METHOD FOR PRODUCING A COMPOSITE PROFILED SECTION AND COMPOSITE PROFILED SECTION

Abstract

The invention concerns a method for the production of a composite profiled section (3) comprising a core (1) and a shell (2), in particular intended for use as a reinforcing element or reinforcing rod in a, preferably thermoplastic, plastic material and/or for use as a reinforcing rod for a spring clip (11), wherein the shell (2) has shell fibres (4) which are laid around the circumference of the core (1), wherein, subsequent to the application of the shell fibres (4) to the core (1), at least one supporting fibre (5) is wound around the shell fibres (4) applied to the core (1) by means of a winding device for the production of a preformed pre-composite profiled section (6). As an alternative and/or in addition thereto, a method for producing an aforementioned composite profiled section (3) is provided, wherein the core (1) is produced continuously by foam extrusion with at least one extruder.

Claims

1. A method for the production of a composite profiled section having a core and a shell for use as a reinforcing element, as a reinforcing rod in a thermoplastic or plastic material, or for the use as a reinforcing rod for a spring clip, the method comprising placing a plurality of shell fibres around a circumference of the core; and winding at least one supporting fibre around the placed shell fibres by means of a winding device for the production of a preformed pre-composite profiled section.

2. The method according to claim 1, wherein the core is fed as a strand in an inline method.

3. The method of claim 1, further comprising the step of continuously producing the core by foam extrusion with at least one extruder.

4. The method of claim 1, wherein the step of winding at least one supporting fibre further comprises spirally winding at least one supporting fibre with a distance between adjacent windings between 1 and 15 mm.

5. The method of claim 1, further comprising the steps of: producing a spring clip strand from the composite profiled section by an inline method; and extruding a jacket on the composite profiled section.

6. A composite profiled section for use as a reinforcing element or reinforcing rod in a thermoplastic or plastic material or for use as a reinforcing rod for a spring clip, the composite profiled section comprising a core and a shell circumferentially surrounding the core, wherein the core is an extruded plastic.

7. The composite profiled section of claim 6, wherein the core has a cylindrical hollow body with a wall thickness greater than 1 mm wherein the outer diameter of the core is less than or equal to 30 mm.

8. The composite profiled section of claim 6, wherein the core comprises a cross-linkable or cross-linked material, having a density of greater than 180 kg/m.sup.3.

9. The composite profiled section of claim 6 wherein at least one spirally shaped encircling supporting fibre is provided on an outside surface of the shell, the supporting fibre selected from one of: a synthetic polymer, a polyester, and an aramid.

10. The composite profiled section of claim 9, wherein the supporting fibre has a diameter of less than or equal to 1.5 mm, and where in the at least one spirally shaped encircling supporting fibre has windings that are spaced greater than or equal to 1 mm from one another.

11. The composite profiled section of claims 6, wherein the composite profiled section is cylindrical with an outer diameter smaller than or equal to 40 mm.

12. The composite profiled section of claim 6, wherein the shell has a wall thickness greater than 0.3 mm, and the shell is constructed from one or more of the following materials: carbon fibres, glass fibres, polymer fibres, aramid fibres, textile fibres, glass fibres, reinforced plastic material, thermosetting plastics, thermoplastic plastics, polypropylene, epoxy resin, a polyurethane, comprising resin, and polyester resin.

13. The composite profiled section of claim 6, wherein a composite profiled section has a thermoplastic or thermosetting jacket and the composite profiled section is used in a spring clip.

14. The composite profiled section of claim 6, wherein a connecting means is arranged at least partially in the core.

15. The composite profiled section of claim 14 where in the connecting means is a screw.

16. The composite profiled section of claim 6, wherein the core is a foamed plastic material.

17. The composite profiled section of claim 8, wherein the core material is selected from one or more of the following materials: an elastomer, a thermosetting material, or a thermoplastic material.

18. The composite profiled section of claim 17, wherein the core material is an amorphous thermoplastic material selected from one of the following: polyethylene, polystyrene, polyethylene terephthalate, polyvinyl chloride, and polypropylene.

19. The composite profiled section of claim 6, where in the core is a cylindrical solid body having an outer diameter less than or equal to 30 mm.

20. The composite profiled section of claim 9 wherein the composite profiled section is cylindrical having a diameter of less than or equal to 14 mm, the core is cylindrical and has diameter less than or equal to 10 mm, and the at least one supporting fibre has a diameter less than or equal to 1.5 mm, wherein the at least one supporting fibre is spirally wound around the core as windings such that windings are spaced greater than or equal to 1 mm from one another.

