AT514852A2 - Reinforcing element, and method for producing such a reinforcing element - Google Patents

Abstract

The invention relates to a reinforcing element (2) consisting of a plastic strand (50), for joining to a matrix of an object, wherein the matrix of the object consists predominantly of at least one, substantially unstretched plastic material, and wherein the reinforcing element (2) at least one partially crystalline , thermoplastic material. The plastic strand (50) is predominantly monoaxially stretched, and a cross-sectional area (51) of the reinforcing element (2) that is perpendicular to the main drawing direction (19) has a substantially rectangular cross-sectional shape. Furthermore, the invention relates to a method for producing such a reinforcing element.

Description

The invention relates to a reinforcing element as specified in claim 1, and a method for producing such a reinforcing element as specified in claim 18.

EP 1 409 244 B1 discloses a monoaxially stretched polyolefin multilayer film, monoaxially stretched polyolefin multilayer tape or yarn of the AB or ABA type, having a total draw ratio of more than 12 and an E modulus of at least 10 GPa. This multilayer film consists essentially of a central layer (B) of a polyolefin selected from polyethylene and polypropylene and one or two further layers (A) of a polyolefin of the same class as the material of the central layer B. Here, the DSC melting point of the material is the other layers (A) lower than the DSC melting point of the material of the central layer (B), wherein the central layer (B) between 50 and 99% by mass of the material and the other layers (A) between 1 and 50 mass -%. For example, this material may be pressed into another material as a reinforcement, where the DSC melting point of the further material is below the DSC melting point of both the A and B layers, and the processing temperature is selected to be between the melting point of the further material and the melting point of the A layer. It is also possible to stack individual layers of the film on each other and to press them, wherein here the processing temperature is chosen so that it lies between the melting point of the A-layer and the melting point of the B-layer. Further, a process for producing a monoaxially stretched polyolefin multi-layer film, a monoaxially stretched polyolefin multi-layer tape or yarn of the AB or ABA type, having a total draw ratio of more than 12 is given. Wherein: 1. an AB or ABA type film, tape or yarn consisting essentially of a central layer (B) of a polyolefin selected from polyethylene and polypropylene and one or two further layers (A) of a polyolefin of the same class as the material of the central layer B, wherein the DSC melting point of the material of the other layers (A) is lower than the DSC melting point of the material of the central layer (B), the central layer (B) being between 50 and 99 mass % of the material and the other layers (A) are between 1 and 50% by mass, provided by coextrusion, and 2. the co-extruded film, coextruded belt or yarn is of single-stage or multi-stage stretching at a temperature below the melting point of the central layer B. is subjected.

The embodiment described in EP 1 409 244 B1 has the disadvantage that a reinforcing element produced in this way is produced very costly and expensive, the strength properties and rigidity properties being insufficient.

The present invention has for its object to provide an improved reinforcing element.

This object of the invention is achieved by the measures according to claim 1, as well as by a method according to claim 18.

According to the invention, a reinforcing element for joining to a matrix of an object, wherein the matrix of the object consists predominantly of at least one, substantially unstretched plastic material, and wherein the reinforcing element comprises at least one semi-crystalline, thermoplastic Kunststoffmate-rial formed. The reinforcing element is predominantly monoaxially stretched. A cross-sectional area of the reinforcing element formed perpendicular to the main direction of expulsion has a substantially rectangular cross-sectional shape. It is advantageous here that essential properties of the plastic material can be improved ver by the monoaxial stretching of the plastic. By aligning the molecular chains in the withdrawal direction favorable improvements are achieved for the application, which concern, for example, the increase in stiffness and strength properties.

Furthermore, it may be provided that the thickness of the reinforcing element along its cross-sectional area at least in sections between 0.2 and 10 mm, in particular at least partially between 0.3 and 7 mm and preferably at least partially between 0.4 and 5 mm. The thickness ranges mentioned have proven to be particularly advantageous in the handling of the reinforcing element. Furthermore, a matrix, which is provided with a reinforcing element of the specified cross-sectional areas, can be excellently connected to the reinforcing element, since the thermal energy introduced during the manufacturing process can be introduced very well into the respectively to be joined regions of the two elements. Furthermore, the illustrated geometries prefer the material-locking connection in a continuing consolidation process with a matrix through advantageous surface connections. The object obtained from a combination of a matrix with a reinforcing element of such thickness has excellent rigidity, strength and resistance properties.

Furthermore, it may be appropriate that the bending stiffness of the reinforcing element with respect to a transverse axis between 67 N * mm2 and 23 * 1 0λ6 N * mm2. Advantageously, a bending stiffness of the reinforcing element is in the ranges of values given here, because in a further consequence, by connecting the reinforcing element with a matrix, an object can be produced which has excellent rigidity properties. Furthermore, the reinforcing element can thereby have a very stable shape per se, as a result of which it can be processed better in the processing process than comparable reinforcing elements.

In addition, it can be provided that the bending stiffness of the reinforcing element with respect to a vertical axis between 10 * 1 0λ3 N * mm2 and 21 * 1 0λ9 N * mm2. Advantageously, a flexural rigidity according to DIN53362 of the reinforcing element is in the ranges of values given here, as in

As a result of connecting the reinforcing element to a matrix, an object can be produced which has excellent rigidity properties. Furthermore, the reinforcing element can thereby have a very stable shape per se, whereby it can be processed better in the processing process than conventional reinforcing elements.

