Curing device for coatings of glass fibers

Abstract

Curing device (1, 2) for coatings of glass fibers (4) with a receiving space (11, 21) for the passage of a coated optical fiber (4) in a direction of movement (A), wherein the receiving chamber (11, 21) has a plurality of UV radiation sources (12, 22) which are designed to harden the coating of the glass fiber (4) by means of UV light, where the UV radiation sources (12, 22) are UV LEDs (12, 22), and wherein the curing device (1, 2), preferably a control unit of the curing device (1, 2), is configured to operate at least one UV LED (12, 22), preferably several UV LEDs (12, 22) simultaneously, particularly preferably all UV LEDs (12, 22) simultaneously, in a pulsed manner, characterized by the fact that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is designed to operate at least one UV LED (12, 22), preferably several UV LEDs (12, 22) simultaneously, particularly preferably all UV LEDs (12, 22) simultaneously, with the maximum operating current of a continuous operation.

Description

Curing device for coatings of glass fibers

[0001] The present invention relates to a curing device for coatings of glass fibers according to the preamble of claim 1.

[0002] Optical fibers are used in many different technical fields today. One high-tech application is the transmission of light using optical fibers. This allows for data transmission via light, which is why optical fibers can also be called waveguides. Optical fibers are also used in medicine, for example, for illumination and for generating images in microscopes, inspection cameras, and endoscopes. Furthermore, optical fibers can be used in sensors, which are then called fiber optic sensors.

[0003] Another application area for optical fibers is laser technology. Here, laser radiation can be guided as signal light from a laser source to a processing point via a passive optical fiber, for example, to perform cutting or welding in material processing or medicine. The laser beam can also be directed to a sample in this way, for example, in metrology, microscopy, or spectroscopy. Such applications are known in mechanical engineering, telecommunications, medical technology, and sensor technology. Optical fibers can also be used to generate or amplify laser light and are then referred to as active optical fibers.

[0004] Glass fibers are typically drawn as thin strands from molten glass, forming a preform. A glass fiber is a long, thin strand made of glass. This preform is usually produced in a preliminary step as a glass rod, typically about 1 meter long and 10 to 50 mm in diameter, which already exhibits the refractive index profile of the final glass fiber. The glass fiber is then drawn from the preform by melting it. This process can be carried out in a fiber drawing tower at temperatures of approximately 2000°C, to which the preform is heated. At this temperature, the glass material of the preform becomes sufficiently soft to be drawn into a glass fiber, which has a significantly smaller diameter and a correspondingly greater length than the preform itself.The refractive index profile of the preform is typically maintained during the drawing process. The drawing speed of the optical fiber from the preform can be controlled depending on the fiber diameter, which can be measured by sensors. Drawing the optical fiber from the preform results in the formation of a bare glass fiber of the preform material, which can be referred to as the glass fiber core, or simply fiber core.

[0005] Typically, immediately after drawing, the glass fiber core is coated with a plastic material such as polyamide, acrylic, or silicone in a further process step within the same manufacturing process. This coating usually serves to mechanically protect the glass fiber core but can also be used to selectively influence the optical properties of the glass fiber. For this purpose, the glass fiber core is fed through an extruder, which provides the plastic in a flowable form and applies it to the outer surface of the glass fiber core. In an immediately subsequent process step, the plastic on the outer surface of the glass fiber core is irradiated with light in the ultraviolet spectrum (UV light), i.e., with electromagnetic radiation in the optical frequency range (light) with wavelengths shorter than visible light, which are in the range between approximately 100 nm and approximately 100 nm.The fibers are located at 405 nm and are cured for coating. The coating can also be called a fiber sheath, or simply fiber coating, which is closed in the circumferential direction and thus completely surrounds the fiber core, except for the two open ends of the fiber or fiber core.

[0006] During the curing process of the coating, which has just been applied to the fiberglass core moving longitudinally in the direction of tension, the coated fiberglass core is passed through a curing device that generates UV light and directs it onto the longitudinally moving coated fiberglass core. The fiberglass core enters the curing device with a freshly applied coating and exits with a cured coating in the opposite longitudinal direction. The generation of the UV light and / or its direction onto the coated fiberglass core can be achieved in various ways.

[0007] US Patent 4,710,638 A describes a device for treating material with radiant energy, particularly suitable for curing photocurable polymeric materials applied to an optical fiber. The device comprises a first and a second reflector, which together form an elliptical reflector; a light source arranged parallel to the optical fiber and positioned at one focal point of the elliptical reflector; and a wire-like material or fiber, such as an optical fiber, coated with photocurable polymer and positioned at the second focal point. An auxiliary reflector is located near the second focal point in such a way that incident light rays are directed toward the second focal point, thereby increasing the amount of energy impinging on the polymer coating.

[0008] US Patent 6,419,749 B1 describes a tubular device for UV curing coatings on a continuous filament. The device includes concentric tubes through which the filament passes after coating to cure the coating. It comprises a first inner tube that directs UV light to cure the filament passing through it, and a second concentric tube positioned above and spaced apart from the first tube. This second tube reflects IR light and transmits UV light to prevent burning and damage to the coating on the filament as it passes through the first tube. The UV light source is tubular and arranged parallel to the continuous filament.

[0009] US 9,132,448 B2 describes devices and methods for curing materials using radiant energy. The devices comprise a first reflector and a second reflector, both of which are semi-ellipses. The ellipses defining the first and second reflectors have axes of different lengths, and the reflectors are aligned so that their focal points overlap. A radiant energy source located at a near focal point of a reflector can supply energy to cure a coating on a substrate at a far focal point of the reflector. The different sizes of the two reflectors reduce the focusing error of the radiant energy, resulting in improved efficiency of the curing system. The radiant energy source is tubular and positioned parallel to the substrate.

[0010] The devices and / or methods described above all utilize a tubular UV light source that extends in the same longitudinal direction as the moving coated glass fiber core and parallel to it. The UV light from the tubular UV light source is reflected and focused towards the moving coated glass fiber core by means of elliptically shaped shields. Accordingly, the moving coated glass fiber core must be positioned precisely at the focal point of the reflected UV light for the coating to cure. If this is not the case, the coating may cure incompletely, unevenly, or not at all. Fluorescent lamps, such as low-pressure gas discharge tubes filled with mercury vapor, can be used as tubular UV light sources.Iron iodide lamps, gallium iodide lamps and amalgam lamps are also well known.

[0011] A disadvantage of generating UV light or irradiation using UV fluorescent tubes is that while these tubes can produce and emit a relatively broad spectrum of UV light, typically only a small portion of the emitted spectrum contributes to curing the coating of the fiberglass core. Approximately 90% of the generated energy is wasted heat, which can overheat and damage the coating material and / or the fiberglass core itself. If the coating material is overheated, its viscosity can decrease significantly, for example, even at temperatures as low as 45°C. This can reduce the coating's durability and / or lifespan, and / or alter its mechanical properties.Additionally or alternatively, this can affect the light-guiding properties of the fiber's coating. Alternatively or additionally, if the fiber core material is heated excessively, it can soften and thus flow more readily during drawing, potentially narrowing the core's cross-section. This can affect the optical properties of the fiber core and / or reduce its mechanical strength.

[0012] A disadvantage here is that the waste heat from the UV fluorescent tubes can also lead to a high temperature increase in the curing device itself, thus putting additional strain on it.

