NL1013584C2 - Method for the fabrication of fabric edges, device therefor and fabric fabric made according to this method. - Google Patents

Description

Method for the fabrication of fabric edges, device therefor and fabric fabric made according to this method.

The invention relates to a method as well as to a device therefor and to a made-up cloth manufactured according to the method. Made-up fabric is used, among other things, for roll-up screens that e.g. can be used as external sun protection, insect protection, wind, rain, closing and blackout screens and as technical and decorative partitions for various purposes. The screens are usually made of plastic material 10, which may or may not be reinforced with plastic fibers, such as is used, for example, with fly screen, polyethylene foil, truck tarpaulins and the like.

However, as soon as such screens are rolled up and / or unrolled with respect to a driven horizontally or vertically disposed roll-up resp. roll-off shaft, technical problems frequently arise which mainly consist of failures during opening or closing. In the first place, after all, an installed fabric screen must always be subject to the requirement that it can be wound tightly around a roll axis and that it can be unrolled, while the fabric quality must be resistant to all kinds of mechanical influences (wind, collisions, etc.) and that it can roll up. and unrolling of the cloth screen takes place absolutely perfectly, without creases, without warping or without permanent deformations of the cloth material. Otherwise, such deficiencies will sooner or later also lead to serious business failures. The most common is electric drive motors for the roll shaft becoming inoperative. It goes without saying that with decorative use, e.g. on the outside of buildings, the observed occurrence of such defects for architects is already reason to no longer use canvas screens.

The object of the invention is therefore to eliminate all of the above-mentioned problems completely. A simple analysis of such problems shows that they can be classified as follows: a. Side guidance of the fabric screen gets stuck or missing when skewed; b. rolling up and unrolling in the middle of the screen is not tight; C. rolling up and unrolling the sides of the screen is not tight; d. the fabric tears in at the seam with the tendon applied for attachment to the roll axis; e. the fabric tears in at the seam for attachment to the bottom profile with weight.

f. the tube motor gets stuck or burns due to irregular (oval) winding and 101358 4 -2-shear pulling.

In principle, solving all problems can only be achieved by the insight that, according to the invention, all attention must be paid exclusively to the fabric screen, which for that purpose must always be wound tightly across its full width about the roller axis. The only meaningful solution to existing problems is to give the fabric screen a uniform thickness over the entire width, so both from the center of the fabric screen to the hemmed sides. In addition, it must then be ensured that as much as possible uniform spiral winding around the roll axis is aimed for, which means that the attachment of the fabric screen to the roll axis does not cause additional irregularities which can contribute to unwanted winding. In the latter case, account will also have to be taken of the specific behavior of the fabric screen material at both high (sun) and low temperature (outdoor or, for example, freezer room application).

The main measure according to the invention is based on the above insight n.I. in order to provide the (cut) side edges of the cloth over their full length with a relatively narrow strip or strip of plastic material which, by means of heat-sealing, imparts optimum edge reinforcement to the two cloth edges, while, however, according to the invention, care must be taken that the thickness of the cloth edge thus assembled on site is substantially equal to the thickness of the cloth screen material used. This measure immediately eliminates all existing winding problems on the side of the side screens of the cloth screen, since it now guarantees the required tightness of winding over the full width of the cloth screen. The method according to the invention can then be applied in various ways, which will be further elucidated in the figure description and the subclaims.

A further source of problems when winding and unwinding relative to the roll axis are the seam joints for the hems at the top and bottom of the fabric screen. For practical reasons, such seam connections always have to be made on the basis of the specified fabric screen dimensions and can therefore not be woven in separately as is proposed in EP 0 794 275, but which measure is not cost-effective. If the fabric screen material is PVC, the seam connection can e.g. can be obtained by hot-welding a fiber-reinforced strip. Normally, a seam connection is obtained with a 101358 4 -3- double cloth thickness by welding a strip on top. In contrast to that method and as has been noted previously, it is important that the total thickness of the composite seam joint does not in principle become thicker than the double cloth thickness when using the new method. The occurrence of tearing on both sides of the fabric screen, mainly due to the multiple composite thickness of the seam seal strip and twice the fabric screen thickness, is due in part to the relatively greater stiffness of that composite seam seal. By now reducing the seam welding connection according to the invention to the double screen fabric thickness, a relatively smooth seam welding connection is obtained, also by a good choice of material of the seam welding strip. This seam welding connection can be applied without problem for the lower edge of the screen cloth according to the invention.