Furthermore, it can be provided that the bending strength of the reinforcing element is between 50 MPa and 800 MPa. It is advantageous if the reinforcing element has at least the aforementioned flexural strength according to ISO 178, since it may be required in particular for the reinforcement of a thin-layered compared to the reinforcing material matrix that the reinforcing material must absorb the bending stresses, wherein the matrix material is responsible for the transverse pressure stability.

Furthermore, it may be appropriate that the torsional stiffness of the reinforcing element about a longitudinal axis between 85 N * mm2 and 30 * 1 0λ6. It is advantageous here that, in a further consequence, by connecting the reinforcing element to a matrix, an object can be produced which has excellent rigidity properties. Furthermore, the reinforcing element can thereby have a very stable shape per se, whereby it can be processed better in the processing process than conventional reinforcing elements.

Furthermore, it can be provided that the draw ratio of the reinforcing element is between 2 and 40, preferably between 4 and 20. With an advantageous draw ratio in the specified range, it can be achieved that the molecular structure of the reinforcing element is oriented sufficiently in order to align the macromolecules accordingly, and thus to obtain an increase in the strength values or stiffness values. Furthermore, this stretching range defines the technically meaningful bandwidth for the raw material, in which there is no damage to the molecular structure.

Furthermore, it can be provided that the modulus of elasticity of the reinforcing element along the main stretching direction (19) is between 2,500 MPa and 15,000 MPa, preferably between 4,000 MPa and 12,000 MPa. The advantage here is that by increasing the modulus of elasticity measured according to ISO 527, the rigidity of the resulting from a reinforcing element and a matrix object can be significantly improved. This effect can be particularly favorable when using materials which should as little as possible deform under load.

Furthermore, it may be expedient for the reinforcing element to have a tensile strength between 100 MPa and 500 MPa, in particular between 150 MPa and 300 MPa, along the main direction of elongation. The increase in the mechanical properties determined in accordance with ISO 527 in the tensile case have the advantage that objects which are equipped with a corresponding reinforcing element, have increased mechanical performance. The desired properties of the matrix material can be retained. For example, objects in which the volume fraction of the reinforcing material is large compared to the volume fraction of the matrix material, and thus between 60 vol% and 95 vol%, allow disproportionately high tensile strength values in the object. On the other hand, if the volume fraction of the reinforcing material is chosen to be small in comparison to the volume fraction of the matrix material, for example between 0.5% by volume and 20% by volume, a high flexural strength can be achieved in the object. The amount of reinforcing material depends on the final application and can be specifically varied by suitable methods. It can be particularly advantageous here to note that by using one or more layers of reinforcing material, the proportion of matrix material can be reduced and thus significantly reduced in terms of total weight.

Furthermore, it can be provided that the reinforcing element has a width of at most 300 mm, in particular a width between 5 and 150 mm, and preferably a width between 10 and 25 mm. It is advantageous when using reinforcing elements with the specified widths that they can be produced flexibly and inexpensively by established methods. The further processing of reinforcing materials with the mentioned widths can be done easily with modern production equipment. In addition, reinforcing elements with the specified widths are correspondingly stiff in order to be able to support a matrix material sufficiently.

Furthermore, it can be provided that the reinforcing element mainly consists of a material selected from the group of polyolefins, polyesters, polyamides or mixtures of these materials. It is advantageous in the case of using a reinforcing element from this group of materials that the desired property changes, such as increase in strength or rigidity, can be achieved very well by stretching with these materials.

In particular, it may be provided that the polyolefin is a polyethylene or a polypropylene. Especially these materials are considered to be advantageous for achieving the above-mentioned properties.

In particular, it may further be provided that the polyester is a polyethylene terephthalate (PET) or polybutylene terephthalate (PBT).

Furthermore, it can be provided that the reinforcing element (2) contains additives. It is advantageous in the use of additives that they can improve, for example, the UV resistance, stretchability, strength properties, impact resistance, flame retardant properties, etc. Additives can also be used to obtain certain optical effects of the reinforcing element, such as thermosensitive additives, phosphorescent additives or color masterbatches.

Furthermore, it may be expedient for the reinforcing element to be geometrically adapted, with respect to its cross-sectional area formed perpendicular to the main direction of extension, to the component to be reinforced with the reinforcing element or the respective intended use and / or load case. It should be emphasized here that when the reinforcing element is adapted to the component to be reinforced, the connection between the reinforcing element and the component to be reinforced can be made surprisingly good.

Furthermore, it can be provided that the reinforcing element is surface-treated on at least one surface. A surface treatment by mechanical, physical or chemical methods can give the reinforcing element further positive properties. These may be, for example, a changed feel, a change in the friction coefficient or surface tension and the like.

In a further development, it can be provided that at least one surface of the reinforcing element has an embossing. An embossing can, for example, bring about an altered feel and appearance as an advantage. A further effect of embossing may involve the enlargement of the surface, whereby a joint connection can be improved by increasing the specific surface area with such a surface-treated reinforcing element, for example.