[0013] A disadvantage of generating UV light or using UV fluorescent tubes is that these tubes require a comparatively high electrical power output, potentially reaching several kilowatts (kW). This can lead to very low efficiency in converting electrical energy into UV radiation, and consequently, very low efficiency in the curing process of the curing device. The resulting high electrical energy demand can lead to correspondingly high costs, which can increase the production costs of the fiber optic cable.

[0014] A further disadvantage of generating UV light or using UV fluorescent tubes is that the power or intensity of the UV radiation in these tubes, as in low-pressure mercury vapor lamps, is fixed by design and must be precisely matched to the known movement or drawing speed of the optical fiber to achieve the desired coating curing while simultaneously preventing excessive UV radiation from stressing or damaging the coating material and / or the core material itself. This, too, can negatively affect the properties and, in particular, the durability of the coating material and / or the core material, as previously described.

[0015] US 8,604,448 B2 describes a method for curing a coating on a glass fiber, comprising: emitting UV radiation from one or more sources in the form of a UV LED or multiple UV LEDs of electromagnetic radiation into a substantially cylindrical cavity with an elliptical cross-section, wherein the cavity has a reflective inner surface, defines the curing chamber and defines a first line focus and a second line focus; allowing a portion of the emitted UV radiation to pass completely through the curing chamber; reflecting at least a portion of the UV radiation toward the second line focus by means of the reflective inner surface; and passing a glass fiber with an incompletely cured coating through the curing chamber along the second line focus to effect the absorption of both the emitted and the reflected UV radiation.

[0016] EP 2 388 239 B1 describes a device for curing a coated glass fiber, comprising: a substantially cylindrical cavity with a substantially elliptical cross-section and a reflective inner surface, wherein the cavity defines a first line focus, a second line focus and a principal axis intersecting the first line focus and the second line focus, the second line focus defining a curing axis; a protective tube that is substantially transparent to UV radiation, wherein the protective tube surrounds the curing axis and is preferably a quartz tube; and a UV LED source positioned inside the cavity at the first line focus, wherein the UV LED source has an emission pattern defining a line of average emission and having an emission angle between the principal axis and between about 30 degrees and 100 degrees.

[0017] LEDs are generally characterized by a comparatively long lifespan, relatively high energy efficiency in converting electrical energy into optical radiation, relatively low electrical energy consumption, relatively low costs, relatively small installation space, and / or relatively low heat generation. Therefore, the previously described disadvantages of UV fluorescent tubes can be at least partially reduced or avoided by using UV LEDs as UV light sources instead.

[0018] A disadvantage of all previously described curing devices using UV radiation remains that the UV light must always be directed onto the coated glass fiber core by means of reflection and focusing in order to achieve the desired curing. This applies both to the generation of UV light using UV fluorescent tubes and UV LEDs as UV light sources. Either planar, especially elliptical, reflectors or lenses can be used for this purpose. In any case, this focuses the UV light in the plane perpendicular to the drawing, movement, or longitudinal direction of the glass fiber onto a curing axis that extends in the longitudinal direction and, as previously described, can be referred to as the focal point or line focus.

[0019] Conversely, this means that effective and complete curing of the glass fiber core's coating using UV light can only be achieved if the coated glass fiber core is positioned as precisely as possible along its longitudinal axis at the line focus or focal point of the reflectors. This must be the case along the entire length of the coated glass fiber core as it passes through the curing device. In other words, the longitudinal or draw axis of the glass fiber and the line focus or focal point of the curing device must be perfectly aligned along the entire length of the curing device.

[0020] This requires a correspondingly precise adjustment of the curing device relative to the fiber drawing tower. The sensitivity of this adjustment is on the order of micrometers compared to the fiber drawing tower, whose dimensions are typically on the order of meters. This means that even a slight misalignment of the curing device's line focus relative to the longitudinal or drawing axis of the glass fiber results in the glass fiber or the coated glass fiber core not being irradiated by UV light at all, or only partially, and consequently, the coating cannot be adequately cured.

[0021] The problem here is that an unevenly or insufficiently cured coating on the glass fiber core can usually only be detected as a manufacturing defect once a large proportion of the glass fiber has already undergone the curing process and has subsequently been wound up. This leads to a correspondingly high production reject rate.

[0022] It is known, for example from EP 2 388 239 B1, as previously mentioned, that in such curing devices a protective tube is arranged within the curing device in such a way that the coated glass fiber core can be drawn through the protective tube in its longitudinal direction without radially contacting the protective tube, and is guided in particular centrally or coaxially to the protective tube. This protects the UV radiation sources and the coated glass fiber core from mutual contact. Such a protective tube can be made of quartz glass, in particular, since quartz glass has very high transparency to UV light and thus allows most of the UV light directed at the coated glass fiber core to reach the coating.

[0023] The protective tube can also be used to allow a protective gas, such as nitrogen, to flow into the interior of the protective tube from one end and exit through the opposite end, see also EP 2 388 239 B1. This allows the curing of the glass fiber coating to take place in an oxygen-free or oxygen-deficient environment, which can prevent or reduce curing defects in the glass fiber coating.

[0024] EP 2 418 183 A2 describes a UV LED device and an associated method that provide increased UV LED intensity to promote efficient curing of a coated optical fiber. The device uses a plurality of UV LED sources, each emitting an oscillating power of ultraviolet radiation. Each UV LED source is operated with a current greater than its maximum rated current. Typically, at least two of the UV LED sources have oscillating powers of ultraviolet radiation that are out of phase with each other. During curing, an incompletely cured coating on an optical fiber absorbs the electromagnetic radiation emitted by the UV LED sources.

[0025] One object of the present invention is to provide a curing device for coatings of glass fibers of the type described above, thereby improving the possibilities for curing the coating of a glass fiber core of a glass fiber to be manufactured. In particular, the degree of curing and thus the quality of the curing of the glass fiber coating is to be improved. Additionally or alternatively, the thermal stress on the material of the glass fiber coating and / or the glass fiber core is to be reduced, and in particular, thermal overload is to be avoided. Additionally or alternatively, the effort required for curing the glass fiber coating is to be kept to a minimum. Additionally or alternatively, the effort required for adjusting the coated glass fiber core to be cured relative to the curing device is to be reduced or eliminated.At least an alternative to known curing devices of this kind for coating glass fibers should be created.

[0026] The problem is solved according to the invention by a curing device for coatings of glass fibers with the features of claim 1. Advantageous embodiments are described in the dependent claims.

[0027] The present invention thus relates to a curing device for coating glass fibers, comprising a receiving chamber for guiding a coated glass fiber in one direction of movement. The receiving chamber includes a plurality of UV radiation sources configured to cure the glass fiber coating using UV light. Such curing devices serve to irradiate a glass fiber during manufacturing—for example, when drawing it from the preform and subsequently applying a coating by means of an extruder—with UV light of a suitable wavelength and to a sufficient degree, so that the coating material, such as polyamide, acrylic, or silicone, can be adequately cured. Known curing devices of this type were described above.The direction of movement of the coated glass fiber usually corresponds to the vertical direction when the curing device is used as intended, which can also be referred to as the longitudinal direction or drawing direction of the coated glass fiber.

