TOUCH FASTENER PART

Abstract

1. Touch fastener part

Description

The invention relates to a touch fastener part, having a first substrate tape having hooking elements arranged on one side thereof and having a second substrate tape which, connected to the first substrate tape, has a connection means on its side facing away from the hooking elements, wherein the second substrate tape is wider than the first substrate tape and at least one free lateral edge area of said second substrate tape projects beyond the adjacent longitudinal edge of the first substrate tape and wherein the two substrate tapes can be bent along and transversely to their longitudinal orientation.

Touch fastener parts have proved their value in many areas as a detachable and functionally reliable joining and fastening technology. For applications for aircraft or vehicle seats, they are used, among other things, to fasten seat covers to foam body parts consisting of a molded foam, wherein the respective touch fastener parts are foamed into the upholstery foam material during the manufacture of the respective seat and the respective other touch fastener parts having the corresponding hooking elements are fixed, in particular sewn, to the upholstery cover material. During the production of the foam body parts, the touch fastener parts are inserted into so-called seating pipes of a foaming mold, and by placing foam material in the free cross-sections of the foaming mold, preferably by inserting polyurethane (PU) foam, the touch fastener parts are attached to the foam body parts during the foaming process. Document DE 10 2004 015 321 A1 discloses a touch fastener part of the genus mentioned above to be attached to foam body parts by a foaming process.

In the case of the known touch fastener part, both the substrate tape of the hooking elements and the second substrate tape are formed from an injection-molded plastic section. The flat composite, formed by the tapes, has a relatively high resistance to bending, mainly in the plane of the tape. If, because of the shape of the foam body parts, curved seam courses occur, wherein along said seam courses touch fastener parts are to be foamed, then one is forced to provide several touch fastener parts of shorter length in bending areas instead of one continuous, long touch fastener part have to be provided. This results at least in a disadvantageous increase in the amount of work required to attach the touch fastener parts during the foaming process.

With regard to this problem, the invention addresses the object of providing a touch fastener part of the genus mentioned at the beginning, which permits being attached to the concerning foam body part during the foaming process even in a curved shape.

According to the invention, this object is solved by a touch fastener part having the features of claim 1 in its entirety.

According to the characterizing part of claim 1, an essential feature of the invention is that at least one free side edge area of the second substrate tape is provided with a weakening of resistance in such a way that bending the two substrate tapes transversely to their longitudinal orientation is facilitated. The reduction in the bending stiffness of the touch fastener parts according to the invention and achieved in this way permits the use of longitudinal touch fastener parts following the course of the seam, despite the connecting areas between the upholstery cover material and the foam body part concerned not running in a straight line.

The weakening of resistance is advantageously arranged at least at the one lateral edge area of the second substrate tape in the direction of the lateral edge area the two substrate tapes are bent.

The arrangement can advantageously be such that one side edge area each of the second substrate tape protrudes beyond both longitudinal edges of the first substrate tape and that both side edge areas have the same surface area and are each provided with an equally effective weakening of resistance.

A particularly favorable bending behavior can be achieved if the respective weakening of resistance of a side edge area of the second substrate tape continuously merges into the first substrate tape.

The arrangement can be particularly advantageous such that the respective weakening of resistance of the first and second substrate tape ends at a bending line that defines the longitudinal axis of at least the first substrate tape.

The arrangement can be particularly advantageous such that the respective weakening of resistance of the first and second substrate tape subdivides the hooking elements of the first substrate tape into adhesive segments which are aligned one behind the other along the respective bending line.

It is indispensable for the functionality of the touch fastener parts that the hooking elements are protected against entry of foam material during the foaming process. In advantageous embodiments the two substrate tapes are provided with a preferably self-adhesive cover sheeting on the sides of the hooking elements to prevent the hooking elements from sticking due to entering foam material and thus becoming inoperative, and after the removal of said cover sheeting the hooking elements are exposed for hooking engagement.

A particularly reliable protection of the hooking elements against entry of foam material can be achieved if a foam barrier is inserted between the cover sheeting and the hooking elements of the first substrate tape, wherein said foam barrier at least partially engages with the spaces between the hooking elements. A carpet pile, wherein the carrier of said carpet pile is in contact with the cover sheeting and the pile threads of said carpet pile form an envelope for the hooking elements, may form such a foam barrier acting in addition to the cover sheeting.

