DE3113810A1 - Plastic profile bar - Google Patents

Abstract

To increase the flexural stiffness of an extruded, board-shaped integral foam bar, reinforcing wires are incorporated into the non-porous integral foam skin during extrusion. <IMAGE>

Description

The invention relates to a profile bar according to the

Preamble of claim 1, that is, a profile rod made of so-called Integral foam, as well as a method and an extrusion nozzle for producing a such profile bar.

"Integral foam profile" means a profile that has a foam core which is porous and has a correspondingly low density. This Foam core merges into one at its edge areas without a discontinuity relatively dense and correspondingly strong outer skin, which almost or even has no pores.

In construction technology, board-like wooden profiles are often used for balcony railings, Stair railings or the like used, which are arranged in the open air.

Wood is used for this purpose because of its weight and strength properties well suited, but requires regular maintenance and is costly to produce. It is therefore desirable to produce such cladding from profile rods, which are more weather-resistant than wood and can also be produced with less effort are. For this purpose, board-shaped integral foam rods have already been extruded, the are beneficial in many ways, but warp under adverse conditions tend.

Solid plastic profiles come because of the heavy weight and in particular the high cost is out of the question.

The familiar comes closest to all previous practical requirements Profile bar (DE-OS 29 45 664) according to the preamble of claim 1, in which a Metal profile inside a so-called. "Integral foam profile" is attached. In which known profile bars provided for door and window frames ensure the tight outer skin and the metal profile for the required mechanical strength and the foam core for maintaining the desired dimensions. The outer skin is also weatherproof.

Because of the use of a metal hollow profile as reinforcement the known profile bar, however, is still relatively expensive, so that it is essentially only useful for windows and doors.

Based on this prior art, the invention creates one Integral foam profile rod, which in particular for balcony cladding or the like can be used, but without inserted rigid metal hollow profile rods has sufficient dimensional stability with adequate flexural strength and breaking strength.

These advantages are highlighted by the characterizing features of the claim 1 reached; this is in the profile rod, which consists of a foam core and a Outer skin is formed, at least one flexible strand of high tensile strength embedded. In contrast to the known profile bar, this reinforcement strand is not in the foam core, but rather essentially embedded in the outer skin, which may have to be kept appropriately thick. Preferably located the or each reinforcement strand is as close as possible under the outer surface the outer skin.

Reinforcement strands are stored wherever they are in a Bending load of the profile bar would be loaded on train. As the reinforcing strands have a high strength, they resist such a tensile load, so that with appropriate dimensioning of the reinforcement strand and / or the Attaching a sufficient number of reinforcement strands is prevented from occurring at a transverse load the profile bar according to the invention deflects excessively or rejects.

The cost of materials and thus the weight and costs, but also the requirements for the accuracy of the shaping is in the case of the invention Profile bar much smaller than the above-mentioned, known profile bar, its overall strength essentially from one embedded in the foam core Depends on the metal hollow profile, which is not subject to tension when the profile bar is subjected to transverse loads, but rather is loaded on bending.

The profile bar according to the invention is thus not only weatherproof and rigid, but also with little material expenditure and thus inexpensive to manufacture, the integral foam structure having a particularly favorable flow of forces under bending loads guaranteed.

Among the multitude of possible reinforcement cords it is according to one Embodiment of the invention of advantage, this reinforcement strand made of a metal wire, Metal tape, glass fiber roving and / or carbon fiber roving to form, with a Optimization of one of the reinforcement strands mentioned according to the properties required in each case turns out to be particularly favorable.

For the above-mentioned purposes it is according to another Embodiment of the invention particularly advantageous, the profile bar the Eorm of a to give narrow nvechtecks in which at least one, better both broadsides several reinforcement strands are distributed over these. For this purpose a metal wire or a metal braid can be used in particular.

For a board profile with a dimension of 100 x 20 mm or 150 or 200 mm x 30 mm has the inclusion of the reinforcement strands mentioned in the profile broadsides a considerable in a particularly simple and cheap way Effect delivered.

