Method for producing a touch-and-close fastener part

Abstract

The invention relates to a method for producing a touch-and-close fastener part, containing at least the following steps: producing a base structure (10) from a thread system having individual loops which are at least partly made of polyamide plastic material or polyester plastic material, cutting open at least some of the loops to form two stem-like loop ends, heating the loop ends with a specifiable temperature and with a specifiable heating time until, under the surface tension of the plastic material, a head shape (18) arises as a thickened portion at each loop end, and forming the head shape (18) with a convex top (22), which transitions, at the location of a line-shaped transition (28), into a concave hooking surface (24), the concave hooking surface being seamlessly transitioned into the adjoining stem-like loop end for a hooking element (6).

Description

[0001] The invention relates to a method for manufacturing an adhesive closure part.

[0002] DE 102 40 986 B3 discloses a planar adhesive fastener part for an adhesive fastener in which detachably corresponding fastener elements can be engaged, with a basic structure comprising a thread system of warp threads and weft threads and with at least one functional thread that partially penetrates the base fabric and forms the fastener elements.By producing the known adhesive fastener component, the respective functional thread is cut at the point where a loop forms, creating a locking hook, or by the application of thermal energy – provided the functional thread is made of a plastic material – causing the cut ends of the locking elements to form mushroom-shaped locking heads, it has been shown that the known fastener components or locking elements, together with their associated fastening devices, form highly strong system connections. These connections, when operated with sufficiently high manually applied forces, can be separated again at any time, similar to a releasable hook-and-loop fastener. Achieving such a connection solution requires specially matched surfaces and individual components, resulting in correspondingly high manufacturing costs.

[0003] US 3 138 841 A concerns the cutting of loops protruding from a fabric and the subsequent heating of the ends of the loops to give these ends a mushroom-shaped structure.

[0004] The mushroom-shaped closure heads, produced using the thermal energy input method, project relatively far radially beyond their associated stems at their edges. Each closure head is axially spaced and connected to the base structure, which is the base tissue. This design is expected to result in high adhesive strength when such a closure head engages with another mushroom-shaped closure head of a further closure component, forming the adhesive closure, or with a corresponding loop material of the further closure component.In practice, however, it has been shown that with correspondingly large interlocking heads, increased penetration resistance can occur unintentionally when the head penetrates the adjacent head or loop material, for example because the head comes into contact with the head or the loop material is compressed by the head material required for interlocking, without the desired interlocking action taking place.

[0005] Based on this prior art, the invention is therefore based on the objective of creating a method for manufacturing an adhesive closure component that can be combined with other closure components to form an adhesive closure, whereby high shear strengths are to be achieved. A method with the features of claim 1 in its entirety solves this objective.

[0006] The inventive method for manufacturing an adhesive closure part is characterized by at least the following steps: Producing a basic structure from a thread system having individual loops that consist at least partially of polyamide or polyester plastic material, cutting open at least one part of the loops to form two stem-like loop ends, heating the loop ends with a predeterminable temperature and heating time until a head shape forms as a thickening at the respective loop end under the surface tension of the plastic material, and forming the head shape with a convex top surface that transitions at the point of a linear transition into a concave interlocking surface, which is seamlessly transferred into the subsequent stem-like loop end for an interlocking element.

[0007] By achieving a convex head shape top surface using the method according to the invention, a kind of protruding sliding surface is created on which the adjacent head or loop material can slide during engagement processes and thus comes into direct contact with the concave interlocking surface for a reliable releasable connection of two assignable adhesive closure parts of a total adhesive closure.

[0008] It is surprising to the average expert in the field of such adhesive fasteners that, at the point of a linear transition on the head part, whose convex upper surface transitions into a concave lower surface, high shear strengths can be achieved without the head part having to project radially beyond the outer circumference of the adjoining stem with a distinct overhang, as was previously the case in the prior art, due to a sharply defined edge formation.

[0009] Although the head section produced by the inventive method, with its convex-concave forming surfaces, is relatively small, which facilitates undisturbed interlocking, sufficiently high interlocking forces and, in particular, corresponding peel strength values ​​are achieved in addition to high shear strength. The overall rigid structure of each interlocking element contributes to this. The polyamide and polyester fibers used in the manufacturing process are therefore high-strength and possess a high degree of stiffness, so that the required interlocking and peel strength forces can readily be derived from the respective interlocking element into its basic structure, even within a miniaturized design for each interlocking element.Furthermore, the plastic materials used have good abrasion and wear resistance; even after prolonged use in a repeatedly openable and resealable overall adhesive closure.

