including a substrate (6) including a stitched fleece (2) and an adhesive layer (7) applied on one side to the substrate (6), wherein the stitched fleece (2) is formed at least 80% of long fibers (3) that have a fiber length (L.sub.1) of 80 mm to 120 mm. The adhesive tape having improved abrasion properties while maintaining a high noise damping.

Claims

1. An adhesive tape comprising a substrate including a stitched fleece and an adhesive layer applied to one side of the substrate, wherein the stitched fleece is formed at least 80% from long fibers, having a fiber length in the range from 80 mm to 120 mm and further comprising in that the stitched fleece contains short fibers which have a length in the range from 40 mm to 60 mm.

2. An adhesive tape according to claim 1, further comprising in that at least one of the long and the short fibers of the stitched fleece are stitched with stitching yarns with a fineness in a range from F 14 to F 24.

3. An adhesive tape according to claim 1, further comprising in that the stitched fleece contains at least one of the long and the short fibers that have a fiber strength in the range from 2 dtex to 3 dtex.

4. An adhesive tape according to claim 1, further comprising in that the long fibers have a proportion in the range from 85% to 95%, and the short fibers correspondingly have a proportion in the range from 15% to 5%.

5. An adhesive tape according to claim 1, further comprising in that the stitched fleece has a grammage in the range from 60 g/m.sup.2 to 230 g/m.sup.2.

6. An adhesive tape according to claim 1, further comprising in that the stitched fleece has a thickness in the range from 0.25 mm to 0.90 mm, according to the standard LV 312.

7. An adhesive tape according to claim 1, further comprising in that the stitched fleece has an elongation at break in the range from 25% to 58% according to the standard LV 312.

8. An adhesive tape according to claim 1, further comprising in that the stitched fleece has a breaking force in the range from 35 N/cm to 65 N/cm according to the standard LV 312.

9. An adhesive tape according to claim 1, further comprising in that at least a part of at least one of the long and the short fibers, or at least one of the long or the short fibers, are completely or partially composed of polyester.

10. An adhesive tape according to claim 1, further comprising in that stitching yarns are stitched in the stitched fleece, wherein at least a part of the stitching yarns or all of the stitching yarns are partially or completely composed of polyester.

11. An adhesive tape according to claim 10, further comprising in that the stitched fleece has a tear resistance in the range from 15,000 mN to 18,000 mN according to the standard LV 312.

12. An adhesive tape according to claim 1, further comprising in that the adhesive layer has an application weight in the range from 30 g/m.sup.2 to 120 g/m.sup.2.

13. An adhesive tape according to claim 1, further comprising in that the adhesive tape has a thickness in the range from 0.25 mm to 0.90 mm, according to the standard LV 312.

14. An adhesive tape according to claim 1, further comprising in that the adhesive tape has an elongation at break in the range from 20% to 25% according to the standard LV 312.

15. An adhesive tape according to claim 1, further comprising in that the adhesive tape has a breaking force in the range from 30 N/cm to 50 N/cm according to the standard LV 312.

16. An adhesive tape according to claim 1, further comprising in that the adhesive tape has a manual tearability in the range from moderate to difficult according to the standard LV 312.

17. An adhesive tape according to claim 1, further comprising in that the adhesive tape has at least a noise damping of class C according to the standard LV 312.

18. An adhesive tape according to claim 1, further comprising in that the adhesive tape has an abrasion resistance according to the standard LV 312 in a range from 350 strokes to 800 strokes.

19. An adhesive tape according to claim 1, further comprising in that the adhesive layer is a pressure-sensitive synthetic-rubber adhesive or a pressure-sensitive UV-curable polyacrylate.

20. An adhesive tape according to claim 1, further comprising in that the short fibers have a length in the range from 45 mm to 55 mm.

21. An adhesive tape according to claim 1, further comprising in that at least one of the long or the short fibers of the stitched fleece are stitched with stitching yarns with a fineness of F 22.

22. An adhesive tape according to claim 1, further comprising in that the stitched fleece has a grammage in the range from 80 g/m.sup.2 to 160 g/m.sup.2.

