METHOD OF MAKING ADHESIVE TAPE FOR WRAPPING CABLES

Abstract

The invention relates to a method for producing an adhesive tape, in particular a wrapping tape to be wrapped around cables in automobiles. In said method, at least one face of a perforated support (1) is coated with an adhesive. According to the invention, a mechanically and/or chemically reinforced nonwoven fabric is used as the perforated support (1).

Claims

1. A method of making an adhesive tape, the method comprising the steps of: mechanically or chemically consolidating a substrate made of nonwoven fabric, before or afterward perforating- the substrate, and thereafter coating the perforated and consolidated substrate with an adhesive on at least one side.

2. The method defined in claim 1, wherein the nonwoven fabric is consolidated chemically by a binder.

3. The method defined in claim 2, wherein the binder is applied on at least one side of the substrate by spraying, rolling, or doctoring.

4. The method defined in claim 1, wherein the nonwoven fabric is consolidated mechanically by overstitching with threads.

5. The method defined in claim 4, wherein the nonwoven fabric is overstitched with longitudinal threads having a thread density of <22 threads/25 mm width of the substrate.

6. The method defined in claim 1, wherein the mechanically or chemically consolidated nonwoven fabric is perforated with the aid of hot needles.

7. The method defined in claim 6, wherein the needles are mounted on a needle roller with a density of at least 3/cm.sup.2.

8. The method defined in claim 6, wherein the needles are provided in a defined pattern that avoids the overstitched longitudinal threads of the substrate to be perforated.

9. The method defined claim 6, wherein the needles have a temperature of greater than 100 C.

10. The method defined in claim 1, wherein the size of the perforations is small enough that there is no penetration to completely through the substrate at the perforations during the subsequent coating with the adhesive, and whereby the perforation holes are prevented from becoming clogged by the adhesive.

11. Use of an adhesive tape with a perforated substrate based on a mechanically or chemically consolidated nonwoven fabric and a one-sided coating with adhesive as defined in claim 1, as a tape for wrapping cables in an automobile.

Description

[0029] The invention is explained in further detail below with reference to a schematic drawing that illustrates only one embodiment. The sole FIGURE shows an adhesive tape made according to the method according to the invention.

[0030] The adhesive tape shown schematically in the FIGURE has a perforated substrate 1 being primarily visible. This substrate 1 is shown in a top view. A coating with adhesive (not shown) is applied to its rear side. The substrate 1 is a perforated nonwoven. It has first been consolidated mechanically and/or chemically for this purpose. Here the substrate 1 has been consolidated by overstitching with the aid of longitudinal threads 2. This is therefore a stitch bonded nonwoven. For this purpose, the longitudinal threads 2 have been applied to the substrate 1 in the embodiment by overstitching with a thread density of <22 threads/25 mm width of the substrate 1. In general, a stitch length of about 3 mm or more is used here for the longitudinal threads 2.

[0031] The substrate 1 consolidated mechanically in this manner by overstitching is then perforated. For this purpose, the mechanically consolidated substrate 1 is worked with the aid of needles 3 shown generally, which are illustrated generally in the sole FIGURE. The needles 3 together form longitudinal strips 4. Longitudinally extending spaces or gaps 5 are thus formed in the substrate 1 between the respective longitudinal strips 4.

[0032] The overall configuration is such that the needles 3 are mounted on a needle roller or on a needle board and have a density of at least 3/cm.sup.2. Moreover, the needles 3 have a defined pattern on the needle roller or on the needle board, which is reflected in the longitudinal strips 4 in FIG. 1. It can be seen that the longitudinal spacing of the needles 3 is about twice as great as their transverse spacing. In fact, the individual longitudinal strips 4 in FIG. 1 can be done by a rolling movement of the needle roller (not shown) in consideration of one revolution. The needles 3 are provided on the needle roller such that the longitudinal strips 4 are respectively formed there, particularly with the interposed spaces or gaps 5. It can be seen that the spaces or gaps 5 between the individual longitudinal strips 4 are of equal size. Moreover, the spaces or gaps 5 are always located in areas in which the overstitched longitudinal threads 2 are provided on the substrate 1. This means that the pattern of the needles 3 on the needle roller or on the needle board is configured and provided on the needle roller or on the needle board such that the overstitched longitudinal threads 2 of the substrate 1 to be perforated are left out, because the spaces or gaps 5 in the area of the longitudinal threads 2 are placed between the individual longitudinal threads 4 during perforation. That is, the needle roller or needle board and the substrate 1 must be aligned opposite to one another during perforation, for example relative to a common reference line longitudinally, which can be one or both longitudinal edges of the substrate 1.

[0033] In this way, the needles 3 on the needle roller or needle board ensure during perforation of the longitudinal substrate 1 in its longitudinal extension that only the areas between the overstitched longitudinal threads 2 are perforated and that no perforation occurs in the area of the longitudinal threads 2, because the needles 3 are left out there on the needle roller, meaning that spaces or gaps 5 are found there. As a result, no collision occurs during perforation between the hot needles 3 and the longitudinal threads 2, so that the strength thereof is not impaired even after perforation.

[0034] Nevertheless, continuous perforation lines 6 are present, particularly in the transverse extension of the substrate 1, which are left out only in the area of the spaces or gaps 5. The adhesive tape made in this manner can be torn transversely without any difficulty along these perforation lines 6, with tensile strengths of less than 10 N/cm being typically observed.

[0035] Consequently, the finished adhesive tape is especially suitable for applications as wrapping tape for wrapping cables in automobiles. This is especially the case in view of the fact that fibers based on polyester, polypropylene, polyamide, etc., are used as fibers for making the substrate or nonwoven substrate 1. Furthermore, the nonwoven fabric can be a spunbond nonwoven or staple-fiber nonwoven. The continuous longitudinal threads 2 provide the necessary strength and longitudinal stretch-to-break, which is generally less than 30% and particularly less than 20%. Nevertheless, the perforation lines 6 provide for the desired manual tearability transversely. These are the basic advantages.