WO2004016847A1 - Method, device and installation for cutting textiles by means of a laser beam - Google Patents

Abstract

According to the invention, a laser beam (24) is used as a cutting tool to cut textiles consisting of synthetic fibres or partly consisting of synthetic fibres, such as airbag materials, said laser beam being focussed onto the textile material (30) from a laser source (22) by means of an expanding optical element (26) and two successive galvanometer scanners (32, 34) driving deviation mirrors (28, 29). The expanding optical element (26) has a variable focal distance due to a motor-driven lens displacement, such that the focal distance is always located on the cutting plane defined by the textile material (30), when the laser beam is deviated by the galvanometer scanners. Said galvanometer scanners are provided with mirrors (28, 29).

Description

 METHOD, DEVICE AND SYSTEM FOR CUTTING TEXTILES

BY LASER

The invention relates to a method for cutting textiles, which consist of plastic fibers or have a proportion of plastic fibers, by means of a laser beam according to a predetermined cutting pattern. Furthermore, the invention relates to a cutting device for performing the method. Finally, the invention relates to a cutting system for cutting textiles by means of such cutting devices. In particular, the present invention relates to the cutting of airbag materials that can be coated or uncoated.

Textiles of this type, which can be made of polyamide, polyester or polyethylene, for example, or have a proportion of such synthetic fibers, are cut in high-layer cutters in order to achieve a high output. Layers of the material to be cut, for example airbag material, and foils are first placed alternately on top of each other. The up to 20 layers lying one above the other are then fed to the laser cutting system and cut in the laser cutting system by means of a laser beam. The film intermediate layers are necessary after otherwise adjacent layers of the textile material would weld together at the cut edges due to the plastic fibers or the plastic fiber portion.

There are some disadvantages to this approach. On the one hand, the additional film intermediate layers are required to avoid welding at the cut edges. When selling the intermediate layers must then be separated out individually from the cut parts, which requires additional work. Since the individual layers in the cutting station cannot be sucked in by means of a vacuum, it cannot be guaranteed that they lie completely flat and there is a high waviness or unevenness of the fabric layers due to air inclusions and by warping of the individual layers. This often leads to inaccurate cuts. Furthermore, there is the risk that clean cut edges do not always result after this requires cutting in the focus area of the laser beam, which in the case of a plurality of layers arranged one above the other always means that the upper and lower layers lie outside the focus area.

An alternative to cutting textiles using high-layer cutters is cutting on a single-layer cutter. As a rule, this is a plotter that moves a laser cutting head in the X and Y directions. The advantages of a single-layer cutter can be seen in the fact that no intermediate layers are required here and the textile material is also relatively flat, which leads to better cutting results and higher accuracy compared to the high-layer cutter. A disadvantage of single-layer cutters is the low working speed. Very fast plotters have a maximum working speed of 2 m / sec with an acceleration of 1.5 g and are therefore not a real alternative to the high-position cutter in terms of the output volume.

The invention is therefore essentially based on the object of creating a cutting system for cutting textiles which are made of plastic or have a proportion of plastics by means of a laser beam, which has the basic advantages of a single-layer cutter, but which on the other hand has very high cutting speeds allowed. To achieve this object, it is essentially provided with regard to the method according to claim 1 that a preferably fixed laser beam is widened, deflected according to the cutting pattern to be generated and focused on the textile to be cut.

Regarding the cutting device for carrying out the method according to the invention, it is provided according to claim 2 that it contains the following: a laser source for generating a laser beam, an expansion lens for expanding the laser beam generated in the laser source, a motor-driven deflection mirror device for deflecting the expanded laser beam in accordance with the one to be generated Cutting pattern, a motor-driven focusing device for focusing the laser beam on the plane of the textile to be cut depending on the deflection of the laser beam, and a control device for controlling the operation of the cutting device.

In a preferred development of the invention, the focusing can be realized in that the expansion optics are equipped with a variable focal length, for which purpose a lens or lens group of the expansion optics can be motor-displaceable in the direction of the laser beam.

