Method and arrangement for the production of profiles from fibre-reinforced plastics

Abstract

The invention relates to a method for producing endless profiles from fibre-reinforced plastics material, comprising the following steps: pultruding a preliminary profile (P40) in a preforming device (40), the preliminary profile being cured to different degrees in successive first and second profile portions (P40a, P40b), the first profile portions (P40a) being cured so that they are dimensionally stable and the second profile portions (P40b) remaining deformable; shaping and irradiating the second profile portions (P40b) in a shaping and irradiating unit (50), the second profile portions (P40b) being shaped by a shaping tool into a shape differing from the first profile portions, and being cured by irradiation with electromagnetic radiation while the shaping tool is in interlocking engagement with the second profile portion. The invention further relates to an assembly for carrying out the method.

Description

[0001] Method and arrangement for the production of profiles made of fiber-reinforced plastics

[0002] Description

[0003] The present invention relates to a method and an arrangement for the production of profiles from fiber-reinforced plastics by means of pultrusion.

[0004] In pultrusion, dry rovings or semi-finished fiber products are generally drawn through an impregnation unit and impregnated, or alternatively, pre-impregnated reinforcement materials can be used. The impregnated fibers are then drawn through a forming tool, where the matrix system is cross-linked or cured, creating a composite profile. The composite profile is continuously drawn off using haul-off units and then cut to size.

[0005] DE 10 2019 127 568 A1 discloses a method and a tool arrangement for producing a fiber-matrix composite profile structure. In a first step, a composite profile strand is produced from reinforcing fibers and matrix material using a first tool module. A first strand section comprises cured matrix material, whereas the second strand section may comprise uncured or incompletely cured matrix material. In a second step, the composite profile strand is deflected in the second strand section using a second tool module. Subsequently, in a third step, the matrix material of the second strand section is cured in another tool module.

[0006] EP 3 283 279 B1, corresponding to DE 10 2015 206 917 A1, discloses a pultrusion device for producing a fiber-reinforced continuous profile with a cross-sectional profile that is discontinuous in the pultrusion direction, as well as a method for producing the same. The pultrusion device comprises a first shaping device, a second shaping device downstream of the first shaping device, and a punching tool arranged therebetween. The punching tool is designed to effect a local shape change in defined sections of the continuous profile produced by the first device. The shaping devices are designed to cure the continuous profile, thereby rendering the profile dimensionally stable.According to the method, an endless profile is produced in the first forming device, which is then punched locally in the punching tool to produce a discontinuous cross-sectional profile, and finally formed into a second discontinuous cross-sectional profile in the second forming device.

[0007] Various methods are already known for curing profiles produced by pultrusion. US Pat. No. 5,470,423 describes a method for microwave curing of thermosetting materials using the pultrusion process. EP 0 290 849 A2 describes a pultrusion process with curing by UV radiation. DE 10 2020 211 066 A1 describes a method for producing a joint between a profile and another component.

[0008] The various processes have different advantages and disadvantages. Compared to UV pultrusion, thermal pultrusion requires significantly more energy. This is especially true when producing profiles with partially cured areas. With thermal pultrusion, forming is only possible via a full B-stage pultrusion. Only with microwave curing would sharp transitions between cured and uncured areas be possible. Heat radiation in the tool makes the design of transitions difficult. Furthermore, microwave systems are only suitable for materials that can absorb microwaves, such as carbon fiber reinforced composites or plastics filled with microwave-absorbing additives.Profiles made of fiber-reinforced plastics produced by pultrusion are versatile and can be used, for example, as rod structures in various applications or further processed into rod-shaped elements. For example, pultruded profiles can be used to produce force-transmitting elements in automotive or aircraft construction, as well as in construction, sports, and industrial applications.

[0009] WO 2023 / 094508 A1, corresponding to DE 102021 130 919 A1, discloses a method for producing a profile in the form of a coupling rod. A continuous profile is produced by pultrusion in a continuous process from continuous fibers embedded in a plastic matrix and partially cured, whereby the profile exhibits lower ductility in the hardened first sections than in the second sections. Subsequently, the continuous profile is formed in the second sections and cured after forming. The fully cured continuous profile is then cut to length to create an elongated connecting element. The connecting element is connected at the ends with joint elements.

[0010] The present invention is based on the object of proposing a method for producing profiles from fiber-reinforced plastics by means of pultrusion, which enables geometrically variable shaping of the profile along its length in a simple and efficient manner. The invention is further based on the object of proposing a corresponding arrangement for producing profiles with cross-sections that vary along their length.

[0011] To achieve this, a method is proposed for producing pultrusion profiles from fiber-reinforced plastic material, in which a pre-profile is pultruded by means of a pre-forming device, wherein the pre-profile is cured to different degrees in successive first and second profile sections, wherein the first profile sections are given a greater hardness than the second profile sections; and the pre-profile is then further processed in a forming device, wherein the second profile sections are formed by means of a forming tool into a shape different from the first profile sections and, while the forming tool is in forming engagement with the second profile section, are cured by irradiation with electromagnetic radiation.One advantage of the process is that a pultrusion profile with a cross-section that varies over its length can be produced with high manufacturing precision, as the forming and curing of the still deformable sections take place in a common device. In process terms, the forming device thus performs two functions with temporal overlap in a single unit: forming and curing. In this respect, the forming device can also be referred to as a forming and blasting unit. After passing through the forming device, the pultrusion profile is completely cured. Undesired deformation of the pultrusion profile in the cured area due to pull-off forces acting on the profile is eliminated. Furthermore, a high level of process reliability is achieved because the forming and curing are carried out synchronously on the second profile sections.The process enables the production of pultrusion profiles with any cross-sectional shape, for example as solid or hollow profiles, each with a round, non-round or square, symmetrical or asymmetrical shape.

