EP0517142A1 - Process for cutting out sheet material, particularly woven material - Google Patents

Abstract

A process for cutting out parts (blanks 1 to 8) from a web of material, in particular a web of woven material, such as a web of fabric (10), is specified, in which the web of fabric (10) is longer than the available cutting surface (17) of a cutting table (16), on which the cutting takes place using a pattern. According to the invention, firstly a first partial surface (11) is cut, if appropriate a separation cut (14) is made transversely to the web of fabric (10) after all the complete blanks and a reference point (15) is defined, preferably in the portion of the web of fabric (10) which has not yet been cut. Subsequently, the unprocessed web of fabric (10) is conveyed on the cutting surface (17) and when the reference point (15) has been found again further cutting is carried out. This procedure can be repeated many times in succession. <IMAGE>

Description

The invention relates to a method for cutting parts (cuts) from a material web, in particular a fabric web, according to the preamble of claim 1.

Such a procedure is common when cutting fabric panels. In this case, a material web of limited length or a package of such material webs arranged one above the other is arranged on a cutting table, the material web dimensions being dimensioned within the surface area of the cutting surface of the cutting table. In the case of fabric webs, it is customary to arrange an air-impermeable film forming the cutting pattern over the fabric web or the package of the fabric webs, and to suck the overall arrangement by means of vacuum against the cutting surface of the cutting table in order to enable a precise cutting. A precise cut is required to reduce the amount of waste in order to optimally arrange the cuts close together.

When limited to a comparatively small area, optimal use of the available area cannot be achieved, in particular towards an end of the available cutting area. There is therefore a desire, with the cutting surface remaining the same, to carry out cuts over a length of material exceeding its dimensions in the longitudinal direction, possibly even without limiting the length of the length of material.

Difficulties in realizing a solution arise because, because of the close arrangement of the blanks, it must be ensured that if the cutting process is interrupted, which is absolutely necessary because of the finite dimensions of the cutting surface, the starting point of the further cutting remains precisely defined, in particular even if a package of panels is used.

It is therefore an object of the invention to further develop the method of the type mentioned at the outset such that safe and precise cutting is also possible if the material web subjected to the cutting is larger than the cutting surface available on the cutting table.

The object is achieved by the characterizing features of claim 1.

The invention is further developed by the features of the subclaims. Furthermore, the method according to the invention is also optimized.

The method according to the invention ensures, on the one hand, that when the blanks which have already been cut and the waste which is inevitably formed are removed, the remaining material web which has not yet been cut remains unchanged and that the optimized cutting start point is reliably reached for the actual cutting start when this remaining material web is transported. In particular, this can be achieved automatically in an automatically operating cutting device that is computer-controlled, using the computer.

In particular, in the case of material webs whose length exceeds the dimensions of the cutting surface of the cutting table, it is ensured that when removing cuts which have already been made and waste which is unavoidably formed, the remaining material web which has not yet been cut remains unchanged and that the optimized cutting starting point is safe for transporting this remaining material web the actual start of cutting is reached. In particular, this can be achieved automatically in an automatically operating cutting device that is computer-controlled, using the computer.

Starting from the prior art according to DE-PS 36 30 363, cutting tables have been developed which have a circumferential bristle band. With such transport devices, in particular Those who work with vacuum suction, it is expedient to ensure the tightness of that section of the bristle band to the outside within which is to be cut. This is because the vacuum performance is an essential factor in the design. The greater the tightness to the outside, even when the cut is carried out, the less the effort for the devices producing the vacuum. To improve this effect, sealing lips have been provided between bristle band sections, which are to be cut through if necessary, these sealing lips being replaced after some time, that is to say if they have been cut through several times.

In the method according to claim 16, there is an overlap of individual cutting sections by at least one bristle band section or by at least one section of the bristle band delimited by adjacent sealing lips.

On the one hand, this facilitates the operation of the cutting table, especially since it is expediently transported in such a way that a sealing lip corresponds to table-side sealing slides or similar sealing devices after the end of the transport. In particular, if it is further ensured that when cutting the sealing lip on the side in the transport direction, but not the sealing lip on the side of the cutting section, is cut, the required vacuum output can be reduced.

