Adhesive tape with fine-stitch stitch-bonded web

Abstract

An adhesive tape, including a substrate including a stitched fleece and an adhesive layer applied one-side on the substrate, wherein the stitched fleece is formed from fibers, which are stitched with stitching yarns. A manually tearable adhesive tape is disclosed, with improved abrasion resistance properties together with a high noise damping. The stitching yarns may be stitched with a fineness of at least F24.

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 from short fibers and long fibers which are stitched with sewing threads, the length of the long fibers being greater than the length of the short fibers, wherein all of the long and short fibers in the stitched fleece completely consist of polyester (PES), the proportion of the long fibers is in the range from 60% to 90% and the proportion of short fibers correspondingly is in the range from 40% to 10% based on the weight of the long and short fibers, wherein the long fibers have a fiber length (L1) in the range from 60 mm to 120 mm, and the short fibers have a fiber length (L2) in the range from 35 mm to 55 mm, wherein the stitching yarns sewing threads are stitched with a fineness of at least F 24, wherein the stitched fleece has a thickness (D.sub.1) in the range of 0.16 mm to 0.27 mm, wherein the stitched fleece has a tear resistance in the range from 8,000 mN to 18,000 mN, an elongation at break in the range from 10% to 50%, and a breaking force in the range from 20 N/cm to 55 N/cm in accordance with standard LV 312; wherein the sewing threads are made from filaments with a filament count in the range from 30 to 48; wherein the adhesive tape has an abrasion resistance in the range from class B to class C.

2. The adhesive tape according to claim 1, wherein the sewing threads are stitched in the stitched fleece with a fineness in a range from F 24 to F 28.

3. The adhesive tape according to claim 1, wherein the sewing threads are stitched in the stitched fleece with a stitch length in a range from 0.7 mm to 1.7 mm.

4. The adhesive tape according to claim 1, wherein the sewing threads have a linear density in the range from 20 dtex to 76 dtex.

5. The adhesive tape according to claim 1, wherein the stitched fleece has an elongation at break in the range from 20% to 50%-according to the standard LV 312.

6. The adhesive tape according to claim 1, wherein the stitched fleece has a breaking force in the range from 35 N/cm to 55 N/cm according to the standard LV 312.

7. The adhesive tape according to claim 1, wherein the adhesive tape has an elongation at break in the range from 17% to 28% according to the standard LV 312.

8. The adhesive tape according to claim 1, wherein the adhesive tape has a breaking force in the range from 20 N/cm to 48 N/cm according to the standard LV 312.

9. The adhesive tape according to claim 1, wherein the fibers have a linear density in the range from 2 dtex to 4 dtex.

10. The adhesive tape according to claim 1, wherein at least a portion of the sewing threads completely or partially comprise polyester (PES).

11. The adhesive tape according to claim 1, wherein the stitched fleece has a grammage in a range of 60 g/m.sup.2 to 92 g/m.sup.2.

12. The adhesive tape according to claim 1, wherein the adhesive layer further comprises a pressure-sensitive adhesive.

13. The adhesive tape according to claim 1, wherein the adhesive layer has an application weight in the range from 40 g/m.sup.2 to 100 g/m.sup.2.

14. The adhesive tape according to claim 12 wherein the pressure-sensitive adhesive comprises a UV-crosslinkable acrylate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic cross section of the inventive adhesive tape including the inventive stitch-bonded web,

(2) FIG. 2a is a schematized cross section of a possible embodiment of the inventive stitch-bonded web with long fibers,

(3) FIG. 2b is a view of a long fiber and a short fiber of the stitch-bonded web, and

(4) FIG. 3 is a view of the stitch-bonded web during manufacturing.

(5) The same parts are marked with the same reference signs in the different figures of the drawings.

DETAILED DESCRIPTION OF THE DRAWINGS AND THE PRESENTLY PREFERRED EMBODIMENTS

(6) For the following description, it is claimed that the invention is not limited to the design examples and thereby is not limited to all or several characteristics of the described characteristic combination, but rather that each individual partial characteristic of the design example also functions separately from all other associated described partial characteristics on its own and also in combination with any characteristics of another design example relevant to the objective of the invention.