A method of manufacturing a reinforcing element, comprising providing at least one semi-crystalline thermoplastic material and melting it in an extrusion device, comprises at least the following sequential process steps: 1) extrusion of the molten plastic material via a raw forming die to a rough-formed primary strand; 2) cooling and preserving the same 3) single or multi-stage heating of the raw primary strand via at least one warm-up device, 4) stretching the raw primary strand to the desired degree of stretching, by means of at least one stretching unit, 5) cooling the stretched strand in its final form by means of at least another cooling device, and 6) assembling in a packaging device to provide the desired form of use.

Furthermore, the method includes at least one further method step for improving the connection or integration of the reinforcing element with or in a matrix of an object, wherein at least one surface of the primary strand and / or the stretched strand is modified or functionalized by means of a surface treatment device.

The advantage of such a method is that by extrusion of the plastic material via a raw-forming nozzle the primary strand can already be considered any shape. Furthermore, when using, for example, an extruder, an endless strand can be produced, which is inexpensive to process in production. By subsequent cooling and the subsequent preservation of the raw form of the primary strand, this can be prepared for further processing. It is advantageous if the heat deflection temperature according to IS075-2 is undercut here in order to be able to process the primary strand further. Furthermore, a subsequent heating of the raw-formed primary strand is conducive because it can be processed in a, subsequently carried out stretching process in the presence of the necessary processing temperature. In a subsequent cooling process, the plastic can be well stabilized in order to finally be able to supply it in a confectioning its final use form. Particularly helpful here is an additional process step in which the surface is modified to improve the connection with or integration of the reinforcing element with or in a matrix.

Furthermore, it can be provided that the at least one further method step for surface treatment of the stretched strand between step 5 and step 6 of the method is carried out. It is advantageous in this case that by modifying the surface in this method step, a final surface can already be produced, which is no longer claimed by mechanical processing in the Fierstellungsverfahren, or changed.

In a further development it can be provided that the at least one further method step is carried out as a cold rolling process for the mechanical structuring of at least one surface of the drawn strand. An advantage of a cold rolling process is that it can be carried out without the input of heat energy, and thus is energy-efficient. Furthermore, in a cold rolling process, the structural change in the material is held backward due to temperature influences.

In an alternative, or in addition, it can be provided that the at least one further process step is carried out as a physical treatment for increasing the surface energy or polarity of at least one surface of the drawn strand. In this case, it is advantageous that the surface tension (dynung) of the amplification object can be increased. As a result, the reinforcing object can be better wetted by printing inks, solvents, aqueous polymer dispersions, adhesives or adhesion promoters. Furthermore, this allows further processing by laminating or coating. Preferably, the increase in surface energy is increased by corona treatment to 38 to 44 mN / m (measured by contact angle measurement). As an alternative to the corona treatment, it can also be provided that a flame treatment, fluorination or plasma treatment is carried out.

Alternatively, or additionally, it may be provided that the at least one further process step is carried out as a chemical treatment of at least one surface of the drawn strand. The advantage of a chemical treatment is that the surface of the element can be adapted according to the requirements for an ideal connection to the substrate.

In addition, it can be provided that a combination of the specified method steps is used for the modification or functionalization of at least one surface of the stretched strand. It is advantageous in the case of a combination of a physical, chemical or mechanical treatment process that effects can be achieved which would not be possible in this way if only one of these processes were used alone.

Furthermore, it may be expedient for an adhesive to be applied to one or both sides of the drawn strand after the at least one further surface treatment step. By applying an adhesive can be advantageously achieved that such a modified reinforcing element can not only be thermally applied to an object to be reinforced, but that it is also possible to stick this in the cold state.

In a further development it can be provided that the adhesive is selected from the class of hot melt adhesives. Of particular advantage here is that such an adhesive can be activated by the introduction of heat energy, therefore in the cooled state does not have the tendency to adhere to non-bonded surfaces. This substantially facilitates the handling of a reinforcing element provided with such a plastic.

Furthermore, it may be expedient that the base polymers of the hotmelt adhesive applied to the same plastic cleavage belong as the material of the reinforcing element. It is advantageous that the recyclability of a reinforcing element formed in this way can be improved. Furthermore, it can be achieved that the hot melt adhesive with the reinforcing element can form a nearly uniform structure.

In addition, it can be provided that the method includes at least one further process step for cutting along the processing direction of the primary strand and / or the stretched strand into a plurality of strands. It may be advantageous that the reinforcing element in addition to the production by a shaping nozzle, by cutting out of a wide extruded and monoaxially stretched web, which occupies the entire production width of an extrusion plant, can be cut. Advantageous in dividing a stretched plastic sheet in a plurality of individual strands, ie reinforcing elements is that in the extrusion process, a single strand can be produced, which has a comparatively large width and therefore is easy to work. Subsequently, this single strand can be split into several strands, which can be processed differently. Therefore, only one extrusion device is needed in the extrusion process, whereupon several different products can be produced simultaneously.

In addition, it can be provided that the at least one further process step is carried out after the drawing step. It is particularly advantageous if this process step is carried out only after the drawing step, since the final width and thickness of the intermediate product to the reinforcing element is already present at this time of the process.

Furthermore, it can be provided that the at least one further process step is carried out after the surface treatment step. It is particularly advantageous if this process step is carried out only after the surface treatment step, since the final shape and surface configuration of the intermediate product is already present at this time of the process.