In a preferred development of the invention, the deflecting mirror device can comprise two deflecting mirrors which can be pivoted in two mutually perpendicular planes, a galvanometer scanner preferably being provided for pivoting each deflecting mirror.

In the case of the present invention, the laser beam serving as a cutting tool is thus focused on the tissue by the laser beam source via the expansion optics and two subsequent galvanometer scanners, the expansion optics being equipped with a variable focal length, which ensures that when the laser beam is deflected via the Galvanometer- Scanner the focal point of the laser beam is always on the cutting plane.

Thus, while in the prior art according to the single-layer cutter described above, only a limited working speed is possible after the complete axes of the plotter and also the cutting head have to be moved in this system, in the case of the present invention very high cutting speeds are involved High acceleration possible after only the deflection mirrors have to be deflected via the galvanometer, which results in small mass movements. Also, in the case of the present invention, the effort that has to be made for the mechanical construction of the cutting system is less than in the prior art, since in the prior art comparatively large masses have to be moved and are thus taken care of in a complex manner for a vibration-free construction must be, which absorbs the corresponding forces.

It is also advantageous that, in the case of the present invention, the textile material can be cut from the roll, as a result of which, in comparison to the high-layer cutters, in which the length of the layers is predetermined by the laying machine used to lay the layers possible nesting of the cuts results in optimal use of the fabric.

In a preferred development of the invention, a cutting system for cutting textiles is provided which has at least two cutting devices according to the invention, a common control device being provided for the at least two cutting devices and the at least two cutting devices being arranged and controllable in such a way that immediately adjacent areas of the to be cut Textiles can be cut. This makes it possible to cut fabric webs of greater width in a single pass, in the case of using two adjacent mutually arranged cutting devices, for example a width of 300 cm, if each cutting device has a working width of 150 cm.

Further advantageous features of the invention emerge from the remaining subclaims and from the following description in which several exemplary embodiments of the invention are explained in more detail with reference to the drawing. The drawing shows in a semi-schematic representation:

1 is a perspective view of the cutting device according to the invention,

Fig. 2 is a front view of a cutting system according to the invention with two cutting devices, and

3 shows a side view of the cutting system according to FIG. 2.

Reference is first made to FIG. 1. The cutting device sketched there is designated overall by the reference number 20 and the textile material to be cut is designated by the reference number 30. The cutting device 20 comprises a fixed laser 22, which generates a laser beam 24. The laser beam 24 first passes through an expansion lens 26 in which the laser beam 24 is expanded. The expanded laser beam 24 'is then successively reflected on two mirrors 28, 29 which then direct the laser beam onto the textile material 30 to be cut in accordance with a predetermined cutting pattern.

The deflecting mirror 28 can be pivoted in a plane parallel to the plane of the textile material 30 and the deflecting mirror 29 can be pivoted in a plane that is perpendicular to the plane of the textile material 30. To pivot the swivel mirrors 28, 29, they are each connected to a galvanometer scanner 32 or 34 in terms of drive. The galvanometer scanners 32, 34 are controlled by a control device (not shown) in such a way that the laser beam 24 'on the textile material 30 generates the cut according to a predetermined cutting pattern. For this it is necessary that the laser beam 24, 24 'is focused on the plane of the fabric 30. In order to achieve an exact focusing of the laser beam on the plane of the textile material 30, regardless of the angle which the moving laser beam occupies with the plane of the textile material 30 and therefore regardless of the length of the laser beam 24 ′, the laser beam moves on the textile material 30 he ordered to continuously refocus the laser beam. For this purpose, the expansion optics 26 are equipped with a variable focal length, the lens 36 of the expansion optics 26 being motor-displaceable in the direction of the laser beam; the above-mentioned control, not shown, takes over the control of the lens shift in order to maintain exact focusing.

Depending on the geometry of the arrangement, the laser beam has a working area of approximately 200 mm x 200 mm to approximately 1,500 mm x 1,500 mm. With a laser power in the range of approximately 500 watts to approximately 3,000 watts, for example, airbag material can be cut at very high speeds, that is to say at speeds of up to approximately 7 m / sec.