[0028] The curing device according to the invention is characterized in that the UV radiation sources are UV LEDs, wherein the curing device, preferably a control unit of the curing device, is configured to operate at least one UV LED, preferably several UV LEDs simultaneously, and particularly preferably all UV LEDs simultaneously, in a pulsed manner. In other words, the UV LED(s) can be operated with comparatively short-term emission of UV radiation and intervening short-term interruptions, so that the UV radiation is emitted as pulses and can thus act in pulses on the coating to be cured. The UV LED(s) are thus switched on and off for comparatively short periods, whereby the UV radiation emitted during the switched-on phases or time periods can be referred to as pulses.These pulses represent a sequence of regularly recurring, identical impulses of UV light and can therefore also be referred to as UV light pulses.

[0029] A UV LED can be operated in such a way that the on and off phases are of equal length. However, the on phases can also be longer than the off phases, or vice versa. If several UV LEDs are operated in parallel with each other in pulsed mode, the duration of their on and off phases can be the same or different. If several UV LEDs are operated simultaneously with on and off phases of equal length, which occur at the same time, this can be described as synchronous operation. If the on and off phases of at least two UV LEDs alternate exactly, so that only one UV LED emits UV radiation at any given time and the other does not, this can be described as asynchronous operation.

[0030] At least one UV LED can be pulsed while at least one other UV LED is operated continuously in parallel, which can be described as a hybrid operating mode. Similarly, at least one UV LED can be pulsed while at least one other UV LED is switched off in parallel. Likewise, at least one continuously operated UV LED can be combined with at least one switched-off UV LED.

[0031] The present invention is based on the understanding that the previously known continuous operation of the UV radiation source of a curing device for glass fiber coatings can exert such a high intensity of UV radiation on the glass fiber coating material and / or the glass fiber core that the material is subjected to significant thermal stress or even overload, i.e., that the material is heated to an unacceptably high degree. This can, for example, lead to damage to the material as described above.

[0032] According to the invention, at least one UV LED is operated as a source of UV light in such a way that the UV LED is not operated continuously as previously known, but rather in pulsed or clocked mode, so that phases with the UV LED switched on and off occur in rapid succession. Accordingly, the UV radiation only acts briefly on the material of the glass fiber coating and / or the glass fiber core, which can increase the design possibilities of the curing process.For example, the previously known continuous operation can be changed to a pulsed operation. While this increases the duration of the curing process for the fiberglass coating material, it allows for a gentler curing process than previously possible. This is achieved by the interruptions in the irradiation, which allow the coating material to cool down and thus keep the thermal stress on the fiberglass coating material lower. Consequently, the desired curing can still be achieved, but the heat generated is reduced, and thermal stress or overload is avoided.This can be particularly advantageous for thermally sensitive materials such as fluoride glass fibers (ZBLAN fibers and AlF3 fibers), hollow core fibers and polymer optical fibers, as these have significantly lower melting temperatures of, for example, approximately 265 °C to approximately 367 °C, compared to quartz glass fibers with a melting temperature of approximately 2000 °C.

[0033] This pulsed operation can be implemented relatively easily by the curing device or its control unit, and in particular without any structural changes to the curing device itself, so that the corresponding properties and advantages can be implemented simply, quickly and / or cost-effectively.

[0034] Overall, the possibilities for influencing the curing process of the fiberglass coating can be increased by not simply operating all UV radiation sources continuously during the process, as is currently common practice. Instead, the use of UV LEDs as UV radiation sources can expand the process design options, since UV LEDs can be switched on and off quickly and frequently, which is technically impossible with UV fluorescent tubes as UV radiation sources. This also allows for variation between pulsed, continuous, and completely off operating modes for at least one UV LED, preferably for several UV LEDs simultaneously, and especially for all UV LEDs simultaneously. With multiple UV LEDs, these operating modes can be adjusted both in the direction of movement of the coated fiberglass being cured and / or...or combine them arbitrarily in the cross-sectional plane perpendicular to the direction of movement in order to ensure or improve the quality of the curing of the glass fiber coating while keeping the thermal load as low as possible or preventing thermal load altogether.

[0035] By using UV LEDs as UV radiation sources, the properties and advantages of UV LEDs can be utilized in the curing device according to the invention. These include a comparatively low consumption of electrical energy, comparatively low waste heat (also for protecting the coating and / or the glass fiber core of the glass fiber), and thus comparatively high energy efficiency, a comparatively compact installation space, and / or a comparatively long service life.

[0036] Preferably, the inner surface of the recording chamber can be at least partially or completely reflective in order to distribute the UV radiation as evenly as possible and / or to utilize it as completely as possible. This can be achieved by means of a mirror coating.

[0037] Preferably, a protective tube or quartz tube, such as that known from EP 2 388 239 B1, is omitted. This can reduce the complexity of the curing device, as a protective tube as a component can be eliminated. This aspect of the invention is based on the understanding that, although, as described above, such a protective tube, particularly one made of quartz glass, exhibits very high transparency to UV light, allowing most of the UV light directed at the coated glass fiber core to reach the coating, Fresnel losses of approximately 7% per interface can still occur at the air-to-glass interface. Consequently, this portion of the primary radiation cannot reach the coating of the glass fiber within the protective tube or quartz tube, but can be reflected back at the outer wall of the protective tube or quartz tube.

[0038] The opacity, i.e., the absorption losses, of the quartz glass itself, which occurs in such quartz tubes, must also be taken into account. These quartz tubes typically have a thickness of at least approximately 2 mm, and the UV light of the primary radiation is usually attenuated further within this length.

[0039] Furthermore, such protective tubes or quartz tubes are usually round and thus represent a curvature for the incoming and partially passing UV light of the primary radiation. Consequently, imaging errors can occur here, which can only be corrected with very high effort, if at all.

[0040] These effects, individually and especially in combination, can reduce the effectiveness of the primary UV radiation on the glass fiber coating, leading to corresponding losses in curing quality or requiring more intense and / or longer irradiation to achieve the desired result. This can increase the complexity of the manufacturing process and thus the cost of the coated glass fiber.

[0041] If, according to the invention, a protective tube or quartz tube is dispensed with, the corresponding disadvantages described above can be avoided.

[0042] Preferably, at least one UV LED is arranged on the first curing unit and at least one UV LED on the second curing unit. This can improve the uniformity of UV radiation generation. In particular, this can increase the design possibilities for UV radiation generation.

[0043] According to one aspect of the invention, the curing device, preferably the control unit of the curing device, is configured to operate at least one UV LED, preferably several UV LEDs simultaneously, and particularly preferably all UV LEDs simultaneously, or alternatively continuously. This can enable the implementation of previously mentioned aspects of the invention.

[0044] According to a further aspect of the invention, the curing device, preferably the control unit of the curing device, is configured to operate at least one UV LED, preferably several UV LEDs simultaneously, and particularly preferably all UV LEDs simultaneously, or alternatively not at all. This can enable the implementation of previously mentioned aspects of the invention.

[0045] According to a further aspect of the invention, the curing device, preferably the control unit of the curing device, is configured to operate at least one UV LED, preferably several UV LEDs simultaneously, and particularly preferably all UV LEDs simultaneously, with a pulse repetition rate and a pulse-pause ratio such that the pulse duration is shorter than the thermal relaxation time of the material of the glass fiber coating and / or the glass fiber core. In this way, thermal overload of the material of the glass fiber coating or the glass fiber core due to curing by means of UV radiation can even be completely ruled out.

