Self-windable, cross-tearable, textile industrial adhesive tape having a knitted substrate

Abstract

A self-windable, transversely tearable textile industrial adhesive tape (1) having a tape-shaped substrate (2) which has a thickness (D2) in the range of 0.05 mm to 1.8 mm, consisting of a knitted fabric (3) having stitches (5) made of yarn (4), and which is provided on one side with a pressure-sensitive adhesive coating (6) which is applied directly to the substrate (2) with a specific weight per unit area in the range of 20 g/m.sup.2 to 300 g/m.sup.2. In order to obtain improved manufacturability as well as improved functional characteristics, in particular an improved dimensional stability during the process, while preserving the advantages of using a substrate (2), it is proposed that the substrate (2) includes weft threads (7) running mutually parallel in the transverse direction, which weft threads (7) are held in the stitches (5) of the knitted fabric (3).

Claims

1. A self-windable, transversely tearable textile industrial adhesive tape consisting of: a tape-shaped substrate which has a thickness (D2) in the range of 0.2 mm to 1.5 mm, the tape-shaped substrate consisting of a fabric, the fabric having stitches made of yarn and weft threads running mutually parallel in a transverse direction (QR), the weft threads being held in the stitches of the fabric, and a pressure-sensitive adhesive coating on one side of the substrate and applied directly to the substrate, such that the adhesive tape has a thickness up to 2.5 mm and a weight that is less than 60 g/m.sup.2, wherein the weft threads have a linear density of 360 to 600 dtex, wherein the substrate has parallel lateral borders and the weft threads have free ends on the lateral borders, wherein the substrate is formed with closed or open stitches, the substrate comprising a basic warp knit construction of either a basic tricot pattern with a double-thread or multi-thread system, or a combination of a pillar stitch with one of a tricot pattern, a cloth pattern, a satin pattern, a velvet pattern, an atlas pattern, or a twill pattern, wherein the weft threads are texturized in such a way that the weft threads have a higher volume than smooth threads and then intermingled such that the weft threads have higher stability with cohesion not being achieved by twisting.

2. The adhesive tape according to claim 1, wherein the weft threads run at right angles to the warp direction in the warp knitted fabric.

3. The adhesive tape according to claim 1, wherein the fabric of the substrate is a stitch-bonded fabric.

4. The adhesive tape according to claim 1, wherein the fabric of the substrate has a gauge in the range of E9 to E 44 according to DIN ISO 8188:2009-02.

5. The adhesive tape according to claim 1, wherein the substrate has a specific weight per unit area of at least 20 g/m.sup.2.

6. The adhesive tape according to claim 1, wherein the substrate has a tear strength in the longitudinal direction of at least 15 N/cm.

7. The adhesive tape according to claim 1, wherein at break in the longitudinal direction, the substrate has an elongation no greater that 60%.

8. The adhesive tape according to claim 1, wherein when the substrate is relieved before reaching a break under longitudinal stress, the substrate has an elongation that is reduced upon being relieved by less than 50%.

9. The adhesive tape according to claim 1, wherein the adhesive coating comprises at least one of a natural or synthetic rubber, a silicone, an acrylate-based adhesive, and a UV crosslinkable adhesive.

10. The adhesive tape according to claim 1, wherein the adhesive coating is applied onto the substrate with a basis weight at least 20 g/m.sup.2.

11. The adhesive tape according claim 1, wherein the substrate has a stitch course count in the range of 2 per cm to 20 per cm.

12. The adhesive tape according to claim 1, wherein the substrate has a stitch wale count in the range of about 3 per cm to 15 per cm.

13. The adhesive tape according to claim 1, wherein the yarn of the stitches or the weft threads comprise at least one of polyester, polyamide (PA), polyethylene (PE), polypropylene (PP), polyacrylic (PAK), polyacrylonitrile (PAN), rayon, or cotton.

14. The adhesive tape according claim 1, wherein the yarn of the fabric has a linear density in the range of about 20 dtex to 167 dtex.

15. The adhesive tape according to claim 1, wherein the weft threads are made of at least one or a staple fiber yarn, a filament yarn, and a monofilament yarn.