2 and 3, which show a cutting system with two cutting devices. The cutting system comprises a feed station 40, from which ribbon-shaped textile material 42 is unwound from a supply roll 44, a cutting station 46, in which the ribbon-shaped material is cut by means of laser beams in accordance with the predetermined cutting pattern and which is covered by a radiation protection housing 54, and a removal station 48, in which the cut parts are removed or transported away on a conveyor belt or a conveyor 52. In the case of the exemplary embodiment, the band-shaped textile material 42 has a width of 3 m. In the cutting station 46, two laser cutting devices are arranged side by side. The laser beams emerging from the laser sources 22 meet, after they have passed through the expansion optics and after deflection via suitable mirrors, to the respective scanner device 25, which in each case comprises the two galvanometer scanners 32, 34 together with mirrors 28, 29. From here, the two laser beams are deflected into the cutting plane 50 onto the textile web according to the predetermined pattern, whereby they are focused in the plane 50. As can be seen from FIG. 2, the two scanner arrangements 25 are arranged next to one another transversely to the fabric web 42 and are capable of processing half the width of the web in each case.

The web of fabric can be transported through the cutting station either step by step, so that when the web of fabric is at a standstill, or continuously, so that the web of web is cut in one pass. In the latter case, the system is particularly compact.

In the described embodiment of the invention, contour cuts with a maximum width of 3000 mm and with a practically unlimited length are possible.

Even with continuous passage of the fabric web, contour cuts are practically of any shape without size limitation, i.e. possible over the entire available width.

Claims

Expectations 1. A method for cutting textiles (30), which consist of plastic fibers or have a proportion of plastic fibers, by means of a laser beam (24, 24 ') according to a predetermined cutting pattern, a laser beam being widened, deflected according to the cutting pattern to be produced and onto which textile (30) to be cut is focused. 2. Cutting device for cutting textiles (30), which consist of plastics or have a proportion of plastics, according to a predetermined cutting pattern, for carrying out the method according to claim 1, wherein the cutting device (20) contains the following: a laser source (22) for Generation of a laser beam (2.-4), expansion optics (26) for expanding the laser beam generated in the laser source, a motor-driven deflection mirror device (28, 29, 32, 34) for deflecting the expanded laser beam in accordance with the cutting pattern to be generated, a motor-driven focusing device (36) for focusing the laser beam (24) onto the plane of the textile (30) to be cut depending on the deflection of the laser beam, and a control device for controlling the operation of the cutting device (20). 3. Cutting device according to claim 2, characterized g e k e n nz e i c h n e t that the expansion optics (26) is equipped with a variable focal length. 4. Cutting device according to claim 3, characterized in that a lens (36) or group of lenses Expansion optics (26) motorized in the direction of the laser beam (24) is movable. 5. Cutting device according to one of claims 2 to 4, characterized in that the deflecting mirror device comprises two deflecting mirrors (28, 29) which can be pivoted in two mutually perpendicular planes. 6. Cutting device according to claim 5, characterized in that a galvanometer scanner (32, 34) is provided for pivoting each deflecting mirror (28, 29). 7. Cutting device according to one of claims 2 to 6, characterized g e k e n n z e i c h n e t that the laser source (22) is stationary. 8. Cutting system for cutting textiles, the at least two cutting devices (20) according to one of claims 2 to 7, wherein a common control device is provided for the at least two cutting devices and the at least two cutting devices are arranged and controllable in such a way that immediately adjacent areas of the textiles to be cut can be cut. 9. Cutting system according to claim 8, wherein a textile web (42) can be fed to a cutting area (50) of the cutting system, in which the textile web is cut according to the cutting pattern, the deflecting mirror devices (25) of the at least two cutting devices (20) transverse to Transport direction of the textile webs (42) are arranged side by side. 10. Cutting system according to claim 9, characterized in that the textile web (42) the cutting area (50) according to the cutting pattern to be cut is gradually 'fed. 11. Cutting system according to claim 9, characterized in that the textile web (42) can be fed continuously to the cutting area (50). 12. Cutting system according to one of claims 9 to 11, characterized in that the textile web (42) can be fed from a supply roll (44).