For the top edge, on the other hand, this seam connection causes greater rigidity at the locally smaller external roller shaft diameter of e.g. 20 to 125 mm. This greater rigidity generally leads to an unround winding of the fabric screen. The remedy against this would then be to make the winding shaft or roller shaft itself out of round (to compensate for the round winding) 15, but such a measure is too expensive.

The solution of this problem is based on the insight according to the invention to provide the heat-sealing seam in the axial direction of the roller axis itself with some additional flexibility, namely by giving a structure that corresponds, as it were, to the flexible profile of corrugated cardboard. After all, corrugated cardboard can be easily rolled up in a direction that is transverse to the corrugation 20 and the hot-sealing seam thus deforms during winding in such a way that a maximum of tight winding is obtained.

Screen cloth material with a self-bending profile of the heat-sealing seam has the advantage that this cloth material flexibly adapts during the winding to the roll diameter which starts small when winding - the tearing takes place just there - and then increases. At the bottom side of the screen cloth material, the problem noted is less because the roll diameter of the rolled cloth is sufficiently large there. All existing problems that have already been listed above are now optimally eliminated by the new combination of measures with a surprising effect according to the invention to a lesser extent (side edge effect) and to a greater extent (rolas effect). A fabric screen that is manufactured according to the new method meets all the required conditions for a guaranteed winding and unwinding phase and as a result, the life of the fabric screen is considerably extended and complaints are a thing of the past.

The invention will be explained below with reference to an exemplary embodiment.

Fig. 1 schematically shows a made-up fabric screen manufactured according to the new method;

Fig. 2 shows a cross section through the fabric screen along the line II-II in FIG. 1; FIG. 3 schematically shows a partial cross-section with perspective view on a side edge of the cloth screen according to FIG. 1;

Fig. 4 shows a perspective view of a seam connection according to the invention;

Fig. 5 shows a perspective view of a particularly flexible embodiment of a seam connection in axial direction according to the invention; FIG. 6 shows a similar seam connection with a different profile and

Fig. 7 schematically shows a perspective drawn device with which the method according to the invention can be carried out.

In Figs. 1-6 an embodiment of a screen cloth 1 made of woven plastic material is shown. In this case a so-called sunscreen is shown, the main dimensions of which are e.g. 4 m (width) x 2.5 m (height). Both side edges 3 and 4 of the woven screen cloth 1 are provided with a narrow strip of glass fiber-reinforced material in the width of approximately 8-10 mm. Using (e.g., high-frequency) welding technology for joining two plastics, the edge zone is now heat-welded such that the woven fabric material and the glass fiber reinforced strip are compressed and form an intimate joint, the externally measured thickness of which is equal to that of the shield fabric material. Due to the equal thickness of the screen cloth 1 and the side edge reinforcement 3, a first condition has already been obtained for the screen cloth to be wound up perfectly and tightly at the two ends of a roller axis (not shown).

The top seam 6 and the bottom seam 7 of the screen fabric 1 are then folded over by a distance such that a profile can be inserted in the axial direction in the seam obtained. For the top seam 6 this is usually a wire-shaped profile that can be accommodated with the seam 6 in a longitudinal recess of the roll axis, for the bottom seam 7 this is usually a flat metal strip (with a certain weight) which is then a tight screen cloth 1 when unrolled yields. In principle, both seam joints are again heat-welded with the aid of a fiber-reinforced welding strip 9 (e.g. high-frequency welding technology) and the combined thickness of the two screen cloth parts 8 and 9 and that welding strip 9 after welding should not be thicker than the double screen cloth material thickness.

Depending on the material to be chosen, the aim here is also to obtain the intimate seam connection 1013584 -5- as previously described for both cloth edges. If the material to be processed would remain too rigid after heat welding to adapt sufficiently to the required flexibility around the roll axis, a greater flexibility can still be obtained after cooling by means of a special profiling of the heat sealing seam thereto. In Figs. 4 and 5 is shown.