The respective weakening of resistance may be formed by at least one reduction of wall thickness and/or perforation and/or recess and/or change in strength of at least one side edge area of the second substrate tape.

In the case of particularly advantageous embodiments, a sequence of recesses is formed, starting from at least one longitudinal edge of the second substrate tape, wherein said recesses extend transversely to the longitudinal direction of the tape in both substrate tapes up to close to the centerline of the tape or the bending line.

A particular increase in flexibility is achieved if a sequence of recesses is formed each starting from both longitudinal edges of the second substrate tape.

In particularly advantageous embodiments, the recesses are formed equally and have a V-shape tapering inwards from the respective longitudinal edges.

The arrangement can be made with particular advantage such that the boundary edges of the respective V-shaped recesses form an angle of 20° to 30°, preferably 25°, between each other.

The arrangement can be made with particular advantage such that the recesses are equidistantly spaced to each other at distances that are preferably smaller than the width of the second substrate tape.

A particularly favorable bending behavior can be achieved if the recesses of the one sequence are aligned with the recesses of the other sequence.

In particularly advantageous embodiments, the arrangement is such that the recesses end in front of the centerline of the substrate tapes at a distance, which is less than ⅛, preferably less than 1/10, of the width of the second substrate tape.

With particular advantage, the recesses can be formed from incisions or punchings in the assignable tape material, wherein said incisions or punchings extend completely through the material.

The arrangement can be made with advantage such that the V-shaped recesses tapering in the direction of the bending line are closing on one side increasingly in the event of bending until the wall parts of the two substrate tapes, delimiting the V-shaped recesses, come into contact with one another, and that, while in the event of bending in one direction the assignable V-shaped recesses on one side are closing, the respective recesses on the opposite side of the two substrate tapes spread apart correspondingly.

According to claim 24, the subject matter of the invention is also the use of a touch fastener part according to any one of claims 1 to 23 in a foaming mold, in particular for manufacturing of vehicle seat cushions, having a seating pipe into which the touch fastener parts can be inserted covered by the cover sheeting, wherein after connecting the molded foam to the connection means while forming at least a part of the seat cushion and after removal from the foaming mold after the cover sheeting has been taken off, the hooking elements are exposed.

Below the invention is explained in detail with reference to embodiments shown in the drawing. In the Figures:

FIG. 1 shows a representation, schematically simplified and not to scale, of a section of a seating pipe for a foaming mold, wherein a touch fastener part is inserted in the mold cavity of the seating pipe according to an embodiment of the invention;

FIG. 2 shows a representation, correspondingly simplified and enlarged by a factor of approx. 2.5 compared to a practical embodiment, of a length segment of the embodiment of FIG. 1, viewed towards the tape side having the hooking elements and without any overlying cover sheeting;

FIG. 3 shows a representation corresponding to FIG. 2 of the top view of the embodiment, wherein a bent state is shown;

FIG. 4 shows a representation, simplified and not to scale, of a second embodiment of the touch fastener part according to the invention, wherein the state before attaching a cover sheeting is shown;

FIG. 5 shows a representation, schematically simplified corresponding to FIG. 1 and not to scale, of a section of a seating pipe for a foaming mold, wherein a touch fastener part is inserted in the mold cavity of the pipe according to a third embodiment of the invention; and

FIG. 6 shows a representation corresponding to FIG. 4 of the third embodiment of the touch fastener part, wherein the state before the cover sheeting is attached is shown.

In FIG. 1, a seating pipe, which is part of a foaming mold that is not shown apart from that, is denoted by 2. The seating pipe 2 has a mold cavity 4 in the form of a recess, the free cross-section of said recess is adapted to the touch fastener part 6 to be received therein. Along the lateral longitudinal edges the mold cavity 4 is delimited by flat wall sections 8. The touch fastener part 6 has a flat substrate tape 10, on one side of said substrate tape 10 hooking elements are arranged. In the example shown, these are formed by mushroom heads 12 (only part of which are numbered in the drawing), which are located on stems projecting from the substrate tape 10. This can be a so-called touch fastener element, in which 200 to 400 or more hooking elements per cm²are provided on a substrate tape 10. It can be formed by a polyamide base fabric having polypropylene stems, on said stems the mushroom heads 12 are formed by thermal processing. The substrate 10 having the mushroom heads 12 can also consist of an injection-molded plastic section. While in the example shown, the hooking elements are formed by mushroom heads 12, the hooking elements can also be formed by slings or loops of a loop material. Touch fastener elements of this type, having mushroom heads 12 as hooking elements, are commercially available by the applicant under the product name Pressotex® and having hooking elements in the form of a fleece material under the product name Klettostar®.