(7) The characteristic parameters listed in the description of the stitch-bonded web 2 and the adhesive tape 1 are determined in accordance with the standard LV 312 (10/2009). For the stitch-bonded web 2, these parameters include the thickness D1, the elongation at tear, the breaking force, tear resistance, adhesion strength on the back of the tape, and air permeability. For adhesive tape 1, the parameters include the thickness D2, elongation at tear, breaking force, adhesion strength on steel, adhesion strength on the back of the tape, unwinding force, hand tearability, noise damping, and abrasion durability. For the last two parameters referring to adhesive tape 1, a further description follows in tables 1 and 2 that show the classification.

(8) FIG. 1 shows an inventive adhesive tape 1, demonstrating a substrate 6 made of a stitch-bonded web 2 and an adhesive layer 7 applied to substrate 6 on one side. The stitch-bonded web 2 includes, preferably, a textile web material, which is a textile surface structure formed by a sequence and/or layering of organized and unorganized fibers 3 and 4. The web material can include longitudinal fibers along the direction of the tape and transverse fibers running transverse to the longitudinal fibers, or a completely randomly laid fiber arrangement.

(9) According to the intervention, stitch-bonded web 2 has two types of fiber, meaning long fibers 3 and short fibers 4. The linear density of fibers 3 and 4 of both types is, in particular, in the area of 2 dtex to 4 dtex. For the formation of stitch-bonded web 2, the long fibers 3 and/or short fibers 4 are preferably sewn with sewing thread 5 that preferably features filaments having a count in the area of 30 to 40, preferred in the area of 34 to 38.

(10) Preferably, the sewing threads 5 are sewn into the stitch-bonded web 2 with a stitch length s in the area of 0.7 mm to 1.7 mm, preferably with a stitch length s of 1.2 mm. The stitch-bonded web 2, in particular, has a surface weight in the area of 60 g/m2 to 82 g/m2. Furthermore, the stitch-bonded web 2 in particular has a thickness D1 in the area of 0.1 mm to 0.5 mm, preferably in the area of 0.16 mm to 0.27 mm. Advantageously, a portion of the fibers 3, 4 or all of the fibers 3, 4 are partially or completely made of synthetic material, preferably polyester (PES). Preferably, a portion of the fibers 3, 4 or all of the fibers 3, 4 partially or completely include polyethylene-terephthalate (PET). In particular, the fibers 3, 4 have a linear density in the area of 1 dtex to 5 dtex, preferably in the area of 2 dtex to 4 dtex. Advantageously, the stitch-bonded web 2 is formed of long fibers 3 and short fibers 4, whereby the share of long fibers 3 is the area of 60% to 90%, preferably in the area of 60% to 80%, and the share of the short fibers 4 respectively is in the area of 40% to 10%, preferably in the area of 40% to 20%. The length L1 of the long fibers 3 is preferably in the area of 60 mm to 120 mm and the length L2 of the short fibers 4 is preferably in the area of 35 mm to 55 mm.

(11) The adhesive tape 1 that is manufactured with the invented stitch-bonded web 2 preferably has of a thickness D2 in the area of 0.25 mm to 0.35 mm, in particular in the area of 0.25 mm to 0.30 mm. Preferably, it hereby possesses noise damping in class C. This classification corresponds to a noise damping greater than 5 dB(A) up to and including 10 dB(A). An overview of the noise damping classification in accordance with standard LV 312 (10/2009) is shown in the following table.

(12) TABLE-US-00001 TABLE 1 classification of noise damping characteristics in accordance with LV 312 (October 2009). Noise damping class Requirement A no noise damping   0 to ≤2 dB(A) B low noise damping  >2 to ≤5 dB(A) C medium noise damping  >5 to ≤10 dB(A) D high noise damping >10 to ≤15 dB(A) E very high noise damping >15 dB(A)

(13) Furthermore, the abrasion characteristics for adhesive tape 1 preferably correspond to the guidelines determined by the standard for class B or C. A corresponding overview regarding the abrasion characteristics in accordance with standard LV 312 (10/2009) is shown in the following table 2.