Fig. 1A bis 1C

die wesentlichen Schritte der erfindungsgemäßen Vorgehensweise;

Fig. 2

ein Beispiel der Anordnung der Zuschnitte auf einer Stoffbahn und deren Zuordnung zu verschiedenen Teilflächen;

Fig. 3

in Seitenansicht schematisch einen Schneidtisch mit umlaufendem Borstenband,

Fig. 4

in Aufsicht eine Materialbahn mit schematischer Zuordnung der Dichtlippen zu den verschiedenen Schneidabschnitten.

The invention is explained in more detail with reference to exemplary embodiments schematically shown in the drawing. Show it:

1A to 1C

the essential steps of the procedure according to the invention;

Fig. 2

an example of the arrangement of the blanks on a fabric web and their assignment to different sub-areas;

Fig. 3

schematically in side view a cutting table with circumferential bristle band,

Fig. 4

in supervision a material web with a schematic assignment of the sealing lips to the different cutting sections.

The invention is explained on the basis of an exemplary embodiment in which strips of fabric arranged one above the other are cut together with an air-impermeable cover sheet in the manner customary in fabric cutting machines. In the following, reference is made to a single fabric web 10, the longitudinal dimension of which is significantly larger than that of the cutting surface 17 of a cutting table 16 which is conventional per se. The cutting table 16 is arranged between a clearing station 18 and a buffer 19, the buffer 19 being, for example, a laying table , a feed table or the like. The fabric 10 shown is finite in length, but it is also possible to pull a fabric directly from a bale (not shown). This fabric web 10 is placed on the cutting surface 17 in such a way that it can be processed on the basis of a cutting pattern with a conventional cutting device, such as a butt knife machine or a cutting head or the like.

The assignment of the blanks 1 to 8 in a pattern is shown in Figure 2. The individual cuts are arranged in such a way that optimal use is made of the predetermined width in such a way that as little waste as possible is produced.

Towards the feed end of the cutting surface 17 of the cutting table 16, a separating cut 14 is provided in the exemplary embodiment, which is carried out over the entire width of the fabric web 10 in such a way that a first partial surface 11 is formed in which all the blanks 1 to 5 that have already been cut are located , and in such a way that a second partial surface 12 adjoins it, which extends over the feed-side end 21 of the cutting surface 17 extends to the buffer 19. If it can be optimized by the arrangement of the blanks, it is advantageous if there are no longer completely feasible blanks in the remaining surface 13 on the cutting surface 17.

In order to be able to remove the blanks and the waste, it is necessary to loosen the position fixation, as is usually achieved by means of vacuum suction. As a result, the remaining surface 13 is loosened in its position, which means that there is a risk that further cuts can no longer be made carefully, this risk being particularly high if packages of fabric webs are used, since these could slip in their position with one another. This is particularly so because the remaining surface 13 of the fabric web 10, which has not yet been cut, and even the entire second partial surface 12 have to be processed.

According to the invention, a reference point 15 is first defined in the second partial area 12, preferably in the remaining area 13, this reference point 15 expediently corresponding to the starting point for the cutting of the second partial area 12.

This can be done, for example, by a manual or automatic visible marking, for example also by a small incision, a color point or the like. This can also be computer-controlled, such that the position of the reference point 15 with respect to the separating cut 14 (and thus the position of the cut first partial area 11) is automatically determined and marked in terms of data. After determining the reference point 15, the second partial surface 12 of the material web 10 is fixed in the exemplary embodiment, preferably by means of a retaining clamp 20, which acts on the second partial surface 12 outside the cutting surface 17 of the cutting table 16. Only then is the position fixing for the fabric web 10 released on the cutting surface 17, whereupon the first partial surface 11, the has already been cut, is transported to the clearing station 18 by means of a transport device known per se, which can also work with the aid of vacuum suction, while the second partial surface including the remaining surface 13 remains in its position due to the effect of the holding clamp 20. The closer the holding by means of the holding clamp 20 takes place near the feed-side end 21 of the cutting surface 17, the more expedient this is.

After removal of the cut first partial surface 11 to the clearing station 18, the rest of the surface 13 is expediently fixed in its position in relation to the transport device without activation of a transport device operating by suction, and the holding clamp 20 is then released and the second partial surface 12 is opened by means of the movement of the transport device the cutting surface 17 is moved.