Description

[0101] It shows:

[0102] FIG. 1A a schematic cross-sectional view of a composite profiled section according to the invention;

[0103] FIG. 1B a schematic cross-sectional view of another embodiment of a composite profiled section according to the invention;

[0104] FIG. 2 a schematic view of a composite profiled section according to the invention;

[0105] FIG. 3 a perspective, schematic representation of a composite profiled section according to the invention;

[0106] FIG. 4 a schematic longitudinal section of a spring clip according to the invention;

[0107] FIG. 5 a schematic cross-sectional view of a spring clip strand according to the invention and/or a spring clip according to the invention;

[0108] FIG. 6 a perspective schematic view of a spring clip according to the invention; and

[0109] FIG. 7 A schematic method sequence for a method for producing a composite profiled section according to the invention or for producing a spring clip according to the invention.

[0110] The method according to the invention is explained below with reference to the schematic flow diagram according to FIG. 7 and with reference to FIGS. 1 to 6, wherein the machine according to the invention for the production of the composite profiled section 3 is not shown.

[0111] The composite profiled section 3 according to FIG. 1 has a core 1 and a shell 2 enveloping the core 1, the shell 2 having shell fibres 4 placed around the circumference of the core 1. According to the method, a first method variant provides that, following the application of the shell fibres 4 to the core 1, at least one supporting fibre 5 is wound around the applied shell fibres 4 by means of a winding device to produce a pre-composite profiled section 6. The pre-composite profiled section 6 differs from the composite profiled section 3 in that it has not yet hardened completely, wherein a preforming or a shaping is carried out by the supporting fibre 5. The outer wrapping of the shell 2 with the supporting fibre 5 is illustrated in FIGS. 2 and 3.

[0112] The supporting fibre 5 is laid around the shell 2 in such a way that an additional shaping by another shaping tool can be omitted. FIG. 2 illustrates that the supporting fibre 5 projects beyond the outside 10 of the shell 2 so that contours and/or recesses 12 result between the individual distances of the windings 7 on the outside 10 of the shell 2.

[0113] It is not shown that in another embodiment the material of the composite profiled section 3 can be compressed by the supporting fibre 5. With this embodiment not shown it is provided that the composite profiled section 3 has a reduced outer diameter in the areas wrapped by the supporting fibre 5. Instead of recesses 12 protrusions are provided for the non-wrapped areas of the composite profiled section 3.

[0114] Furthermore, it is not shown that compression can also be achieved by the supporting fibre 5 of the material of the shell 2 and/or the core 1 in the heating device.

[0115] There is no additional adhesive layer between core 1 and shell 2 in the example shown. In addition, a joint in shell 2 is also avoided, as it is provided according to the method that the strand of core 1 is continuously fed to the machine for the production of composite profiled section 3 in the inline method. The core 1 provides a supporting or holding function for the shell 2, with the core 1 not necessarily having to be integrally bonded to the shell 2.

[0116] In the method sequence in step A, it is provided in the exemplary embodiment shown that core 1 is first produced continuously by foam extrusion with at least one extruder. The extrusion of the core can also be provided independently and/or alternatively to the wrapping of the shell fibres 4 with the supporting fibre 5. The example shown in FIG. 7 finally shows a combination of both embodiments of the method.

[0117] The steps B and C according to FIG. 7 include the preparation of the shell 2, whereby the shell fibres 4 are spread out in a spreading device in step B. The spreading device comprises a fibre creel from which the individual shell fibres 4 are extracted, wherein, before entering the fibre creel, the shell fibres 4 have been stored on a coil creel in individual coils wound up. The individual shell fibres 4 are then treated in step C in an impregnating tank and/or in an impregnating bath, wherein the jacketing of each shell fibre 4 is covered with the material of the shell 2, in particular a plastic material.

[0118] The impregnating bath can be designed in such a way that the resin of the shell 2 in the impregnating bath is permanently liquid.

[0119] The core 1 produced in step A is fed in step D to the machine for producing the composite profiled section 3, the shell fibres 4 being laid around the core 1, preferably longitudinally in the production direction. The shell fibres 4 nest against the outside 13 of core 1 so that core 1 supports the shell fibres 4.