23. An adhesive tape according to claim 1, further comprising in that the stitched fleece has a thickness in the range from 0.30 mm to 0.60 mm, according to the standard LV 312.

24. An adhesive tape according to claim 1, further comprising in that the adhesive tape has a thickness in the range from 0.30 mm to 0.60 mm according to the standard LV 312.

25. An adhesive tape according to claim 1, further comprising in that the adhesive tape has an abrasion resistance according to the standard LV 312 in a range from 450 strokes to 750 strokes.

26. An adhesive tape comprising a substrate comprised exclusively of a stitched fleece wherein the stitched fleece is formed at least 80% from long fibers having a fiber length in the range from 80 mm to 120 mm, and further comprising in that the stitched fleece contains short fibers which have a length in the range from 40 mm to 60 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention shall be explained in greater detail based on the exemplary embodiments depicted in the drawings:

(2) FIG. 1 shows a schematic cross-section of an inventive adhesive tape including an inventive stitched fleece,

(3) FIG. 2a shows a schematically depicted cross-section of a first embodiment of an inventive stitched fleece including long fibers,

(4) FIG. 2b shows a view of a long fiber of the stitched fleece according to the first embodiment,

(5) FIG. 3a shows a schematically depicted cross-section of a second embodiment of an inventive stitched fleece including long fibers and short fibers,

(6) FIG. 3b shows a view of a short fiber of the stitched fleece according to the second embodiment, and

(7) FIG. 4 shows a view of a stitched fleece during manufacturing.

FURTHER DESCRIPTION OF THE INVENTION

(8) In the different figures of the drawings identical parts are always provided with the same reference numbers so that as a rule they are only described once.

(9) For the subsequent description it is emphasized that the invention is not limited to the exemplary embodiments and here not limited to all or a plurality of features of described feature combinations, but rather each individual partial feature of the exemplary embodiment or of each exemplary embodiment is also of significance for the subject matter of the invention in itself and also in combination with any features of another exemplary embodiment, even separate from all other partial features described in connection therewith.

(10) The property parameters of the stitched fleece 2 and of the adhesive tape 1, which property parameters are embodied in the description, are determined according to the standard LV 312 (October 2009). For the stitched fleece 2 these parameters include the thickness D.sub.1, the elongation at break, the breaking force, the tear resistance, and the manual tearability. For the adhesive tape 1 these parameters include the thickness D.sub.2, the elongation at break, the breaking force, the adhesive force on steel, the adhesive force on the tape back, the unrolling force, the manual tearability, the noise damping, and the abrasion resistance. For the last two parameters a classification occurs hereinafter.

(11) FIG. 1 shows an inventive adhesive tape 1, including a substrate 6 formed from a stitched fleece 2, and an adhesive layer 7 applied one-side on the substrate 6. The stitched fleece 2 preferably formed of a textile fleece material, which is a textile sheet mane from a sequential connection and/or sequential layering of ordered and unordered fibers. The fleece material can be formed of long fibers extending along the tape extension direction and transverse fibers extending transverse to the longitudinal fibers, or a completely disordered placement of fibers.

(12) According to the invention, the stitched fleece 2 includes long fibers 3. The stitched fleece 2 advantageously includes two fiber types, i.e., long fibers 3 and short fibers 4. The fiber strength of the fibers 3, 4 of both types falls in particular in the range from 2 dtex to 3 dtex. To form the stitched fleece 2 to the long fibers 3 and/or short fibers 4 for are advantageously stitched with stitching yarns 5, which have a fiber strength of preferably 50 dtex. In particular, the stitched fleece 2 has a grammar in the range from 120 g/m.sup.2 to 140 g/m.sup.2. Furthermore, the stitched fleece 2 preferably has a thickness D.sub.1 in the range from 0.40 mm to 0.55 mm, in particular in the range from 0.45 mm to 0.50 mm. This thickness is measured according to the standard DIN EN 1942. Preferably a proportion of the fibers 3, 4 or all fibers 3, 4 are formed partially or completely of plastic, preferably polyethylene terephthalate (PET).