5 As shown in FIG. 5 to give a corrugated profiling 10 in axial direction which has the aspect of a corrugated pattern, an additional flexibility is created in the corrugated valleys. In FIG. 6, a different profiling 11 has been chosen, which however has the same effect on the flexibility of the seam connection. The axially profiled welding seams which are obtained according to the new method now appear to solve all existing winding and unwinding problems at screens. The new method can be carried out using a fixed pressure profile or by means of a profile roller. For flat rolling at the seam joint in Fig. 4, only for the bottom seam 7, a smooth seam connection will suffice and a smooth outer circumference of the roller or a flat heat sealing profile will be used. In contrast, the seam joints of FIG. 5 and 6 use a ribbed roller or a ribbed welding profile. By an appropriate choice of material of the screen cloth material to be heat-welded and heat-seal strip, any open unwinding problem that has hitherto arisen in screen cloth installations can be solved by applying the new method. In connection with the foregoing, "screen cloth" should also be understood to mean any windable film screen of other material with which the same problems can be solved. It is not even a requirement that a "screen" only consists of a woven textile material, because for example also very narrow strips of aluminum foil, colored or un-colored, can be woven into the woven textile material. On the one hand, the aluminum side can then act as a solar reflector and the other side can have a decorative function.

Fig. 7 shows the principle of a machine for carrying out the new method. On the top 12 of a make-up table, a screen cloth 13 is supplied laterally in the direction of the arrow P. This screen cloth 13 has previously been passed through a seam-wrapping device (not shown) and thus comes to lie in the drawn position under a per se known hold-down, whereby the curvature of the seam 14 comes to lie against the measuring ruler 15. The retracted hem part 30 16 should now be connected on-site by means of heat welding with screen cloth part 17 located below. This can now be done as follows.

Above the top of the assembly table 12 is the projecting arm 18 of a conventional heat-sealing machine, which is not shown in more detail. The welding machine can be installed on the work floor behind the assembly table. This welding machine can e.g. operated with a foot pedal and this arm 18 carries the operational part for performing the method. In FIG. 7 this is shown very schematically. At its free end, the arm 18 merges into a horizontal supporting part 19 with a hydraulic pressure cylinder 20. This pressure cylinder 20 is directly connected to a heat sealing bar 21 (copper / brass) which is received and fixed in a recess 22 of inverted Y- profile 23. The heat sealing bar 21 is provided here with a number of axially extending relatively narrow recesses 24. These are intended to provide such a welding thickness of the double cloth seam when using heat and pressure at the welded joint to be formed at 16 and 17. obtain that the aforementioned flexibility of the weld joint arises in order to overcome the drawbacks already mentioned. Partly depending on the specification and composition of the screen cloth material to be processed, a wide range of e.g. 50 Hz to 50 MHz are desired. It has been found that heat welding using HF welding technology now yields considerable energy and time savings, since cooling also takes less time now.

In order to give the heat-seal joint the highest possible strength and at the same time guarantee the desired flexibility in the circumferential direction of the roll axis, this heat-seal joint can also be combined with the application of the strip, which is then also anchored in the weld joint. This strip can be supplied axially from a supply roll (not shown) under the heat sealing bar and thus be integrated into the fabric 24. For clarification, in fig. 7 shows an enlarged detail of the screen cloth parts 16 and 17, the strip 29 to be pressed into the screen cloth layers 16 and 17 and the profiled heat sealing bar 21. 1 2 3 4 5 6 1013 584

The power supply for the heat sealing bar 21 is provided from the heat welding machine by means of a 2 copper foil 25 which is connected via the arm 18 in the interior of the heat welding machine to 360V. The HF technology for the welding heat generated via the copper foil 25 in the heat sealing bar 21 is of a harmless nature, so that no special safety measures 5 have to be taken.

6

While in the foregoing there is talk of a heat-sealing bar which thus operates discontinuously, it is also possible to heat-weld continuously with a roller roller wheel in which recesses are also provided on the outer circumference with the ultimate aim of obtaining a profiled flexible seam connection. For making-up it does not matter whether the roller takes up a permanent place or whether the roller is guided over the seam joint to be heat-sealed. In FIG. 7, the up and down movement of the heat sealing bar 21 is indicated by arrow 26. The pressing punch 28 can exert the desired pressing pressure over a full length, if the width of the heat-sealing bar is not too great. In case the length of the heat sealing bar would be too great, it becomes necessary to counteract its deformation and this can be done by installing two clamping devices 27 whereby both ends of the heat sealing bar are pressed down via the Y-shaped holder 23.