(14) TABLE-US-00002 TABLE 2 Classification for abrasion characteristics in accordance with LV 312 (October 2009). Abrasion class Requirement A no abrasion protection <100 strokes B low abrasion protection 100-499 strokes C medium abrasion protection 500-999 strokes D high abrasion protection 1000-4999 strokes E very high abrasion protection 5000-14,999 strokes F extremely high abrasion protection 15,000-29,999 strokes G abrasion protection for special >30,000 strokes applications

(15) The adhesive layer 7 of adhesive tape 1 preferably includes pressure-sensitive adhesives, in particular based on synthetic rubber. These types of adhesives are advantageous due to their high starting adhesion and their good adhesion to polar and non-polar surfaces (e.g. surfaces made of polypropylene and polyethylene). Furthermore, a UV-cross-linkable adhesive can be used as pressure-sensitive adhesive for the adhesive tape examples listed in table 4.

(16) FIG. 2a shows a possible example of the invention for a utilized stitch-bonded web 2 on substrate 6. The characteristics of different design examples of this web 2 are displayed in the following table 3. The characteristics listed in this table are relevant to the invention individually on their own or in any combination. Furthermore, the characteristics of the different design examples are listed for comparison of two webs in accordance with the state of the art (third column and seventh column from the left of table 3). The label “PES Virgin” in table 3 for the material for fibers 3, 4 and the sewing yarn 5 hereby means that fibers 3, 4 and the stitching yarn 5 are preferably partially or completely made of a non-recycled polyester (PES).

(17) TABLE-US-00003 TABLE 3 Overview of substrate materials Construc- Construc- Construc- Construc- 65 g/m.sup.2 tion tion tion 80 g/m.sup.2 tion standard 1 2 3 standard 4 Fineness n/25 mm F 22 F 24 F 28 F 28 F 22 F 28 Yarn dtex 50 50 33 50 50 50 strength Filament number 36 36 36 36 36 36 count Stitch length mm 1.2 1.2 1.2 1.2 1.2 1.2 Yarn — PES PES PES PES PES PES material virgin virgin virgin virgin virgin virgin Fiber — PES PES PES PES PES PES material virgin virgin virgin virgin virgin virgin Fiber dtex 2.1 2.0-4.0 2.0-4.0 2.0-4.0 2.0-4.0 2.0-4.0 fineness long-fiber Fiber dtex 3.3 2.0-4.0 2.0-4.0 2.0-4.0 2.0-4.0 2.0-4.0 fineness short-fiber Long fiber % 60-80 60-80 60-80 60-80 60-80 60-80 proportion Short fiber % 40-20 40-20 40-20 40-20 40-20 40-20 proportion Fiber length mm 76  60-120  60-120  60-120  60-120  60-120 long-fiber Fiber length mm 51 35-55 35-55 35-55 35-55 35-55 short-fiber Grammage g/m.sup.2 65 +/− 5 65 +/− 5 65 +/− 5 65 +/− 5 84 +/− 5 84 +/− 5 Thickness mm 0.175 +/− 0.175 +/− 0.175 +/− 0.175 +/− 0.24 +/− 0.24 +/− 0.015 0.015 0.015 0.015 0.03 0.03 Elongation % 15-25 15-27 10-20 15-30 15-42 20-50 at break Breaking N/cm 27-42 30-55 20-35 40-55 30-42 35-55 force Tear mN MW MW MW MW MW MW resistance 13,000 15,000 8,000 18,000 13,000 18,000 Air l/m.sup.2 *s 2500- 2400 2000 1800 3000 1800 permeability 3000

(18) According to the invention stitching yarns 5 having a fineness of at least F 24 are sewn in the stitched fleece 2. An illustration of the “English fineness,” which specifies the number n of sewing needles 9, 9′, 9″ allocated to the distance K of an English inch (25.4 mm), and thus the stitch density, is shown in FIG. 3. Here in the schematically depicted stitched fleece 2, n=3, for example, needles 9, 9′, 9″ were used over a distance K for manufacturing the stitched fleece 2.

(19) 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 sewing-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.

(20) 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.

(21) In a solely exemplary and non-limiting manner the interacting sewing-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.

(22) 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 sewn 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.