Then, unless the transport device also fixes the position for the cutting process, fixes the position for the cutting process for the second partial surface 12. Then reference point 15 is retrieved. On the one hand, this can be done manually, namely by tracking the cutting device to the defined reference point 15 on the second partial surface 12. This can also be done automatically by the cutting device looking for the marked reference point 15. This is particularly expedient if the reference point 15 coincides with the cutting start point for the second partial surface 12. If the cutting device is computer-controlled, the above-mentioned data obtained for the reference point 15 can be updated depending on the transport movement, so that the information about the reference point 15 is available in every position of the second partial surface 12 on the cutting surface 17 for the cutting device and so that it can also be evaluated for the cutting process, which can shorten the search process considerably.

The cutting process for the second partial surface 12 is now carried out, in the manner mentioned for the first partial surface 11, the reference point for the beginning of the cutting being the reference point 15.

By setting and retrieving the reference point 15, any displacement of the material web due to the “floating arrangement” on the transport device, which usually has a bristle band, is counteracted during transport.

The method according to the invention can be used several times in succession if, after the first partial surface 11 has been cut, the remaining surface of the fabric web 10 is still too large to find space entirely within the cutting surface 17 of the cutting table 16.

This results in the possibility of practically endlessly forming the fabric web 10, preferably unwinding it directly from a fabric bale.

The invention is therefore suitable not only for the formation of new cutting tables 16, but also for upgrading existing cutting tables 16, the cutting surfaces 17 of which have predetermined dimensions.

The invention is also applicable when proceeding without a cut 14. Then, after performing the cuts in a section corresponding to the first partial surface 11, the reference point 15 is determined and marked, which can then also be near the end of the first partial surface 11 on the feed side. This is followed by the joint transport of the machined partial area and the unmachined material web, fixing the position of this unmachined material web, locating the reference point 15, etc.

It is also possible to proceed in this way despite a separating cut 14. The separating cut 14 then facilitates the work in the clearing station 18.

3 shows a side view of a raised cutting table 22 with a circumferential bristle band 24. The bristle band 24 runs over transport rollers 27 and 28 mounted at the end, the drive device of which is not shown. Sealing slides 29 and 30 are provided near these transport rollers 27, 28 in the region of the upper side of the cutting table 22. In the area between the sealing slides 29, 30, a vacuum device, not shown, is provided, which draws air in through the bristle band 24 in a manner known per se. If there is an air-permeable material web, for example a multi-layer material web, which is covered by an air-impermeable film, lies on the section of the bristle band 24 between the sealing slides 29, 30, this is firmly sucked in and can be moved easily and without displacement of the individual layers with one another by means of a cutting device, not shown get cut. Such cutting tables 22 are basically known with different designs. For example, reference is made to DE-PS 36 30 363.

In practice, the bristle band 24 consists of individual bristle elements that are even interchangeably arranged on a carrier. To reduce the required vacuum capacity of the vacuum device, it is advisable to provide an air-impermeable sealing lip 26 between individual bristle band sections 25, the arrangement of these sealing lips 26 and the transport movement being such that after a transport process (and before a cutting process) a sealing slide 29, 30 is provided corresponds to a sealing lip 26.

Since it cannot always be guaranteed that the dimensions of an individual blank are such that it and its position can be fixed between two adjacent sealing lips 26, the sealing lips 26 are formed on the one hand so that they can be cut through by the cutting device and on the other hand designed so that they can be replaced after several such cuts.

In a practical exemplary embodiment, the entire cutting table 22 has a length of approximately 12.28 m and the distance between the sealing slides 29.30 is approximately 10.36 m. In such an embodiment, the distance between adjacent sealing lips 26 is selected so that a total of three such bristle band sections 25 correspond to the distance between the two sealing slides 29,30. That is, with such a cutting table 22, a cutting section corresponding to three bristle band sections 25 is available (cf. FIG. 4).

From Fig. 4 it can now be seen how the blanks are assigned to the individual partial areas and how they are to be assigned to the bristle band sections 25.