Finally, provision can be made for the fabrication step to include at least one shaping device. It is advantageous here that the reinforcing element can thereby be given an arbitrary shape, in order to adapt it to certain purposes.

For a better understanding of the invention, this will be explained in more detail with reference to the following figures.

In each case, in a highly simplified, schematic representation:

Fig. 1 is a schematic representation of a system 1 for Flerstellen a reinforcing element;

2 is a perspective view of a reinforcing element. 2

By way of introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or the same component names, wherein the disclosures contained in the entire description can be mutatis mutandis to the same parts with the same reference numerals or component names. Also, the location information chosen in the description, such as top, bottom, side, etc. related to the immediately described and illustrated figure and these position information in a change in position mutatis mutandis to transfer to the new location.

1 shows the schematic representation of a plant 1 for producing a reinforcing element 2, or the schematic process sequence for producing the reinforcing element 2.

In a first method step, thermoplastic material 3 is melted in an extrusion device 4 and pressed through a molding die 5.

It can be provided that the reinforcing element 2 consists of a polymer selected from the group of polyolefins, polyesters, polyamides or mixtures of these materials. In addition, it can be provided that the reinforcing element 2 comprises a polymer selected from the group of the group of polyolefins, polyesters, polyamides or mixtures of these materials. It is advantageous here that especially these polymers are outstandingly suitable for processing in an extrusion process. Furthermore, these plastics can be stretched very well, whereby very good strength properties can be achieved.

In particular, it may be provided that the polyolefin is a polyethylene or a polypropylene. Furthermore, it can be provided that polyester is a polyethylene terphthalate (PET) or polybutylene terephthalate (PBT). As further plastics polyamides for use as reinforcing element 2 are conceivable.

A plastic in the sense of this description is an organic, polymeric solid which is produced synthetically or semi-synthetically from monomeric organic molecules or biopolymers.

A polyolefin in the sense of this description is a collective term for polymers prepared from alkenes such as ethylene, propylene, 1-butene or isobutene by polymerization or else polyolefin copolymers such as polyethylene, polypropylene, HDPE, LDPE or LLDPE.

Mixtures of the individual plastics can be produced by mixing during the extrusion process.

The shaping nozzle 5 is fastened here to a shaping tool 6. By the extrusion process, a primary strand 7 is generated, which receives its shaping by the shaping nozzle 5. In other words, the forming tool is attached to the extrusion device 4. The shaping takes place by means of a smooth or structured shaping die 5 or a mandrel or web holder. The shaping tool 6 can be designed as a hose head, pipe head, crosshead or spinneret.

It is quite conceivable that instead of only one shaping nozzle 5, a plurality of shaping nozzles 5 are attached to the shaping tool 6. In this case, in a practical embodiment, eight shaping nozzles 5 can be attached to the shaping tool 6, as a result of which a plurality of primary strands 7 can be produced, which can also be processed simultaneously. Of particular advantage here is that an extrusion device 4 can simultaneously produce a plurality of primary strands 7, which may have different or the same cross-sectional shapes. The individual primary strands 7 can then run parallel and be processed together in the further process steps. However, it is also possible for the individual primary strands 7 to be supplied to different further processing processes.

The shaping nozzle 5 can be exchangeably mounted in the shaping tool 6. This makes it possible that the system 1 and the extrusion device 4 can be easily and quickly converted to the production of various, cord-like plastic objects 2. In this case, the individual shaping nozzles 5 can be provided approximately for the extrusion of different shapes and sizes of the outer contour.

The exiting from the die 5 primary strand 7 can then be performed on the extrusion process by a cooling device 8 in order to be able to perform a further processing. Furthermore, it can be provided that the exiting from the die 5 primary strand 7 in the air, is cooled so far that the primary strand 7 is solid and thus can be further processed.

The cooling device 8 can be designed, for example, as a water bath 9. In principle, however, any type of cooling device 8 for cooling the primary strand 7 is conceivable.

The water bath 9 used in this embodiment has a length 10 of about 3 meters in order to allow the primary strand 7 to cool sufficiently. To increase the cooling power can also be provided that the primary strand 7 is not shown as shown only once through the water bath 9, but that in the water 9 Umlenkorgane are arranged, whereby the primary strand 7 can be performed several times through the water 9. Furthermore, a longer water bath 9 can be provided to increase the cooling capacity.

Furthermore, it can be provided that the water bath 9 is divided, for example, by partitions 11 into a plurality of zones 12. In these individual zones 12, for example, water with different temperatures can be used. It is also conceivable that in individual zones 12, the water is vortexed to increase the cooling capacity. Advantageously, the water bath 9 is provided with a fresh water supply to provide constantly cool water can.

Subsequent to the water bath 9, a spraying device 13 may be provided, through which the primary strand 7 is further cooled.

Subsequently, a trigger device 14 may be provided for the withdrawal of the primary strand 7 from the water bath 9. The take-off device 14 may be designed, for example, as a galette trio. In order to further cool the primary strand 7, it may also be provided that the individual roller elements 15 of the draw-off device 14 are cooled.

