DE102021115380A1 - Curing device for coatings of glass fibers - Google Patents

Abstract

The present invention relates to a curing device (1, 2) for coating glass fibers (4) with a receiving space (11, 21) for guiding a coated glass fiber (4) in a direction of movement (A), the receiving space (11, 21) having a Has a plurality of UV radiation sources (12, 22), which are designed to cure the coating of the glass fiber (4) by means of UV light. The curing device (1, 2) is characterized in that the UV radiation sources (12, 22) are UV LEDs (12, 22), the curing device (1, 2), preferably a 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) at the same time, particularly preferably all UV LEDs (12, 22) at the same time, in a pulsed manner.

Description

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

Glass fibers are nowadays used in many different technical fields. One of the highly technical applications is the transmission of light using glass fibers. This can be used for data transmission using light, so that the glass fibers can also be referred to as optical waveguides. Glass fibers are also used in medicine, for example for lighting and for generating images, for example in microscopes, in inspection cameras and in endoscopes. Furthermore, glass fibers can be used in sensors, which can then be referred to as fiber-optic sensors.

Another area of application for glass fibers is laser technology. Here, the laser radiation can be guided as signal light radiation by means of a passive glass fiber from a laser radiation source as a signal light radiation source to a processing point in order to carry out cutting or welding there, for example in material processing or in medicine . In this way, the laser beam can also be supplied as laser radiation to a sample, for example in metrology, in microscopy or in spectroscopy, for example. Such applications are known, for example, in mechanical engineering, in telecommunications, in medical technology and in sensor technology. Glass fibers can also be used to generate or amplify laser light and are then referred to as active glass fibers.

Glass fibers are usually drawn as a blank as thin threads from a glass melt, so that a glass fiber is a long, thin fiber made of glass. The blank can also be referred to as a preform. The preform is usually produced in a preceding work step, usually as a glass rod typically about 1 m in length and about 10 mm to about 50 mm in diameter, which already has the refractive index profile of the subsequent glass fiber. The glass fiber is then drawn from the preform by melting it, which can be done in a fiber drawing tower at temperatures of around 2000°C, to which the preform is heated for this purpose. At this temperature, the glass material of the preform becomes sufficiently soft so that the glass material of the preform can be drawn into a glass fiber, which has a significantly smaller diameter with a correspondingly greater length than the preform. The refractive index profile of the preform is usually preserved during the drawing process. The speed at which the glass fiber is pulled out of the preform can be regulated as a function of the diameter of the glass fiber, which can be detected by sensors for this purpose. Pulling the glass fiber out of the preform leads to the formation of a bare glass fiber from the material of the preform, which can be referred to as the glass fiber core, or fiber core for short.

Usually, immediately after drawing, the glass fiber core is provided or covered with a coating of plastic such as polyamide, acrylic or silicone in a further process step in the same manufacturing process, which usually serves to mechanically protect the glass fiber core but also specifically to influence the optical properties of the Glass fiber can be used. For this purpose, the glass fiber core of the glass fiber is guided through an extruder, which provides the plastic in a free-flowing 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 etched by irradiating it with light in the ultraviolet spectrum (UV light), i.e. with electromagnetic radiation in the optical frequency range (light) with shorter wavelengths than the light visible to humans, which occurs in the range between about 100 nm and about 405 nm are cured for coating. The coating can also be referred to as a glass fiber cladding, which is closed in the circumferential direction and thus completely surrounds the glass fiber core, apart from the two open ends of the glass fiber or glass fiber core.

Thus, when curing the coating which has just been applied to the fiberglass core moving in a longitudinal direction as the pulling direction, the coated fiberglass core is passed through a curing device which can generate UV light and direct it onto the coated fiberglass core moving in the longitudinal direction. The glass fiber core enters the curing device with a freshly applied coating and exits with a cured coating in the longitudinal direction opposite. The generation of the UV light and/or the alignment of the UV light onto the coated glass fiber core can take place in different ways.

the US 4,710,638A describes an apparatus for treating material with radiant energy, particularly suitable for curing photocurable polymeric materials coated on an optical fiber. The device includes first and second reflectors which in combination form an elliptical reflector, one arranged parallel to the optical fiber Light source positioned at one focal point of the elliptical reflector and photohardenable polymer coated wire-like material or fiber, such as an optical fiber, positioned at the second focal point. An auxiliary reflector is located near the second focus in a position to direct light rays impinging thereon to the second focus, thereby increasing the amount of energy impinging on the polymeric coating.