[0012] To produce the pre-profile, continuous fibers are impregnated with a plastic in a continuous process and pass through the pre-forming device. Here, the pultrudate is pre-formed into the desired cross-sectional shape and alternately cured in first profile sections and not or only partially cured in second profile sections. The second profile sections of the pre-profile thus retain the viscoelasticity required for forming and can be further formed in the subsequent process step to produce a final profile with a cross-section that varies along its length. The curing of the pre-profile, like the curing to the final profile, is preferably carried out by electromagnetic radiation, particularly preferably by UV radiation. In contrast to thermal curing, radiation curing can create sharply defined transitions between the dimensionally stable first regions and the deformable second regions.The pre-profile is produced, in particular, with a constant cross-section along its length. In the forming and blasting unit, the second profile sections are formed and cured relative to the first profile sections, so that the resulting pultrusion profile has a variable cross-section along its length. For the purposes of this disclosure, the term "pultrusion profile" generally refers to the profile throughout the entire process. "Pre-profile" refers to the pre-formed profile after the first forming step in the pre-forming device. "Continuous profile" refers to the fully cured profile with varying cross-sections along its length.

[0013] The first profile sections are cured during preforming to become dimensionally stable. The more ductile second profile sections can remain completely soft or uncured during preforming. Alternatively, the second profile sections can also be partially cured, particularly so that they become somewhat rubber-like. The second profile sections remain deformable if the elastic component of the plastic is smaller than the viscosity component. In other words, the storage modulus, which represents the stiffness of the material, remains smaller than the loss modulus, which represents the convertible vibration energy. The gel point is reached approximately when the storage modulus is equal to the loss modulus.

[0014] The continuous fibers form the reinforcement structure of the composite material to be produced. Radiation-permeable fibers can be used, which is particularly advantageous when curing is carried out using a radiation source. For example, carbon, glass, natural, synthetic, organic, and / or inorganic fibers can be used. The fiber orientation can be predominantly unidirectional. Alternatively or additionally, the reinforcement structure can also include non-crimp fabrics, braids, woven fabrics, and / or mats with different fiber directions.

[0015] If the pultrusion profile is produced as a hollow profile, irradiation can be carried out, in particular, from the inside using a beam source located within the hollow profile. Generally, various options are possible, namely irradiation only from the outside, only from the inside, or both from the outside and inside. Preferably, irradiation for curing is carried out from the inside and / or from the outside in such a way that, viewed in cross-section through the pultrusion profile, a total circumferential area of ​​at least 180° up to 360° around the profile's longitudinal axis is irradiated.

[0016] Curing in the preforming device and / or in the forming and blasting unit is preferably carried out by irradiation with UV radiation. Alternatively, other electromagnetic radiation, such as microwaves, electron beams, or infrared rays, can be used instead of UV radiation. The electromagnetic radiation activates and cures the plastic. Irradiation is preferably carried out in a wavelength range of 200 nm to 480 nm.

[0017] The beam source can be moved along with the pultrusion profile during irradiation, either at the same or different speed. Preferably, a beam zone and an adjacent shadow zone are formed, alternating along the length. In the beam zone, the pre-profile is cured, forming the first profile sections. In the shadow zone, the pre-profile remains soft, forming the second profile sections. Various options for curing by irradiation are possible.

[0018] According to a first option, the beam source can be moved mechanically together with the mold, whereby the inner and / or outer radiation source is moved together with the pultrusion profile. Relative movement between the beam source and pultrudate is also possible. According to a second option, the radiation source is moved electronically, i.e. the beam source remains stationary, while the radiation emitted by it moves longitudinally. This can be achieved electronically, for example, using one or more rows of LED radiation sources arranged one behind the other and connected in series. One advantage of electrical control, in contrast to mechanical movement, is that a stable or static overall system is achieved, since there is no need to move components. Overall, the control is therefore particularly precise and flexible.The process can be controlled by appropriate electrical control of the radiation sources, with LEDs being particularly suitable. For example, the degree of curing can be controlled via the radiation intensity of the radiation sources. A third option is to have the beam source mounted in a stationary position and designed with a static illumination area. In this case, the beam source is alternately switched on during the drawing of the pultrusion profile, so that the passing profile is cured, or switched off, so that the passing profile is not cured or only reaches a partial degree of curing. There can be a relatively narrow transition area between the areas. The type of movement of the beam source can be selected depending on the arrangement of the haul-off device relative to the second forming process. For example, a mechanically moving beam source is well suited for forming upstream of the haul-off device.A static arrangement of the beam unit with electronically moving irradiation is particularly advantageous for a forming process located behind the take-off device. However, a reverse configuration is also possible in principle.

[0019] The beam source can be designed based on the required energy, for example in joules, relative to the volume of the material to be cured. The number and extent of the beam sources can be determined accordingly.

[0020] According to a possible implementation of the process, the pultrusion profile can be drawn off at a speed of more than 1 m / min.

[0021] The fully cured endless profile can be cut in a subsequent step by means of a cutting device into a profile element which has at least a first profile section and a second profile section with a cross-section different from the first profile section.

[0022] The object is further achieved by means of an arrangement for producing profile elements from fiber-reinforced plastic material, comprising: a forming device configured to form plastic-impregnated continuous fibers into a pre-profile and to cure them to different degrees in successive first and second sections; and a forming and blasting unit comprising a forming tool and a blasting source and configured to form the second sections of the pre-profile and, while the forming tool is in engagement with the second sections, to cure them by means of the blasting unit.