16. The adhesive tape according to claim 1, wherein the weft threads are embedded in each course or wale of the fabric, wherein at least one of the stitches contains two or more of the weft threads.

17. The adhesive tape according to claim 16, wherein each of the stitches contains two or more of the weft threads.

18. The adhesive tape according to claim 1, wherein the weft threads have a thread count in the range of 5 to 100 threads per cm.

19. The adhesive tape according to claim 1, wherein the adhesive tape has an adhesive strength in the range of 2.0 N/cm to 15 N/cm on back of the tape.

20. The adhesive tape according to claim 1, wherein the substrate has an air permeability in the range of 50 l/m.sup.2s to 6000 l/m.sup.2s at a test pressure of 100 Pa when tested according to DIN 53 887.

21. The adhesive tape according to claim 1, wherein the adhesive tape has a noise reduction of at least Class C when tested according to LV 312.

22. The adhesive tape according to claim 1, wherein the adhesive tape has an abrasion resistance of at least Class C when tested according to LV 312.

23. The adhesive tape according to claim 1, wherein the adhesive tape has a tear strength in the range of 2000 mN to 30000 mN in an Elmendorf test in order to achieve tearability by hand.

24. The adhesive tape according to claim 1, wherein the fabric is free of runs.

25. The adhesive tape according to claim 1, wherein the weft threads extend in the fabric of the substrate at least in sections as partial wefts across one part (B1) of a width (B) of the substrate or at least in sections as full wefts across the entire width (B) of the substrate, wherein the weft threads run parallel or diagonally to courses or as transverse wefts diagonally to the courses with direction changes.

26. The adhesive tape according to claim 1, wherein the adhesive tape consists of the tape-shaped substrate and the pressure-sensitive adhesive coating, and the adhesive tape has been wound onto itself.

27. The adhesive tape according to claim 1, wherein the warp knitted fabric comprises a tricot lap.

28. The adhesive tape according to claim 1, wherein the warp knitted fabric comprises a pillar stitch, a satin lap, or a combination thereof.

29. A method of manufacturing an adhesive tape, the method consisting of the steps of: providing a tape-shaped substrate consisting of a fabric, the fabric having stitches made of yarn and weft threads running mutually parallel in the transverse direction (QR), the weft threads being held in the stitches of the fabric for the manufacture of a self-windable, transversely tearable textile industrial adhesive tape, wherein the substrate has a thickness (D2) in the range of 0.2 mm to 1.5 mm, wherein the weft threads have a linear density of 360 to 600 dtex, wherein the substrate has parallel lateral borders, and the weft threads have free ends on the lateral borders, and the weft threads are texturized and then intermingled in such a way that the weft threads have a higher volume than smooth threads and stability with cohesion not being achieved by twisting, wherein the substrate is formed with closed or open stitches, the substrate comprising a basic warp knit construction of either a basic tricot pattern with a double-thread or multi-thread system, or a combination of a pillar stitch with one of a tricot pattern, a cloth pattern, a satin pattern, a velvet pattern, an atlas pattern, or a twill pattern; and applying a pressure sensitive adhesive coating directly to the substrate, such that the adhesive tape has a thickness up to 2.5 mm and a weight that is less than 60 g/m.sup.2.

30. The method of manufacturing adhesive tape according to claim 29, further comprising: operating a substrate manufacturing means of a system consisting of, bars and knitting elements, which at least has an individual needle bar and a slider bar, a stitch sinker bar, a knock-over sinker bar with a knock-over sheet, one or two ground guide bars, one filler thread bar, which is configured as a guide or sinker and a weft insertion bar, or manufacturing by means of a system which at least comprises an individual needle bar and slider bar, one, two or three ground guide bars and a weft insertion bar, and manufacturing the substrate as a stitch-bonded fabric with open or closed stitches.

31. The method of manufacturing adhesive tape according to claim 29 further comprising: manufacturing the substrate without rubber elastic or elastomeric threads or yarns, manufacturing the substrate without washing out of spinning oil, without thermosetting and without calendaring, wherein the adhesive tape consists of the tape-shaped substrate and the pressure sensitive adhesive coating, and winding the adhesive tape onto itself.