On its side facing away from the hooking elements, the substrate tape 10 is firmly connected to a second substrate tape 16 via an adhesive layer 14. In this example, the adhesive layer 14 consists of a moisture cross-linking adhesive containing polyurethane. An iron wire 18 is embedded in the center of the adhesive layer 14 and extends over the entire length of the touch fastener part 6, perpendicular to the drawing plane. In conjunction with permanent magnetic elements (not shown) in the foaming mold, the iron wire 18 forms a magnetic holding device fixing the touch fastener part 6 in the seating pipe 2. The second substrate tape 16, attached via the adhesive layer 14, is an injection-molded plastic section having round protrusions 20 in the form of free-standing rods formed on the side facing away from the adhesive layer 14. These form a connecting means that ensures for good adhesion of the molded foam during the foaming process. As can be seen in the drawing, the second substrate tape 16 has a greater width than the first substrate tape 10 and a side edge area 22 each, which have the same width, of the second substrate tape 16 protrudes laterally beyond the first substrate tape 10. With the side facing away from the projections 20, these edge areas 22 each form a connecting zone 24, to which a cover sheeting 26 can be attached in a detachable manner. In this example, the cover sheeting 26 is formed by a sheeting, for instance made of polyester, which is provided in the manner of an adhesive tape with a pressure-sensitive adhesive 28, and the longitudinal edges of the cover sheeting are detachably glued by said adhesive 28 to the connecting zones 24 of the side edge areas of the second substrate tape 16. FIG. 1 shows this state in which, in preparation for a foaming process, the touch fastener part 6 together with the cover sheeting 26 are inserted in the seating pipe 2, wherein said cover sheeting tightly encloses the entire area of the hooking elements (mushroom heads 12) and protects them against the entry of molding foam during the foaming process. After removing the cover sheeting 26, the mushroom heads 12 are available in fully functional state for the subsequent establishment of the adhesive connection with the respective corresponding further touch fastener part.

FIG. 2 shows a top view of a length segment of the embodiment of the touch fastener part 6 of FIG. 1 after the detachable cover sheeting 26 has been removed. As shown, starting from the longitudinal edges designated 25 of the second substrate tape 16, recesses 27 are formed, which extend in both tapes 16 and 10 in a direction perpendicular to the longitudinal direction of the tape up to close to the centerline of the tape. More precisely, the recesses 27 each end equidistantly from the embedded iron wire 18 running in the centerline of the tape. In the example shown, the distance between the inner ends of the recesses 27 and the centerline of the tape is smaller than 1/10 of the width of the second substrate tape 16. The identically formed recesses 27 of both lateral sequences are equally formed and are arranged in alignment with each other and each have a V-shape, wherein the width of said V-shape decreases from the outer longitudinal edge (25 in FIG. 1) inwards and ends in a tip. The spacing between the equidistantly arranged recesses 27 is equal to the width of the second substrate tape 16 or preferably slightly less than that.

As mentioned above, mainly due to the material properties of the second substrate tape 16 formed by a plastic section, the touch fastener part 6 has a relatively high stiffness against bending in the tape plane, i.e. in the plane of FIG. 2. The recesses 27 result in a considerable reduction of this stiffness and provide sufficient flexibility to allow the touch fastener part 6 to be arranged in a course deviating from the straight line.

In this respect, FIG. 3 shows the example of a length segment having a curved course, wherein the longitudinal direction of the tape is angled by approximately 90°. Due to the fact that the recesses 27, because of the V-shape, form material cutouts having a larger width at the longitudinal edges, there are free spaces available on the inside at bends, as shown in FIG. 3, which allow the walls of the recesses 27 to approach each other while tapering the V-shape, while the V-shape spreads apart on the outside of the bend. As a result, tighter bends, such as those shown in FIG. 3, can be achieved without bulging.