[0023] With the arrangement according to the invention, a pultrusion profile with a cross-section that varies over its length can be produced efficiently and with high precision. The arrangement offers the same advantages as the method according to the invention, so reference is made to the above description for the sake of brevity. It is understood that all features mentioned in connection with the method can be transferred to the arrangement, and vice versa.

[0024] The arrangement according to the invention can comprise a guide unit designed to guide continuous reinforcing fibers and an impregnation device designed to impregnate the continuous reinforcing fibers with plastic. The continuous reinforcing material, which is in particular made of fibers, is unwound from the unwinding device, impregnated with polymerizable plastic in the impregnation device, and guided by means of guide means optionally arranged upstream and / or downstream of the impregnation device. It then passes, in the desired cross-sectional shape, with continuous movement into the shaping device. In the shaping device, the still-soft intermediate product made of fibers embedded in plastic is continuously shaped into the desired cross-sectional shape and cured in such a way that the pre-profile is produced with cured first sections and second sections with a relatively low degree of curing.

[0025] The forming device for producing the pre-profile with a variable degree of curing along its length can be designed according to requirements. The forming tool is designed according to the desired pultrudate cross-section, which can be solid or hollow, round or non-round, symmetrical or asymmetrical.

[0026] To produce a hollow pre-profile, an inner shaping element is preferably provided, which in particular comprises a radiation-conducting material. The inner shaping element can also be referred to as a mold core. A shell of the inner shaping element can be made of metal, for example. A core arranged in the shell can be made of quartz glass, plastic, or another radiation-conducting material, for example. An outer shaping element of the shaping device, which determines the outer shape of the pultrudate, can be made of an energy- or radiation-permeable material. The material of the shaping elements is selected, in particular, to prevent adhesion to the matrix material of the pultrudate. For example, PTFE, PVDF, POM, PMMA, all glass materials, ceramic materials, or mixtures thereof can be used. The shaping elements can be coated or uncoated.Any of the materials mentioned can also be used as a base material with another of the materials mentioned as a coating.

[0027] A favorable design in terms of a common parts concept is achieved when the forming unit uses similar electromagnetic beam sources as the downstream forming and blasting unit. For example, the same type of beam source can be used for preforming as for final forming, whereby the number of individual beam sources can be based on the length of the pultrudate to be irradiated or cured. For example, the forming unit can use a beam source with several times the length and / or several times the number of lamps as the forming and blasting unit.

[0028] If the molding device has a curing device in the form of an electromagnetic radiation source, a material that can be cured using electromagnetic radiation is preferably used as the plastic matrix. According to a first option, the radiation source can be integrated into the molding tool, meaning the molding tool itself emits the radiation. Alternatively, the radiation source can be arranged separately from the molding tool, surrounding it, with the radiation being guided through the tool. An advantage of this design is that radiation-induced heating of the tool is avoided. The radiation source can, for example, be arranged at a distance of up to 50 mm from the tool.

[0029] The length of the beam source(s) is preferably selected so that the desired degree of curing is achieved in the respective sections.

[0030] The arrangement can further comprise a withdrawal device for moving the endless profile. There are various options for the arrangement and design of the withdrawal device. For example, the withdrawal device can be designed in the form of a caterpillar track, or it can comprise two gripper units arranged one behind the other in the pultrusion direction and working alternately. The movement can be brought about by friction or positive engagement between the withdrawal elements and the profile. In further detail, the withdrawal device can be arranged as a separate unit between the forming device and the forming and blasting unit, according to a first option. Alternatively, the withdrawal device for the pultrusion profile can also be arranged behind the forming and blasting unit. In this design, the forming and blasting unit is preferably close to orarranged behind the withdrawal device so that the path length has the least possible influence on the shape of the still soft sections. In one exemplary embodiment, the distance between the forming-blasting unit and the withdrawal device is smaller than the length of a cured first section of the pultrudate. According to a third possibility, the forming device can be integrated into the withdrawal device. For this purpose, the forming tool can be designed such that it engages in the (initially still) deformable second sections, creating a positive connection, and is driven in the withdrawal direction of the pultrudate and blasted at the same time. In this way, the forming and blasting unit is integrated into the withdrawal device. One advantage of this design is its high efficiency, as forming, curing / blasting and transport take place in one process. In addition, this design is particularly space-saving.

[0031] The forming and blasting unit can be moved passively, coupled to the movement of the discharge device. Alternatively, the forming and blasting unit can also be moved actively, i.e., with a separate drive, especially for the return stroke.

[0032] Preferred embodiments are explained below with reference to the drawing figures. Herein:

[0033] Figure 1A shows a method and an arrangement according to the invention for the production of pultrusion profiles from fiber-reinforced plastic material in a first embodiment;

[0034] Figure 1 B shows a detail of the preforming unit from Figure 1 A in longitudinal section;

[0035] Figure 2A shows a preforming unit for the arrangement according to Figure 1A in axial view in the pultrusion direction;

[0036] Figure 2B shows a detail of the preforming unit from Figure 2A with radiation sources in longitudinal section; Figure 2C shows another detail of the preforming unit from Figure 2B in three-dimensional view, partially in section;

[0037] Figure 3A shows the forming and blasting unit from Figure 1A as a detail;

[0038] Figure 3B shows the forming and blasting unit from Figure 1 A as a detail in a further

[0039] work step;

[0040] Figure 3C shows the forming and blasting unit from Figure 1A as a detail in a further work step;

[0041] Figure 4 shows a preforming unit for the method or arrangement according to the invention according to Figure 1 A in a modified embodiment;

[0042] Figure 5 shows a preforming unit for the method or arrangement according to the invention according to Figure 1A in a further modified embodiment;

[0043] Figure 6 shows a preforming unit for the method or arrangement according to the invention according to Figure 1A in a further modified embodiment;