32. The method of manufacturing adhesive tape according to claim 29 further comprising: applying the pressure-sensitive adhesive coating to the substrate using a roller application method or using a nozzle application method, including one of direct coating, contact coating or pressure-less, indirect coating.

33. A self-windable, transversely tearable textile industrial adhesive tape consisting of: a tape-shaped substrate which has a thickness (D2) in the range of 0.05 mm to 1.8 mm, the tape-shaped substrate consisting of a fabric, the fabric having stitches made of yarn and weft threads running mutually parallel in a transverse direction (QR), the weft threads being held in the stitches of the fabric, and a pressure-sensitive adhesive coating on one side of the substrate and applied directly to the substrate with a specific weight per unit area in the range of 20 g/m.sup.2 to 300 g/m.sup.2, such that the resulting adhesive tape exhibits a tear strength that is in the range of 2,000 mN to 10,000 mN, wherein the weft threads have a linear density of 360 to 600 dtex and a thread count on the order of 10 to 20 threads per cm, wherein the substrate has parallel lateral borders and the weft threads have free ends on the lateral borders, wherein the substrate is formed with closed or open stitches, the substrate comprising a basic warp knit construction of either a basic tricot pattern with a double-thread or multi-thread system, or a combination of a pillar stitch with one of a tricot pattern, a cloth pattern, a satin pattern, a velvet pattern, an atlas pattern, or a twill pattern, wherein the weft threads are texturized in such a way that the weft threads have a higher volume than smooth threads and then intermingled such that the weft threads have higher stability with cohesion not being achieved by twisting.

34. A self-windable, transversely tearable textile industrial adhesive tape consisting of: a tape-shaped substrate which has a thickness (D2) in the range of 0.2 mm to 1.5 mm, the tape-shaped substrate consisting of a fabric, the fabric having stitches made of yarn and weft threads running mutually parallel in a transverse direction (QR), the weft threads being held in the stitches of the fabric, and a pressure-sensitive adhesive coating on one side of the substrate and applied directly to the substrate, such that the adhesive tape has a thickness up to 2.5 mm and a weight that is less than 60 g/m.sup.2, wherein the resulting adhesive tape exhibits a tear strength that is in the range of 2,000 mN to 10,000 mN, wherein the weft threads have a linear density of 360 to 600 dtex and a thread count on the order of 10 to 20 threads per cm, wherein the substrate has parallel lateral borders and the weft threads have free ends on the lateral borders, wherein the substrate is formed with closed or open stitches, the substrate comprising a basic warp knit construction of either a basic tricot pattern with a double-thread or multi-thread system, or a combination of a pillar stitch with one of a tricot pattern, a cloth pattern, a satin pattern, a velvet pattern, an atlas pattern, or a twill pattern, wherein the weft threads are texturized in such a way that the weft threads have a higher volume than smooth threads and then intermingled such that the weft threads have higher stability with cohesion not being achieved by twisting.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantageous embodiments of the invention are contained in the subclaims as well as in the special description below. The invention will be explained in more detail with reference to several exemplary embodiments.

(2) The invention will be exemplified in more detail by means of the drawing, which shows:

(3) FIG. 1 a schematic cross-section of an adhesive tape according to the present invention,

(4) FIG. 2 a schematic top view of a first embodiment of a substrate of an adhesive tape according to the present invention,

(5) FIG. 3 a schematic top view of a second embodiment of a substrate of an adhesive tape according to the present invention,

(6) FIG. 4 a schematic top view of a third embodiment of a substrate of an adhesive tape according to the present invention,

(7) FIG. 5 an enlarged top view of the border of the third embodiment of the substrate of an adhesive tape according to the present invention

(8) FIG. 5a a view of the substrate of the adhesive tape according to the present invention, similar to that in FIG. 5, but at the beginning of a transverse tear,

(9) FIG. 6 an overview in the form of a table (Table 1) of the characteristics of a substrate of an adhesive tape according to the present invention and three different constructions,

(10) FIG. 7 an overview in the form of a table (Table 2) of the characteristics of an adhesive tape according to the present invention with the constructions according to FIG. 6 compared with those of two known adhesive tapes,

(11) FIG. 8 a schematic top view of a fourth embodiment of a substrate of an adhesive tape according to the present invention.