[0046] According to the invention, the curing device, preferably the control unit of the curing device, is designed to operate at least one UV LED, preferably several UV LEDs simultaneously, and particularly preferably all UV LEDs simultaneously, with the maximum operating current of continuous operation. In other words, the curing process can be carried out as previously known, but with UV LED(s) instead of a tubular UV light source and with intermittent irradiation instead of continuous irradiation, as described above. Using the maximum operating current of continuous operation of the UV light source, i.e., without overcurrent, can fully utilize its capabilities to achieve the most intensive irradiation and thus the fastest possible curing, even though the interruptions in the UV light pulses result in a slowdown or...The curing process of the fiberglass coating material is extended, resulting in less heating and thus a gentler curing of the fiberglass coating material.

[0047] According to a further aspect of the invention, the UV LEDs are preferably configured as a first plurality of UV LEDs, preferably of the first curing unit, and as a second plurality of UV LEDs, preferably of the second curing unit, wherein the two pluralitys of UV LEDs extend linearly in the direction of movement of the coated glass fiber and / or wherein the two pluralitys of UV LEDs are arranged diametrically opposite each other perpendicular to the direction of movement of the coated glass fiber.

[0048] Using multiple UV LEDs along the direction of movement of the coated optical fiber allows the coating to be cured with UV light over a sufficiently long distance, thus increasing the curing efficiency. Arranging the UV LEDs in a line along the direction of movement of the coated optical fiber can simplify the fabrication of the curing device.

[0049] This method also eliminates the need for optical imaging for beam shaping and / or deflection, allowing effective UV irradiation of the fiber optic coating even without adjusting the coated fiber by superimposing the UV radiation. This creates an adjustment-free system, thus preventing adjustment or operator errors and the resulting production defects.

[0050] Arranging at least two pluralitys of UV LEDs diametrically opposite each other and perpendicular to the direction of movement of the coated optical fiber ensures that the coating of the optical fiber can be irradiated and cured with UV light from at least two opposite sides, resulting in sufficient curing. If exactly two pluralitys of UV LEDs are used in this arrangement, the desired curing can be achieved sufficiently due to the avoidance of optical image loss, and the effort required can be kept comparatively low, since almost all of the emitted primary radiation of the UV light can be used for curing. This can keep the acquisition costs of the UV LEDs and their energy consumption low. Accordingly, the curing device according to the invention can be operated economically, which can keep the manufacturing costs of the optical fiber low.

[0051] According to a further aspect of the invention, the curing device, preferably the control unit of the curing device, is configured to operate at least one UV LED of the first plurality of UV LEDs in a pulsed manner and simultaneously at least one UV LED of the second plurality of UV LEDs in a pulsed manner, wherein the two UV LEDs • in the direction of movement of the coated glass fiber, preferably directly adjacent to each other, offset from each other or • perpendicular to the direction of movement of the coated glass fiber, diametrically opposite each other are arranged. This can enable the implementation of previously mentioned aspects of the invention.

[0052] According to a further aspect of the invention, the curing device, preferably the control unit of the curing device, is configured to operate at least one UV LED of the first plurality of UV LEDs in a pulsed manner and at the same time at least one UV LED of the second plurality of UV LEDs continuously, wherein the two UV LEDs • in the direction of movement of the coated glass fiber, preferably directly adjacent to each other, offset from each other or • perpendicular to the direction of movement of the coated glass fiber, diametrically opposite each other are arranged. This can enable the implementation of previously mentioned aspects of the invention.

[0053] According to a further aspect of the invention, the curing device, preferably the control unit of the curing device, is configured to pulse at least one UV LED of the first plurality of UV LEDs and simultaneously not operate at least one UV LED of the second plurality of UV LEDs, wherein the two UV LEDs • in the direction of movement of the coated glass fiber, preferably directly adjacent to each other, offset from each other or • perpendicular to the direction of movement of the coated glass fiber, diametrically opposite each other are arranged. This can enable the implementation of previously mentioned aspects of the invention.

[0054] According to a further aspect of the invention, the curing device, preferably the control unit of the curing device, is configured to continuously operate at least one UV LED of the first plurality of UV LEDs and simultaneously continuously operate at least one UV LED of the second plurality of UV LEDs, wherein the two UV LEDs • in the direction of movement of the coated glass fiber, preferably directly adjacent to each other, offset from each other or • perpendicular to the direction of movement of the coated glass fiber, diametrically opposite each other are arranged. This can enable the implementation of previously mentioned aspects of the invention.

[0055] According to a further aspect of the invention, the curing device, preferably the control unit of the curing device, is configured to continuously disable at least one UV LED of the first plurality of UV LEDs and simultaneously disable at least one UV LED of the second plurality of UV LEDs, wherein the two UV LEDs • in the direction of movement of the coated glass fiber, preferably directly adjacent to each other, offset from each other or • perpendicular to the direction of movement of the coated glass fiber) diametrically opposite each other are arranged. This can enable the implementation of previously mentioned aspects of the invention.

[0056] According to a further aspect of the invention, the curing device, preferably the control unit of the curing device, is configured to not operate at least one UV LED of the first plurality of UV LEDs and simultaneously not operate at least one UV LED of the second plurality of UV LEDs, wherein the two UV LEDs • in the direction of movement of the coated glass fiber, preferably directly adjacent to each other, offset from each other or • perpendicular to the direction of movement of the coated glass fiber, diametrically opposite each other are arranged. This can enable the implementation of previously mentioned aspects of the invention.

[0057] According to a further aspect of the invention, the curing device comprises a first curing unit with a first receiving half-space and a second curing unit with a second receiving half-space, wherein the first receiving half-space of the first curing unit and the second receiving half-space of the second curing unit are configured to jointly form the receiving space of the curing device, and wherein the first curing unit and the second curing unit are configured to be movable relative to each other, preferably translationally, in order to open and close the receiving space of the curing device. Both receiving half-spaces can have a semicircular, oval, triangular, rectangular, square, hexagonal, other polygonal, or other contour in the horizontal direction, which is suitable for implementing the corresponding aspects of the invention. The contour can be uniform or different throughout in the vertical direction.

[0058] In other words, the curing device, or a component thereof, can be designed in at least two parts such that the two curing units are movable relative to each other or to another component, allowing the receiving space to be closed or opened and made accessible. This can be achieved by a purely translational movement of at least one curing unit relative to the other evaluation unit or another component, or of both curing units relative to each other or another component, which simplifies the implementation of the movement. Alternatively, however, a rotational movement, a pivoting movement, or a combined rotational and translational movement can also be used.In any case, this method allows the receiving chamber to be opened and closed around a coated fiber located there, which may be easier than passing a coated fiber with an open end through an upper opening of the receiving chamber to prepare for the manufacturing process.

[0059] Preferably, the two curing units can be identical, allowing one curing unit design to be used twice. This can reduce manufacturing costs.