[0044] Figure 7A shows a pultrusion profile in cross section in a first embodiment;

[0045] Figure 7B shows a pultrusion profile in cross section in a further embodiment;

[0046] Figure 7C shows a pultrusion profile in cross section in a further embodiment;

[0047] Figure 7D shows a pultrusion profile in cross section in a further embodiment;

[0048] Figure 7E shows a pultrusion profile in cross section in a further embodiment;

[0049] Figure 7F shows a pultrusion profile in cross section in a further embodiment;

[0050] Figure 7G shows a pultrusion profile in cross section in a further embodiment;

[0051] Figure 7H shows a pultrusion profile in cross section in a further embodiment;

[0052] Figure 7I shows a pultrusion profile in cross section in a further embodiment;

[0053] Figure 7J shows a pultrusion profile in cross section in another embodiment;

[0054] Figure 7K shows a pultrusion profile in cross section in a further embodiment;

[0055] Figure 8A shows an embodiment of a pultrusion profile produced using the method or arrangement according to the invention shown in Figure 1A; Figure 8B shows a further embodiment of a pultrusion profile produced using the method or arrangement according to the invention shown in Figure 1A;

[0056] Figure 8C shows a further embodiment of a pultrusion profile produced using the method or arrangement according to the invention shown in Figure 1A;

[0057] Figure 8D shows a further embodiment of a pultrusion profile produced using the method or arrangement according to the invention shown in Figure 1A;

[0058] Figure 9 shows an embodiment of a component cut to length from the endless pultrusion profile;

[0059] Figure 10 shows a forming and blasting unit for the method or arrangement according to the invention according to Figure 1A in a modified embodiment;

[0060] Figure 11 shows the arrangement from Figure 1 A with additional components;

[0061] Figure 12 shows a guide device of the arrangement from Figure 11 as a detail in cross section;

[0062] Figure 13A shows a method and arrangement according to the invention for the production of pultrusion profiles from fiber-reinforced plastic material in a further embodiment;

[0063] Figure 13B shows a system with an arrangement according to the invention from Figure 13A;

[0064] Figure 14A shows a method and arrangement according to the invention for the production of pultrusion profiles from fiber-reinforced plastic material in a further embodiment;

[0065] Figure 14B shows the take-off forming unit from Figure 14A in detail;

[0066] Figure 14C shows a system with an arrangement according to the invention from Figure 14A; Figure 15A shows a method and arrangement according to the invention for the production of pultrusion profiles from fiber-reinforced plastic material in a further embodiment;

[0067] Figure 15B shows the drawing-forming-jet unit from Figure 15A as a detail in side view;

[0068] Figure 15C shows a system with an arrangement according to the invention from Figure 15A;

[0069] Figure 16A shows a further embodiment of a profile element of an endless profile produced according to the invention;

[0070] Figure 16B shows the profile element from Figure 16A in axial view according to arrows;

[0071] Figure 17A shows a further embodiment of a profile element of an endless profile produced according to the invention;.

[0072] Figure 17B shows the profile element from Figure 17A in axial view;

[0073] Figure 18A shows a further embodiment of a profile element of an endless profile produced according to the invention;

[0074] Figure 18B shows the profile element from Figure 18A in an axial view;

[0075] Figure 19A shows a further embodiment of a profile element of an endless profile produced according to the invention;

[0076] Figure 19B shows the profile element from Figure 19A in an axial view;

[0077] Figure 20A shows a further embodiment of a profile element of an endless profile produced according to the invention; and

[0078] Figure 20B shows the profile element from Figure 20A in an axial view.

[0079] Figures 1A and 1B schematically show a method and an arrangement 90 according to the invention for producing endless profiles P50 made of fiber-reinforced plastic material with a cross-section that is variable over the length in a first embodiment.

[0080] The assembly 90 comprises a preforming device 40 and a forming and blasting unit 50. The preforming device 40 is designed to form plastic-impregnated continuous fibers F20 into a continuous profile P40, wherein the continuous profile is cured to varying degrees in successive first sections P40a and second sections P40b. In this respect, the preforming device 40 can also be referred to as a shaping device. The forming and blasting unit 50 downstream of the preforming device is designed to form and cure the still-deformable second sections P40b into the desired geometry that deviates from the first cross-sectional shape.

[0081] The preforming device 40 can be designed according to the desired geometry of the profile P40 to be produced. Any cross-section is possible: solid or hollow, round or non-round, symmetrical or asymmetrical. In the present exemplary embodiment, the preforming device 40 is configured to produce a hollow continuous profile P40 with alternating longer first sections P40a and shorter second sections P40b. The continuous profile P40 produced by the preforming device 40 is a pre-profile with a substantially constant cross-section over its length, which is formed and cured in the downstream forming and blasting unit 50 into the desired end product with a cross-section that varies over its length.

[0082] As input material, fibers F20 impregnated with plastic are fed to the preforming device 40, which are then preformed into the desired cross-sectional shape and cured alternately in the first profile sections P40a and not or only partially cured in the second profile sections P40b.

[0083] To produce the hollow pre-profile, the preforming device 40 comprises a radially inner shaping element 41 and one or more radially outer shaping elements 42, 43, between which the profile P40 is shaped to the desired cross-section. The inner shaping element 41 can also be referred to as a mold core. A casing 44 of the inner shaping element 41 can be made of metal, for example. A core 45 arranged in the casing can be made of quartz glass, plastic, or another radiation-conducting material, for example. The outer shaping elements 42, 43, which determine the outer shape of the pultrudate, can be made of an energy- or radiation-permeable material. The material of the shaping elements 41, 42, 43 is selected, in particular, such that adhesion to the matrix material of the pultrudate is avoided.For example, PTFE, PVDF, POM, PMMA, all glass materials, ceramic materials, or mixtures thereof can be used. The shaping elements 41, 42, 43 can be coated or uncoated. Each of the mentioned materials can also be used as the base material with another of the mentioned materials as the coating.