FIG. 4 shows a second embodiment, wherein however, unlike in FIG. 1, the touch fastener part is shown in a partially finished state. The embodiment of FIG. 4 corresponds to the embodiment of FIGS. 1 to 3, apart from the fact that the pressure-sensitive adhesive 28 of the cover sheeting 26 is not in direct contact with the mushroom heads 12, but that a protective layer 38 is applied to the adhesive 28. The protective layer 38 is formed by a sheeting, for example of polyester, wherein the width of the sheeting corresponds to the width of the first substrate tape 10. In the partially finished state of FIG. 4, the protective layer 38 of the cover sheeting 26 is in contact with the mushroom heads 12, but not yet glued to the connecting zones 24 of the edge areas 22 of the second substrate tape 16 by moving the side edges of the cover sheeting 26 as indicated by arrows 36. The protective layer 38 extending over the entire width of the first substrate tape 10 protects the mushroom heads 12 from an application of the pressure-sensitive adhesive 28 of the cover sheeting 26.

FIGS. 5 and 6 illustrate a third embodiment in which, in contrast to the embodiments described above, an additional foam barrier is provided to protect the mushroom heads 12 from entering of molding foam during the foaming process. This foam barrier is formed by a carpet pile, wherein the carrier 52 of the carpet pile, instead of the protective layer 38, rests on the pressure-sensitive adhesive 28 of the cover sheeting 26 and is glued to the cover sheeting 26. The pile threads 53 of the carpet pile form a wrapping of the mushroom heads 12 as an additional foam barrier. At the same time, the carrier 52 protects the mushroom heads 12 from contact with the pressure-sensitive adhesive 28. FIG. 6 shows, corresponding to FIG. 4, the partially finished state before the cover sheeting 26 is glued to the connecting zones 24 at the edge areas 22 of the second substrate tape 16.

Claims

1. A touch fastener part having a first substrate tape (10) having hooking elements (12) arranged on one side thereof, and having a second substrate tape (16) which, connected to the first substrate tape (10), has a connection means (20) on its side facing away from the hooking elements (12), wherein the second substrate tape (16) is wider than the first substrate tape (10) and at least one free lateral edge area (22) of the second substrate tape (16) projects beyond the adjacent longitudinal edge of the first substrate tape (10), and wherein the two substrate tapes (10, 16) can be bent along and transversely to their longitudinal orientation, characterized in that at least one free side edge area (22) of the second substrate tape (16) is provided with a weakening of resistance (27) in such a way that bending the two substrate tapes (10, 16) transversely to their longitudinal orientation is facilitated.

2. The touch fastener part according to claim 1, characterized in that the weakening of resistance is arranged at least at the one lateral edge area (22) of the second substrate tape (16), in the direction of the lateral edge area (22) the two substrate tapes (10, 16) are bent.

3. The touch fastener part according to claim 1, characterized in that one side edge area (22) each of the second substrate tape (16) protrudes beyond both longitudinal edges of the first substrate tape (10) and that both side edge areas (22) have the same surface area and are each provided with an equally effective weakening of resistance (27).

4. The touch fastener part according to claim 1, characterized in that the respective weakening of resistance of a side edge area (22) of the second substrate tape (16) continuously merges into the first substrate tape (10).

5. The touch fastener part according to claim 1, characterized in that the respective weakening of resistance (27) of the first (10) and second substrate tape (16) ends at a predetermined distance from a bending line defining the longitudinal axis (18) of at least the first substrate tape (10).

6. The touch fastener part according to claim 1, characterized in that the respective weakening of resistance (27) of the first (10) and the second substrate tape (16) subdivides the hooking elements (12) of the first substrate tape (10) into touch fastener segments, which are arranged in an insular manner and which are aligned one behind the other at the respective bending line, and that the hooking elements (12) continuously extend past the assignable weakening of resistance (27) in a longitudinal tape from touch fastener segment to touch fastener segment along the bending line.