[0120] A shaping takes place in step E by wrapping the shell 2 on its outside 10 with at least one supporting fibre 5. The spirally shaped wrapping with the supporting fibre 5 causes the intermediate area, thus the recesses 12, to be free of the wrapping. The supporting fibre 5 is laid spirally shaped around the outside 10 of the shell 2 in the embodiment shown, so that the distance of the windings 7 is between 1 and 15 mm, in further versions between 2 and 10 mm. The resulting pre-composite profiled section 6 is therefore preformed.

[0121] When wrapping the pre-composite profiled section 6 with the supporting fibre 5, the pre-composite profiled section 6 is not yet fully hardened in the version shown, in particular the resin of the shell 2 is not yet hardened.

[0122] The pre-composite profiled section 6 wrapped with the supporting fibre 5 is fed to a heating device in step F so that the outside 10 of the shell 2 can harden.

[0123] A high heating temperature is required at the entry into the heating section in order to set the chemical reaction of the reaction resin, which leads to hardening, in motion very quickly. The temperature in the heating section is then kept as constant as possible in step G in order to maintain the initiated chemical reaction. The pre-composite profiled section 6 is guided through the heating section as contact-free as possible, if necessary supported on some supporting rollers, so that in contrast to pultrusion no high extraction forces are required.

[0124] After the heating section, in step H it is planned that either the composite profiled section 3 is completely hardened, wherein it can be separated into individual profiles by means of a separating device in accordance with an embodiment not shown, and thus can be temporarily stored.

[0125] In step H, it can also be provided that the pre-composite profiled section 6, which has not yet hardened completely, is fed to further devices for the production of a spring clip strand 8. It is not necessarily intended that the hardening reaction of the pre-composite profiled section 6 is complete. Despite the superficial external cooling of the shell 2, the exothermic hardening reaction, which takes place inside the pre-composite profiled section 6, is not interrupted.

[0126] Steps I to M include the production of a spring clip strand 8 and/or a spring clip 11. It is understood that in an exemplary embodiment not shown it can also be provided that the method is ended after step H, wherein the pre-composite profiled section 6 results in the composite profiled section 3 after complete hardening.

[0127] In the method procedure shown in FIG. 7, however, the production steps for producing a spring clip 11 are provided. In step I, the composite profiled section 3 is provided with a jacket 9 of the spring clip strand 8. It is intended that the composite profiled section 3 is continuously fed in the inline method to the production of the spring clip strand 8. The jacket 9 can be extruded onto the composite profiled section 3. The extrusion of the jacket 9 onto the composite profiled section 3 is a classic extrusion process sequence.

[0128] Consequently, after applying the jacket 9, the pre-spring clip strand 14 passes through a calibration basin in step J in order to reshape the outer contour of the jacket 9 and to support it during solidification. In step K, it is planned that the pre-spring clip strand 14 should pass through at least one cooling basin after the calibration basin, so that the jacket 9 is completely solidified. No vacuum calibration is provided and is also not necessarily required because the composite profiled section 3 acts sufficiently supportively and already prevents the jacket 9 from collapsing.

[0129] In step L, the extraction of the jacketed spring clip strand 14 is provided via at least one extraction device, after which the spring clip strand 14 is fed to a separating machine in step M. In a separating device not shown, the separating machine includes an accompanying sawing device in order to separate the individual spring clips 11 from the spring clip strand 8. The accompanying sawing device is necessary for a continuous inline method so that the process does not have to be interrupted.

[0130] In addition, a composite profiled section 3, which is intended for use in a spring clip 11, is provided in accordance with all the exemplary embodiments shown. In an exemplary embodiment (not shown), the spring clip 11 can be part of a slat base springing for supporting a mattress or cushion. The composite profiled section 3 is produced in the exemplary embodiment shown according to the above method and therefore has a core 1 and a shell 2 surrounding the core 1 circumferentially. The core 1 has an extruded, foamed plastic.

[0131] If composite profiled section 3 is not used as shown for a spring clip 11, in particular for the base springing, composite profiled section 3 or shell 2 adopts the load-bearing properties of the entire spring clip 11. The spring clip 11 shown in the exemplary embodiment achieves high load-bearing strengths when used as a base springing. The core 1 does not impair the load-bearing capacity, it serves only as a support and/or mounting function for the shell 2.

[0132] FIG. 1 shows that core 1 can be a solid body (FIG. 1A) or a hollow body (FIG. 1B). The wall thickness of a hollow body of core 1 according to FIG. 1B is greater than 1 mm, in other embodiments greater than 2 mm. The outer diameter of core 1 is less than or equal to 30 mm, in other embodiments less than or equal to 20 mm.