Such a profile bar is according to one aspect of the invention by Extrusion produced in an extrusion die, the strand or strands are introduced directly into the extrusion nozzle and together with the outer skin and the foam are coextruded. This procedure is not only special simple and cheap, but also delivers a profile bar with an impeccable outer surface, as is required for many architectural purposes.

About the transfer of shear forces between reinforcement strand and To ensure outer skin, it is according to a further embodiment of the invention It is advantageous to remove the strand or strands before introducing them into the extrusion nozzle to roughen and / or coat with an adhesion promoter or an adhesive. This measure according to the invention enables, in particular, the use in a proportionate manner thin reinforcement strands that have only a relatively small outer surface have, which is in contact with the material of the outer skin.

In order to carry out the aforementioned method, the invention is also used proposed an extrusion nozzle, as used for the production of the known integral.

schaumorofils is required; strand guides are in this extrusion nozzle arranged, which have a strand channel, the inner mouth of which into the extrusion channel protrudes while the outer mouth is open to the outside of the extrusion nozzle.

In operation, the reinforcement strands are passed through the respective strand channels introduced into the melt, which is located inside the nozzle. Here is preferably the part of the guide elements which dips into the melt, as in known ones Torpedo carriers streamlined so that there are no Stagnation of the melt can occur.

As it is desirable to achieve the most effective reinforcement possible the reinforcement strands are to be attached as close as possible to the outer surface preferably expediently the strand guides adjustable in their submerged depth.

It is also advantageous to achieve the thickest possible outer skin, which can be influenced by temperature control in the nozzle and calibration.

With a thickness of the outer skin of approx. 2 mm, the reinforcing strands should have a diameter or a thickness of about 0.5 to 1.5 mm.

According to one embodiment of the invention is on the outside of the Extrusion nozzle and in front of the inlet of the respective strand channel a pair of opposite one another Knurled rollers provided, between which the reinforcing strand to be inserted, preferably a wire, inserted and thus at the same time roughened in the surface will. It is also possible to use the knurled rollers with a feed drive for the reinforcement strand equip.

As an alternative or additional solution, it is advisable to the reinforcing strand with an adhesive and / or before it is introduced into the strand channel Coating adhesion promoter.

The subject of the invention is based on the attached, schematic Drawings, for example, explained in more detail; They show: FIG. 1 a cross section by a profile bar according to the invention and FIG. 2 is a half section through a extrusion nozzle according to the invention.

The profile shown in Fig. 1 is preferably a board profile in practice with the dimensions 100 mm x 20 mm or a balcony profile with the dimensions 150 mm or 200 mm x 30 mm.

The profile bar 1 shown has a foam core 3, the foam structure of which towards its outer surface continuously into a practically pore-free outer skin 2 passes over, in which reinforcement strands 4 are lathered in. In the example shown are each in the broad sides with the same distance to each other and each other opposite five reinforcement strands arranged, which are parallel to each other and in the longitudinal direction of the profile bar 1 extend so that a symmetrical design is achieved.

The reinforcement strands have a diameter of about 0.5 mm up to 1.5 mm. The outer skin has a thickness of about 2 mm to ensure that the reinforcement strands are embedded in the outer skin on all sides. So it is the outer skin is thicker than that of comparable, conventional integral foam profiles the case is. It is known how the thickness of the outer skin depends on the temperature control in a.

Extrusion nozzle and the calibration can be influenced.

When using five steel wires as reinforcement cords 4 on each broad side of the profile bar 1, as a balcony railing profile with the above was formed, the following measurement results were obtained: The The profile bar was subjected to bending loads in the transverse direction with a force of 55 kp, which acted with a support distance of 1.25 m. This bent the profile bar by 45 mm.

An unreinforced integral profile bar was among the same Loaded conditions and achieved a deflection of 80 mm.

It has been found that integral foam profiles in particular made of PVC, polyethylene, polypropylene and polystyrene for embedding reinforcement cords are particularly well suited.

