METHOD AND APPARATUS FOR MAKING ADHESIVE TAPE

Abstract

A method of making adhesive tape has the steps of advancing a substrate band longitudinally in a machine direction from a supply to an array of laser units, cutting the band longitudinally with the laser units into a plurality of longitudinal strips, and then cutting each of the longitudinal strips longitudinally into a plurality of tapes. An adhesive is applied to a face of each of the tapes, and the tapes are wound up individually.

Claims

1. A method of making adhesive tape, the method comprising the steps of: advancing a substrate band longitudinally in a machine direction from a supply to a plurality of laser units; cutting the band longitudinally with the laser units into a plurality of longitudinal strips; cutting each of the longitudinal strips longitudinally into a plurality of tapes; applying an adhesive to a face of each of the tapes; and winding the tapes up individually.

2. The method according to claim 1, wherein the longitudinal strips abut one another transversely without spacing and extend over an entire width of the substrate band.

3. The method according to claim 1, wherein a respective laser unit is assigned to each of the longitudinal strips and cuts same into the tapes.

4. The method according to claim 3, wherein the tapes of each longitudinal strips are all laser cut to a predetermined width.

5. The method according to claim 1, wherein each of the longitudinal strips is cut into tapes of a predetermined width.

6. The method according to claim 1, wherein each laser unit has a respective laser source and a respective beam deflector, the method comprising the step of: deflecting a laser beam of each of the laser sources by the respective beam deflector to form a plurality of longitudinal laser cuts subdividing the respective longitudinal strip into a plurality of the tapes of predetermined length.

7. The method according to claim 6, wherein each beam deflector is deflected to make parallel longitudinal cuts of a predetermined longitudinal length in the respective longitudinal strip.

8. The method according to claim 7, wherein a number of the longitudinal cuts determines a number of tapes in the respective longitudinal strip.

9. The method according to claim 6, wherein the longitudinal cuts extend in the machine direction adjacent one another.

10. The method according to claim 9, wherein the band is subdivided into longitudinally succeeding zones that are longitudinally succeed one another and the extend continuously without transverse offset from each zone to the longitudinally adjacent zones.

11. The method according to claim 1, further comprising the steps of: displacing the laser units synchronously with the substrate band.

12. A method of making adhesive tapes, the method comprising the steps of: advancing a substrate band longitudinally at a travel speed in the machine direction from a supply past the an array of transversely spaced laser units such that longitudinally succeeding zones of the band pass the array; displacing the laser units synchronously downstream with the band over each of the zones while cutting the band longitudinally with the laser units into a plurality of longitudinal strips and cutting each of the longitudinal strips longitudinally into a plurality of tapes; and winding the tapes up individually.

13. An apparatus for making adhesive tapes, the apparatus comprising: a source of a substrate band extending longitudinally in a machine direction from the source; a plurality of laser units spaced longitudinally from the source and adjacent; and control means connected to the laser units for cutting the band longitudinally with the laser units into a plurality of longitudinal strips, and cutting each of the longitudinal strips longitudinally into a plurality of tapes.

14. The apparatus according to claim 13, wherein each laser unit has a respective laser source and beam deflector.

15. The apparatus according to claim 13, wherein each beam deflector has two deflection mirrors each pivotable in two mutually perpendicular planes.

16. The apparatus according to claim 15, wherein each laser unit includes a respective galvanometer scanner for pivoting the respective two mirrors.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0027] The above and other objects, features, and advantages will become more readily apparent from the following description, it being understood that any feature described with reference to one embodiment of the invention can be used where possible with any other embodiment and that reference numerals or letters not specifically mentioned with reference to one figure but identical to those of another refer to structure that is functionally if not structurally identical. In the accompanying drawing:

[0028] FIG. 1A is a schematic view of the apparatus according to the invention for making adhesive tape;

[0029] FIG. 1B is a top view of the substrate band;

[0030] FIG. 2 is an enlarged perspective view of the apparatus according to the invention;

[0031] FIG. 3 is a section through the apparatus of FIG. 2 in the area of the laser units; and

[0032] FIG. 4 is a schematic detail view of the beam deflector.

SPECIFIC DESCRIPTION OF THE INVENTION

[0033] As seen in FIG. 1, a substrate band 1 is fed from a supply roll 2 in a machine direction MR that coincides with the longitudinal extent of the substrate band 1. The substrate band 1 is specifically a fabric, for example a PA web. It is provided with an adhesive coating over all of one of its faces.