That US 6,419,749 B1 describes a tubular apparatus for UV curing of coatings on a continuous filament in which concentric tubes are provided and through which the filament passes after coating to cure the coating, the apparatus having the first inner tube which transmits the UV light through the tube conducts to cure the filament passing therethrough, and a second concentric tube, disposed over and spaced from the first tube, which reflects IR light and transmits UV light to prevent burning and destruction of the coating on the filament to prevent when it passes through the first tube. The UV light source is tubular and arranged parallel to the continuous filament.

That U.S. 9,132,448 B2 describes apparatus and methods for curing materials with radiant energy. The devices include a first reflector and a second reflector which are semi-ellipses. The ellipses that define the first reflector and the second reflector have axes of different lengths, and the reflectors are aligned such that the focal points of the reflectors overlap. A source of radiant energy at a near focus of a reflector can provide energy to cure a coating on a substrate at a far focus of the reflector. The different sizes of the two reflectors reduce the focussing error of the radiant energy and provide improved efficiency of the curing system. The radiant energy source is tubular and arranged parallel to the substrate.

The devices and/or methods described above have in common that a tubular UV light source is used in each case, which extends in the same longitudinal direction as the moving coated glass fiber core and parallel to the glass fiber core. 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 located exactly in the focal point of the reflected UV light so that its coating can be cured. If this is not the case, the coating can be cured incompletely, unevenly or even not at all. Fluorescent lamps, for example, can be used as a tubular UV light source, which can be implemented as low-pressure gas discharge tubes with mercury vapor as the gas filling. However, iron iodide lamps, gallium iodide lamps and amalgam lamps are also known.

However, the disadvantage of generating UV light or UV irradiation using UV fluorescent tubes is that UV fluorescent tubes can generate and emit a comparatively broad spectrum of UV light, but usually only a small range of the emitted spectrum of the UV Light helps to cure the coating on the fiber optic core. Approx. 90% of the energy generated is lost heat, which excessively heats up the material of the coating and/or the glass fiber core and can damage it as a result. If the material of the coating of the glass fiber core is heated or heated too much, the viscosity of the coating can drop sharply, for example from a temperature of approx mechanical properties of the material of the coating of the glass fiber core can be changed. Additionally or alternatively, this can affect the light-guiding properties of the coating of the glass fiber. If, alternatively or additionally, the material of the glass fiber core is warmed up or heated too much, the material can become softer and thus flow more when it is pulled, as a result of which the cross section of the glass fiber core can narrow. This can affect the optical properties of the glass fiber core and/or reduce the mechanical strength of the glass fiber core.

Another disadvantage here is that the heat loss from the UV fluorescent tubes can also lead to high heating of the curing device itself and can also stress it as a result.

The generation of UV light or UV irradiation by means of UV fluorescent tubes also has the disadvantage that UV fluorescent tubes require a comparatively high electrical output during operation, which can amount to several kilowatts (kW). This can lead to a very low efficiency of the conversion of electrical energy into UV radiation and thus to a very low efficiency of the curing process of the curing device. The corresponding need for electrical energy can lead to correspondingly high costs, which can increase the production costs of the glass fiber.

Another disadvantage of the generation of UV light or UV irradiation using UV fluorescent tubes is that the power or the intensity of the UV radiation in UV fluorescent tubes such as low-pressure mercury vapor lamps is structurally fixed and provided the known movement or drawing speed of the glass fiber must be coordinated in order to achieve the desired curing of the coating and at the same time not to stress or damage the material of the coating of the glass fiber core and/or the material of the glass fiber core itself by excessively strong UV radiation. to damage. This can also have a negative effect on the properties and in particular on the durability of the material of the coating of the glass fiber core and/or the material of the glass fiber core, as already described above.