(13) The manufacturing of a stitched fleece 2 occurs, for example, as schematically depicted in FIG. 4. Here FIG. 4 schematically shows a stitched fleece 2, wherein stitching yarns 5 are stitched with a fineness F. Here the fineness F is a measure for the stitch density. It is based on the “English fineness,” which specifies in a numbering system used in knitters and knitting machines the number n of stitching needles 9, 9′, 9″ allocated to an English inch (25.4 mm) over the distance K, and thus the stitch density.

(14) In the stitched fleece schematically depicted in FIG. 4, for example, at least n=3 needles 9, 9′, 9″ disposed over a distance K have been used for manufacturing the stitched fleece 2. The English fineness F is defined in DIN ISO 8188:2009-02 “Textilmaschinen and Zubehör—Teilung von maschenbildenden Maschinen”. According to the invention here finenesses in the range F 14 to F 24, in particular F 22, are preferred.

(15) For example, for manufacturing a stitched fleece 2, two sewing-yarn systems (i.e., two bars) are used to form stitches through a raw fleece 2a. However, one-bar or three-bar systems are also possible. With the two-bar system a stitching yarn 5 is guided by a first set of movable stitching-yarn guides 8, 8′, 8″, which are supported by a first guide bar (not shown), for an interacting, complete yarn engagement with the needles 9, 9′, 9″, etc. over the width of the raw fleece 2a.

(16) To produce the stitches in the stitched fleece 2, in operation the stitching yarns 5 are moved in engagement with the needles 9, 9′, 9″, which in turn guide the sewing yarns 5 in a back-and-forth manner through the raw fleece 2a. An arrangement of interacting stitching-yarn stitches 10 is thereby formed, which extend in rows, spaced with respect to one another, along the raw fleece 2a.

(17) In a solely exemplary and non-limiting manner the interacting stitching-yarn stitches 10 can be held in a complete chain-stitch configuration, although other known stitch arrangements, e.g., tricot stitches and the like, can also be used.

(18) In particular, the stitched fleece 2 can be produced using the stitch-bonding technology “Maliwatt.” According to the Maliwatt method, a raw fleece 2a is strengthened by it being configured as an introduced crosswise plaited fibrous web or a tangled fleece stitched by one or two yarn systems. For this purpose a compound-needle/closingwire system pierces the fibrous web, and during the backward movement pulls one or two of the placed stitching yarns 5 through the to-be-strengthened raw fleece 2a. The reducing of the previous stitches and the withdrawal of the product downward follow.

(19) Preferably the stitching yarns 5 are stitched into the stitched fleece 2 with a stitch length s of 1.0 mm. The “stitch length s” here is understood to mean the distance between the entry point of the stitching yarn 5 in the fiber structure and its exit point.

(20) The adhesive tape 1 manufactured using the stitched fleece 2 preferably has an unrolling force in the range from 5.6 N/cm to 5.8 N/cm. The unrolling force here is the force required for unrolling an adhesive-tape roll. It affects the winding tension during the taping of cable sets, which, for example, affects the winding hardness of a cable harness. Too-high unrolling forces can result in a twisting, and thus in a shortening, in particular of thin cable strands. Too-low unrolling forces can result in handling problems and, in addition, soft cable strands with unclean, limp windings.

(21) TABLE-US-00001 TABLE 1 Classification of noise-damping properties according to LV 312 (10/2009) Noise damping class Requirement A - no noise damping 0 to ≦2 dB(A) B - slight noise damping >2 to ≦5 dB(A) C - moderate noise damping >5 to ≦10 dB(A) D - high noise damping >10 to ≦15 dB(A) E - very high noise damping >15 dB(A)

(22) The adhesive tape preferably has a noise damping of class C. This level corresponds to a noise damping greater than 5 dB(A) up to and including 10 dB(A). An overview of the noise damping classes according to the standard LV 312 (October 2009) is shown in Table 1.