Fig. 4 shows in a first partial surface 11 blanks 1 ', 2', 3 ', 4' and 5 ', which are highlighted by cross hatching. Individual cuts 6 'and 7' exceed the area of a sealing lip 25, it being assumed that this is the sealing lip 25 at the end of a first cutting section. Therefore, this should not be cut. Rather, a separating cut 14 'is to be provided on the side in the transport direction and also to be provided on the side of the sealing lip 25, which in this first cutting section is at the end of the entire first cutting section on the side in the transport direction.

The end of the cutting operation is now carried out in the first cutting section as in the embodiment according to FIGS. 1 and 2. It is only necessary to note that the bristle band 24 is moved further in such a way that the sealing lip closest to the separating cut 14 'in the transport direction is located away 26 is arranged corresponding to the sealing slide 29 remote in the transport direction. This results in terms onto the available bristle band sections 25, the second cutting section, which in the exemplary embodiment comprises three such bristle band sections 25. The cuts that can be made within this area are shown without hatching. The procedure is as explained in the first exemplary embodiment, and a separating cut 14 ″ is again carried out in a similar manner at the end of this second cutting section. This is followed by a third cutting section analogous to the above-mentioned description, the individual cuts carried out there being simply hatched, etc.

It can be seen that the cutting sections each intersect around a bristle band section 25.

In the event that individual cuts are made in such a way that they would cross two sealing lips 26, the overlap of adjacent successive cutting sections is to be dimensioned correspondingly larger.

Of course, the number of bristle band sections 25 assigned to a cutting section can be greater than the number shown, but it is expedient to choose this number not less than 3.

Through the chosen arrangement and procedure an optimization with extremely low necessary vacuum performance is achieved.

Claims (17)

Process for cutting parts (cuts) from a material web, in particular a fabric web,
in which the material web is arranged on a cutting table, is fixed in position and is cut using a hand-guided or automatically guided cutting device based on a cutting pattern,
characterized by
that within a partial area of the material web arranged on the cutting table, all possible blanks are cut there,
that a reference point on the material web is preferably established outside the cut partial area in the remaining area of the material web,
that the material web is transported over the area of the cutting table which was previously occupied by the first partial area,
that the material web having this remaining surface is fixed in position on the cutting table,
that the reference point is determined and on the basis of which a cutting start point is sought and
that the process steps are repeated until the entire web is cut. Method according to claim 1,
characterized by
that the position is fixed by means of vacuum suction. Method according to claim 1 or 2,
characterized by
that the transport is carried out using vacuum suction. Method according to one of claims 1 to 3,
characterized by
that the reference point is found manually. Method according to one of claims 1 to 3,
characterized by
that the reference point is found again automatically with the help of suitable markings. Method according to one of claims 1 to 5,
characterized by
that the reference point is determined so that when it is determined it is within the section of the material web deposited on the cutting table. Method according to claim 6,
characterized by
that the reference point is defined outside the cut first partial area in the remaining area on the cutting table. Method according to one of claims 1 to 7,
characterized by
that the reference point and the cutting start point match. Method according to one of claims 1 to 8,
characterized by
that to remove blanks and waste in the former partial area, these are transported to a clearing station or the like. Method according to one of claims 1 to 9,
characterized by
that the remaining area is held in the area in front of the cutting table, such as on a buffer feed or laying table. Method according to one of claims 1 to 10,
characterized by
that a separating cut is made over the entire width of the material web at the end of the partial area. A method according to claim 11,
characterized by
that the remaining area is held and the blanks and the waste in the cut partial area are removed after loosening the position fixation and then the material web having the remaining area is transported. Method according to claim 12,
characterized by
that the holding is carried out by means of a clamping bar or the like, which acts on the material web across its width. Method according to one of claims 1 to 13,
characterized by
that the material web is drawn off directly from a bale. Method according to one of claims 1 to 14,
characterized by
that a package is cut from several superimposed material webs. Method according to one of claims 1 to 15,
characterized by
that a cutting table (22) with circumferential bristle band (24) is used, in which individual bristle band sections (25) are separated from one another transversely to the transport direction by sealing lips (26), and
that the partial surface (11, 12) is delimited on both sides by a sealing lip (26). A method according to claim 16,
characterized by
that in the case of individual cutting patterns (1 ', 5', 6 ', 7') crossing a sealing lip (26), only the sealing lip (26) remote in the transport direction is cut by means of the cutting device.

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