That U.S. 8,604,448 B2 describes a method for curing a coating on an optical fiber, comprising: emitting UV radiation from one or more sources in the form of a UV LED or UV LEDs of electromagnetic radiation into a substantially cylindrical cavity with an elliptical cross section, the cavity having a reflective inner surface, defining the cure space, and defining a first line focus and a second line focus; allowing a portion of the emitted UV radiation to pass completely through the curing space; reflecting at least a portion of the UV radiation toward the second line focus by the reflective inner surface; and passing an optical fiber with an incompletely cured coating through the curing space along the second line focus to cause absorption of both emitted and reflected UV radiation.

That EP 2 388 239 B1 describes an apparatus for curing a coated optical fiber, comprising: a substantially cylindrical cavity having a substantially elliptical cross-section and a reflective inner surface, the cavity defining a first line focus, a second line focus, and a major axis defining the first line focus and the second line focus intersects, the second line focus defining a cure axis; a protective tube that is substantially transparent to UV radiation, the protective tube surrounding the cure axis and preferably being a quartz tube; and a UV LED source positioned within the cavity at the first line focus, the UV LED source having an emission pattern that defines a line of average emission and an emission angle between the major axis and between about 30 degrees and 100 degrees having.

LEDs are generally characterized by a comparatively long service life, by a comparatively high energy efficiency in the conversion of electrical energy into optical radiation, by a comparatively low consumption of electrical energy, by comparatively low costs, by a comparatively small installation space and/or by a comparatively small warming up. Thus, the disadvantages of UV fluorescent tubes described above can be at least partially reduced or avoided by using UV LEDs as UV light sources instead.

However, all the previously described curing devices using UV radiation still have the disadvantage that it is always necessary to align the UV light by reflecting and focusing it on the coated glass fiber core in order to bring about the desired curing. This applies both to the generation of UV light using UV fluorescent tubes and using UV LEDs as UV light sources. For this purpose, either flat, in particular elliptical, reflectors or lenses can be used. 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 which extends in the longitudinal direction and, as described above, can be referred to as the focal point or as the line focus.

Conversely, however, this means that the coating of the glass fiber core can only be cured effectively and as completely as possible using UV light if the coated glass fiber core lies as exactly as possible with its longitudinal axis on the line focus or in the focal point of the reflectors. This must be done accordingly over the entire length with which the coated glass fiber core runs through the curing device. In other words, the longitudinal or pulling axis of the glass fiber and the line focus of the curing device or the focal point must lie one above the other over the entire length of the curing device.

This requires a correspondingly exact adjustment of the curing device in relation to the fiber drawing tower. The sensitivity of this adjustment is in the order of microns compared to the fiber drawing tower, whose dimensions are usually more in the order of meters. As a result, even a slight misalignment of the line focus of the curing device with respect to the longitudinal or pulling axis of the glass fiber means that the glass fiber or the coated glass fiber core is not or only partially irradiated by the UV light and the coating tion can only be cured insufficiently as a result.

The problem here is that an uneven or insufficiently cured coating of the glass fiber core can usually only be recognized as a manufacturing defect when a large proportion of the glass fiber has already gone through the process step of curing and has subsequently been wound up. This leads to a correspondingly high level of rejects in production.

It is known in such curing devices, for example from EP 2 388 239 B1 , as already mentioned above, furthermore, to arrange a protective tube within the curing device in such a way that the coated glass fiber core can be pulled through the protective tube in its longitudinal direction in its pulling, moving or longitudinal direction without touching the protective tube radially, and in doing so 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 in particular be made of quartz glass, since quartz glass has a very high transparency for UV light and thus the UV light directed onto the coated glass fiber core can largely reach the coating of the glass fiber.

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 to exit through the opposite end from the interior of the protective tube, see also EP 2 388 239 B1 . As a result, the coating of the glass fiber can be cured in an oxygen-free or low-oxygen environment, which can avoid or reduce errors in the curing of the coating of the glass fiber.

One object of the present invention is to provide a curing device for coatings of glass fibers of the type described at the beginning, so that the possibilities for curing the coating of a glass fiber core of a glass fiber to be produced can be improved.