[0133] The core 1 has a material which is extruded and foamed in further embodiments. In addition, in the exemplary embodiment shown, core 1 has a thermoplastic material, in this case polyethylene (PE). Other thermoplastics such as polystyrene (PS) and/or polyethylene interrephthalate (PET) and/or polyvinyl chloride (PVC) and/or polypropylene (PP) and/or thermosetting plastics are also possible in the case of other embodiment variants not shown.

[0134] Furthermore, it is not shown that the material of core 1 has a cross-linked and/or cross-linkable material, where an elastomer and/or a thermoplastic and/or a thermosetting material can serve as the cross-linked or cross-linkable material. Polyamide (PA) and/or acrylonitrile-butadiene-styrene copolymers (ABS), which in particular are not foamed, can be used as material in even further embodiments. The porosity of core 1 can be characterized, among other things, by the weight per unit volume at a known density and/or pure density of the material of core 1. The density of core 1 is greater than 180 kg/m3, preferably greater than 220 kg/m3, in particular greater than or equal to 250 kg/m3.

[0135] To shape the composite profiled section 3, a spirally shaped supporting fibre 5 is provided around the outside 10 of the shell 2 as shown in FIGS. 2 and 3. The supporting fibre 5 completely takes over the shaping of the pre-composite profiled section 6. The supporting fibre 5 has a material made of plastic, in the example shown a synthetic polymer, here polyester. In an embodiment which is not shown, it is intended that the material should have and/or consist of aramide.

[0136] The height of the recesses 12 is determined by the size and/or thickness and/or by the diameter of the supporting fibre 5, the size and/or thickness and/or the diameter of the supporting fibre 5 is less than or equal to 1.5 mm, for other embodiments less than 0.3 mm. Accordingly, the maximum height of the recesses 12 in the exemplary embodiment shown is less than or equal to 1.5 mm.

[0137] In another embodiment (not shown), it is provided that the non-wrapped areas of the composite profiled section 3, which do not have a supporting fibre 5, have protrusions instead of recesses 12. The height of the protrusions may be greater than 0.3 mm, in other embodiments greater than or equal to 1.5 mm. A compression of the material of the composite profiled section 3 may be provided in the areas of the composite profiled section 3 wrapped by the supporting fibre 5.

[0138] The distance of the windings 7 of the supporting fibre 5 on the outside 10 of the shell 2 indicates the maximum possible distance between windings 7 with a shape of the pre-composite profiled section 6 to be obtained and a minimum consumption of material of the supporting fibre 5. The distance of the windings 7 is greater than or equal to 1 mm, for other embodiments greater than or equal to 4 mm and/or at least substantially greater than or equal to 7 mm.

[0139] FIG. 1 shows that the core 1 is formed as a circular tube, so that the composite profiled section 3 adopts at least substantially the shape of a cylinder by being folded over with shell fibres 4, wherein the composite profiled section 3 has an outer diameter of less than or equal to 40 mm, in the case of further embodiment variants less than or equal to 16 mm and/or at least substantially less than or equal to 14 mm. The difference between the external diameter of the composite profiled section 3 and the external diameter of the core 1 results in twice the wall thickness of the shell 2. The wall thickness of the shell 2 is greater than 0.3 mm in this case and greater than 0.8 mm in the case of further embodiment variants.

[0140] By different wall thicknesses of the shell 2 it is possible to create different properties when bending a spring clip 11, so that corresponding “hard” and “soft” spring clips can be formed.

[0141] In the exemplary embodiment shown, the material of shell 2 is a polyester resin reinforced with glass fibres. In the case of further embodiment variants not shown, the use of a material which has a plastic material reinforced with carbon fibres and/or polymer fibres, preferably aramid fibres and/or textile fibres, is provided, wherein it is possible that thermosetting plastics and/or thermoplastic plastics and/or epoxy resin and/or polyurethanes (PU) having resin may be provided. Polypropylene (PP) can be provided as a material for a thermoplastic synthetic material.

[0142] Furthermore, in the exemplary embodiment shown, a spring clip 11 is shown, which has a composite profiled section 3 with a jacket 9. The jacket 9 has a thermoplastic plastic. In the case of other embodiments which are not clearly specified, the use of a thermosetting and/or other thermoplastic is intended. In the example shown, it is intended that the thermoplastic plastic has polypropylene (PP).