[0060] An exemplary embodiment and further advantages of the invention are presented and explained in more detail below in purely schematic terms in connection with the following figures. These figures show: Fig. 1 a perspective view of a curing device according to the invention with an open receiving chamber; Fig. 2 the representation of the Fig. 1 with enclosed recording room; Fig. 3 a top view of the curing device with closed receiving chamber; Fig. 4 a frontal view of the curing device with closed receiving chamber; Fig. 5 a sectional view of the Fig. 4; Fig. 6 a detailed view of the upper middle area of ​​the Fig. 5; Fig. 7 a side view of a first curing unit of the curing device; Fig. 8 a detailed view of the upper middle area of ​​the Fig. 7; Fig. 9 a detailed view of the middle area of ​​the Fig. 3 as the first horizontal section; Fig. 10 a detailed view of the middle area of ​​the Fig. 3 as the second horizontal section; and Fig. 11 the representation of the Fig. 5 with a pulsed operating mode of all UV LEDs of both curing units; Fig. 12 the representation of the Fig. 5 with the UV LEDs of the first curing unit switched off and with a pulsed operating mode of the UV LEDs of the second curing unit; Fig. 13 the representation of the Fig. 5 with oppositely switched-off and pulsed UV LEDs of both curing units; Fig. 14 the representation of the Fig. 5 with offset, switched-off and pulsed UV LEDs of both curing units; Fig. 15 the representation of the Fig. 5 with pulsed UV LEDs of the first curing unit and with a continuous operating mode of the UV LEDs of the second curing unit; Fig. 16 the representation of the Fig. 5 with opposing pulsed and continuously operated UV LEDs, as well as offset switched-off UV LEDs of both curing units; and Fig. 17 the representation of the Fig. 5 with opposing pulsed or continuously operated and switched-off UV LEDs of both curing units.

[0061] The figures above are viewed in Cartesian coordinates. A longitudinal direction X extends, which can also be called depth X or length X. Perpendicular to the longitudinal direction X extends a transverse direction Y, which can also be called width Y. Perpendicular to both the longitudinal direction X and the transverse direction Y extends a vertical direction Z, which can also be called height Z and corresponds to the direction of gravity. The longitudinal direction X and the transverse direction Y together form the horizontal X,Y, which can also be called the horizontal plane X,Y.

[0062] A curing device 1, 2 according to the invention for coating glass fibers 4 comprises a first curing unit 1 and a second curing unit 2, which are identical in design. The two curing units 1, 2 can each also be referred to as curing modules 1, 2. The two curing units 1, 2 together enclose a receiving chamber 11, 21, through which a coated glass fiber 4 can be guided vertically from top to bottom in a direction of movement A during a manufacturing process. In addition to the two curing units 1, 2, the curing device 1, 2 according to the invention also comprises rails 3, various fluid and inert gas hoses, electrical supply lines, data and control cables, a control unit, and other components, as will be explained in more detail below, which are not shown in the figures for the sake of clarity and comprehensibility.

[0063] The coated glass fiber 4 is drawn from a preform, which is why the direction of movement A can also be referred to as the drawing direction A. This is done using a fiber drawing tower (not shown) of a production plant for coated glass fibers 4 in the vertical direction Z from top to bottom by appropriately heating the preform, which is then coated with a plastic coating such as polyamide, acrylic, or silicone in a further process step. To cure the coating of the glass fiber 4 using UV light, the coated glass fiber 4 is guided through the receiving chamber 11, 21 of the curing device 1, 2 and irradiated with UV light, as will be described in more detail below. Subsequently, the coated glass fiber 4 with the cured coating can be wound up.

[0064] As mentioned previously, the two curing units 1, 2 are identically designed, so that in the following the first curing unit 1 will be described in detail and this applies accordingly to the second curing unit 2.

[0065] The first curing unit 1 has a housing 10, which encloses the first curing unit 1 externally and essentially contains its elements internally. The housing 10 is essentially cuboid in shape and has a semicircular arc-shaped indentation facing the transverse direction Y of the second curing unit 2, which forms a first receiving half-space 11 of the first curing unit 1. When the curing device 1, 2 is closed, the first receiving half-space 11 of the first curing unit 1 and the corresponding second receiving half-space 21 of the housing 20 of the second curing unit 2 form its cylindrical receiving space 11, 21. During the manufacturing process of the coated glass fiber 4, the coated glass fiber 4 is guided through the cylindrical receiving space 11, 21 in the vertical direction Z from top to bottom along the longitudinal axis or central axis (not designated) of the cylindrical receiving space 11, 21.

[0066] In the longitudinal direction X, centrally located in the semicircular first receiving chamber 11, a plurality of UV radiation sources 12 in the form of UV LEDs 12 are arranged vertically one above the other in the vertical direction Z, and can therefore also be referred to as a UV LED array 12. The corresponding UV LEDs 22 of the second curing unit 2 are located diametrically opposite the UV LEDs 12 of the first curing unit 1 to the coated glass fiber 4 or to the longitudinal axis of the cylindrical receiving chamber 11, 21. In this way, the coating of the glass fiber 4 can be irradiated from both sides with UV light as primary radiation B and thus cured as it passes through the receiving chamber 11, 21 of the curing device 1, 2 with minimal effort regarding the use of UV LEDs 12, 22. The speed of movement of the coated glass fiber 4 can thus be controlled by the number orThe power of the UV LEDs 12, 22 in the vertical direction Z is adjusted so that the coated glass fiber 4 has a fully cured coating when exiting the receiving chamber 11, 21 of the curing device 1, 2.

[0067] Compared to known curing devices 1, 2 for coating glass fibers 4, this method eliminates the need to align the coated glass fiber 4 with the typically tubular UV radiation sources, thus avoiding the effort and associated errors associated with alignment. Furthermore, the advantageous properties of UV LEDs 12, 22, such as comparatively low energy consumption, comparatively low heat loss, comparatively small installation space, comparatively low heating of the coating on the glass fiber 4, and / or a comparatively long lifespan, can be utilized.

[0068] In order to operate the UV LEDs 12, 22 of the two curing units 1, 2 at a predetermined temperature during operation and to protect them at least from overheating, the curing device 1, 2 according to the invention has two fluid lines 13a, 23a extending vertically in the direction Z for each curing unit 1, 2, serving as cooling water lines 13a, 23a, which are each cylindrical and extend directly in the vicinity of the UV LEDs 12, 22 within the housing 10, 20. The area of ​​the curing unit 1, 2 between the fluid lines 13a, 23a and the UV LEDs 12, 22 is formed by a particularly thermally conductive material in order to promote the transfer of heat from the UV LEDs 12, 22 away from the area of ​​the fluid lines 13a, 23a, or vice versa.

[0069] The cooling water lines 13a, 23a each have fluid connections 13 at their ends in the form of cooling water connections 13, 23. The eight cooling water connections 13, 23 are each connected by flexible hoses. Cooling water can be supplied to the two curing units 1, 2 via half of the cooling water connections 13, 23. The cooling water can be discharged from the respective curing unit 1, 2 via the other half of the cooling water connections 13, 23 after flowing through it, and then cooled or tempered again if necessary. The supply and discharge of the cooling water can be effected by the curing unit 1, 2 using appropriate pumps, hoses, heat exchangers, and the like (not shown).

[0070] In the simplest case, this method allows the heat generated by the UV LEDs 12, 22 during operation to be dissipated to a certain extent via the cooling water, thus increasing the lifespan of the UV LEDs 12, 22 and preventing overheating, which could lead to damage or even destruction of the UV LEDs 12, 22. Depending on the temperature and flow rate of the cooling water, this can at least achieve a certain stable operating point during the operation of the curing device 1, 2 or during the manufacturing process of the coated glass fiber 4.