In particular, the degree of curing and thus the quality of the curing of the coating of the glass fiber should be improved. Additionally or alternatively, thermal stress on the material of the glass fiber coating and/or the glass fiber core should be reduced and, in particular, thermal overload should be avoided. Additionally or alternatively, the effort involved in curing the coating of the glass fiber should be kept as low as possible. Additionally or alternatively, the effort involved in adjusting the coated glass fiber core to be cured in relation to the curing device can be reduced or avoided. At the very least, an alternative to known curing devices of this type for coating glass fibers should be created.

The object is achieved according to the invention by a curing device for coatings of glass fibers with the features of claim 1. Advantageous developments are described in the dependent claims.

The present invention thus relates to a curing device for coatings of glass fibers with a receiving space for guiding a coated glass fiber through in a direction of movement, the receiving space having a plurality of UV radiation sources which are designed to cure the coating of the glass fibers using UV light. Such curing devices are used to irradiate a glass fiber during production when pulling it out of the preform and then applying a coating, for example by means of an extruder, in a further process step with UV light of a suitable wavelength and to a sufficient extent, so that the material of the coating like for example polyamide, acrylic or silicone can be cured sufficiently. Known curing devices of this type have been described in the introduction. 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 pulling direction of the coated glass fiber.

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 designed to have at least one UV LED, preferably several UV LEDs at the same time, particularly preferably all UV LEDs at the same time , to operate in pulsed mode. In other words, the UV LED or the UV LEDs can be operated with comparatively short-term emission of the UV radiation and short-term interruptions in between, so that the UV radiation can be emitted as pulses and can therefore act in a pulsed manner on the coating to be cured. The UV-LED or the UV-LEDs are thus switched on and off for a comparatively short time, with the UV radiation emitted in the switched-on phases or periods of time being referred to as pulses. These pulses represent a sequence of regularly recurring pulses of the same type of UV light and can therefore also be referred to as UV light pulses.

A UV LED can be operated in such a way that the switched-on and switched-off phases are of equal length. However, the switched-on phases can also be longer than the switched-off phases, or vice versa. If a number of UV LEDs are operated in pulsed fashion in parallel with one another, these UV LEDs can be operated in the same way or differently with regard to the duration of their switched-on and switched-off phases. If several UV LEDs are operated at the same time with switched-on and switched-off phases of the same length, which take place at the same time, this can be referred to as synchronous operation. If the switched-on and switched-off phases of at least two UV LEDs alternate exactly so that only one UV LED emits UV radiation and the other UV LED does not at this point in time, this can be referred to as asynchronous operation.

At least one UV LED can also be operated in a pulsed manner and at least one further UV LED can be operated continuously in parallel, which can be referred to as a hybrid operating mode. Likewise, at least one UV LED can be operated in a pulsed manner and at least one further UV LED can be switched off in parallel. Likewise, at least one continuously operated UV LED can be combined with at least one UV LED that is switched off.

The present invention is based on the finding that the previously known continuous operation of the UV radiation source of a curing device for coatings of glass fibers with such a high intensity of UV radiation can affect the material of the glass fiber coating and/or the glass fiber core that Material is thermally heavily loaded or even overloaded, d. H. that the material is excessively heated. This can lead to damage to the corresponding material, for example, as described above.

According to the invention, at least one UV LED is therefore operated as a radiation source of UV light in such a way that the UV LED is not operated continuously, as was previously known, but in a pulsed or clocked manner, so that phases with UV LEDs switched on and switched off alternate in quick succession UV LED present. Accordingly, the UV radiation only acts for a short time on the material of the glass fiber coating and/or the glass fiber core, which can increase the design options for the curing process. For example, the previously known continuous operation can be changed to pulsed operation, whereby the duration of the curing process can be increased if the material of the coating of the glass fiber is to be cured, but the curing of the material of the coating of the glass fiber can be carried out more gently than previously known due to the interruptions in the irradiation, the material of the coating of the glass fiber can be cooled and thus the thermal stress on the material of the coating of the glass fiber can be kept lower than previously known. Accordingly, the desired hardening can still be achieved, but the heating that occurs in this way is reduced and thermal stress or overloading can be avoided. This can be advantageous in particular for thermally sensitive materials such as fluoride glass fibers (ZBLAN fibers and AIF3 fibers), hollow-core fibers and polymer optical fibers, since these have significantly lower melting temperatures of, for example, around 265 °C to around 367 °C in comparison to quartz glass fibers with a melting temperature of approx. 2000 °C.