[0143] The material of the jacket 9 lays itself around the outside 10 of the shell 12 of the composite profiled section 3 and/or in the recesses 12. The jacket 9 completely surrounds the composite profiled section 3. The spring clip strand 8 is shown in FIG. 5 and/or the spring clip 11 is shown in FIGS. 5 and 6. By filling the recesses 12 with the material of the jacket 9, a mechanical interlocking and/or toothing of the external shell 2 of the composite profiled section 3 with the jacket 9 is created. This secure connection prevents these two components from separating from each other and/or from shifting against each other due to different shrinkage behavior when cooling the thermoplastic jacket 9 and the composite profiled section 3. In the embodiment variant shown, the method does not necessarily require a complete hardening of the composite profiled section 3 before being fed into the extrusion machine of the jacket 9 for the production of the spring clip strand 8, so that the hardening process continues inside the composite profiled section 3 under certain circumstances after the spring clip strand 8 has been produced. However, due to the positive interlocking of the jacket 9 with the composite profiled section 3, subsequent deformation is also prevented during the remaining hardening process during storage or transport

[0144] At this point, however, it should be noted that the pre-composite profiled section 6 has already been dimensionally stable in its original form due to the supporting fibre 5. The composite profiled section 3 is stable against buckling. The subsurface layers of the composite profiled section 3 are hardened before entering the extrusion machine of the jacket 9 and easily withstand the melt pressure of the extrusion machine.

[0145] According to FIGS. 5 and 6, it is clear from the spring clip 11 that the jacket 9 has at least one radially projecting leg 15. In the version shown, the jacket 9 has one leg 15, 16 each on opposite sides. The legs 15, 16 of the finished spring clip 11 provide an enlarged contact surface of the base springing for a mattress or for a cushion. The mechanical loads of the spring clip 11 are absorbed and compensated by the jacket 9 and/or shell 2. The bearing strength is mainly and/or exclusively taken over by the shell 2.

[0146] The core 1 does not have to take any load, it serves as a support and/or holding function for the shell 2. The jacket 9 is arranged symmetrically in relation to a horizontal and in relation to a vertical cross-section axis, so that accumulation of material on one side in the cross-section is prevented, whereby deformations of the spring clip during subsequent cooling are avoided. The legs 15, 16 have a rounded, elongated, elliptical-shaped cross-sectional shape. They also have two recesses 17 in the embodiment shown, but these can also be omitted. According to FIG. 5, the recess 17 has an arc-shaped cross-sectional shape and thus creates a wave-shaped end of the legs 15, 16 in the cross-sectional view.

[0147] It is not shown that the composite profiled section 3 can be used for connection with a fastening means, in particular a screw. Furthermore, it is not shown that the connection means can be arranged at least partially in the core 1. This applies both to the configuration of core 1 as a solid body and as a hollow body. In the case of a hollow body design, the free area and/or hollow cavity of core 1 can ultimately serve as a thread for the fastening means. In the end, the core 1 of the composite profiled section 3 acts as a kind of dowel for the fastening means.

[0148] In this context, it is understood that a plurality of composite profiled sections 3 and/or spring clips 11 and/or reinforcing rods and/or reinforcing elements exhibiting the composite profiled section 3, preferably with a thermoplastic and/or thermosetting jacket 9 and/or protective shell, can also be arranged against each other by means of further connecting means. Thus, it may be provided that a connecting means, in particular a screw or the like, is arranged in the core 1 and at the same time also in a further connecting means, in particular a branching means, for connection to further reinforcing rods and/or reinforcing elements and/or spring clips 11 and/or composite profiled sections 3. The branching means may have a plurality of openings for arrangement

[0149] In addition, the possible application areas of the composite profiled section 3 are not shown. In particular, it is not shown that the composite profiled section 3 and/or the spring clip 11 and/or the reinforcing element and/or the reinforcing rod with a preferably thermoplastic and/or thermosetting protective jacket or jacket 9 can be used as a fence system, visual protection, roof support, base springing, in particular slatted frame system, shelving system and/or for undercut creation in injection molding.

REFERENCE CHARACTER LIST

[0150] 1 Core

[0151] 2 Shell

[0152] 3 Composite profiled section

[0153] 4 Shell fibres

[0154] 5 Supporting fibre

[0155] 6 Pre-composite profiled section

[0156] 7 Distance of windings

[0157] 8 Spring clip strand

[0158] 9 Jacket

[0159] 10 Outside of the shell

[0160] 11 Spring clip

[0161] 12 Recesses

[0162] 13 Outside core

[0163] 14 Pre-spring clip strand

[0164] 15 Leg

[0165] 16 Leg

[0166] 17 Recesses