[0071] Furthermore, the curing device 1, 2 according to the invention is based on the finding that the wavelength of the emitted primary radiation B of UV LEDs 12, 22 can be influenced by their operating temperature. Thus, by achieving a stable operating point during the manufacturing process of the coated glass fiber 4 through cooling with cooling water, the wavelength of the emitted primary radiation B of the UV light can also be kept stable.

[0072] Furthermore, this relationship between the wavelength of the emitted primary radiation B of the UV LEDs 12, 22 and its operating temperature can be used to operate the UV LEDs 12, 22 within a certain range at a predetermined wavelength by regulating the temperature of the cooling water to a predetermined temperature. For this purpose, a temperature sensor 15, 25 is arranged directly adjacent to each UV LED 12, 22 of both curing units 1, 2, so that the temperature in the immediate vicinity of each UV LED 12, 22 can be measured by the temperature sensors 15, 25, which can then be attributed to the respective UV LED 12, 22.By means of a control unit (not shown) of the curing device 1, 2, the temperatures of all UV LEDs 12, 22 can be measured and, in relation to a predetermined temperature corresponding to a predetermined wavelength of the primary radiation B, used to regulate the temperature and / or the flow rate of the cooling water. The temperature of the cooling water can therefore be comparatively high, and the curing device 1, 2 can even heat the cooling water to achieve the predetermined wavelength of the primary radiation B. Accordingly, instead of cooling the UV LEDs 12, 22, one can also speak of tempering the UV LEDs 12, 22, since the cooling water or fluid can also be heated.

[0073] This makes it possible to predetermine the wavelength of the primary radiation B solely by controlling the temperature of the fluid or cooling water. This allows the UV LEDs 12, 22 to be operated to a certain extent with different predetermined wavelengths of the primary radiation B, enabling the use of different coatings on the glass fiber 4, which can then be effectively cured using the UV light of the primary radiation B.

[0074] The two curing units 1, 2 each have two protective gas lines 14a, 24a, which can receive or release a protective gas at their two ends via protective gas connections 14, 24. The eight protective gas connections 14, 24 are each connected to other components of the curing device 1, 2 via a flexible hose, so that a protective gas, such as nitrogen, can be supplied from a source, such as a tank (not shown), and pumped to half of the protective gas lines 14a, 24a by means of at least one pump (not shown). The other half of the protective gas lines 14a, 24a lead via hoses to at least one pump (not shown), which can draw in the protective gas and discharge it into a storage tank (not shown).

[0075] The four protective gas lines 14a, 24a run in the vertical direction Z parallel to the respective receiving chambers 11, 21 of the respective curing units 1, 2. Two protective gas branches 14b, 24b extend straight and radially from the respective protective gas lines 14a, 24a in the vertical direction Z, at the midpoint between two UV LEDs 12, 22, respectively, and open into the respective receiving chambers 11, 21 via protective gas openings 14c, 24c. When protective gas is supplied to the corresponding protective gas line 14a, 24a, it can enter the corresponding receiving chambers 11, 21 via all protective gas openings 14c, 24c that are connected to this protective gas line 14a, 24a via the protective gas branches 14b, 24b. These shielding gas openings 14c, 24c can accordingly be referred to as shielding gas openings 14c, 24c for inflow or also as shielding gas inlets 14c, 24c.If the protective gas is discharged or extracted from the corresponding receiving half-space 11, 21 via the corresponding protective gas line 14a, 24a, these protective gas openings 14c, 24c can accordingly be referred to as protective gas openings 14c, 24c for escape or also as protective gas outlets 14c, 24c.

[0076] The configuration of the two curing units 1, 2 with respect to the protective gas openings 14c, 24c, which are used for the inflow and extraction of the protective gas into the receiving chamber 11, 21 of the curing device 1, 2, can be quickly and easily adjusted or changed by connecting the hoses for conveying the protective gas. For example, one protective gas line 14a, 24a can be used for inflow and the other for exhaust of the protective gas in each curing unit 1, 2. This can be done, for example, in a crisscross pattern in the horizontal X, Y, so that, viewed circumferentially around the coated glass fiber 4, the protective gas openings 14c, 24c for inflow and the protective gas openings 14c, 24c for exhaust alternate.

[0077] In this way, according to the invention, the protective gas can be supplied to the coated glass fiber 4 as evenly as possible throughout the entire receiving chamber 11, 21 of the curing device 1, 2, both in the vertical direction Z and within the horizontal planes X, Y, in order to enable the curing of the coating of the glass fiber 4 to take place in a protective gas environment that is as uniform as possible. This can improve the quality of the cured coating of the glass fiber 4. At the same time, by allowing the protective gas to escape, be drawn off, or extracted from the receiving chamber 11, 21, it can be prevented that the protective gas, including harmful vapors that may be generated during the curing process of the coating of the glass fiber 4, can enter the environment of the curing units 1, 2.

[0078] Furthermore, the temperature of the protective gas within the receiving chamber 11, 21 can also be measured using the previously described temperature sensors 15, 25. The curing device 1, 2 can heat the protective gas to a predetermined temperature before it enters the receiving chamber 11, 21, which can promote the curing of the coating on the glass fiber 4. This can influence the reaction rate or polymerization rate of the coating on the glass fiber 4 and, in particular, increase it by raising the temperature. This can make it possible to increase the drawing speed of the glass fiber 4 from the preform and thus the production speed of the coated glass fiber 4, which can lead to increased productivity of the entire manufacturing process and therefore to reduced manufacturing costs of the coated glass fiber 4.

[0079] To operate the two curing units 1, 2, they can be connected to the control unit of the curing device 1, 2 via control lines (not shown) at control terminals 16, 26 of their housings 10, 20. This allows at least the temperature sensors 15, 25 and the UV LEDs 12, 22 to be operated and controlled. The two curing units 1, 2 can also be connected to the control unit of the curing device 1, 2 or to another electrical power supply via corresponding electrical supply terminals 17, 27 and electrical supply lines (not shown) to provide power to at least the temperature sensors 15, 25 and the UV LEDs 12, 22.

[0080] Furthermore, the curing device 1, 2 according to the invention is based on the finding that the heating of the coated glass fiber, i.e., both of the material of the glass fiber coating and of the material of the glass fiber core itself, can be reduced or regulated by operating the UV LEDs 12, 22 not continuously but in pulsed mode or not at all. These three operating modes—pulsed operation, continuous operation, and the switched-off state or non-operation—can be combined as desired for individual UV LEDs 12, 22 as well as for pairs or groups of UV LEDs 12, 22, both along the direction of movement A and perpendicular to the direction of movement A, in order to achieve the desired curing of the coating of the coated glass fiber 4 by means of the UV radiation of the UV LEDs 12, 22 and at the same time to keep the thermal stress on the material(s) of the coated glass fiber 4 low.to avoid thermal overload. These operating modes of the UV LEDs 12, 22 can be implemented by the previously mentioned control unit of the curing device 1, 2 according to the invention.