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

Overall, the options for influencing the curing process of the glass fiber coating can be increased by the fact that the UV radiation sources are not all only operated continuously during the process, as has been customary up to now. Rather, the use of UV LEDs as UV radiation sources can increase the design possibilities of the process, since UV LEDs can be switched on and off quickly and frequently, which is not technically possible with UV fluorescent tubes as UV radiation sources. As a result, a variation between the pulsed, continuous and completely switched-off operating modes can also take place for the at least one UV-LED, preferably for a plurality of UV-LEDs at the same time and very particularly for all UV-LEDs at the same time. In the case of several UV LEDs, these operating modes can be combined as desired both in the direction of movement of the coated glass fiber to be cured and/or 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 and at the same time reduce the thermal load as much as possible to keep it low or to prevent thermal stress.

By using UV LEDs as UV radiation sources, the properties and advantages of UV LEDs can be used in the curing device according to the invention. For this purpose, a comparatively low consumption of electrical energy, a comparatively low Waste heat, also to protect the coating and/or the glass fiber core of the glass fiber, and associated with it a comparatively high energy efficiency, a comparatively compact installation space and/or a comparatively long service life.

Preferably, the interior surface of the receiving space can be designed to be reflective, at least in sections or completely, in order to be able to distribute the UV radiation as evenly as possible and/or to be able to use it as completely as possible. This can be achieved by means of a mirror coating.

Preferably, a protective tube or a quartz tube such as from the EP 2 388 239 B1 known renounced. This can reduce the complexity of the curing device, since a protective tube can be dispensed with as a component. This aspect of the invention is based on the knowledge that, as described at the beginning, such a protective tube, in particular made of quartz glass, has a very high transparency for UV light and thus the UV light directed onto the coated glass fiber core can largely reach the coating of the glass fiber . Nevertheless, Fresnel losses of approx. 7% per interface can occur at the air-to-glass interface, so that this proportion of the primary radiation does not reach the coating of the glass fiber inside the protective tube or quartz tube as losses, but on the outer wall of the protective tube or quartz tube can be reflected back.

Up to now, the opacity, i.e. the absorption losses, of the quartz glass itself, which occurs in quartz tubes of this type, has also had to be taken into account. Quartz tubes of this type usually have a thickness of at least approx. 2 mm and the UV light of the primary radiation is usually weakened again in this section.

Furthermore, such protective tubes or quartz tubes are usually round and thus represent a curvature for the incident and partially passing UV light of the primary radiation. Consequently, imaging errors can occur here, which can only be compensated for with great effort, if at all.

These effects can individually and especially in combination with each other reduce the effect of the UV light of the primary radiation on the coating of the glass fiber, which can lead to a corresponding loss of quality in curing or to a correspondingly more powerful and/or longer-lasting irradiation in order to achieve the desired result to obtain. This can increase the complexity of the manufacturing process and thus also the cost of the coated glass fiber.

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

At least one UV LED is preferably arranged on the first curing unit and at least one UV LED is arranged on the second curing unit. This can promote uniformity in the generation of UV radiation. In this way, in particular, the design options for generating the UV radiation can be increased.

According to one aspect of 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, particularly preferably all UV LEDs simultaneously, alternatively continuously. This can enable the implementation of previously mentioned aspects of the invention.

According to a further aspect of 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 at the same time, particularly preferably all UV LEDs at the same time, alternatively not to operate. This can enable the implementation of previously mentioned aspects of the invention.

According to a further aspect of the invention, the curing device, preferably the control unit of the curing device, is designed to have at least one UV LED, preferably several UV LEDs at the same time, particularly preferably all UV LEDs at the same time, with such a pulse repetition rate and with such a pulse pause ratio to operate pulsed, so 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 overloading of the material of the glass fiber coating or of the glass fiber core as a result of curing using UV radiation can even be completely ruled out.