In FIG. 2 is an extrusion nozzle for making the one shown in FIG Profile bar shown. The extrusion nozzle 5 has an extrusion channel 8, through which a stream of plastic is pressed in the direction of the arrow. By storage a core 6 and by appropriate control of the boundary conditions, in particular the temperature of a downstream, cooled calibration device, not shown, a profile rod 1 is formed at the downstream end of the extrusion nozzle 5, which has a foam core 3 in its interior, which is on all sides by a dense outer skin 2 is enclosed, in which the reinforcing wires are embedded are.

The extrusion channel 8 is approximately in its center with a drilling provided, which to the upstream side of the extrusion nozzle 5 by one Angle of about 600 is inclined. This drilling shows three from the inside outside in diameter each increasing, cylindrical sections of which the middle one is threaded.

A strand guide 9 is screwed into this thread, which at its lower end has a cylindrical extension, which exactly in the inner Section of the through hole fits and the end a little bit into the extrusion channel 8 protrudes.

Here is the one that dips into the extrusion channel and thus into the melt Part of these strand guides 9 rounded so that the melt is not dammed up.

The strand guide 9 has a through hole 10 coaxial with it on, which forms a strand guide channel.

The top of the strand guide 9 is provided with a transverse slot for insertion a screwdriver provided, by means of which the immersion depth in the extrusion channel 8 can be regulated.

Outside the extrusion nozzle 5 is permanently assigned to this one Wire supply roll 6 is provided on which a wire 4 is wound, which later to form the reinforcement strand 4 in the final profile rod 1.

The wire 4 is passed through two knurled rollers 7, which provide it with a roughening.

If necessary, it can be done by driving either or both of these knurled rollers the proper advance of the wire can be supported, as far as the wire 4 is not due to its adhesion in the outer skin 2 of the finished profile bar 1 automatically withdrawn from the wire supply roll 6 as the extrusion process progresses and is dragged through the knurled rollers 7.

The number of reinforcement strands 4 provided in a profile bar 1 is limited at the top by the minimum distance that the strand guides 9 or their receiving bores to one another in the outer wall of the extrusion nozzle 5 have to.

Blank page

Claims (8)

Plastic profile rod claims 1. Extruded plastic profile rod with a foam core and one that significantly increases the strength of the rod, almost or completely pore-free outer skin and with an embedded, enclosed on all sides Reinforcement made from a material that is significantly higher than that of plastic Strength that runs in the longitudinal direction of the rod and transfers shear forces with the Plastic is connected, d a d u r c h e k e n n n z e i c h n e t that the reinforcement consists of at least one strand (4) with high strength, which lies in the area of the outer skin (2). 2. Profile bar according to claim 1, d a d u r c h g e -k e n n z e i c h n e t that the strand or strands (4) run in the outer skin (2). 3. Profile bar according to claim 1 or 2, d a d u r c h g e k e n n z e i c h e t that the strand (4) made of metal wire, metal tape, glass fiber roving, Plastic fiber roving, carbon fiber or Kevlar fiber or a combination of these Materials is formed. 4. Profile bar according to one of claims 1 to 3, d a -d u r c h g e it is not possible to say that it is designed as a narrow rectangular profile (1) and that several strands (4) are distributed over their broad sides. r Method for producing a profile bar according to one of the claims 1 to 4 by extrusion into an extrusion nozzle, d u r c h g e n n n -z e i n e t that the strand or strands (4) into the extrusion nozzle (5) are introduced and coextruded together with the outer skin (2) and foam core (3) will. 6. The method according to claim 5, d a d u r c h g e -k e n n z e i c h n e t that the strand or strands (4) before being introduced into the extrusion nozzle (5) roughened and / or coated with an adhesion promoter or adhesive. 7. Extrusion nozzle for performing the method according to one of the claims 5 or 6, d u r c h e k e n n n z e i c h n e t that at least one in the Extrusion channel protruding by a preferably adjustable immersion depth (9) is provided, which forms an outwardly leading strand channel (10). 8. Extrusion nozzle according to claim 7, d a d u r c h g e k e n n z e i c h n e t that on the outside in front of the inlet of the strand channel (10) knurled rollers (7) are arranged for roughening the respective strand (4).