1013584

Claims (14)

1. Method for the so-called fabrication of cloth edges, such as of 5 pre-cut cloth edges for use for shielding rollable decoration screens, e.g. from inner and outer screens as sunscreens in which the fabric edge ends are folded inwards at the top and bottom and are connected to the fabric and in which the side edges of the fabric are provided with an edge reinforcement, characterized in that the side edges of the fabric their full length is provided with a relatively narrow band or strip, which by means of heat-welding give the edge of the cloth on the spot such edge reinforcement that in this way the combined thickness of the cloth edge thus processed does not or hardly exceeds the thickness of the cloth. 2. Method according to claim 1, characterized in that the narrow strip or strip is formed by local rolling and partial deformation of the cloth material, all this in such a way that the resulting total thickness of this side edge does not exceed the thickness. of the canvas. 3. Method according to claim 2, characterized in that the cloth material is laminated on at least one side with the addition of a separate tape or strip of such a thermoplastic material that an intimate heat-sealing connection is made with the cloth material. Method according to claim 3, characterized in that the individual strip or strip is longitudinally provided with a fiber-reinforced reinforcement. 5. A method according to any one of the preceding claims 1-4, characterized in that the cloth edge ends in a direction perpendicular to the aforementioned side edges 25 are first retracted and then connected to the cloth to a relatively narrow joining weld using heat welding while the resulting joint cloth seam thickness, whether or not with the simultaneous application of a separate band or strip, at the connecting seam is smaller or at most equal to the double cloth thickness. Method according to claim 5, characterized in that the joint welding seam and / or both side edges are heat-sealed, in particular using frequency welding, with a frequency range of 50 Hz to 50 MHz, both fabric parts 101 3584 -9 - connects. Method according to claim 5, characterized in that the joint-welding seam is obtained while simultaneously supplying a separate heat-sealing strip under the heat-sealing bar or under the heat-sealing roller. Method according to claim 5, characterized in that the connecting seam is provided transversely of its longitudinal direction (axially) with at least two elevations continuously extending in that longitudinal direction with a height greater than the cloth seam thickness as defined in claim 5, such that thereby significantly increasing the flexibility of the joining seam in a direction transverse to the roller axis for the screen fabric. Method according to claim 8, characterized in that the ridges in the form of ribs extend into the area of the cloth edge. 10. Made-up cloth, manufactured using the method according to any one of the preceding claims, characterized in that the cloth edges are provided with a heat-welded relatively narrow band or strip with a thickness that is less than or equal to the cloth thickness, while the connecting weld seams at the other cloth ends perpendicular thereto, by heat welding also in their total thickness smaller or at most equal to the single cloth thickness. Finished fabric according to claim 10, characterized in that the connecting weld seams are profiled in a cross-section, i.e. show alternating grooves which now offer sufficient flexibility to the otherwise relatively rigid connecting seam in a cross-section. 12. Heat-sealing strip provided with a fiber reinforcement, for use for the production of side edges for cloth screens as well as for the production of connection welds for top and bottom edges of cloth screens. 13. Device for heat-welding cloth screen material using a heat-sealing bar, characterized in that using the new method according to any one of the preceding claims 1-9, wherein the making-up table is provided with heat-sealing means, in particular wherein the required welding heat is generated, on the one hand for the heat-sealing connection and on the other hand for the necessary flexibility of the screen fabric material in the winding direction and under 1 0 * 353 4 -10- using LF or HF frequency within a range of 50 Hz to 50 MHz which, via a sheet foil of copper / brass is fed to the heat sealing bar. 14. Device as claimed in claim 13, characterized in that, using the method according to any one of the preceding claims 1-9, a hot-rolled roller wheel is used for hot-welding, wherein the tread of the roller is alternately provided with recesses which give flexibility of the seam-welding connection. transverse to the roll axis direction. 101358 4