Following the extraction device 14, a further transport device 16 may be provided, which may also be designed as a galette trio. In this case, it is possible that the individual roller elements 15 are heated in order to heat the primary strand 7.

Following these upstream devices is a stretching unit 17. At the beginning of the stretching unit 17, a certain travel speed for the primary strand 7 is predetermined by the transport device 16. At the end of the stretching unit 17 is another transport device 18. The withdrawal speed of the further transport device 18 is chosen to be greater than that of the transport device 16. Thus, the primary strand 7 along the stretching unit 17 in its main direction of drawing 19 is pulled substantially monoaxially in the length. This stretching results in a stretched strand 20, which is present in the process sequence from the transport device 18. The draw ratio is in a range between 2 and 40, preferably between 4 and 20.

In order to be able to carry out the stretching operation, provision can be made for one or more warming devices 21 to be provided along the stretching unit 17, by means of which the primary strand 7 is brought into an advantageous processing temperature for the drawing process. The selection of the advantageous processing temperature depends on the particular plastic to be processed.

Subsequent to the further transport device 18, the stretched strand 20 can be guided through a further cooling device 22 in order to bring it to a corresponding temperature for further processing. In addition, or as a substitute for it is also conceivable that, for example, the individual roller elements 15 of the further transport device 18 are cooled in order to achieve the necessary cooling of the stretched strand 20.

In the process, following the stretching unit 17, a surface treatment device 23 is shown, in which at least one surface 24 of the primary strand 7 and / or the drawn strand 20 is modified or functionalized.

Not only may the surface treatment device 23 be subsequently installed on the stretching unit 17, but it is also possible for the surface treatment device 23 to be installed at a different position in the process sequence, before the stretching unit 17.

The surface treatment device 23 described here by way of example is located adjacent to the stretching unit 17 and thus treats the stretched strand 20. A surface treatment device 23 which is installed in front of the stretching unit naturally treats the primary strand 7. All the information relating to the surfaces 24 to be treated then also relate on the primary strand 7.

The surface treatment device 23 may be, for example, an apparatus for mechanical surface treatment, physical surface treatment, or chemical surface treatment.

A surface treatment device 23 for mechanical surface treatment may, for example, be implemented by a roller pair 25. The roller pair 25 may be provided by means of a first roller 26 and a second roller 27 for the mechanical structuring of at least one surface 24 of the drawn strand 20. Here, the stretched strand 20 extends between the two rollers 26, 27th

The two rollers 26, 27 can be pressed against one another by means of a pretensioning device 28 in order to be able to carry out the stretched strand 20 independently of its thickness 29 with a constant clamping force between the rollers 26, 27.

Alternatively, it can be provided that the two rollers 26, 27 are arranged in their position to each other adjustable and lockable to each other in order to adapt to the thickness 29 of the stretched strand 20 can.

In order to process the surface 24 of the stretched strand 20 accordingly, a roll structure 30 must be provided in at least one of the rolls 26 or 27. By means of this roller structure 30, one side surface 24 can be given a mechanical structuring.

It is also possible that both rollers 26, 27 are formed with a roller structure 30. As a result, the stretched strand 20 can be provided on both sides on its surface 24 with a mechanical structuring.

The roll structure 30 may be formed, for example, by protruding structural shapes such as pyramids and the like. It is also conceivable that the roller structure 30 is formed approximately by needle-shaped objects which are designed to penetrate into the surface 24 of the stretched strand 20.

As an alternative to the embodiment with two rollers 26, 27, it is also conceivable that only one roller 27 is carried out, which clamps the stretched strand 20 with a flat counter-holding plate.

Alternatively or in addition to the mechanical surface treatment by a roller pair 25, a physical surface treatment device 31 may be provided.

A physical surface treatment device 31 may be necessary because the stretched strand 20 may have a non-polar, electrically well insulating and water-repellent surface 24. This surface 24 may be poorly wettable by printing inks, solvents, aqueous polymer dispersions, adhesives or adhesion promoters. This is the case in particular with polyethylene, polypropylene and polyester materials.

For example, one possible physical surface treatment device 31 may be embodied as a corona treatment device. For example, the goal of such a physical surface treatment device 31 may be to increase the polarity of the surface 24, thereby significantly improving wettability and chemical affinity.

Preferably, the physical surface treatment device 31 is embodied in the form of a corona treatment device at the end of the manufacturing process. The stretched strand 20 is exposed to a high-voltage electrical discharge. This occurs between a grounded, polished roller 32 of steel or aluminum and a closely fitting insulated electrode 33. The stretched strand 20 lies on the polished roller 32, so that only the surface 33 of the stretched strand 20 facing the electrode 33 is treated.

Occurs an air gap between the roller 32 and the stretched strand 20, the roller 32 facing surface 24 is treated with. The electrode 33 is powered by a high frequency generator with an AC voltage of 10 to 20 kV and a frequency between 10 and 60 kHz.

Due to the corona treatment, the surface tension (dynung) in the stretched strand 20 becomes 38 mN / m to 44 mN / m. Since the surface tension is caused by dispersive and polar interaction components, the introduction of polar functional groups in particular increases the polar component of the surface tension.

In order to achieve an effective treatment of the surface, the surface tension of the drawn strand 20 should be above the surface tension of the desired coating material. In addition, the ratio of polar and dispersive interaction should be as close as possible to the surface tension of the drawn strand 20 and the desired coating material.

A test method for measuring the surface tension represents the contact angle measurement or contact angle measurement. In this case, a liquid drop is placed on the surface 24 on a test piece of the drawn strand 20 and the contact angle of the droplet compared to the surface 24 is determined under high magnification. The smaller the angle, the better the wetting.

Share by contact angle measurements with several chemically pure test liquids with known surface tension and known dispersive and polar to the polar and dispersive fractions of the surface tension of the film can be determined.

Alternatively to the corona treatment, a flame treatment, a fluorination or a plasma treatment can be carried out.

Alternatively or in addition to the mechanical surface treatment by a roller pair 25 and / or to a physical surface treatment device 31, a chemical surface treatment device 34 may be provided. For the chemical surface treatment, oxidizing agents may be provided for the plastic classes used in each case. These can be, for example, acids and alkalis.

In a further method step, it may be provided that an adhesive 35 is applied to a side surface 36, which may be a part of the surface 24 of the drawn strand 20. For this process step, it may be necessary to perform a physical surface treatment beforehand.

Furthermore, a further process step may be provided in which, viewed along a processing direction 37, the primary strand 7 or the stretched strand 20 is divided into a plurality of divided strands 38. This can be done by means of a dividing device 39, which is shown symbolically here.

The dividing device 39 may comprise, for example, a cutting unit 40 in the form of a cutting blade or in the form of a cutting roller. The primary strand 7 or the stretched strand 20 can in this case be divided in any orientation and thus converted into a plurality of divided strands 38. However, it is preferable that the primary strand 7 or the stretched strand 20 is divided as seen in its width.

As a further process step it can be provided that in a confectioning device 41 the stretched strand 20, or else a strand 38 divided therefrom, is transferred to its final reuse form. The packaging device 41 may comprise, for example, a spool 42 and a spool cutting unit 43, as shown for the lower strand 38.

Such coils 42 may serve for bulk portioning of reinforcing elements 2. Such wound coils 42 can be transported, for example, to a further processing plant located at a remote location, where they are fed to their further processing.

Furthermore, it is also possible that the packaging device 41, for example, a piece cutting unit 44 includes, as shown for the upper strand 38. This piece cutting unit 44 can be designed to cut the stretched strand 20 or even the split strand 38 into short pieces, which can then be fed to their further processing. Ideally, the bit cutting unit 44 is formed by a cutting tool traveling along with the stretched strand 20 or else with the split strand 38 in order to enable a continuous production process. In an alternative variant, it can also be provided that the piece cutting unit 44 is formed by a cutting roller 45, which comprises a peripheral cutting unit 46. It can be provided that the cutting unit 46 corresponds to a recess 47 of a counter-holder roller 48.

Furthermore, it can be provided that, subsequent to the piece cutting unit 44, a shaping device 49 is provided, through which the reinforcing element 2 is brought into a special shape. The forming device 49 may include, for example, a die and a punch. Furthermore, it is also conceivable that the shaping device comprises forming rollers for the continuous production of a specific profile.

Furthermore, it is also possible that further process steps are inserted between the process steps described here, in order to obtain the most advantageous reinforcing element.

Fig. 2 shows a schematic representation of a reinforcing element 2 in a perspective view. The reinforcing element 2 illustrated here consists of a plastic strand 50. The reinforcing element 2 has a cross-sectional area 51 on the face side with a substantially rectangular cross-sectional shape. However, it is possible for the cross-sectional area 51 to have various rib-like stiffening shapes 52 extending along the main stretching direction 19, which can contribute to increasing the rigidity of the reinforcing element 2.

A thickness 53 of the reinforcing element 2 has a significant influence on the bending stiffness with respect to a transverse axis 54. The larger the thickness 53 of the reinforcing element is chosen, the greater is the bending stiffness about the transverse axis 54 of the reinforcing element 2. Also attached to a broad side 55 of the reinforcing element 2 Stiffeners 52 may help to increase the flexural stiffness about the transverse axis 54.

Analogously, it behaves with a width 56 of the reinforcing element 2, which has a significant influence on the flexural rigidity of the reinforcing element 2 about its vertical axis 57. Again, attached to a narrow side 58 of the reinforcing element 2 stiffening 52 can lead to an increase in bending stiffness.

To increase the torsional stiffness of the reinforcing element 2 about a longitudinal axis 59, the entire geometry of the cross-sectional area 51 contributes substantially.

Furthermore, it can be provided that the reinforcing element 2 has an embossing 60 at least on a surface 24. The surface 24 includes the broad side 55 and the narrow side 58. The embossment 60 may be, for example, a diamond-like geometry, which is mounted in relief on the reinforcing element.

The embossing 60 can also be introduced, for example, in the form of micropores 61 into the reinforcing element 2, which are particularly well suited for improving, for example, the connection to a further material. The micropores 61 may be formed, for example, in the form of piercing holes 62 which have been produced by mechanical processing, for example by means of needle rollers.

An embossing 60 may, for example, also be designed in the form of a fraying 63 for increasing the surface roughness, which leads to an increased ability of the surface to bond to another material.

In addition, it can be provided that the surface 24 has been prepared for example by a physical surface treatment, or by a chemical surface treatment for the connection of the surface 24 to another element.

In this case, it may be necessary, for example, that the surface tension was increased by the surface treatment method in order to facilitate this connection.

This may be necessary since an untreated reinforcing element 2 may have a nonpolar, electrically well insulating and water-repellent surface 24. This surface 24 may be poorly wettable by printing inks, solvents, aqueous polymer dispersions, adhesives or adhesion promoters. This is the case in particular with polyethylene, polypropylene and polyester materials. Also, the quality of connection to a material to be joined to the reinforcing element may be worse to insufficient due to an untreated surface.

For example, the goal of such a physical surface treatment may be to increase the polarity of the surface 24, thereby significantly improving wettability and chemical affinity.

In this case, for example, the surface tension can be increased, for example by a physical surface treatment method such as the corona treatment.

The surface tension that the reinforcing element has depends on how long the surface treatment process has already taken place. Immediately after the surface treatment, a surface tension of between 38 mN / m and 44 mN / m may be present at the surface 24 of the reinforcing element 2. If the surface treatment process is already 4 weeks ago, then a reduction of the surface tension of about 10% can be determined.

As an alternative to corona treatment, the surface tension may have been increased by flame treatment, fluorination or plasma treatment.

A test method for measuring the surface tension is the contact angle measurement or contact angle measurement. In this case, a liquid drop is placed on the surface 24 on the reinforcing element 2 and the contact angle of the droplet is determined to be much larger than that of the surface 24. The smaller the angle, the better the wetting.

By contact angle measurements with several chemically pure test liquids with known surface tension and known dispersive and polar fractions, the polar and dispersive fractions of the surface tension of the film can be determined. All material parameters are determined at room temperature and at a sufficient measuring speed so that no creeping processes occur in the material.

The embodiments show possible embodiments of the reinforcing element 2, and a system 1 for producing such a reinforcing element 2, it being noted at this point that the invention is not limited to the specifically illustrated embodiments thereof, but rather also various combinations of the individual embodiments with each other possible and this possibility of variation is due to the Leh re technical action by objective invention in the skill of those working in this technical field expert.

Furthermore, individual features or combinations of features from the different exemplary embodiments shown and described can also represent independent, inventive or inventive solutions.

The task underlying the independent inventive solutions can be taken from the description. All statements of value ranges in the present description should be understood to include any and all sub-ranges thereof, e.g. is the statement 1 to 10 to be understood that all sub-areas, starting from the lower limit 1 and the upper limit 10 are included, ie. all sub-areas begin with a lower limit of 1 or greater and end at an upper limit of 10 or less, e.g. 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

Above all, the individual embodiments shown in FIGS. 1 and 2 can form the subject of independent solutions according to the invention. The relevant objects and solutions according to the invention can be found in the detailed descriptions of these figures.

For the sake of order, it should finally be pointed out that for a better understanding of the structure of the reinforcing element 2, as well as a plant 1 for producing such a reinforcing element 2, these or their constituents were shown partially unevenly and / or enlarged and / or reduced in size.

REFERENCE SIGNS LIST 1 Appendix 29 Thickness 2 Reinforcement element 30 Roll structure 3 Thermo-plastic 31 Physical surface material handling device 4 Extrusion device 32 Corona treatment roller 5 Molding nozzle 33 Electrode 6 Forming tool 34 Chemical surface 7 Primary strand handling device 8 Cooling device 35 Adhesive 9 Water bath 36 Side surface 10 Length 37 Processing direction 11 Dividing wall 38 Divided strand 12 Zone 39 Dividing device 13 Spraying device 40 Cutting unit 14 Take-off device 41 Packing device 15 Rolling element 42 Bobbin 16 Transporting device 43 Bobbin cutting unit 17 Stretching unit 44 Piece cutting unit 18 Further transporting device 45 Cutting roller 19 Main stretching direction 46 Cutting unit 20 Drawn strand 47 Opening 21 Heating device 48 Counter roll 22 Further cooling device 49 Shaping device 23 Surface preparation 50 Plastic strand direction 51 Qu Cutting surface 24 Surface 52 Stiffening mold 25 Roll pair 53 Thickness 26 First roll 54 Transverse axis 27 Second roll 55 Broadside 28 Prestressing device 56 Width 57 Vertical axis 58 Narrow side 59 Longitudinal axis 60 Embossment 61 Micropores 62 Recessing hole 63 Fraying

Claims (30)

1. reinforcing element (2) consisting of a plastic strand (50), for connecting to a matrix of an object, wherein the matrix of the object consists predominantly of at least one, substantially unstretched plastic material, and wherein the reinforcing element (2) at least a partially crystalline, comprises thermoplastic plastic material, characterized in that the plastic strand (50) is predominantly monoaxially stretched, and a perpendicular to the main direction of elongation (19) formed cross-sectional area (51) of the reinforcing element (2), a substantially rectangular cross-sectional shape. Second reinforcing element (2) according to claim 1, characterized in that the thickness (53) of the plastic strand (50) along its cross-sectional area (51) at least partially between 0.2 and 10 mm, in particular at least partially between 0.3 and 7 mm and preferably at least in sections is between 0.4 and 5 mm. 3. reinforcing element (2) according to claim 1 or 2, characterized in that the flexural rigidity of the plastic strand (50) with respect to a transverse axis (54) between 67 N * mm2 and 23 * 1 0λ6 N * mm2. 4. reinforcing element (2) according to any one of the preceding claims, characterized in that the flexural rigidity of the plastic strand (50) with respect to a vertical axis (57) between 10 * 1 0λ3 N * mm2 and 21 * 1 0λ9 N * mm2. 5. reinforcing element (2) according to any one of the preceding claims, characterized in that the bending strength of the plastic strand (50) is between 50 MPa and 800 MPa. 6. reinforcing element (2) according to any one of the preceding claims, characterized in that the torsional stiffness of the plastic strand (50) about a longitudinal axis (59), between 85 N * mm2 and 30 * 1 0λ6 N * mm2. 7. reinforcing element (2) according to any one of the preceding claims, characterized in that the draw ratio of the plastic strand (50) is between 2 and 40. 8. reinforcing element (2) according to any one of the preceding claims, characterized in that the modulus of elasticity of the plastic strand (50) along the main direction of elongation (19) is between 2,500 MPa and 15,000 MPa. 9. reinforcing element (2) according to any one of the preceding claims, characterized in that the plastic strand (50) along the Hauptverstreckungsrichtung (19) has a tensile strength between 100 MPa and 500 MPa. 10. reinforcing element (2) according to any one of the preceding claims, characterized in that the plastic strand (50) has a width (56) between 5 and 150 mm. 11. reinforcing element (2) according to any one of the preceding claims, characterized in that the plastic strand (50) consists mainly of a material selected from the group of polyolefins, polyesters, polyamides or mixtures of these materials. 12. reinforcing element (2) according to claim 11, characterized in that the polyolefin is a polyethylene or a polypropylene. 13. Reinforcing element (2) according to claim 11, characterized in that the polyester is a polyethylene terephthalate (PET) or polybutylene terephthalate (PBT). 14. Reinforcement element (2) according to one of the preceding claims, characterized in that the plastic strand (50) contains additives. 15. Reinforcing element (2) according to one of the preceding claims, characterized in that the plastic strand (50) with respect to its perpendicular to the main direction of extension (19) formed cross-sectional area (51) geometrically to the reinforcement element (2) to be amplified component or the respective Purpose and / or load case is adjusted. 16. reinforcing element (2) according to any one of the preceding claims, characterized in that the plastic strand (50) is surface-treated on at least one surface. 17. reinforcing element (2) according to claim 16, characterized in that at least one surface (24) of the plastic strand (50) has an embossing (60). 18. A method for producing a reinforcing element (2), comprising providing at least one semicrystalline, thermoplastic plastic material and its melting in an extrusion device (4), the method having at least the following successive method steps: 7) extrusion of the molten plastic material via a raw-forming nozzle ( 8) Cooling and Preservation of This Raw Form of the Primary Strand (7) in at least One Cooling Device (8), 9) One or More-Stage Heating of the Raw-Formed Primary Strand (7) via at least One Warm-Up Device (21) , 10) stretching the rough-formed primary strand (7) to the desired degree of stretching by means of at least one stretching unit (17), 11) cooling the stretched strand (20) in its final form by means of at least one further cooling device (22), and 12) assembling in a packaging device (41) to Ber Provision of the desired form of use. characterized in that the method comprises at least one further method step for improving the connection or integration of the reinforcing element (2) with or in a matrix of an object, wherein by means of a surface treatment device (23) at least one surface (24) of the primary strand (7) and / or the stretched strand (20) is modified or functionalized. 19. The method according to claim 18, characterized in that the at least one further process step for the surface treatment of the drawn strand (20) between step 5 and step 6 of the method is carried out. 20. The method according to claim 19, characterized in that the at least one further method step is performed as a cold rolling process for the mechanical structuring of at least one surface (24) of the drawn strand (20). 21. The method according to claim 19, characterized in that the at least one further process step is performed as a physical treatment for increasing the surface energy or polarity of at least one surface (24) of the drawn strand (20). 22. The method according to claim 19, characterized in that the at least one further process step is performed as a chemical treatment of at least one surface (24) of the drawn strand (20). 23. The method according to any one of claims 20 to 22, characterized in that for the modification or functionalization of at least one surface (24) of the drawn strand (20), a combination of the specified method steps is used. 24. The method according to any one of claims 18 to 23, characterized in that after at least one further process step for surface treatment on at least one of the side surfaces (36) of the drawn strand (20), an adhesive (35) is applied. 25. The method according to claim 24, characterized in that the adhesive (35) is selected from the class of hot melt adhesives. 26. The method according to claim 25, characterized in that the base polymers of the hot melt adhesive applied to the same plastic class belong, as the material of the reinforcing element. 27. The method according to any one of claims 18 to 26, characterized in that the method at least one further process step for cutting along a processing direction (37) of the primary strand (7) and / or the stretched strand (20) into a plurality of divided strands ( 38). 28. The method according to claim 27, characterized in that the at least one further process step is carried out after the drawing step. 29. The method according to claim 27 or 28, characterized in that the at least one further process step is carried out after the surface treatment step. 30. The method according to claim 18, characterized in that the confectioning step includes at least one forming device (49).