[0010] In a further preferred embodiment of the method according to the invention, it is provided that the basic structure consists of a Fabrics made of warp and weft threads, into which individual pile threads are woven to form loops; knitted fabrics with a thread system in which the individual loops are always connected in sequence; or knitted fabrics with a multitude of parallel threads that, when pushed into one another, form the loops. is formed. Ultimately, it is important that the respective basic structure has a protruding loop material, after which the head parts with their desired convex and concave surface shapes are created after cutting and heating or flame-treating.

[0011] In a further particularly preferred embodiment of the method according to the invention, the respective loop is cut at a height between a lower region and an upper region, starting from the base structure, in a straight line and in a predefinable cutting plane, preferably running parallel to the base structure, for example in a range between 30% and 90%, particularly preferably in a range between 50% and 80% of the associated apex height of the loop minus the respective thread diameter. This results in stems of varying lengths measured from the base structure to the beginning of the respective head section, so that very different structures of closure parts can be generated with just one manufacturing process.

[0012] In a further preferred embodiment of the method according to the invention, it is provided that in the straight-line cut by means of an area where the fiber of a loop has a slight curvature up to the arc-shaped transition, a symmetrical head shape is formed by subsequent heating, and by means of an area where the fiber of the loop is more strongly curved in the direction of the arc-shaped transition, an asymmetrical head shape is formed by subsequent heating.

[0013] While a symmetrical head shape results in comparable interlocking forces and peel strength values ​​in all directions, an asymmetrical head shape allows for a preferred direction for closing and opening an adhesive fastener in the direction of the more curved arc transition.

[0014] In a further preferred embodiment of the method according to the invention, a loop end in the form of a cylindrical stem is produced as a preform for obtaining a symmetrical head shape, and a stem with an obliquely inclined head surface projecting beyond the stem is produced as a preform for obtaining an asymmetrical head shape. This head surface transitions into the cylindrical stem with a concave interlocking surface from its projection. In each case, the material volume stored in the stem is sufficient to form the required head shape, whether within the framework of a symmetrical or an asymmetrical structure.

[0015] In another preferred manufacturing process, the axial length of each preform is shortened by heating it as it forms the respective head shape in the direction of the final shape. This shortening during the forming process results in a more uniform and dense material distribution within the stem for each interlocking element, leading to improved stiffness values.

[0016] In order to ensure good penetration into the respective sealing material of an associated sealing part for the maintenance of the overall adhesive seal, while simultaneously ensuring good adhesion of the adjacent interlocking sealing elements, it is provided that the curvature of the convex upper surface is equal to or substantially equal to the curvature of the interlocking surface, which is concave in this respect, for a single head shape.

[0017] In a further preferred embodiment of the method according to the invention, a circular surface is formed in the symmetrical head shape when viewed from above, and an elongated surface, particularly in the form of an ellipse, is formed in the asymmetrical head shape when viewed from above, by heating. While the circular surface, as the head shape, forms the linear transition and thus allows for uniform interlocking in all directions, the elliptical shape specifies a preferred direction with improved interlocking for the elliptical portions projecting beyond the stem.

[0018] The invention further relates to an adhesive fastener component, manufactured by a method as described above, comprising a plurality of spaced-apart interlocking elements made of a polyamide or polyester plastic material, each provided with a stem and a head, and each head having a basic structure formed from a thread system and projecting to one side as part of individual, cut loops, and the head having a head shape with a convex upper surface that transitions at a linear point into a concave interlocking surface, which seamlessly merges into the adjoining stem. The method according to the invention allows such adhesive fastener components to be produced in large quantities in a cost-effective manner.In particular, such an adhesive fastener can be used in the area of ​​so-called floor assembly textiles, for example, to secure a floor mat equipped with corresponding adhesive fasteners in the interior of motor vehicles. This ensures that the floor mat is securely attached to the vehicle floor and can also be easily removed for cleaning or replacement and, if necessary, reattached in a non-slip position.

[0019] In a preferred embodiment of the adhesive closure element according to the invention, the ratio of the diameter D at the point of the linear transition between the convex head shape and the concave interlocking surface to the diameter d of the stem is ≤ 2.5, preferably ≤ 2, and particularly preferably ≤ 1.8. Particularly with such diameter ratios, good penetration has been achieved for the adhesive closure element, combined with a high degree of adhesion to associated adhesive closure elements of an overall adhesive closure due to the inherent rigidity of the interlocking element.

[0020] The inventive method for manufacturing an adhesive closure component is explained in more detail below using exemplary embodiments of such an adhesive closure component. The following are shown in a general and not to-scale representation: Figure 1 shows a partial side view of an adhesive fastener part with individual head shapes, as shown in the Figure 4 Figures 2 to 5 show, in a highly simplified representation, the individual manufacturing steps for obtaining an adhesive closure component according to the Figure 1 ; and Figures 6 to 9, again broken down according to individual manufacturing steps, show the obtaining of a modified embodiment compared to the Figures 1 to 5 .

[0021] The Figure 1 shows a section of an adhesive fastener component consisting of a basic structure 10 made of a thread system having individual loops 12, as exemplified in the Figures 2 and 6 for a single interlocking element 26. The individual loops 12 are made of a polyamide or polyester plastic material. How further the Figures 2 and 6The loops 12 shown are cut along a cutting line 14, which in the given case runs parallel to the basic structure 10. However, it is also possible to choose a different, all-around inclined cutting plane (not shown).

[0022] The separated loop ends 16 are heated or flamed at a predetermined temperature and for a predetermined heating time until a head shape 18 forms as a thickening at the respective loop end 16 under the surface tension of the molten or softened plastic material, as shown in the illustration. Figures 4 and 8 . In the Figures 3 and 7 The loop end 16 is the leftmost stem element, viewed from the perspective of the Figures 2 or 6, reproduced. While when cutting through the loop structure according to the Figure 2Essentially, a straight cylindrical loop end 16 or stem part is created; the thread structure used is determined by the Figure 6 thicker in diameter than the thread after the Figure 2 , so that, due to the inherent tension of the thread material, a loop end structure forms in an elevated manner with an inclined plane following the Figure 7 results.

[0023] Partly in the Figures 3 and 7 The stems 20 shown, in the form of the loop ends 16, are then heated from above above the softening temperature of the plastic material, which is not shown in detail, whereby in a configuration according to the Figure 3 a head shape 18 or head part according to the Figures 4 and 5 adjusts and at the loop end 16 after the Figure 7 a head shape 18 or head part according to figures 8 and 9, wherein the Figure 5 a top view of the head shape 18 after the Figure 4 represents and Figure 9In the case of an elliptical design, the top view of the head shape 18 according to the Figure 8 .

[0024] Both head shapes 18 according to the Figures 4 and 8 They have a convex upper surface 22 and a laterally adjacent, circumferential concave interlocking surface 24. Between the respective convex upper surface 22 and the concave interlocking surface 24 below it is a linear transition 28, which, according to the illustration, Figure 5 circular or as shown in the representation Figure 9 for the interlocking element 26 after the Figure 8 is elliptically shaped. All interlocking elements 26 are formed in one piece and the individual head shapes 18 transition seamlessly into the stems 20 and the loop ends 16, respectively.

[0025] As can be seen in particular from the Figure 1The resulting basic structure 10 is formed from a fabric 30 of warp and weft threads, into which individual pile threads 32 are woven, forming loops 12. Such a fabric structure for an adhesive fastener component is shown by way of example in DE 102 40 986 B3 and is known for multifilament systems from DE 10 2007 003 287 A1. The number of individual interlocking elements 26 on the basic structure 10 can be 100 to 200 pieces / cm², with a respective stem diameter for an interlocking element 26 in the range of 150 to 250 mm. µ m. Furthermore, the height of the respective interlocking element 26, measured from the base at the foot of the basic structure 10 to the outermost end of the head section, can be 1200 to 2200 µ The diameter of the headboard (D) at its greatest widening can be in the range of 200 to 400 meters. µ m lie. In this respect, very long stems 20 are, which according to the illustration after the Figure 1perpendicular and parallel to each other, with a very small dimensioned head section provided with the respective head shape 18.

[0026] Instead of the in Figure 1 The fabric 30 shown, as a basic structure 10, can also consist of a knitted fabric with a yarn system in which the individual loops 12 are always connected sequentially. Furthermore, it is possible to create a knitted fabric with a multitude of parallel threads, which are then interlocked to form the loops 12. Since such knitted and knitted fabrics are common in the field of manufacturing adhesive fastener components, they will not be discussed in further detail here.

[0027] As can be further seen from the Figure 2The respective loop 12 is cut in a straight line at a height between a lower and an upper region, starting from the respective base structure 10, and in a predefinable cutting plane, preferably running parallel to the base structure 10 along line 14, for example in a range between 30% and 90%, particularly preferably in a range between 50% and 80% of the associated apex height of the loop 12 minus the respective thread diameter for the thread used. Thus, the cutting line 14 for the embodiment according to the Figure 2 approximately half through loop 12 and in the embodiment according to the Figure 6 approximately 80% of the stated crown height minus the thread diameter.

[0028] As can be further seen from the Figures 3 and 7 results, will be in the Figures 2 and 6The straight section shown through an area where the fiber of a loop 12 has a slight curvature up to the arc-shaped transition 15, subsequently heated to a symmetrical head shape according to the illustration. Figure 4 formed, or, in the case of a cut through an area where the fiber of the loop is more strongly curved in the direction of the arc-shaped transition 17, an asymmetrical head shape 18 is formed by the aforementioned subsequent heating, as shown in the illustration. Figures 8 and 9 , with an already asymmetrical intermediate transition position for the loop end 16 according to the representation after the Figure 7 . To obtain a symmetrical head shape 18 according to the illustrations according to the Figures 4 and 5 The straight cut produces a loop end 16 as a preform in the shape of a cylindrical stem 20 as shown in the illustration. Figure 3 , whereas for the maintenance of an asymmetrical head shape according to the Figures 8 and 9As a preliminary form, a stem 20 with an obliquely inclined head surface projecting beyond the stem 20 is produced according to the illustration after the intermediate step in Figure 7 , which transitions from its overhang 34 with a concave interlocking surface 24 into the otherwise foot-side cylindrical stem 20.

[0029] As can be seen further from the depictions according to the Figures 7 and 8 As a result, in the asymmetrical solution, the concave interlocking surface 24, viewed in the direction of the figures, is more pronounced on the right side than on the left. This results in an overall asymmetrical elliptical transition surface between the otherwise cylindrical stem 20 and the linear transition 28 at the head shape 18. As can further be seen from the manufacturing step of the Figures 3 after 4 or from the Figure 7 According to section 8, the axial length of the respective preform is greater than the later length at which the corresponding final form is constructed. Figures 4and 8 by heating the stem-dividing end to form the respective head shape 18, it is shortened. It has proven particularly advantageous if the curvature of the convex upper surface 22 corresponds to the curvature of the concave interlocking surface 24, as in the embodiment according to the Figure 8 the most concave interlocking surface 24 corresponds to. It has proven particularly advantageous for the adhesive fastener part if, as shown in the illustration, the Figures 4 and 5 as well as 8 and 9, the ratio of the diameter D at the point of the linear transition 28 between convex head shape 22 and concave interlocking surface 24 to the diameter d of the stem 20 is ≤ 2.5, preferably ≤ 2, particularly preferably ≤ 1.8. This results in a particularly inherently stable, interlock-proof adhesive closure structure, as exemplified in the Figure 1 is represented in principle.

[0030] It is understood that all figures, particularly those with regard to their outer contours, are depicted in an idealized manner. Thus, due to the nature of the material, irregularities in the form of indentations or protruding points arise on the outer circumference of each head shape 18, especially along its linear transition 28. Particularly good results have been achieved when the pure pile yarn of the base fabric 30 with the loops 12 is made of 100% polyester and is subjected to the following production parameters: Production speed: 10 - 12.4 m / min; Shear blade speed: 1200 - 1410 rpm; Shearing height: 2 - 2.4 mm; Flame height: 1.50 - 1.55 mm.

[0031] For the identification of the respective adhesive fastener product, it can be advantageous to use polyamide, so that the product as a whole appears black, or to construct it from polyester material, resulting in a transparent fastener structure. Overall, an adhesive fastener component is realized with slender stems 20 and adjoining small-dimensioned head shapes 18, so that the fastener component according to the invention can be easily integrated into other fastener materials. The fastening device shown achieves high shear strengths with the associated floor assembly textile, so that unwanted slippage is prevented in all cases. The small head geometries according to the invention result in sufficient adhesive and peel strength values ​​to ensure sufficiently secure anchoring of the floor mat to the floor assembly textile without the head parts damaging the floor assembly textile through roughening processes.This has no equivalent in the state of the art.

Claims

1. Method for manufacturing an adhesive closure part, comprising at least the following steps: - producing a basic structure (10) from a thread system comprising individual loops (12) which consist at least partially of polyamide plastic material or polyester plastic material, - cutting open at least part of the loops (12) to form two stem-like loop ends (16), - heating the loop ends (16) to a predeterminable temperature and for a predeterminable heating time until a head shape (18) is formed as a thickening at the respective loop end (16) under the surface tension of the plastic material, and - forming the head shape (18) with a convex upper side (22) which merges at the point of a linear transition (28) into a concave hooking surface (24) which is seamlessly transferred into the adjoining stem-like loop end (26) for a hooking element (26).

2. Method according to claim 1, characterized in that the basic structure (10) is formed from - a fabric (30) of warp and weft threads, into which individual pile threads are woven to form the loops (12), - knitted fabrics with a thread system in which the individual loops (12) are always connected in sequence, or - knitwear with a plurality of threads running parallel to each other which, when pushed into each other, form the loops (12).

3. Method according to claim 1 or 2, characterized in that the respective loop (12) is cut at a height between a lower region and an upper region, starting from the basic structure (10) in a straight line and in a predeterminable cutting plane, preferably running parallel to the basic structure (10), for example in a region between 30% and 90%, particularly preferably in a region between 50 and 80% of the associated apex height of the loop (12) minus the respective thread diameter.

4. Method according to one of the claims 1 to 3, characterized in that, in the case of a straight cut - through a region in which the fiber of a loop (12) has a slight curvature up to the arcuate transition (15), a symmetrical head shape (18) is formed by subsequent heating, and - through an area in which the fiber of the loop (12) is more curved in the direction of the arcuate transition (17), an asymmetrical head shape (18) is formed by subsequent heating.

5. Method according to claim 3 and claim 4, characterized in that, in order to obtain the symmetrical head shape (18), the straight cut produces as a preform a loop end (16) in the form of a cylindrical stem (20) and, in order to obtain the asymmetrical head shape (18), a stem (20) with a head surface inclined at an angle and protruding beyond the stem (20) is produced as a preform, which, starting from its protrusion (34), merges into the cylindrical stem (20) with a concave hooking surface (24).

6. Method according to claim 5, characterized in that the axial length of the respective preform is shortened by heating to form the respective head shape (18) in the direction of the final shape.

7. Method according to one of the preceding claims, characterized in that the curvature on the convex upper side essentially corresponds to the curvature of the concave hooking surface (24) provided for hooking, for a head shape (18), preferably being formed with the same curvature.

8. Method according to one of the preceding claims and claim 4, characterized in that, in the case of the symmetrical head shape (18) in plan view, a circular surface is formed by heating, and in the case of the asymmetrical head shape (18) in plan view, an elongated surface, in particular in the manner of an ellipse, is formed by heating.

9. Adhesive closure part manufactured using a method according to one of the preceding claims, characterized in that it consists of a plurality of spaced-apart hooking elements (26) made of a polyamide plastic material or a polyester plastic material, each being formed from a base structure (10) and being provided with a stem (20) and a head part, protrude from a thread system to one side as part of individual, cut-open loops (12), and that the head part has a head shape (18) with a convex upper side (22) which merges at the point of a linear transition (28) into a concave hooking surface (24) which opens seamlessly into the adjoining stem (20).

10. Adhesive closure part according to claim 9, characterized in that the ratio of the diameter D at the point of the linear transition between the convex head shape (18) and the concave hooking surface (24) to the diameter d of the stem is ≤ 2.5, preferably ≤ 2, and particularly preferably ≤ 1.8.

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