(23) In a first embodiment of the stitched fleece 2, the fibers 3, 4 are stitched with stitching yarns 5 having a linear density of 50 dtex and having a fineness of F 24. In this embodiment the grammage of the stitched fleece 2 falls in a range between 60 g/m.sup.2 and 70 g/m.sup.2. Furthermore, this embodiment of the stitched fleece 2 has an elongation at break in a range of 12% to 30%, preferably in a range of 15% to 27%, and a breaking force in a range from 25 N/cm to 60 N/cm, preferably in a range from 30 N/cm to 55 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 falls in a range of 8,000 mN to 18,000 mN, preferably having a value of 15,000 mN. The tear resistance or the notch resistance is the property of a material to not tear further even with the presence of a notch. Furthermore, the air permeability of the stitched fleece 2 falls in a range from 2200 l/m.sup.2s to 2600 l/m.sup.2s.

(24) The use of this stitched fleece 2 as substrate 6 leads to an adhesive tape 1 having the properties as shown in the following Table 4, column 4.

(25) In particular, the adhesive tape 1 has an application of adhesive on the substrate 6 in a range from 40 g/m.sup.2 to 60 g/m.sup.2 and is 0.25 mm thick. Furthermore, the adhesive tape 1 has an elongation at break in a range from 15% to 30%, preferably of 19%, and a breaking force in a range from 20 N/cm to 30 N/cm, preferably of 25 N/cm. Moreover, the adhesive force on steel is 4.7 N/cm, the adhesive force on a tape back is 6.5 N/cm, and the unrolling force is 5.4 N. In particular, the adhesive tape 1 is easily tearable manually. The noise damping here corresponds to class C, and the abrasion resistance corresponds to class B.

(26) TABLE-US-00004 TABLE 4 Overview of adhesive tapes Adhesive Adhesive Adhesive Adhesive Standard tape of tape of tape of Standard tape of adhesive construc- construc- construc- adhesive construc- tape tion tion tion tape tion 8551 1 2 3 8550 4 Substrate g/m.sup.2 65 65 65 65 65 65 material Adhesive — Synthetic Synthetic Synthetic Synthetic Synthetic Synthetic type rubber rubber rubber rubber rubber rubber Adhesive g/m.sup.2 50-100 40-60 40-60 40-60 50-100 50-100 application Thickness mm 0.25 0.25 0.25 0.25 0.3 0.3 Elongation % 18 19 17 20 25 28 at break Breaking N/cm 28 25 20 28 45 45 force Adhesive N/cm 4.5 4.7 4.9 4.6 5.5 6.0 force steel Adhesive N/cm 7.8 6.5 6.2 7.8 8.1 8.1 force on tape back Unrolling N 6.2 5.4 5.2 6.2 5.4 5.5 force Manual LV easy easy easy easy easy easy tearability 312 Noise- LV C C C C C C damping 312 class Abrasion- LV A B B/C B/C B B/C resistance 312 class

(27) In a second embodiment of the stitched fleece 2 the fibers 3, 4 are preferably stitched with stitching yarns 5 having a linear density of 33 dtex and having a fineness of F 28. In this exemplary embodiment the grammage of the stitched fleece 2 falls in a range between 60 g/m.sup.2 and 70 g/m.sup.2. Furthermore, this embodiment of the stitched fleece 2 has an elongation at break in a range of 10% to 20% and a breaking force in a range from 15 N/cm to 40 N/cm, preferably in a range from 20 N/cm to 35 N/cm. The tear resistance has a value of 8,000 mN. Furthermore, the air permeability of the stitched fleece 2 falls in a range from 1800 l/m.sup.2s to 2200 l/m.sup.2s.

(28) The use of this stitched fleece 2 as substrate 6 leads to an adhesive tape 1 having the properties as shown in Table 4, Column 5.

(29) Here the features listed in table 4 are essential to the invention both individually and in any combination.

(30) The adhesive tape 1 has an application of adhesive on the substrate 6 in a range from 40 g/m.sup.2 to 60 g/m.sup.2 and is 0.25 mm thick. Furthermore, the adhesive tape 1 has an elongation at break of preferably 17%, and a breaking force in a range from 15 N/cm to 25 N/cm, preferably of 20 N/cm. Moreover, the adhesive force on steel is 4.9 N/cm, the adhesive force on a tape back is 6.2 N/cm, and the unrolling force is 5.2 N. The adhesive tape 1 is easily tearable manually. The noise damping here corresponds to class C, and the abrasion resistance corresponds to class B or class C.