According to a further aspect of 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 at the same time, particularly preferably all UV LEDs at the same time, with the maximum operating current of continuous operation. In other words, the curing process, as previously known, can be carried out with UV LEDs or UV LEDs instead of a tubular UV light source and with under refracted irradiation instead of continuous irradiation, as previously described. Using the maximum operating current of the continuous operation of the UV light source, i.e. without excess, can exhaust its possibilities in order to achieve the most intensive possible irradiation and thus the fastest possible curing, albeit a slowdown due to the interruptions in the pulses of the UV light or extension of the curing process of the material of the coating of the glass fiber takes place, in favor of less heating and thus in favor of a more gentle curing of the material of the coating of the glass fiber.

According to a further aspect of 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 at the same time, particularly preferably all UV LEDs at the same time, with an operating current which is preferably at least 25 %, more preferably at least 50%, is greater than a maximum operating current of continuous operation. In other words, in this case the UV-LED or UV-LEDs can be operated with a current that is greater, in particular by 25% or 50%, than the permissible operating current, so that due to the correspondingly greater optical power of the emitted UV -Light the hardening of the material of the coating of the glass fiber compared to an operation of the UV-LED or UV-LEDs with the maximum permissible operating current can be accelerated again. Due to the pulsation, a comparatively gentle hardening of the material of the coating of the glass fiber can nevertheless be achieved. It may also be possible for the UV LED or UV LEDs to exceed the maximum operating current due to the pulsation, i.e. it does not have to lead to damage or destruction or to a reduction in service life.

According to a further aspect of the invention, the UV LEDs are, preferably precisely, designed 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, with the two pluralities of UV-LEDs each extend linearly in the direction of movement of the coated glass fiber and/or wherein the two pluralities of UV-LEDs are arranged diametrically opposite one another perpendicularly to the direction of movement of the coated glass fiber.

The use of a plurality of UV LEDs along the moving direction of the coated optical fiber can be used to cure the coating of the optical fiber by UV light over a correspondingly long distance, which can increase the curing efficiency. Arranging the UV LEDs in a line along the direction of movement of the coated glass fiber can simplify the production of the curing device.

In this way, the use of optical images for the purpose of beam shaping and/or beam deflection can also be dispensed with, so that the coating of the glass fiber can be effectively irradiated with UV light without adjusting the coated glass fiber in a superimposition of the UV radiation can. In this way, an adjustment-free system can be created, which means that corresponding adjustment errors or operating errors can be ruled out and faulty production caused thereby can be avoided.

Arranging the at least two pluralities of UV LEDs diametrically opposite each other perpendicular to the direction of movement of the coated glass fiber can ensure that the coating of the glass fiber can be irradiated and cured with UV light from at least two opposite sides, which can lead to sufficient curing . If exactly two pluralities of UV LEDs are used in this arrangement, the desired curing can be sufficiently effected due to the avoidance of optical imaging losses and the effort for this 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. The curing device according to the invention can be operated correspondingly economically and inexpensively, which can keep the production costs of the glass fiber low.

• • in der Bewegungsrichtung der beschichteten Glasfaser, vorzugsweise unmittelbar benachbart, zueinander versetzt oder
• • senkrecht zur Bewegungsrichtung der beschichteten Glasfaser einander diametral gegenüberliegend

angeordnet sind. Dies kann die Umsetzung zuvor bereits erwähnter Aspekte der Erfindung ermöglichen.According to a further aspect of the invention, the curing device, preferably the control unit of the curing device, is designed 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 in a pulsed manner, wherein the two UV LEDs

• • offset from one another in the direction of movement of the coated glass fiber, preferably immediately adjacent, or
• • perpendicular to the direction of movement of the coated glass fiber, diametrically opposed to each other

are arranged. This can enable the implementation of previously mentioned aspects of the invention.