(23) Furthermore, the abrasion properties of the adhesive tape 1 advantageously correspond to the conditions of class C established by the standard. Underlying this is that the adhesive tape 1 advantageously withstands 700 to 800 strokes before it is worn through. In contrast thereto, adhesive tapes known to date of the type mentioned can only withstand 450 strokes. A corresponding overview of the abrasion classes according to the standard LV 312 (October 2009) is shown in Table 2 below.

(24) TABLE-US-00002 TABLE 2 Classification of abrasion properties according to LV 312 (10/2009) Abrasion class Requirement A - no abrasion protection <100 strokes B - slight abrasion protection 100-499 strokes C - moderate abrasion protection 500-999 strokes D - high abrasion protection 1000-4999 strokes E - very high abrasion protection 5000-14999 strokes F - extremely high abrasion protection 15000-29999 strokes G - abrasion protection for special ≧30000 strokes applications

(25) The adhesive layer 7 of the adhesive tape 1 preferably is formed of pressure-sensitive adhesives, in particular based on polyacrylate, which can be used due to their good aging resistance. These acrylate adhesive materials can as a rule be applied either as dispersion or crosslinked hot-melt adhesives via UV radiation. In principle it is also possible to use solvent acrylates or even acrylate-monomer mixtures or acrylate prepolymers. After coating these are optionally polymerized and crosslinked either thermally or using UV radiation. In addition, the use of other adhesive classes, such as, e.g., adhesives based on synthetic rubber, such as SIS (styrene-isoprene-styrene copolymers) or SBS (styrene-butadiene-styrene block copolymers) or adhesives based on silicon or polyurethane is possible.

(26) FIG. 2a shows a first embodiment of an inventive stitched fleece 2 used as substrate 6. This embodiment is referred to below as “long-fiber fleece 100%”, since it is formed 100% of long fibers 3. The properties of this stitched fleece 2 can be inferred from Table 3. The features listed in this table can be significant to the invention individually or in any combination. In addition, in Table 3 the properties of the “long-fiber fleece 100%” are contrasted with those of a comparison fleece according to the prior art (middle column of table 3).

(27) The specification “PES virgin” in Table 3 below for the material of the fibers 3, 4 and the stitching yarns 5 means here that the fibers 3, 4 and the stitching yearns 5 are preferably formed partially or completely of a non-recycled polyester. However, stitching yarns 5 made from a recycled polyester also appear to be usable.

(28) Furthermore, the stitching yarns 5 can also be formed—at least partially—of polyethylene (PE), or polypropylene (PP), or polyurethane (PUR), viscose, or polyamide. In particular, such PA P stitching yarns 5 are then partially or completely formed of homopolyamides, e.g., PA 6.6 (PA made from hexamethylendiamine and adipic acid [NH—(CH.sub.2).sub.6—NH—CO—(CH.sub.2).sub.4—CO].sub.n) or PA6 (PA made from caprolactam [NH—(CH.sub.2).sub.5—CO].sub.n). Homopolyamides are derived from an amino acid or a lactam or a diamine and a dicarboxylic acid.

(29) Table 3 below gives an overview of the preferred properties of stitched fleeces 2 usable according to the invention as substrate materials.

(30) In Table 3, the fiber strengths, the filament count, stitch lengths, and the fiber material are listed. These parameters are in particular the same for the “long-fiber fleece 100%” and the comparison fleece. A stitching yarn 5 having a fiber strength of 50 dtex us preferably used for the “long-fiber fleece 100%.” The fiber material can be partially or completely formed of textile fibers. For example, yarns can be used wherein yarns made from staple fibers or filaments can be used.