[0084] The curing of the P40 pre-profile can be achieved, for example, by electromagnetic irradiation, in particular by UV radiation, but is not limited to this. The length, number, arrangement, and power of the beam source(s) are selected as required to achieve the desired degree of curing in the respective first and second profile sections P40a, P40b. When manufacturing hollow profiles, various options are generally possible: irradiation only from the inside using a beam source located inside the hollow profile, irradiation only from the outside using a beam source located outside the hollow profile, or irradiation from both the outside and inside.

[0085] In the present embodiment according to Figures 1 and 2, several outer beam sources 46 are provided, which are connected to the upper mold, several outer beam sources 47, which are connected to the lower mold, and an inner beam source 48, which is guided through the inner shaping element 41. The inner beam source 48 projects axially beyond the inner shaping element 41, so that radiation is emitted at the tip of the shaping element and the plastic-impregnated continuous fibers F20 can cure. Simultaneously or staggered, the continuous fibers F20 are irradiated from the outside by means of the outer beam sources 46, 47. The radiation sources 46, 47, 48 are designed and arranged such that the pultrusion profile P40 is irradiated all around, thus achieving particularly rapid and uniform curing in the irradiated longitudinal sections.

[0086] As can be seen particularly in Figures 2A and 2B, the radiation source 46 is arranged around the outer shaping element 42 or, with respect to the pultrusion axis A, radially outside the shaping element 42. The same applies analogously to the radiation source 47, which is arranged below the shaping element 43. The shaping elements 42, 43 are made of a radiation-permeable material, as described above, so that the rays emitted by the radiation sources 46, 47 are guided through the tool to cure the impregnated plastic. An advantage of this design is that radiation-induced heating of the mold is avoided.

[0087] In order to enable the pultrudate to harden to varying degrees along its length using the radiation sources 46, 47 during the stripping process, first sections are irradiated, while second sections alternating along its length are not irradiated or are irradiated to a lesser extent. The radiation sources 46, 47, 48 can be moved along with the pultrusion profile P40 during irradiation, and can be moved at the same or different speeds. In the present exemplary embodiment, irradiation takes place in such a way that a radiation region B and an adjacent shadow region S are formed alternately along its length. In the radiation region B, the preliminary profile is hardened, so that first profile sections P40a are formed. In the shadow region S, the preliminary profile remains soft or deformable, so that the second profile sections P40b are formed here.

[0088] According to the present embodiment, the radiation sources 46, 47 are preferably moved electrically, i.e., the radiation sources 46, 47 remain stationary together with the mold, while the radiation emitted thereby travels in the longitudinal direction. This can be accomplished, for example, electronically by one or more rows of radiation sources 46, 47 arranged one behind the other, which can be controlled independently of one another, so that a radiation movement pattern is generated. This is schematically illustrated in Figure 1A with an arrow M40. An advantage of electrical control is that a stable or static overall system is provided, since movement of components can be dispensed with. For control, an appropriate electronic unit (CPU) can be provided, which controls the radiation sources 46, 47, 48 accordingly in order to achieve the desired degree of curing over the desired length.LEDs, for example, can be used as light sources.

[0089] Alternatively, the radiation sources 46, 47 can also be moved together with the forming tool in or against the withdrawal direction, although this is technically more complex. Another possibility is for the radiation sources 46, 47 to be arranged in a fixed location and designed with a static illumination zone. In this case, the radiation sources are alternately switched on during the drawing of the pultrusion profile, so that the passing profile is cured, or switched off, so that the passing profile remains uncured. A transition zone can occur between the zones.

[0090] Irradiation can be carried out, for example, in a wavelength range from 200 nm to 480 nm. In a design using radiation-curable plastic, radiation-permeable fibers, such as carbon, glass, natural, synthetic, organic, and / or inorganic fibers, can be used for particularly good curing behavior. The radiation sources 46, 47, 48 can be designed based on the required energy in relation to the volume of the material to be cured. The number and extension of the radiation sources can be determined accordingly.

[0091] The continuous F20 fibers form the reinforcement structure, and the impregnated plastic forms the matrix of the composite material produced from them by curing. The design and ratio of fibers to plastic can be selected as needed according to the technical requirements of the product to be manufactured. The orientation of the F20 fibers can be predominantly unidirectional. The reinforcement structure can also include non-crimp fabrics, braids, woven fabrics, and / or mats with different fiber directions.

[0092] Because the second profile sections P40b are not irradiated, the pre-profile retains the viscoelasticity necessary for deformation. Further deformation takes place in a subsequent process step using the forming and blast unit 50, resulting in a pultrusion profile P50 with a cross-section Q that varies along its length.

[0093] The forming and blasting unit 50 comprises a particularly multi-part forming tool 51, 51' with one or more radiation sources 52, 52'. In the present exemplary embodiment, the forming and blasting unit 50 is divided into two parts, with a first part that acts on the pultrudate from a first side, for example from above, and an opposite second part that acts on the pultrudate from an opposite second side, for example from below. Each of the parts has a forming tool 51, 51' and a radiation source 52, 52' firmly connected thereto. The radiation source and tool are accommodated in a frame 53 and are moved together relative to the frame. The still deformable second sections P40b are formed by the forming and blasting unit and, while the forming tool 51 is engaged with the second sections P40b, are cured by means of the radiation source 52.The forming and blasting unit 50 thus fulfills two functions, namely forming and curing, in one assembly, with the forming tool 51 and the radiation source 52 interacting. The individual processing steps are shown in detail in Figures 3A to 3C.