7. The touch fastener part according to any one of the preceding claim 1, characterized in that the two substrate tapes (10, 16) are divided into the individual insular touch fastener segments, which are interconnected adjacent to one another at the points of weakening of resistance (27) along the bending line via articulation points formed in such a way that both the hooking elements (12) and the connection means (20) extend from one touch fastener segment to the adjacent touch fastener segment beyond the assignable articulation points.

8. The touch fastener part according to claim 1, characterized in that the two substrate tapes (10, 16) are provided with a preferably self-adhesive cover sheeting (26) on the sides of the hooking elements (12), wherein after removal of said cover sheeting (26) the hooking elements (12) are exposed for hooking engagement.

9. The touch fastener part according to claim 1, characterized in that a foam barrier (52, 53) is inserted between the cover sheeting (26) and the hooking elements (12) of the first substrate tape (10), wherein said foam barrier (52, 53) at least partially engages with the spaces between the hooking elements (12).

10. The touch fastener part according to claim 1, characterized in that the respective weakening of resistance is formed by at least one reduction of wall thickness and/orperforation and/orrecess (27) and/orchange in strength

11. The touch fastener part according to claim 1, characterized in that a sequence of recesses (27) is formed, starting from at least one longitudinal edge (25) of the second substrate tape (16), wherein the recesses (27) extend transversely to the longitudinal direction of the tape in both substrate tapes (10, 16) up to close to the centerline (18) of the tape or the bending line.

12. The touch fastener part according to claim 1, characterized in that a sequence of recesses (27) is formed each starting from both longitudinal edges (25) of the second substrate tape (16).

13. The touch fastener part according to claim 1, characterized in that the recesses (27) are formed equally and have a V-shape tapering inwards from the respective longitudinal edge (25).

14. The touch fastener part according to claim 1, characterized in that the boundary edges of the respective V-shaped recesses (27) form an angle of 20° to 30°, preferably 25°, between each other.

15. The touch fastener part according to claim 1, characterized in that the recesses (27) are equidistantly spaced to each other at distances that are preferably smaller than the width of the second substrate tape (16).

16. The touch fastener part according to claim 1, characterized in that the recesses (27) of one sequence are aligned with the recesses (27) of the other sequence.

17. The touch fastener part according to claim 1, characterized in that the recesses (27) end in front of the centerline (18) of the substrate tapes (10, 16) at a distance which is less than ⅛, preferably less than 1/10, of the width of the second substrate tape (16).

18. The touch fastener part according to claim 1, characterized in that the recesses (27) are formed by incisions or punchings in the assignable tape material, wherein said incisions or punchings extend completely through the material.

19. The touch fastener part according to claim 1, characterized in that the V-shaped recesses (27) tapering in the direction of the bending line are closing increasingly on one side, in the event of bending, until the wall parts of the two substrate tapes (10, 16), delimiting the V-shaped recesses (27), come into contact with one another.

20. The touch fastener part according to claim 1, characterized in that while in the event of bending in one direction the assignable V-shaped recesses (27) on one side are closing, the respective recesses (27) on the opposite side of the two substrate tapes (10, 16) spread apart correspondingly.

21. The touch fastener part according to claim 1, characterized in that the weakening of resistance (27) subdivides the two substrate tapes (10, 16) into individual touch fastener segments, which are interconnected to each other at the point of weakening of resistance, and that the connection means (20) extend from touch fastener segment to touch fastener segment across the assignable weakening of resistance.

22. The touch fastener part according to claim 1, characterized in that the first substrate tape (10), having its connection means (20), is free of weakenings of resistance in a longitudinal strip between the tough fastener segments.

23. The touch fastener part according to claim 1, characterized in that the recesses (27) on both sides of the tapes (10, 16) are formed equally and are arranged in alignment with one another and each have a V-shape, wherein the width of the V-shape decreases inwards from the outer longitudinal edge (25) and ends in the tip.

24. The use of a touch fastener part according to claim 1 in a foaming mold, in particular for manufacturing of vehicle seat cushions, having a seating pipe (2) into which the touch fastener parts (6) can be inserted covered by the cover sheeting (26), wherein after connecting of the molded foam to the connection means (20) while forming at least a part of the seat cushion and after removal from the foaming mold after removing the cover sheeting (26), the hooking elements (12) are exposed.