(31) TABLE-US-00003 TABLE 3 Properties of the inventive stitched fleece. Long-fiber Long-fiber 130 g/m.sup.2 fleece 90% fleece 100% Fineness n/25 mm F 22 F 22 F 22 Yarn Strength dtex 50 50 50 Filament count number 36 36 36 Stitch length mm 1 1 1 Yarn material — PES virgin PES virgin PES virgin Fiber material — PES virgin PES virgin PES virgin Fiber fineness dtex 2.11 2.0-3.0 2.0-3.0 long fiber Fiber fineness dtex 2.43 2.0-3.0 2.0-3.0 short fiber Fiber length mm 76 80 120 long fiber Fiber length mm 51 50 ./. short fiber Proportion of % 60-80 90 100 long fibers Proportion of % 40-20 10 0 short fibers Grammage g/m.sup.2 130 +/− 10 130 +/− 10 130 +/− 10 Thickness mm 0.55 +/− 0.1 0.50 +/− 0.1 0.45 +/− 0.1 Elongation at % 15-50 25-55 28-58 break Breaking force N/cm 30-50 35-55 42-65 Tear resistance mN <13,000 15,000 18,000 Manual LV 312 yes difficult difficult tearability Tape back N/cm >4.0 >4.0 >4.0 values

(32) A staple-fiber yarn is formed of endlessly-long fibers, which are twisted during spinning. A filament yarn is formed of filaments. A filament is a fiber of unlimited length (according to the standard DIN 60000 (October 1990)) or has at least a length of 1000 mm (according to the standard DIN 60001 (October 1990)). On the other hand, fibers of limited length are referred to as staple fibers. Staple fibers can be divided in turn into actually twistable staple fibers and very short flock fibers, wherein the boundary is 15 mm. Stitching fibers 5 can also be manufactured from staple fibers. Smooth yarns, in particular, so-called pre-oriented yarns (POY—pre oriented yarn) or so-called fully-drawn yarns (FDY—fully drawn yarn) are preferably used for the stitching yarns 5.

(33) The manufacturing of a filament yarn occurs by the swirling of the individual filaments. The number of filaments preferably falls in a range from 34 to 38. In general the stitching yarns 5 can contain from 24 to 144 filaments.

(34) The fiber fineness of the long fiber 3 in the stitched fleece 2 preferably falls in a range from 2 dtex to 3 dtex. The long fiber 3 inventively has a length L.sub.1 in the range from 80 mm to 120 mm, preferably its length L.sub.1 falls in a range from 110 mm to 130 mm. In a particularly preferred embodiment it is 120 mm. A long fiber 3 for use in a stitched fleece 2, as shown in FIG. 2a, is shown in FIG. 2b. The grammage of this fleece embodiment falls in particular in a range of 60 g/m.sup.2 to 230 g/m.sup.2, preferably in a range from 80 g/m.sup.2 to 160 g/m.sup.2. For the manufacturing of the stitched fleece 2 the long fiber 3 is advantageously exclusively used. Due to the use of such a long fiber 3, in particular stitched-fleece thicknesses D.sub.1 in the range from 0.40 mm to 0.50 mm are achieved, preferably in the range from 0.44 mm to 0.46 mm.

(35) Furthermore, the “long-fiber fleece 100%” advantageously has an elongation at break in the range from 28% to 58% and a breaking force in the range from 42 N/cm to 65 N/cm. Here the breaking force is a measure for the loadability of the adhesive tape 1 during use. The elongation at break is a measure for the elasticity of the adhesive tape 1. The tear resistance is advantageously 18,000 mN. The tear resistance or notch resistance is the property of a material, even with the presence of a notch, of not tearing further. The “long-fiber fleece 100%” is advantageously difficult to tear manually.

(36) The use of a “long-fiber fleece 100%” as substrate 2 advantageously leads to an adhesive tape 1 having the properties shown in Table 4 below, column 5. Here the features listed in Table 4 are of inventive significance individually or in any combination.