(31) In both embodiments it has been shown that by increasing the fineness F or reducing the yarn strength of the adhesive tape 1, less adhesive force can arise on the tape back than an adhesive tape of the above-described type of the prior art, which includes a stitched fleece 2 having a lesser fineness F and is this thus more coarsely meshed. Simultaneously an improved adhesive force on steel can advantageously be achieved. These features are advantageously achieved for the inventive adhesive tape 1 with a simultaneous noise damping compared to an adhesive tape of the above-described type and an improved abrasion-resistance class.

(32) In a third embodiment of the stitched fleece 2 the fibers 3, 4 are stitched with stitching yarns 5 having a linear density of 50 dtex and having a fineness of F 28. In this embodiment the grammage of the stitched fleece 2 falls in a range between 60 g/m.sup.2 and 70 g/m.sup.2. Furthermore, this embodiment of the stitched fleece 2 has an elongation at break in a range of 15% to 30% and a breaking force in a range from 20 N/cm to 55 N/cm, depending on the type of stitching yarn used. The tear resistance has a value of 18,000 mN. Furthermore, the air permeability of the stitched fleece 2 falls in a range from 1600 l/m2s to 2000 l/m2s.

(33) The use of this stitched fleece 2 as substrate 6 leads to an adhesive tape 1 having the properties as shown in the following Table 4, column 6.

(34) The adhesive tape 1 has an application of adhesive on the substrate 6 in a range from 40 g/m.sup.2 to 60 g/m.sup.2 and is 0.25 mm thick. Furthermore, the adhesive tape 1 has an elongation at break of preferably 20%, and a breaking force in a range from 20 N/cm to 36 N/cm, preferably of 28 N/cm. Moreover, the adhesive force on steel is 4.6 N/cm, the adhesive force on a tape back is 7.8 N/cm, and the unrolling force is 6.2 N. The adhesive tape 1 is easily tearable manually. The noise damping here corresponds to class C, and the abrasion resistance corresponds to class B or class C.

(35) Here the adhesive tape 1 including a stitched fleece 2, which includes a stitched stitching yarn 5 of the same yarn strength and greater fineness F than a fleece-stitching yearn of an adhesive tape of the prior art and of the above described type has similar properties, wherein the applied quantity of adhesive can advantageously be significantly reduced. Furthermore, the abrasion resistance can advantageously be increased.

(36) In a fourth embodiment of the stitched fleece 2, stitching yarns 5 are stitched having a linear density of 50 dtex and having a fineness of F 28. In this embodiment the grammage of the stitched fleece 2 falls in a range between 76 g/m2 and 92 g/m2. Furthermore, this embodiment of the stitched fleece 2 has an elongation at break in a range of 20% to 50% and a breaking force in a range from 35 N/cm to 55 N/cm. The tear resistance has a value of 18,000 mN. Furthermore, the air permeability of the stitched fleece 2 falls in a range from 1600 l/m.sup.2s to 2000 l/m.sup.2s.

(37) The use of this stitched fleece 2 as substrate 6 leads to an adhesive tape 1 having the properties as shown in the following Table 4, column 8.

(38) The adhesive tape 1 has an application of adhesive on the substrate 6 in a range from 50 g/m2 to 100 g/m2 and is 0.25 mm thick. Furthermore, the adhesive tape 1 has an elongation at break of preferably 28%, and a breaking force in a range from 40 N/cm to 56 N/cm, preferably of 48 N/cm. Moreover, the adhesive force on steel is 6.0 N/cm, the adhesive force on a tape back is 8.1 N/cm, and the unrolling force is 5.5 N. The adhesive tape 1 is easily tearable manually. The noise damping here corresponds to class C, and the abrasion resistance corresponds to class B or class C.

(39) Compared to a known adhesive tape of the above-described type (compare, e.g., column 7 of table 4) the adhesive tape 1 including an inventive more-finely-stitched fleece-stitching yearn 5 has, in particular, an improved elongation at break and breaking force. The adhesive force on steel is also advantageously better compared to adhesive tapes of the prior art and of the above-described type.

(40) 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.