CONTINUED DESCRIPTION OF THE INVENTION

(12) With respect to the description below, it is expressly pointed out that the invention has not been restricted to the exemplary embodiments and also not restricted to all or several combinations of characteristics, but each individual partial characteristic of each exemplary embodiment, in particular in relation to the lines in both tables, can also be fundamental to the present invention independently of all other partial characteristics described in connection therewith, for example, other lines of the tables as such and also combined with any characteristics of another exemplary embodiment.

(13) The same parts will always be designated with same reference numerals in the figures of the drawing, so that they have each only been described once.

(14) FIG. 1 shows a self-windable, transversely hand-tearable, textile industrial adhesive tape 1 which has a thickness D and a tape-shaped substrate 2. The substrate 2 preferably has a thickness D2 in the range of 0.05 mm to 1.00 mm and consists of a knitted fabric 3 with stitches made of yarn 4. The substrate 2 is provided with a pressure-sensitive adhesive coating 6, which is directly applied with a specific weight per unit area in the range of 20 g/m.sup.2 to 350 g/m.sup.2 and consists of a natural or synthetic rubber and/or acrylate and/or silicone containing preferentially crosslinkable adhesive.

(15) According to the present invention, it is provided that the substrate 2 includes mutually parallel weft threads 7 in the transverse direction QR of the adhesive tape 1 according to the present invention, which weft threads 7 are held in the stitches 5 of the knitted fabric 3. The weft threads 7 in particular run at right angles to the longitudinal direction LR of the adhesive tape.

(16) The first embodiment of a substrate 2 of an adhesive tape 1 according to the present invention shown in FIG. 2 shows a very simple embodiment. In this case, the knitted fabric 3 is available as open pillar stitch lapping, and a weft thread 7 is pulled through each course. In the warp knitted fabric, the weft threads 7 are at right angles to the warp direction KR or to the basic direction of the length of the wales, which in this embodiment is identical to the longitudinal direction LR of the adhesive tape 1. The latter is also the case in the embodiments of the substrate 2 shown in FIGS. 3 and 8.

(17) In the second embodiment of the substrate 2 shown in FIG. 3, the knitted fabric 3 is a tricot lap. A weft thread 7 is pulled through each course here as well. Owing to the different marking (black and white) of the threads 4 of the knitted fabric 3, it is clear that it is a system with two threads (4afirst yarn thread, 4bsecond yarn thread) in a warp knitted fabric. The weft threads 7 are crosshatched in the drawing.

(18) FIGS. 4 to 7 refer to three different constructions of an adhesive tape according to the present invention 1, in which the knitted fabric 3 of the substrate 2 likewise is a warp knitted fabric and at the same time a stitch-bonded fabricthat is, a so-called warp stitch fabric. The basic overlap type is a pillar stitch. FIGS. 4, 5 and 5a should in particular be allocatedwith respect to the parameters of the knitted fabric 3 and of the weft threads 7to the construction 1 of FIGS. 6 and 7 outlined in the Tables 1 and 2.

(19) It is apparent from the top views of the embodiment of the substrate 2 of the adhesive tape 1 according to the present invention shown in FIGS. 4, 5 and 5a that the knit fabric 3 of the substrate 2 can preferably be a warp stitch fabric. A characteristic of the shown knitted fabric 3 is not only that the weft threads 7 are embedded in each course 5a of the knitted fabric 3, but also that two weft threads 7 are pulled through each stitch 5 of the knitted fabric 3. In this connection, however, two adjacent weft threads 7, which are both located in a stitch 5 in one course 5a, are not in a stitch 5 in the consecutive course 5a but together in a stitch 5 with the respective weft thread 7 located next to the weft thread 7 on the other side. As a result, a very stable fabric-like structure is obtained. This is also the purpose of the optional weft threads 4a running in the longitudinal direction LR, that is, along the course 5a, by means of which weft threads 4a the stitches 5 can become closed stitches. The course of wales in the stitches 5 is designated with the reference numeral 5b.