[0094] Figure 3A shows the pultrusion profile P40 with its hardened sections P40a and its still deformable sections P40b. The movement of the pultrusion profile is marked with arrow R. The forming and blasting unit 50 is moved relative to the pultrusion profile in order to bring the forming tool 51 into overlap with a still deformable section P40b. In this overlap state, the forming and blasting unit 50 is moved along with the pultrusion profile at the same speed v50. During the joint longitudinal movement in the withdrawal direction of the pultrudate, the forming tool 51 is closed in order to bring the still deformable section P40b into the desired shape. This step is shown in Figure 3B, where the arrows C1 and C2 symbolize the closing movement and the arrow F the tool force.While the forming tool 51 is engaged with the second sections P40b, the radiation source(s) 52 are switched on and emit radiation, so that the second section P40b is cured. After the second section P40b has completely cured, the forming tool 51, 51' is opened again, which is represented in Figure 3C by the arrows O1, O2 pointing away from the pultrudate. After the forming tool 51, 51' has been opened, the forming and blasting unit 50 is moved counter to the withdrawal direction to the next section P40b to be formed, represented by arrow m50, and the described forming and curing process is repeated.

[0095] The specific design of the forming tool 51 and, accordingly, of the radiation source(s) 52 depends on the desired contour of the second profile sections P40b to be produced. The same applies analogously to the design of the forming unit 50 and its forming tools 42, 43. In general, the method and arrangement according to the invention can be used to produce pultrusion profiles with any cross-sectional shape, for example, solid or hollow profiles, each with a round, non-round or square, symmetrical or asymmetrical shape.

[0096] As already described above, the design, arrangement, and power of the beam source(s) can be selected as required and adapted to the particular pultrusion profile to be produced. Figures 4, 5, and 6 schematically show modified designs of the preforming device 40, which can be used instead of the design shown in Figures 1 and 2, respectively. In the design according to Figure 4, only one radiation source 48 is provided for irradiation from the inside. This is only possible for the production of hollow profiles. Figure 5 shows a design with an internal core for the production of hollow profiles, wherein only radiation sources 46, 47 arranged outside the forming tool or pultrudate are provided. The design shown in Figure 6 is designed for the production of solid profiles. No core is provided, and irradiation occurs only from the outside using radiation sources 46, 47 arranged outside the forming tools.

[0097] The arrangement according to Figure 1A can further comprise a take-off device 60, which can have various designs, particularly in cooperation with the forming and blasting unit 50, as will be described in more detail below. In the present embodiment according to Figure 1A, the take-off device is designed as a separate unit and arranged behind the forming and blasting unit 50 in the take-off direction R. The take-off device 60 is designed here in the manner of a caterpillar track and comprises a first take-off element 61 and a second take-off element 62, between which the pultrusion profile P50 is moved in the take-off direction R using force and / or form locking. For this purpose, the take-off elements 61, 62 can have circumferential form-locking or friction elements which come into contact with the pultrusion profile P50 and move it in the take-off direction R as a result of the circumferential movement.At least one of the first take-off element 61 or the second take-off element 62 can be driven by a drive unit 63. The take-off device 60 can be configured to move the pultrusion profile P50 at a speed v60 of more than 1 m / min. Figures 7A to 7K show various embodiments of possible pultrusion profiles, respectively after preforming and in cross-section through a first section. The preforming device 40 and the number and design of the forming tools can be configured depending on the cross-sectional profile to be produced.

[0098] The same applies to the design of the forming and blasting unit 50, with the contour of the forming tool being based on the shape of the formed section to be produced. A second section P40b is further formed relative to the first section P40a and receives a modified cross-sectional shape, for example, flattened, spread, corrugated, perforated, twisted, and / or compressed. Exemplary embodiments of formed second sections P40b are shown in Figures 8A, 8B, 8C, and 8D.

[0099] Figure 10 shows a modified embodiment of a forming and blasting unit 50 suitable for producing a second profile section P40b as shown in Figure 8A. The forming tool is designed to be rounded accordingly.

[0100] Figure 11 shows the arrangement according to Figure 1 with further optional components that together form a system 100 for producing continuous profiles. The system can comprise a creel 10 configured to store a plurality of fiber spools 11 and provide continuous fibers F10. Downstream can be a guide unit 15 that deflects the dry fibers so that they can be drawn off in a parallel alignment. Furthermore, an impregnation device 20 configured to impregnate the continuous reinforcing fibers with plastic can be provided. The continuous fibers can be unwound from the creel 10 and impregnated with curable plastic in the impregnation device 20 and guided by means of guide means 30 that are optionally arranged upstream and / or downstream of the impregnation device. A guide device 30 is shown in an axial view by way of example in Figure 12.An inner guide part 31 with a sleeve 34 can be seen, through which a radiation conductor 35 can be passed as a core, as well as a plurality of outer guide parts 32 with through openings around this, through which the continuous fibers F20 are guided around the longitudinal axis A. In the withdrawal direction behind the guide means 30, the preforming device 40 is arranged, in which the plastic-impregnated fibers F20 are brought into the desired cross-sectional shape under continuous withdrawal movement and cured in such a way that an intermediate product with cured first sections P40a and still deformable second sections P40b is produced.

[0101] Figure 13A shows a further embodiment of a method or arrangement 90 according to the invention. This largely corresponds to that shown in Figures 1 and 2, to whose description reference is made. Identical or corresponding details are provided with the same reference numerals as in the above figures.