• • in der Bewegungsrichtung der beschichteten Glasfaser, vorzugsweise unmittelbar benachbart, zueinander versetzt oder
• • senkrecht zur Bewegungsrichtung der beschichteten Glasfaser einander diametral gegenüberliegend

angeordnet sind. Dies kann die Umsetzung zuvor bereits erwähnter Aspekte der Erfindung ermöglichen.According to a further aspect of the invention, the curing device, preferably the control unit of the curing device, is designed to operate at least one UV LED of the first plurality of UV LEDs in a pulsed manner and at the same time to operate at least one UV LED of the second plurality of UV LEDs continuously, wherein the two UV LEDs

• • offset from one another in the direction of movement of the coated glass fiber, preferably immediately adjacent, or
• • perpendicular to the direction of movement of the coated glass fiber, diametrically opposed to each other

are arranged. This can enable the implementation of previously mentioned aspects of the invention.

• • in der Bewegungsrichtung der beschichteten Glasfaser, vorzugsweise unmittelbar benachbart, zueinander versetzt oder
• • senkrecht zur Bewegungsrichtung der beschichteten Glasfaser einander diametral gegenüberliegend

angeordnet sind. Dies kann die Umsetzung zuvor bereits erwähnter Aspekte der Erfindung ermöglichen.According to a further aspect of the invention, the curing device, preferably the control unit of the curing device, is designed to pulse at least one UV LED of the first plurality of UV LEDs and at the same time not operate at least one UV LED of the second plurality of UV LEDs, wherein the two UV LEDs

• • offset from one another in the direction of movement of the coated glass fiber, preferably immediately adjacent, or
• • perpendicular to the direction of movement of the coated glass fiber, diametrically opposed to each other

are arranged. This can enable the implementation of previously mentioned aspects of the invention.

• • in der Bewegungsrichtung der beschichteten Glasfaser, vorzugsweise unmittelbar benachbart, zueinander versetzt oder
• • senkrecht zur Bewegungsrichtung der beschichteten Glasfaser einander diametral gegenüberliegend

angeordnet sind. Dies kann die Umsetzung zuvor bereits erwähnter Aspekte der Erfindung ermöglichen.According to a further aspect of the invention, the curing device, preferably the control unit of the curing device, is designed to operate at least one UV LED of the first plurality of UV LEDs continuously and at the same time at least one UV LED of the second plurality of UV LEDs continuously, wherein the two UV LEDs

• • offset from one another in the direction of movement of the coated glass fiber, preferably immediately adjacent, or
• • perpendicular to the direction of movement of the coated glass fiber, diametrically opposed to each other

are arranged. This can enable the implementation of previously mentioned aspects of the invention.

• • in der Bewegungsrichtung der beschichteten Glasfaser, vorzugsweise unmittelbar benachbart, zueinander versetzt oder
• • senkrecht zur Bewegungsrichtung der beschichteten Glasfaser) einander diametral gegenüberliegend

angeordnet sind. Dies kann die Umsetzung zuvor bereits erwähnter Aspekte der Erfindung ermöglichen.According to a further aspect of the invention, the curing device, preferably the control unit of the curing device, is designed not to operate at least one UV LED of the first plurality of UV LEDs continuously and at the same time at least one UV LED of the second plurality of UV LEDs, wherein the two UV LEDs

• • offset from one another in the direction of movement of the coated glass fiber, preferably immediately adjacent, 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.

• • in der Bewegungsrichtung der beschichteten Glasfaser, vorzugsweise unmittelbar benachbart, zueinander versetzt oder
• • senkrecht zur Bewegungsrichtung der beschichteten Glasfaser einander diametral gegenüberliegend

angeordnet sind. Dies kann die Umsetzung zuvor bereits erwähnter Aspekte der Erfindung ermöglichen.According to a further aspect of the invention, the curing device, preferably the control unit of the curing device, is designed not to operate at least one UV LED of the first plurality of UV LEDs and at the same time not to operate at least one UV LED of the second plurality of UV LEDs, wherein the two UV LEDs

• • offset from one another in the direction of movement of the coated glass fiber, preferably immediately adjacent, or
• • perpendicular to the direction of movement of the coated glass fiber, diametrically opposed to each other

are arranged. This can enable the implementation of previously mentioned aspects of the invention.