(20) Closed stitches 5 are understood to be stitches 5 whose feet intersect. Warp knitted fabrics are produced with closed and open stitches 5, knitwear and twill fabrics are produced with open stitches only. Closed stitches occur in warp knitted fabrics when the guide bar swings off after the overlap and carries out an overlap in the opposite direction.

(21) As FIGS. 5 and 5a show, the weft threads 7 are cut off on the borders of the substrate 2. The free ends 7a formed in that way facilitate the transverse tearability of the adhesive tape 1 according to the present invention, as is in particular exemplified in FIG. 5a. The weft threads 7 or the space Z between two adjacent weft threads 2 each form a point at which the tear can be started, and from where the stitches 5 can also be easily torn andcompared with a knitted fabric 3 without weft threads 7with less effort because the spread-out ends 7a of the adjacent weft threads 7 in this case act as a wedge on the substrate 2, in particular on its stitches 5. This is the case during the entire tearing process, in which one stitch 5 after the other is successively torn in the transverse direction QR.

(22) The constructions of the substrate 2 of the adhesive tape 1 according to the present invention have the properties listed in Table 1 (FIG. 6). As is apparent from a comparison of the corresponding columns of the table, the constructions in particular differ in the fiber strength of the yarn 4 of the knitted fabric 2 (indicated as sewing thread in Table 1), the weft thread strength (weft insertion), the type and strength of the fibers of the weft threads 7, as well as in the air permeability and transverse tearability (Elmendorf tear strength) of the substrate 2. Open stitches 5 were used in the construction 1 and 3, and closed stitches 5 were used in the construction 2.

(23) Both substrate constructions were converted to adhesive tapes 1 according to the present invention in the usual manner by coating them with an acrylate-based adhesive coating. The adhesive tapes 1 produced according to the present invention have the properties listed in Table 2 (FIG. 7). These properties are compared with those of a known, non-inventive adhesive tape with a stitch-bonded fabric substrate (PET stitch-bonded nonwoven fabric), which is known as Coroplast 8551 and designated with V1. Another comparable adhesive tape V2 known as Coroplast 847 X with a substrate consisting of a PET knitted fabric is listed in Table 2.

(24) The parameters indicated as basic data of the substrates and of the adhesive tapes were determined according to the following standards: EN ISO 2286-1 for the specific weight of the substrate 1, wale and wale course density according to DIN EN 14971, fiber strength (gauge) according to DIN 53830-3, thread density according to DIN EN 1049-2, DIN EN 1942 for the thickness D of the substrates, DIN EN 14410 for the mechanical values, DIN EN 1939 for the adhesive force, DIN EN 1944 for the unwinding force of the adhesive tapes, DIN 53 887 for the air permeability of the substrate, DIN EN 21974 for the tear strength. The flagging behavior, the noise dampening, and the abrasion resistance were determined according to LV 312.

(25) Table 1 (FIG. 6) in particular highlights the air permeabilities of the substrate 2, which, at a test pressure of 100 Pa was in an overall range of 50 l/m.sup.2s to 6000 l/m.sup.2s or in the preferred range of 100 l/m.sup.2s to 4000 l/m.sup.2s. In this case, the Elmendorf tear strength was from 6 N to 8 N, these values being characteristic for tearability by hand. In general, an adhesive tape 1 according to the present invention can have a tear strength in the range of 2000 mN to 30000 mN in an Elmendorf test, wherein in particular it can be in the range of 2000 mN to 10000 mN, preferentially in the range of 3000 mN to 8000 mN in order to achieve hand-tearability. The construction 3 shows a lower range limit of only 2000 mN for this parameter.

(26) In this connection, the acronyms in Table 2 (FIG. 7) mean: s/wpartly white, partly black substrate, i. O.all right, that is, no flagging after 30 minutes and 24 hours. The parameters indicated in Table 2 document the advantageous properties that can be obtained according to the present invention, in particular the comparable high abrasion values (Class 2 on the 5-mm pin in construction 2) and noise dampening (Class B or C in both constructions) with a low tear strength and tape thickness D as well as with a high adhesive force. The adhesive strength of the adhesive tape 1 according to the present invention can in particular be in the range of 2.0 N/cm to 15 N/cm, preferably in the range of 4.0 N/cm to 10 N/cm on steel and in the range of 2.0 N/cm to 15.0 N/cm, preferably in the range of 3.0 N/cm to 8.0 N/cm on the back of the tape.