[0102] A special feature of the arrangement 90 shown in Figure 13A is that the forming and blasting unit 50 is arranged behind the discharge device 60 in the discharge direction. The forming and blasting unit 50 is arranged as close as possible to the discharge device 60 so that the path length has the least possible influence on the shape of the still soft sections P40b. Preferably, the distance between the discharge device 60 and the forming and blasting unit 50 is smaller than the length of one or two of the already hardened sections P40a.

[0103] Figure 13B shows a system 100 for producing continuous profiles from fiber-reinforced plastic material with an arrangement 90 according to Figure 13A. The system according to Figure 13B otherwise corresponds to that according to Figure 12, to whose description reference is made in abbreviated form.

[0104] Figures 14A and 14B show a further embodiment of a method and arrangement 100 according to the invention. This largely corresponds to that shown in Figure 13A, to whose description reference is made. Identical or corresponding details are provided with the same reference numerals as in the above figures.

[0105] A special feature of the embodiment shown in Figure 14 is that the forming and blasting unit 50 is integrated into the withdrawal device 60, which together form a withdrawal-forming-blasting unit. For this purpose, the forming tool 51, 51' is designed such that it engages in the (initially still) deformable second sections P40b, so that a positive connection is created, and is driven in the withdrawal direction R of the pultrudate and simultaneously irradiated by means of the radiation sources 52, 52'. Several groups of forming tools 51, 51' or radiation sources 52, 52' can be arranged one behind the other in the withdrawal direction R. The radiation sources 52, 52' can be fixedly connected to a respective forming tool 51, 51' and rotate together with it. Alternatively, the radiation sources can also be arranged stationary in the extraction unit and illuminate the passing molds from behind.The present embodiment with integrated extraction, forming and blasting unit offers high efficiency and is particularly space-saving.

[0106] Figure 14C shows a system for producing continuous profiles from fiber-reinforced plastic material with an arrangement according to Figures 14A and 14B. The system according to Figure 14C otherwise corresponds to that according to Figure 12, to whose description reference is made for short.

[0107] Figures 15A and 15B show a further embodiment of a method and arrangement 100 according to the invention. This embodiment largely corresponds to that shown in Figure 14 and the preceding figures, to whose description reference is made. Identical or corresponding details are provided with the same reference numerals as in the preceding figures.

[0108] A special feature of the embodiment shown in Figures 15A, 15B is that the forming and blasting unit 50 and the withdrawal device 60 are integrated into a common withdrawal-forming-blasting unit 70. Specifically, a first forming and blasting unit 50 with a first withdrawal device 60 is provided, as well as a downstream second forming and blasting unit 50' with a second withdrawal device 60', which move the pultrusion profile P40 in the withdrawal direction R in an alternating movement.

[0109] For this purpose, the first forming tool 51 first engages a second section P40b to be formed and is then moved in the withdrawal direction R while simultaneously curing it using the first beam source. The second forming tool 51' then engages a second section P40b to be formed and moves in the withdrawal direction R while simultaneously further curing it using the second beam source. While the second unit moves in the withdrawal direction R, the first unit is moved back in the opposite direction to grip the next section P40b to be formed, and so on. In this way, the deformable second sections P40b are formed and cured and at the same time the pultrusion profile is moved in the withdrawal direction R. The back and forth movement of the two units is marked with arrows m60, m60'.

[0110] Figure 15C shows a system 100 for producing continuous profiles from fiber-reinforced plastic material with an arrangement according to Figures 15A, 15B. The system according to Figure 15C otherwise corresponds to that according to Figure 12, to whose description reference is made for short. A cutting device 80 is also schematically shown, which is designed to cut the pultrusion profile P into individual profile elements P80. Such a cutting device can also be provided in any of the systems described above.

[0111] Using the method and arrangement according to the invention, pultrusion profiles with a cross-section that varies along their length can be produced with high manufacturing precision. The forming and curing of the still-formable sections takes place in a single device. Undesired deformation due to withdrawal forces is eliminated.

[0112] Figures 16 to 20, which are described together below, show various further embodiments of profile elements P80 that have been separated from a respective endless profile produced according to the invention. The profile elements P80 each have a first profile section P80a, which corresponds to the first section P40a of the preliminary profile P40 or originates therefrom, and a second profile section P80b, which corresponds to the second section P50 of the finished pultrusion profile P50 or originates therefrom.

[0113] In the exemplary embodiments, the preliminary profile is produced in particular as a hollow profile, i.e. the first profile sections P80a are hollow, preferably with an annular cross-section, for example as shown in Figure 7A. The second profile sections P80b are formed according to the tool contour of the forming and blasting unit and each have a transition section 81 and an end section 82 with an end face 83. The end section 82 is preferably solid, as can be seen from the axial views according to Figures 16B, 17B, 18B, 19B and 20B. Any cross-sectional shapes are possible, with a cylindrical or slightly conical shape (Figure 16), an oval shape (Figure 17), a square shape (Figure 18), a cross-shaped shape (Figure 19) and a star-shaped shape (Figure 20) being shown here as examples.Further examples are possible, for example other cross-sectional shapes of the second sections or profile elements in which both ends have a formed second section.