(37) TABLE-US-00004 TABLE 4 Properties of the inventive adhesive tapes. Standard Adhesive Adhesive adhesive tape of the tape of the tape long-fiber long-fiber 8510 X fleece 90% fleece 100% Substrate g/m.sup.2 130 130 130 material Adhesive type — Acrylate Acrylate Acrylate Adhesive g/m.sup.2 50-100 50-100 50-100 application Thickness mm 0.5 0.5 0.5 Elongation at % 18 20 25 break Breaking force N/cm 35 30-36 36-50 Adhesive force N/cm 3.2 2.0-4.1 3.5-8.0 steel Adhesive force N/cm 4.2 4.5 4.3 on tape back Unrolling force N 5.5 5.8 5.6 Manual LV 312 easy moderate difficult tearability Noise-damping LV 312 C C C class Abrasion- LV 312 B B-C C resistance class Abrasion strokes 200-300 450-650 700-800 resistance

(38) In particular, the adhesive tape 1 has an adhesive application on the substrate 2 in a range from 50 g/m.sup.2 to 100 g/m.sup.2. Furthermore, the adhesive tape 1 including a “long-fiber fleece 100%” preferably has an elongation at break of 25% and a breaking force in a range from 36 N/cm to 50 N/cm. Moreover, the adhesive force on steel falls in a range from 3.5 N/cm to 8.0 N/cm, the adhesive force on a tape back is 4.3 N/cm, and the unrolling force is 5.6 N. Like the stitched fleece 2 the adhesive tape 1 is also difficult to tear manually. Both the noise damping and the abrasion resistance correspond to class C.

(39) FIG. 3a represents a further embodiment of the inventive stitched fleece 2, which is referred to below as “long-fiber fleece 90%.” Two different lengths of fibers 3, 4 are used for manufacturing this stitched fleece 2. Of these the long fibers 3 have a proportion in the range from 85% to 95%, and the short fibers a proportion from 15% to 5%. Especially preferably, the stitched fleece 2 has a long-fiber proportion of 90% and a short-fiber proportion of 10%.

(40) With respect to fineness, yarn strength, filament count, stitch length, and yarn material, the properties of the “long-fiber fleece 90%” preferably correspond to those of the “long-fiber fleece 100%.”

(41) The fiber fineness of the long fiber 3 in the stitched fleece 2 falls in particular in a range from 2 dtex to 3 dtex. The short fibers 4 in particular have a fiber fineness in a range from 2 dtex to 3 dtex. The length L.sub.2 of the short fibers 4 processed in the “long-fiber fleece 90%” falls in particular in a range from 40 mm to 60 mm, preferably at 50 mm. A view of the fibers 3, 4 processed in the “long-fiber fleece 90%” is shown in FIG. 3b. The long fibers 3 processed in the “long-fiber fleece 90%” advantageously have a length L.sub.1 in the range from 70 mm to 90 mm, in particular a length L.sub.1 of 80 mm.

(42) The grammage of the “long-fiber fleece 90%” is preferably 130 g/m.sup.2. The thickness D.sub.1 of the stitched fleece 2 falls in particular in a range from 0.45 mm to 0.55 mm, preferably in a range from 0.49 mm to 0.51 mm.

(43) The stitched fleece 2 advantageously has an elongation at break in the range from 25% to 55% and a breaking force of preferably 35 N/cm to 55 N/cm. Furthermore, in particular it has a tear resistance of 15,000 mN and is in particular difficult to tear manually.

(44) The properties of an exemplary embodiment of an adhesive tape 1 including a “long-fiber fleece 90%” are shown in Table 4, column 4. The adhesive tape 1 advantageously has an adhesive application in the range from 50 g/m.sup.2 to 150 g/m.sup.2. Such an adhesive tape 1 preferably has an elongation at break of 20% and a breaking force in a range from 30 N/cm to 36 N/cm. Advantageously the adhesive force on steel is in a range from 2.0 N/cm to 4.1 N/cm, the adhesive force on a tape back is 4.5 N/cm, and the unrolling force is 5.8 N. In particular, the manual tearability of an inventive adhesive tape 1 is “moderate” (according to the standard LV 312 (October 2009)), the noise damping preferably corresponds to class C, and the abrasion resistance corresponds to between class B and class C (compare Tables 1 and 2).

(45) The embodiments of the adhesive tape 1 including a “long-fiber fleece 90%” and a “long-fiber fleece 100%” advantageously each have thicknesses D.sub.2 in the range from 0.25 to 0.90 mm, preferably in the range from 0.30 to 0.50 mm.

(46) While the above description constitutes the preferred embodiment of the present invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims.