CLOSURE PART

Abstract

A closure part, for vulcanization into products which are produced at least in part by vulcanization, includes at least a rear side, a function side and a barrier layer. The rear side is integrally bonded to a rubber material. The function side has individual hook-and-loop elements that are kept free of the rubber material and produce a releasable hook-and-loop closure when engaged with corresponding hook-and-loop elements. The barrier layer is between the rear and the function side. The barrier layer prevents liquid rubber material and/or flowable vulcanization products from entering the function side from the rear side during vulcanization.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Patent Application No. DE 10 2022 127 854.9, filed Oct. 24, 2022, the entire contents of which are hereby incorporated in full by this reference.

DESCRIPTION

Field of the Invention

The invention relates to a closure part for vulcanizing into products which are produced at least in part by vulcanization.

Background of the Invention

Closure parts or touch-and-close closure parts have proven themselves in many fields as a releasable and functionally reliable connection and closure technology. Inserts for aircraft or vehicle seats are used for, among other things, attaching seat covers to foam body parts, consisting of a molded foam, wherein each one of the respective touch-and-close closure parts are foamed into the polymeric foam material when the respective seat is produced, and the respective other touch-and-close closure part is fixed, in particular, sewn to the corresponding hook elements on the cushion covering material. In the production of the foam body parts, the touch-and-close closure parts are placed in so-called receiving holes of a foaming mold, and by introducing foam material into the open cross sections of the foaming mold, preferably by introducing polyurethane foam, the touch-and-close closure parts are attached to the foam body parts during the foaming process.

It is essential for the functionality of the touch-and-close closure parts that the hook elements are protected from the penetration of foam material during the foaming process. For this purpose, DE 10 2017 011 245 A1 proposes a closure part or touch-and-close closure part, comprising a first carrier strip having hook elements arranged on one side and a second carrier strip, which has a connecting means on its side facing away from the hook elements for adhesion of a shaped foam, wherein the hook elements are covered at least temporarily by a cover film which is connected in a detachable manner to components of the touch-and-close closure part. Due to the fact that, in the known solution, a separate sealing element is provided in film form which covers the hook elements during the foaming process, it is ensured that the hook elements are securely held by the molded foam during the foaming process, so that the hook elements are fully functional after the completion of the foaming process and the detachment of the cover film. Although the known solution has proven to be extremely successful in practice in the context of foaming processes, it proves to be unsuitable if closure parts of the type mentioned are to be vulcanized with the production of vulcanization products. In particular, the high pressures and high temperatures that occur during vulcanization allow the known film cover solution to appear as not very suitable.

In contrast, DE 10 2013 009 091 A1 discloses a method for producing a connecting part using an injection molding method, wherein in a first step a closure part forming a component of a touch-and-close closure is produced with touch-and-close or hook-and-loop elements and is introduced as an insert part into an injection mold in which, in a second step, the connecting part is formed by means of a back-injection process in the form of a component that contains the closure part as a one-piece component. In this way, a plate-shaped closure part product is preferably obtained which can be fixed to floor groups in the interior of vehicles with a bottom latching hook. For securing the position of an associated floor mat, which can also regularly consist of a rubber mat obtained by vulcanization, said mat has glued-on, circular hook-and-loop elements, which are brought into engagement with the corresponding hook-and-loop elements of the disk, which enables the floor mat or the rubber mat to be releasably attached to the vehicle floor. In rough everyday operation, however, it cannot be ruled out completely that the hook-and-loop elements glued on the floor mat might become detached, which leads to the mat fastening being unusable and, in particular, such adhesive solutions have proven unsuitable if products produced over a large area by vulcanization are t be equipped with such hook-and-loop elements as part of a Velcro® touch-and-close closure.

SUMMARY OF THE INVENTION

Accordingly, the object of the invention is to provide a closure part solution which can be permanently bonded to products which are obtained in the context of vulcanization processes. This object is achieved by a closure part having the features of claim 1 in its entirety.

Since the closure part according to the invention is at least constructed from: a rear side, which can be integrally bonded to a rubber material; a function side, which is kept free from the rubber material, has individual hook-and-loop elements which produce a releasable hook-and-loop closure with corresponding hook-and-loop elements; and a barrier layer between the rear and function sides which prevents liquid rubber material and/or flowable vulcanization products from entering the function side from the rear side during vulcanization,

a connecting part made of individual components that are connected to one another is provided, which components on the one hand ensure that the vulcanized closure part remains “hookable,” that a secure anchoring in the vulcanized product is obtained, and that due to the barrier layer the aforementioned rear and function sides can fulfill their different respective tasks in the joining without interference. In particular, it has been shown that, in spite of the high pressures and high temperatures, a secure bond is achieved in the vulcanized product and the hookability of the closure part is completely maintained, i.e., the ability to obtain a hook-and-loop closure which, as a whole, is repeatedly releasable and reclosable with correspondingly formed hook-and-loop elements of a third component. There is nothing in the prior art that corresponds to this.

The rear side and/or the function side can each be formed from a hook-and-loop element. The respective hook-and-loop element can have hook structures, loops and/or mushroom structures.

In a preferred embodiment of the closure part according to the invention, it is provided that the rear side and the function side are each formed from a velour. In other words, the hook-and-loop elements are each formed as a velour. Preferably, the velour used for the rear side and the function side is formed from a knitted fabric with a fiber covering made of closed pile loops. In this way, a closure part is created, with a “back-to-back” velour, and the closed pile loops are designed be robust enough and subject to a high enough inherent stress that, after the production pressure during vulcanization has been removed, and therefore after production of the product, the pile loops can also be set back up into their original position and thereby remain fully functional in order to serve as part of a hook-and-loop closure or as an anchoring material for an integral joining to the initially plastic rubber material, which is elastic after curing within the context of vulcanization.

It has proven advantageous here that the velour of the rear side, relative to the velour of the function side, is made thinner in terms of a predefinable projection than a carrier part, and preferably the respective velour for the rear and function sides consists of a polyamide material.

Preferably, the closure part is constructed in layers, wherein for bonding to the rubber material—which, by way of example, later yields a rubber mat—a thin velour made of polyamide is used which is bonded along its carrier part to a reactive polyurethane adhesive as a rear side with a temperature-resistant film with a melting point greater than 180° Celsius, preferably in the form of a polyethylene terephthalate film, as a barrier layer having high surface energy. For an increase of the surface energy, the film or barrier layer is treated, preferably on both sides, by means of gas phase fluorination. The system formed in this way is then in turn glued with a reactive polyurethane adhesive to the carrier part of a thicker velour, and, due to its thickness, this velour remains capable of being hookable as a function side even after the vulcanization.

The invention further relates to a closure system with a closure part described here and a corresponding hook-and-loop element. The closure part is connected to the corresponding hook-and-loop element, in particular, in a non-destructive manner, by means of its hook-and-loop elements of the function side. The corresponding hook-and-loop element can have closure hooks and/or mushroom-head-like closure elements.

Proceeding from this, a method for producing a vulcanization product, such as a rubber mat, provides at least the following method steps: inserting the closure part with its rear side into the still soft plastic rubber material mass; performing a vulcanization process by applying pressure and temperature to the connection of the closure part to rubber material; and removing the finished vulcanization product after vulcanization, in which the hook-and-loop elements of the function side project beyond the elastic rubber material.

The method mentioned here can be carried out, in particular, in the context of continuous production for large-area products, such as the continuous production of rubber mats of any length; however, it is also suitable for obtaining small sizes in so-called batch operation. In this way, rubber mats of a predefinable size as required, for example, in the footwell of motor vehicles, can be produced cost-effectively with appropriate packaging in very large quantities.

It has been found to be particularly advantageous to place such a vulcanization product in the form of a rubber mat with correspondingly hookable closure parts over a large area of a tipping platform of a tipper vehicle, such as a dump truck, and to releasably fasten it with corresponding hook-and-loop elements that are already there to form a Velcro® touch-and-close closure. Since of the rubber mat, the tipping platform can also be loaded and unloaded with heavy bulk material, such as rock material from a quarry, wherein a noise-reduction damping is carried out by means of the rubber mat, with the result that it is also possible to work on site with such tipper vehicles when quiet times need to be observed also for reasons of noise protection.

BRIEF DESCRIPTION OF THE DRAWINGS

The closure part according to the invention is explained in more detail below with reference to an exemplary embodiment according to the drawing. In the drawings, which are schematic representations that are not to scale:

FIG. 1 shows a side view of a detail of the closure part; and

FIG. 2 in a schematically greatly simplified manner shows a rubber mat which is provided with two closure parts, the loop material of which can be hooked in a releasable manner with corresponding hook-and-loop elements, such as hook elements or mushroom-head closure elements.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

FIG. 1 shows in a highly simplified and schematic representation a closure part for vulcanizing into products which are produced at least in part by vulcanization. The closure part consists of a rear side 10 which is integrally bonded to a rubber material which, according to the illustration according to FIG. 2, is correspondingly cured in the elastic state of part of the rubber mat 12. Furthermore, the closure part has a function side 14 that has individual hook-and-loop elements 16 which are kept free from the rubber material and which are brought into engagement with corresponding hook-and-loop elements 18 in accordance with the schematic representation according to FIG. 2, yielding a releasable hook-and-loop closure which has become known under the brand term Velcro® touch-and-close closure.

Furthermore, there is a barrier layer 20 between the rear side 10 and the function side 14 which prevents liquid rubber material and/or flowable vulcanization products from being able to pass from the rear side 10 to the function side 14 during vulcanization, which could otherwise lead to the hookable material on the function side 14 becoming unusable if the latter were to be glued or otherwise soiled by the rubber material or the by-products thereof, which can occur within the context of vulcanization.

Both the rear side 10 and the function side 14 are each formed from a velour, and the inserted velour consists of a knitted fabric 22 with a fiber covering made of closed pile loops 24. The respective pile loops 24 of the knitted fabric 22 extend from a carrier part 26. Alternatively, a fabric having pile loops 24 could also be used on a carrier part 26, as shown by way of example in DE 10 2007 003 287 A1, DE 102 40 986 B3 and DE 10 2013 022 112 A1.

In any case, the velour of the rear side 10 is designed for the integration into the rubber material or into the later vulcanized rubber with a smaller protrusion relative to its carrier part 26 than the respective velour for the function side 14. This also results directly from the illustration according to FIG. 1. Furthermore, the respective velour for the rear side 10 and the function side 14 should consist of a polyamide plastic material.

The already mentioned barrier layer 20 preferably consists of a polyethylene terephthalate film (PET), which is preferably fluorinated on both sides, so that on both sides of the barrier layer 20—i.e., at the top and bottom in the illustration shown according to FIG. 1—said barrier layer can be provided with an adhesive layer 28 which is formed from polyurethane, preferably consisting of a reactive polyurethane adhesive. This adhesive has a weight per unit area of approximately 35 g/m2. The velour for the rear side 10 is described in order number 88293-99 (Fb. 0999), and the velour for the function side 14 under the order number 88295-00 (Fb. 1002). The PET film as a protective layer 20 preferably has a thickness of approximately 36 μm.

Therefore, for bonding to the rubber material, for example a rubber mat 12, the thin velour 88296-99 made of polyamide is used and is bonded to the reactive polyurethane adhesive to form an adhesive layer 28 having the PET film 20 with high surface energy. The PET film serves as a barrier layer 20 and prevents liquid phases from penetrating from the rear side 10 in the direction of the function side 14 during vulcanization. The aforementioned composite is in turn bonded to the thicker velour 88295-00 as a further adhesive layer 28 with a reactive polyurethane adhesive. Due to its predetermined thickness, this velour remains hookable even after the vulcanization, and the thinner velour on the rear side 10 results in good integration into the rubber material during rubber production.

The hookable velour for the function side 14 preferably has a thickness of greater than 1.5 mm. The overall system of a closure part shown in FIG. 1 is extremely temperature-resistant and certainly contributes to production temperatures for a production period of up to 150° C. for up to 60 minutes. The PET film as a barrier layer 20 has a very high surface energy, which proves advantageous in connection with the adhesive layers 28 made of polyurethane. Tests have shown that, after the vulcanization of the hookable velour of the function side 14 with a standard mushroom closure of the intellectual property holder, which is sold under the Pressotex® brand name, the number 75161-00 has an average minimum peel strength of 15 N/cm and an average minimum shear strength of 50 N/cm2.

Vulcanization refers to methods in which thermoplastic natural rubbers or synthetic rubbers are converted into elastomeric plastics (rubbers). In addition to the classical sulfur vulcanization, rubbers are frequently crosslinked by means of peroxide, metal oxides or high-energy radiation. In principle, covalent crosslinking is formed between the macromolecules of the rubbers during vulcanization, so that the molecules can no longer move freely relative to one another, which leads to an elastic behavior of the vulcanized product starting from a plastic material behavior.

As is evident, in particular, from FIG. 2, the method for producing a vulcanization product, such as a rubber mat 12, has the following method steps: inserting the closure part according to FIG. 1 with its rear side 10 into the still soft plastic rubber material mass; performing a vulcanization process as indicated above by applying pressure and temperature to the connection of closure parts to the rubber material; and removing the finished vulcanization product after vulcanization, in which product the hook-and-loop elements of the function side 14 in the form of the pile loops 24 protrude through the elastic rubber material then obtained, for example, in the form of the rubber mat 12.

As can be seen by way of example from FIG. 2, the rubber mat 12 can be produced continuously, but there is also the possibility of a piece production in so-called batch operation. The rubber mat 12 shown in FIG. 2 having the respective closure part according to FIG. 1 can then be inserted into a tipping platform of a tipper vehicle (not shown) and fixed there by means of a respective corresponding closure part 18 to form repeatedly releasable hook-and-loop closures on the tipping platform.

According to the schematic representation according to FIG. 2, the corresponding hook-and-loop elements 18 can be formed from closure hooks 30 or from mushroom-shaped closure elements 32.

It is to be understood that the use of the described closure part is not limited to the above use; rather, it can always be used where the described closure part is to be vulcanized into a vulcanization product, with remaining hookable elements on the function side 14 for interacting with corresponding closure elements, forming an always releasable and closable Velcro® touch-and-close closure. There is nothing in the prior art that corresponds to this.

Claims

1. A closure part configured for vulcanizing into products which are produced at least in part by vulcanization, the closure part at least consisting of:

a rear side, which can be bonded to a rubber material by integral bonding;

a function side, which has individual hook-and-loop elements that are kept free of the rubber material and produce a releasable hook-and-loop closure when engaged with corresponding hook-and-loop elements; and

a barrier layer between the rear and the function side, which barrier layer prevents liquid rubber material and/or flowable vulcanization products from entering the function side from the rear side during vulcanization.

2. The closure part according to claim 1, wherein the rear side and/or the function side is/are each formed from a hook-and-loop element.

3. The closure part according to claim 2, wherein the rear side and/or the function side are each formed from a velour.

4. The closure part according to claim 3, wherein the velour used for the rear side and/or the function side consists of a knitted fabric with a fiber covering made of closed pile loops.

5. The closure part according to claim 3, wherein the velour of the rear side is formed thinner relative to the velour of the function side, in terms of a predeterminable projection relative to a carrier part, and the respective velour for the rear and function side consists of a polyamide.

6. The closure part according to claim 4, wherein the velour of the rear side is formed thinner relative to the velour of the function side, in terms of a predeterminable projection relative to a carrier part, and the respective velour for the rear and function side consists of a polyamide.

7. The closure part according to claim 1, wherein the barrier layer consists of a temperature-resistant film having a melting point greater than 180° C.

8. The closure part according to claim 7, wherein the barrier layer is made of a polyethylene terephthalate film.

9. The closure part according to claim 8, wherein the barrier layer is fluorinated on both sides.

10. The closure part according to claim 1, wherein the film-like barrier layer is treated by means of a gas phase fluorination for increasing the surface energy.

11. The closure part according to claim 1, wherein the film-like barrier layer is treated by means of a gas phase fluorination for increasing the surface energy on both sides.

12. The closure part according to claim 3, wherein the barrier layer is joined to the two opposite velours by means of an adhesive layer.

13. The closure part according to claim 1, wherein the respective adhesive layer is formed from a polyurethane.

14. The closure part according to claim 1, wherein the respective adhesive layer is formed from a polyurethane being a reactive polyurethane adhesive.

15. A closure system comprising the closure part according to claim 1 and a corresponding hook-and-loop element, the closure part being connected to the corresponding hook-and-loop element via the hook-and-loop elements of the function side.

16. A method for producing a vulcanization product, being at least one rubber mat, comprising at least the following method steps:

inserting the closure part with a rear side into a still soft plastic rubber material mass;

performing a vulcanization process by applying a pressure and a temperature to the connection of the closure part to the plastic rubber material mass; and

removing the finished vulcanization product after the vulcanization, during which the hook-and-loop elements of the function side project past the elastic rubber material mass.

17. The method according to claim 16, wherein the at least one rubber mat having at least one closure part according to claim 1 is produced, in the context of a continuous production or in a batch operation.

18. A use of the vulcanization product in the form of the at least one rubber mat, comprising the at least one closure part according to claim 12, wherein the at least one rubber mat is inserted into a tipping platform of a tipper vehicle, being a dump truck, and is fixed to the tipping platform by means of a respective closure part, forming hook-and-loop closures.