[0114] List of reference symbols

[0115] 10 creels

[0116] 11 Fiber spool

[0117] 15 management unit

[0118] 20 Impregnation device

[0119] 30 guidance device

[0120] 31 inner guide part

[0121] 32 outer guide part

[0122] 34 sleeve

[0123] 35 radiation conductors

[0124] 40 Preforming device / shaping device

[0125] 41 inner shaping element

[0126] 42 outer shaping element

[0127] 43 outer shaping element

[0128] 44 coat

[0129] 45 core

[0130] 46 external beam source

[0131] 47 external beam source

[0132] 48 inner beam source

[0133] 49 frame

[0134] 50 forming and blasting unit

[0135] 51 , 51 ' molding tool

[0136] 52, 52' radiation source

[0137] 53 frame

[0138] 60 trigger device

[0139] 61 first trigger element

[0140] 62 second trigger element

[0141] 63 Drive unit

[0142] 70 Extraction-forming-blasting unit

[0143] 80 Separator

[0144] 81 Transition section

[0145] 82 final section

[0146] 83 Front face 90 Arrangement 100 System

[0147] A axis

[0148] B beam area

[0149] C Close

[0150] F Continuous fibers

[0151] K force m movement

[0152] 0 Open

[0153] P Pultrusion profile

[0154] P40 pre-profile

[0155] P40a first profile section

[0156] P40b second profile section

[0157] P50 end profile

[0158] P50a first profile section

[0159] P50b second profile section

[0160] P80 profile element

[0161] P80a first profile section

[0162] P80b second profile section

[0163] Q cross-section

[0164] R direction

[0165] S Shadow area v Speed

Claims

Claims 1. Process for the production of endless profiles made of fiber-reinforced plastic material with the following steps: Pultruding a pre-profile (P40) in a pre-forming device (40), wherein the pre-profile is cured to different degrees in successive first and second profile sections (P40a, P40b), wherein the first profile sections (P40a) are cured in a dimensionally stable manner and the second profile sections (P40b) remain deformable; characterized by Forming and irradiating the second profile sections (P40b) in a forming and blasting unit (50) such that the second profile sections (P40b) are formed by means of a forming tool into a shape different from the first profile sections and, while the forming tool is in form engagement with the second profile section, are cured by irradiation with electromagnetic radiation.

2. Method according to claim 1, characterized in that the pre-profile (P40) is produced in a continuous process from continuous fibers (F10) which are impregnated with a plastic, wherein in particular radiation-permeable fibers are used as continuous fibers (F10).

3. Method according to claim 1 or 2, characterized in that the pre-profile (P40) is produced in the pre-forming device (40) with a constant cross-section over the length, and that the second profile sections (P40b) are formed in the forming and blasting unit (50) relative to the first profile sections (P40a), so that the pultrusion profile (P50) thus produced receives a variable cross-section (Q) over the length.

4. Method according to one of claims 1 to 3, characterized in that the preliminary profile (P40) is produced as a hollow profile, wherein the irradiation takes place in particular from the inside by means of a beam source (48) arranged within the hollow profile, wherein the irradiation takes place over a circumferential area of ​​at least 180° to 360° as viewed in cross section through the hollow profile.

5. Method according to one of claims 1 to 4, characterized in that the first profile sections (P40a) are cured by irradiation with electromagnetic radiation, in particular by means of UV radiation, and / or that the second profile sections (P40b) are irradiated with UV radiation in the forming and blasting unit (59) for curing, wherein the irradiation is carried out in a wavelength range of in particular 200 nm to 480 nm.

6. Method according to one of claims 1 to 5, characterized in that the beam source (52, 52') is moved along with the pultrusion profile (P) during irradiation, whereby a beam region (B) and a shadow region (S) adjacent thereto are formed, which are moved at the same or relative speed to the pultrusion profile (P).

7. Method according to one of claims 1 to 6, characterized in that the preliminary profile (P40) is drawn off at a speed (v) of more than 1 m / min.

8. Method according to one of claims 1 to 7, characterized in that it is further provided: cutting the fully cured pultrusion profile (P50) into a profile element (P80) which has at least a first profile section (P80a) and a second profile section (P80b).

9. Arrangement for the production of pultrusion profiles from fiber-reinforced plastic material comprising: a preforming device (40) which is designed to form plastic-impregnated continuous fibers (F20) into a pre-profile (P40) and to cure said pre-profile to different degrees in successive first and second sections (P40a, P40b), characterized by a forming and blasting unit (50) which comprises a forming tool (51, 51') and a blasting source (52, 52') and is designed to form the second sections (P40b) and to cure them by means of the blasting source (52, 52') while the forming tool (51, 51') is in engagement with the second sections (P40b).

10. Arrangement according to claim 9, characterized in that the preforming device (40) is provided with an inner shaping element (41) for producing a hollow pre-profile (P40), wherein the inner shaping element (41) comprises in particular a radiation-conducting material, and / or that the preforming device (40) has an outer shaping element (42, 43) made of a radiation-permeable material.

11. Arrangement according to claim 9 or 10, characterized in that a take-off device (60) is provided to move the pultrusion profile (P), wherein the take-off device (60) is arranged in the direction of movement (R) of the pultrusion profile (P) behind the forming and blasting unit (50) or between the preforming device (40) and the forming and blasting unit (50), or is integrated into the forming and blasting unit (50), wherein the forming tool (51, 51') is driven in the take-off direction of the pultrusion profile.

12. Arrangement according to one of claims 9 to 11, characterized in that the extraction device (60) is designed in the form of a caterpillar train, or that the extraction device (60) comprises two extraction units arranged one behind the other in the extraction direction and operating alternately.

13. Arrangement according to one of claims 9 to 12, characterized in that the forming and blasting unit (50) is designed to be moved in the direction of movement (R) of the pultrusion profile (P).

14. Arrangement according to one of claims 9 to 13, characterized in that the beam source (52, 52') of the forming and blasting unit (50) is arranged radially outside and with axial overlap with the forming tool (51, 51') of the forming and blasting unit (50) with respect to a longitudinal axis (A) of the pultrusion profile (P). is arranged, wherein the molding tool (51, 51') is made in particular from a radiation-permeable material.

15. Arrangement according to one of claims 9 to 13, characterized by a guide device (30) designed to guide continuous reinforcing fibers (F20), and an impregnation device (20) designed to impregnate the continuous reinforcing fibers (F10) with plastic.

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