[0081] This shows Fig. 11 a representation of the Fig. 5, in which all UV LEDs 12, 22 of both curing units 1, 2 are operated in pulsed mode, so that all pulses occur simultaneously and thus act on the coated glass fiber 4 at the same time; that is, the UV LEDs 12 of the first curing unit 1 and the UV LEDs 22 of the second curing unit 2 are operated in synchronous pulsed mode. The pulses of all UV LEDs 12, 22 are thus synchronized with each other, so that the on and off phases are of equal length and occur in parallel or simultaneously. This allows for a reduced but still comparatively high curing effect using UV radiation and thus a still comparatively fast curing process with at least a somewhat reduced heating of the coated glass fiber 4.

[0082] The Fig. 12 shows a representation of the Fig. 5, in which only the UV LEDs 22 of the second curing unit 2 are pulsed and the UV LEDs 12 of the first curing unit 1 are switched off. This significantly reduces the incident UV radiation, while the side of the coated glass fiber 4 opposite the UV LEDs 22 of the second curing unit 2 can be reached by UV radiation from the UV LEDs 22 of the second curing unit 2, which can be reflected from the inner surface of the first receiving chamber 11 of the first curing unit 1. To promote this, the two receiving chambers 11, 21 can be provided with a reflective coating.

[0083] The Fig. Figure 12 can also represent a pulsed operation of both the UV LEDs 12 of the first curing unit 1 and the UV LEDs 22 of the second curing unit 2, in which the switched-on and activated phases are not simultaneous and, in particular, are precisely offset from each other, so that either the UV LEDs 12 of the first curing unit 1 are switched on and the UV LEDs 22 of the second curing unit 2 are switched off, or vice versa, which represents an asynchronous operation of the UV LEDs 12 of the first curing unit 1 and the UV LEDs 22 of the second curing unit 2. This represents a comparable process to that shown in the Fig. 11 describes, whereby the curing is slowed down but the thermal stress is also reduced by the asynchronous operation of the UV LEDs 12 of the first curing unit 1 and the UV LEDs 22 of the second curing unit 2.

[0084] The Fig. Figure 13 shows a representation of the Fig. 5, in which the upper and lower UV LEDs 12, 22 of the two curing units 1, 2 in the vertical direction Z are pulsed synchronously, and the middle UV LEDs 12, 22 located between them along the direction of movement A are switched off. This allows the material(s) of the coated glass fiber 4 to cool down again in the middle region of the receiving chamber 11, 21 during movement in the direction of movement A, before the lower UV LEDs 12, 22 of the two curing units 1, 2 can pulse onto the coated glass fiber 4.

[0085] The Fig. Figure 13 can also represent a pulsed operation of both the UV LEDs 12 of the first curing unit 1 and the UV LEDs 22 of the second curing unit 2, in which the on and off phases are not simultaneous but are offset from each other between the upper and lower groups of UV LEDs 12, 22 and the intermediate middle group of UV LEDs 12, 22, so that either the upper and lower UV LEDs 12, 22 or the middle UV LEDs 12, 22 are in the on phase, or vice versa. The upper and lower UV LEDs 12, 22 of the two curing units 1, 2 are thus operated asynchronously with the respective middle UV LEDs 12, 22, which can lead to comparatively fast curing with comparatively high heating, but at a lower temperature than previously known.

[0086] The Fig. 14 shows a representation of the Fig. 5, in which the pulsed UV LEDs 12, 22 of the two curing units 1, 2 are precisely offset from each other in the direction of movement A, and the corresponding UV LEDs 12, 22 opposite each other in the transverse direction Y are switched off. This allows both sides of the coated glass fiber 4 to be alternately pulsed and heated.

[0087] The Fig. Figure 14 can also represent a pulsed operation of both the UV LEDs 12 of the first curing unit 1 and the UV LEDs 22 of the second curing unit, in which the on and off phases are not simultaneous but alternate along the direction of movement A at the first curing unit 1 or the second curing unit 2, so that the upper and lower UV LEDs 22 of the second curing unit 2 and the middle UV LEDs 12 of the first curing unit 1 are alternately in the on phase, or vice versa, i.e., operated asynchronously. This allows for different results compared to operation according to the Fig. 13. The hardening process is slowed down, but at the same time the thermal stress is reduced.

[0088] The Fig. 15 shows a representation of the Fig. 5, in which the UV LEDs 12 of the first curing unit 1 are pulsed and the UV LEDs 22 of the second curing unit 2 are operated continuously. This allows the right side of the coated glass fiber 4 in the transverse direction Y to be continuously cured and heated with UV radiation, while the left side of the coated glass fiber 4 opposite in the transverse direction Y is cured and heated in a pulsed manner.

[0089] The Fig. 16 and Fig. 17 show further representations of the Fig. 5, in which all three operating modes of a pulsed operation or a continuous operation of the UV LEDs 12, 22 of the two curing units 1, 2 are combined with completely switched-off UV LEDs 12, 22 of the two curing units 1, 2.

[0090] In any case, by using pulsed operating mode for at least some of the UV LEDs 12, 22 of the two curing units 1, 2, the desired curing of the coated glass fiber 4 can be achieved, albeit by means of a longer process or a lower speed of the coated glass fiber 4 in the direction of movement A, and at the same time the thermal stress can be reduced, since at least during the switched-off phase of the UV LEDs 12, 22 no UV radiation has a heating effect on the coated glass fiber 4. This can reduce the thermal stress or prevent thermal overload, which can be of great importance, especially for coated glass fibers 4 with a comparatively low melting point of the coating material and / or the fiber core.Overall, the numerous combination and variation possibilities, which UV LEDs 12, 22 of the two curing units 1, 2 are operated in which operating mode and in pulsed operation with which phase duration, significantly increase the design possibilities for the curing and heating of the coated glass fiber 4 compared to the previously known purely continuous operation of the UV radiation source or all UV radiation sources.

[0091] To facilitate access to the receiving chamber 11, 21 of the curing device 1, 2, the two curing units 1, 2 are each movably mounted on a common pair of rails 3 extending horizontally in the transverse direction Y. The rails 3 can be fixedly mounted on a frame of the fiber drawing tower, allowing the two curing units 1, 2 to be moved outwards in the transverse direction Y relative to the longitudinal axis of the coated glass fiber 4 running in the vertical direction Z, either away from or towards it. The movement of the two curing units 1, 2 can be effected by electric drives for the curing units 1, 2, which, as described above, can be operated and controlled, or electrically supplied, by the control unit of the curing device 1, 2.However, such electric drives can be provided on the side of rails 3 in order to keep the effort and weight of the two curing units 1, 2 low.

[0092] Moving the two curing units 1, 2 towards the longitudinal axis of the coated glass fiber 4 closes the receiving chamber 11, 21. In this position, the two curing units 1, 2 can also be mechanically secured externally to their housings 10, 20 (not shown). The manufacturing process of the coated glass fiber can then be carried out as described above. A gas-tight seal of the closed receiving chamber 11, 21 in the longitudinal direction X can be ensured by seals extending in the vertical direction Z, for example, made of rubber.