[0034] The prefabricated substrate band 1 is now cut in the machine direction MR with the aid of laser units 4, 5 in the longitudinal or machine direction MR to form individual adhesive tapes 6 that can be seen at the downstream end. For this purpose, the laser units 4, 5 form cuts 7 and 7′ in the substrate band extending in the longitudinal or machine direction MR, as can be seen from the top view of the substrate band 1.

[0035] According to the invention, several laser units 4, 5 are used. To distinguish the laser units 4, 5 they are each identified individually at 4.sub.1, 5.sub.1; 4.sub.2, 5.sub.2; and 4.sub.3, 5.sub.3. This can be seen from FIGS. 2 and 3. The several laser units 4, 5 or 4.sub.1, 5.sub.1; 4.sub.2, 5.sub.2; and 4.sub.3, 5.sub.3 now ensure that the substrate band is transversely subdivided at the cuts 7 into longitudinal strips 8.sub.1, 8.sub.2, and 8.sub.3. The overall design is such that the laser unit 4.sub.1, 5.sub.1 forms the longitudinal strip 8.sub.1, the laser unit 4.sub.2, 5.sub.2 forms the longitudinal strip 8.sub.2, and the laser unit 4.sub.3, 5.sub.3 forms the longitudinal strip 8.sub.3.

[0036] The longitudinal strips 8.sub.1, 8.sub.2, and 8.sub.3 each extend longitudinally of the substrate band 1, that is in the machine direction MR. Furthermore, it can be seen that the individual longitudinal strips 8.sub.1, 8.sub.2, and 8.sub.3 are transversely subdivided in the zone 9 extending in the longitudinal or machine direction MR by the cuts 7′.

[0037] The individual longitudinal strips 8.sub.1, 8.sub.2, and 8.sub.3 abut one another transversely without spacing and, taken together, extend over the entire width B of the substrate band 1. This width B of the substrate band 1 can be between several centimeters and up to 1 m or even more. In fact, the substrate band 1 is fed from the supply unit 2 that is designed as a drum to the laser unit 4, 5 or the several laser units 4.sub.1, 5.sub.1; 4.sub.2, 5.sub.2, and 4.sub.3, 5.sub.3, via deflection rollers 10. After the laser units 4.sub.1, 5.sub.1; 4.sub.2, 5.sub.2; and 5.sub.3, 4.sub.3 have been used to form longitudinal cuts 7 in the substrate band 1, the adhesive tapes 6 made in this way are separated and wound up on respective take-up reels 11 and, for example, made up into spiral adhesive tape rolls.

[0038] Several adhesive tapes 6 are thus formed in each of the three longitudinal strips 8.sub.1, 8.sub.2 and 8.sub.3 with the aid of the associated laser unit 4.sub.1, 5.sub.1; 4.sub.2, 5.sub.2; and 4.sub.3, 5.sub.3. According to this embodiment, the laser unit 4.sub.1, 5.sub.1 forms three cuts 7 in the longitudinal strip 8.sub.1, making in this way and at the output end a total of four strip-shaped adhesive tapes 6 from the longitudinal strip 8.sub.1 of the substrate band 1. A similar procedure can be followed for the other longitudinal strips 8.sub.2 and 8.sub.3. However, it is also possible for the laser unit 4.sub.2 and 5.sub.2 to make a different number of cuts 7 in the respective longitudinal strip 8.sub.2, so that this also results in a different number of adhesive tapes 6 at the output end compared to the longitudinal strip 8.sub.1. This is not shown in detail. This means that the adhesive tapes 6 produced in the respective longitudinal strips 8.sub.1, 8.sub.2 and 8.sub.3 are cut with respective different widths. In addition, the design is such that the substrate band is divided by the cuts 7′ in a transverse direction Q perpendicular to the machine or longitudinal direction MR into the longitudinal strips 8.sub.1, 8.sub.2, and 8.sub.3 all of the same width.

[0039] FIGS. 2 and 3 show that the three laser units 4.sub.1, 5.sub.1; 4.sub.2, 5.sub.2; and 4.sub.3, 5.sub.3 comprise respective laser sources 4.sub.1, 4.sub.2, and 4.sub.3 and respective beam deflectors 5.sub.1, 5.sub.2, and 5.sub.3. The laser sources 4.sub.1, 4.sub.2, and 4.sub.3 are spaced transversely to the machine direction MR. The beam deflectors 5.sub.1, 5.sub.2, 5.sub.3, each deflect a respective laser beam 12 emitted by the respective laser source 4.sub.1, 4.sub.2, and 4.sub.3 and shown in particular in FIG. 4 to create the individual adhesive tapes in the respective longitudinal segment 8.sub.1, 8.sub.2, or 8.sub.3 each extending longitudinally to make the individual cuts 7 of predetermined length L. In fact, the design is such that the beam deflectors 5.sub.1, 5.sub.2, and 5.sub.3 make the cuts 7 in the respective longitudinal strips 8.sub.1, 8.sub.2, and 8.sub.3 of the predetermined length L in the zone 9.