(27) The invention is not restricted to the shown and described exemplary embodiments, but also comprises all embodiments consistent with the invention. Thus as already mentioned, the substrate material 1 can also be a knitted fabric 3 with other types of lap than that shown. In this connection, it is not strictly necessary that the weft threads 7 are at exactly right angles to the warp direction KR or to the basic direction of the of the length of the wales and that the longitudinal direction LR of the adhesive tape 1 is identical to the warp direction KR. Thus cloth, satin and velvet weaves, for example, have a basic direction KR of the length of their wales, which can be inclined at an acute angle to the right or left side relative to the warp direction KR of the pillar stitch weave shown in FIG. 2 (FIG. 7), and thus to the longitudinal direction of the adhesive tape 1. Therefore the weft threads 7 are not exactly at right angles to this warp direction KR in the knitted fabric 3, but still transverse thereto, and should in any case always and preferablyas shown in FIG. 2run transversely to the longitudinal direction LR of the adhesive tape 1 because their orientation essentially determines the course of the tear when tearing in the transverse direction. The resulting tear then likewise is at right angles to the longitudinal direction LR of the adhesive tape 1.

(28) The person skilled in the art can also expand the invention by means of additional advantageous measures without abandoning the scope of the invention. The adhesive tape 1 according to the present invention can thus for example be optionally provided with a flame-resistant finishing. That the adhesive tape according to the present invention is a self-windable adhesive tape implies that it can be self-woundthat is, wound on its own backand again unwound therefrom without the need for a siliconized interliner, which is reflected by the corresponding preferred adhesive forces in the range of 3.0 N/cm to 8.0 N/cm. The use of an interliner, however, is not beyond the scope of the invention, if, for example, these adhesive forces are required to be higher for certain applications.

(29) Furthermore, it should still be pointed out with reference to FIG. 8, which shows a fourth embodiment of a substrate 2, that on warp knitting, the weft thread 7 is interlaced between the needle loop and the sinker loop 5 of the fabric ground. Here the weft thread 7as shown in FIGS. 2 to 5, and in part in FIG. 8can either run across the entire width B of the substrate 2 of the adhesive tape 1 when it is called full weft and/or the weft thread 2as is especially shown in FIG. 8runs across only one part B1 of this width B, when it is called partial weft.

(30) The weft thread 7 can run horizontally, diagonally oronly in case of partial weftsvertically in the warp knitted fabric 3. Conventional guide bars which exclusively insert their warp threads in an underlap position into the substrate 2 are used to produce partial wefts. In the case of underlaps of different lengths and direction changes, inversion points U of the partial wefts result within the width B of the substrate 2.

(31) Full wefts can be inserted into a warp knitted fabric 3 as a parallel weft (parallel to the courses 5a), as a diagonal weft (diagonal to the courses 5a) or as a cross weft (diagonal to the courses 5a with direction changes). They are produced by means of so-called magazine weft insertion devices. Full wefts are produced according to the course or not according to the course. Monoaxial, biaxial and multiaxial knitted fabrics 3 can be produced by means of full wefts. Full wefts can provide the substrate 2 with dimensional stability or elasticity along their axis, depending on the yarn 4 used.

(32) In an adhesive tape 1 according to the present invention, the weft threads 1 can extend in the knitted fabric 3 of the substrate 2 at least in sections as partial wefts across one part B1 of the width B of the substrate 2 and/or at least in sections preferably as full wefts across the entire width B of the substrate 2, wherein the weft threads 7 run parallel or diagonally to the courses 5a or also as transverse wefts diagonally to the courses 5a with direction changes. Although free ends 7a of the weft threads 7 are preferred owing to their higher wedge effect, cutting of the inversion points U of the weft threads can be dispensed with in particular if their linear density is in a range below 200 dtex.Z

(33) 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.