[0093] Moving the two curing units 1, 2 away from each other in the transverse direction Y opens the receiving chamber 11, 21. The two receiving chambers 11, 21 of the two curing units 1, 2 are sufficiently spaced apart in the transverse direction Y to allow a coated glass fiber 4 to be positioned in the longitudinal direction X between the two receiving chambers 11, 21 of the two curing units 1, 2. This avoids the need to insert a coated glass fiber 4 from above in the vertical direction Z into a permanently closed receiving chamber of a known curing device, which can be comparatively complex and time-consuming. REFERENCE MARK LIST (Part of the description) A Direction of movement; direction of pulling B Primary radiation X Longitudinal direction; Depth; Length Y transverse direction; width Z vertical direction; height X, Y Horizontal; horizontal plane pulsed operating mode continuous operating mode switched off; no operation 1, 2 Curing device for glass fiber coatings 4 11, 21 Recording Room 1 first curing unit; first curing module 10 cases 11 first recording half-space 12 UV radiation source; UV LEDs; UV LED series 13 fluid connections; cooling water connections 13a Fluid lines; cooling water lines 14 shielding gas connections 14a Shielding gas lines 14b Shielding gas branches 14c Shielding gas openings; shielding gas inlets; shielding gas outlets 15 temperature sensors 16 control connections 17 electrical supply connections 2. Second curing unit; second curing module 20 cases 21 second recording half-space 22 UV radiation source; UV LEDs; UV LED series 23 fluid connections; cooling water connections 23a Fluid lines; cooling water lines 24 shielding gas connections 24a Shielding gas lines 24b Shielding gas branches 24c Shielding gas openings; shielding gas inlets; shielding gas outlets 25 temperature sensors 26 control connections 27 electrical supply connections 3 rails 4 coated fiberglass

Claims

[1] Curing device (1, 2) for coatings of glass fibers (4) with a receiving space (11, 21) for the passage of a coated optical fiber (4) in a direction of movement (A), wherein the receiving chamber (11, 21) has a plurality of UV radiation sources (12, 22) which are designed to harden the coating of the glass fiber (4) by means of UV light, where the UV radiation sources (12, 22) are UV LEDs (12, 22), and wherein the curing device (1, 2), preferably a control unit of the curing device (1, 2), is configured to operate at least one UV LED (12, 22), preferably several UV LEDs (12, 22) simultaneously, particularly preferably all UV LEDs (12, 22) simultaneously, in a pulsed manner, characterized by , that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is designed to operate at least one UV LED (12, 22), preferably several UV LEDs (12, 22) simultaneously, particularly preferably all UV LEDs (12, 22) simultaneously, with the maximum operating current of a continuous operation. [2] Curing device (1, 2) according to claim 1, characterized by , that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is designed to operate at least one UV LED (12, 22), preferably several UV LEDs (12, 22) simultaneously, particularly preferably all UV LEDs (12, 22) simultaneously, or alternatively continuously. [3] Curing device (1, 2) according to claim 1 or 2, characterized by, that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is configured to operate at least one UV LED (12, 22), preferably several UV LEDs (12, 22) simultaneously, particularly preferably all UV LEDs (12, 22) simultaneously, or alternatively not to operate. [4] Curing device (1, 2) according to one of the preceding claims, characterized by , that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is configured to operate at least one UV LED (12, 22), preferably several UV LEDs (12, 22) simultaneously, particularly preferably all UV LEDs (12, 22) simultaneously, with such a pulse repetition rate and with such a pulse-pause ratio, such that the pulse duration is shorter than the thermal relaxation time of the material of the glass fiber coating and / or the glass fiber. [5] Curing device (1, 2) according to one of the preceding claims, characterized by , that the UV LEDs (12, 22), preferably exactly, as a first plurality of UV LEDs (12), preferably of the first curing unit (1), and as a second plurality of UV LEDs (22), preferably of the second curing unit (2), are configured, wherein the two plurals of UV LEDs (12, 22) extend linearly in the direction of movement (A) of the coated glass fiber (4) and / or wherein the two plurals of UV LEDs (12, 22) are arranged diametrically opposite each other perpendicular to the direction of movement (A) of the coated optical fiber (4). [6] Curing device (1, 2) according to claim 5, characterized by , that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is configured to operate at least one UV LED (12) of the first plurality of UV LEDs (12) in pulsed mode and at the same time at least one UV LED (22) of the second plurality of UV LEDs (22) in pulsed mode, where the two UV LEDs (12, 22) • in the direction of movement (A) of the coated glass fiber (4), preferably directly adjacent to each other, offset or • perpendicular to the direction of movement (A) of the coated glass fiber (4) diametrically opposite each other are arranged. [7] Curing device (1, 2) according to claim 5 or 6, characterized by , that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is configured to operate at least one UV LED (12) of the first plurality of UV LEDs (12) in a pulsed manner and at the same time at least one UV LED (22) of the second plurality of UV LEDs (22) continuously, where the two UV LEDs (12, 22) • in the direction of movement (A) of the coated glass fiber (4), preferably directly adjacent to each other, offset or • perpendicular to the direction of movement (A) of the coated glass fiber (4) diametrically opposite each other are arranged. [8] Curing device (1, 2) according to one of claims 5 to 7, characterized by , that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is configured to pulse at least one UV LED (12) of the first plurality of UV LEDs (12) and simultaneously not operate at least one UV LED (22) of the second plurality of UV LEDs (22), where the two UV LEDs (12, 22) • in the direction of movement (A) of the coated glass fiber (4), preferably directly adjacent to each other, offset or • perpendicular to the direction of movement (A) of the coated glass fiber (4) diametrically opposite each other are arranged. [9] Curing device (1, 2) according to any one of claims 5 to 8, characterized by , that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is configured to operate at least one UV LED (12) of the first plurality of UV LEDs (12) continuously and simultaneously at least one UV LED (22) of the second plurality of UV LEDs (22) continuously, where the two UV LEDs (12, 22) • in the direction of movement (A) of the coated glass fiber (4), preferably directly adjacent to each other, offset or • perpendicular to the direction of movement (A) of the coated glass fiber (4) diametrically opposite each other are arranged. [10] Curing device (1, 2) according to any one of claims 5 to 9, characterized by , that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is configured to continuously operate at least one UV LED (12) of the first plurality of UV LEDs (12) and simultaneously not operate at least one UV LED (22) of the second plurality of UV LEDs (22), where the two UV LEDs (12, 22) • in the direction of movement (A) of the coated glass fiber (4), preferably directly adjacent to each other, offset or • perpendicular to the direction of movement (A) of the coated glass fiber (4) diametrically opposite each other are arranged. [11] Curing device (1, 2) according to any one of claims 5 to 10, characterized by , that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is configured to not operate at least one UV LED (12) of the first plurality of UV LEDs (12) and simultaneously not operate at least one UV LED (22) of the second plurality of UV LEDs (22), where the two UV LEDs (12, 22) • in the direction of movement (A) of the coated glass fiber (4), preferably directly adjacent to each other, offset or • perpendicular to the direction of movement (A) of the coated glass fiber (4) diametrically opposite each other are arranged. [12] Curing device (1, 2) according to one of the preceding claims, characterized by , that the curing device (1, 2) comprises a first curing unit (1) with a first receiving half-space (11) and a second curing unit (2) with a second receiving half-space (21), wherein the first receiving half-space (11) of the first curing unit (1) and the second receiving half-space (21) of the second curing unit (2) are configured to jointly form the receiving space (11, 21) of the curing device (1, 2), and wherein the first curing unit (1) and the second curing unit (2) are designed to be movable relative to each other, preferably translationally, in order to open and close the receiving space (11, 21) of the curing device (1, 2).

Images