[0040] In fact, the cuts 7 in the zone 9 consequently may have the length L of, for example, 50 mm to 100 mm or even more. After the laser unit 4.sub.1, 5.sub.1, has created the first cut 7 in the longitudinal strip 8.sub.1, the laser beam 12 jumps to the second cut 7 and creates it with the same length L until, according to this embodiment, all three cuts 7 have been produced in the longitudinal strip 8.sub.1 at the section 9 and with the length L. This means that the beam deflector 5 or the laser unit 4 in general produces parallel cuts of the same length L in the respective longitudinal strips 8.sub.1, 8.sub.2, and 8.sub.3. The number of cuts 7 determines the number of tapes 6 at the output end. In addition, the design is such that the laser unit 4, 5 or the beam deflector 5 creates the parallel cuts 7 of the specified length L adjacent to each other in the machine direction MR in the respective longitudinal strip 8.sub.1, 8.sub.2 and 8.sub.3. The speed of the beam deflector must be at least be three times the speed of the substrate band 1.

[0041] In order to now provide a total of the strip-shaped adhesive tapes 6 with a length of several meters on the output end in this embodiment and according to the design, the parallel cuts 7 are connected longitudinally to each other without any offset. This means that as soon as the laser unit 4.sub.1, 5.sub.1, in the first section 9 of the longitudinal strip 8.sub.1 has produced the three cuts 7 with the length L provided and shown in the example, the overall feed of the strip-shaped cut 7 ensures that the three parallel cuts 7 are aligned with each other without offset in the machine direction MR so that the cuts in the longitudinal strip 8.sub.1 can then be produced in the following section 9. The parallel cuts 7 adjoin each other without offset. In addition, the design is such that the speed of the substrate band 1 and that of the beam deflector 5.sub.1, are conformed to each other in the example of the longitudinal strip 8.sub.1. A central controller 13 takes care of the synchronization. For this purpose, the central controller 13 receives signals from a sensor 20 that detects the travel speed of the substrate band 1 and transmits it to the central controller 13. In addition, the central controller 13 is connected to each of the individual laser units 4.sub.1, 5.sub.1; 4.sub.2, 5.sub.2 and 4.sub.3, 5.sub.3 in order to control them accordingly so that with their aid the longitudinal cuts 7 can be produced in the respective section 9 of the corresponding longitudinal strips 8.sub.1, 8.sub.2, and 8.sub.3. Not expressly shown is the further possibility that, the central controller 13 operates a drive for the substrate band 1 for setting its speed in the machine direction MR as a function of the signals from the sensor 20.

[0042] The detailed view of FIG. 4 shows that the beam deflector is equipped with at least two deflection mirrors 14, 15. These two deflection mirrors 14, 15 can be pivoted in two mutually perpendicular planes. For this purpose, each deflection mirror 14 is equipped with a respective galvanometer scanner 16, 17 that in turn is controlled and actuated with the aid of the central controller 13.

[0043] FIG. 4 also shows that the laser beam 12 is focused on the plane of the substrate band 1. For this purpose spreader optics 18 are provided that refocus the laser beam 12. The spreader optics 18 has a lens 19 that can be moved by a drive parallel to the laser beam 12. The lens 19 is, like the galvanometric scanners 16, 27, operated by the controller 13.

[0044] In addition to changing the focus of the laser beam 12 with the aid of the controller 13, the latter is finally also capable of correcting the position of the substrate band 1 in the transverse direction Q. For this purpose, for example, individual or all of the deflection rollers 10 (as well as the supply unit 2, if applicable) can be moved in their longitudinal direction and thus in the transverse direction Q with the aid of the controller 13, if necessary, in order to ensure that the individual cuts 7 actually connect to each other from section 9 to section 9 without offset. Not shown is the option of cooling the beam deflector 5 in each case with water, for example, in order to achieve maximum positional stability of the deflection mirrors 14,15. Also not shown is the option of the central controller 13 being connected to a higher-level network, for example the Internet, in order in this way to facilitate remote monitoring or to import programs from outside for controlling the respective laser unit 4, 5.