According to a further aspect of the invention, the curing device has a first curing unit with a first receiving half-space and a second curing unit with a second receiving half-space, the first receiving half-space of the first curing unit and the second receiving half-space of the second curing unit being designed to jointly form the receiving space of the curing device , and wherein the first curing unit and the second curing unit are designed to be movable relative to one another, preferably translationally, in order to open and close the receiving space of the curing device. Both recording half-spaces can have a semi-circular, oval, triangular, rectangular, quadrangular, hexagonal, other polygonal or other horizontal contour which is suitable for implementing the relevant aspects of the invention. The contour can be consistently the same or different in the vertical direction.

In other words, the curing device or a component of the curing device The device can be designed in at least two parts in such a way that the two curing units can be moved in relation to one another or in relation to another component in such a way that the receiving space can be formed closed or opened and made accessible. This can be done by a purely translational movement of at least one curing unit relative to the other evaluation unit or another component or both curing units relative to one another or a further component, which can keep the movement simple to implement. Alternatively, however, a rotational movement, a pivoting movement or a combined rotational and translational movement can also be used for this purpose. In any case, in this way the receiving space can be opened and closed around a coated glass fiber located there, which can be easier than guiding an open end of a coated glass fiber through an upper opening of the receiving space in preparation for the manufacturing process.

The two curing units can preferably be configured identically, so that one type of curing unit can be used twice. This can reduce the manufacturing cost.

• 1 eine perspektivische Darstellung einer erfindungsgemäßen Aushärtevorrichtung mit geöffnetem Aufnahmeraum;
• 2 die Darstellung der 1 mit geschlossenem Aufnahmeraum;
• 3 eine Draufsicht auf die Aushärtevorrichtung mit geschlossenem Aufnahmeraum;
• 4 eine Frontalansicht auf die Aushärtevorrichtung mit geschlossenem Aufnahmeraum;
• 5 eine Schnittansicht der 4;
• 6 eine Detailansicht des oberen mittleren Bereichs der 5;
• 7 eine seitliche Ansicht auf eine erste Aushärteeinheit der Aushärtevorrichtung;
• 8 eine Detailansicht des oberen mittleren Bereichs der 7;
• 9 eine Detailansicht des mittleren Bereichs der 3 als ersten horizontalen Schnitt;
• 10 eine Detailansicht des mittleren Bereichs der 3 als zweiten horizontalen Schnitt; und
• 11 die Darstellung der 5 mit einer gepulsten Betriebsart aller UV-LEDs beider Aushärteeinheiten;
• 12 die Darstellung der 5 mit ausgeschalteten UV-LEDs der ersten Aushärteeinheit und mit einer gepulsten Betriebsart der UV-LEDs der zweiten Aushärteeinheit;
• 13 die Darstellung der 5 mit einander gegenüberliegenden ausgeschalteten und gepulsten UV-LEDs beider Aushärteeinheiten;
• 14 die Darstellung der 5 mit zueinander versetzten ausgeschalteten und gepulsten UV-LEDs beider Aushärteeinheiten;
• 15 die Darstellung der 5 mit gepulsten UV-LEDs der ersten Aushärteeinheit und mit einer kontinuierlichen Betriebsart der UV-LEDs der zweiten Aushärteeinheit;
• 16 die Darstellung der 5 mit einander gegenüberliegenden gepulsten und kontinuierlich betriebenen UV-LEDs sowie zueinander versetzten ausgeschalteten UV-LEDs beider Aushärteeinheiten; und
• 17 die Darstellung der 5 mit einander gegenüberliegenden gepulsten oder kontinuierlich betriebenen und ausgeschalteten UV-LEDs beider Aushärteeinheiten.

An exemplary embodiment and further advantages of the invention are shown purely schematically and explained in more detail below in connection with the following figures. It shows:

• 1 a perspective view of a curing device according to the invention with open receiving space;
• 2 the representation of 1 with closed recording room;
• 3 a plan view of the curing device with a closed receiving space;
• 4 a front view of the curing device with a closed receiving space;
• 5 a sectional view of 4 ;
• 6 a detailed view of the upper middle area of the 5 ;
• 7 a side view of a first curing unit of the curing device;
• 8th a detailed view of the upper middle area of the 7 ;
• 9 a detailed view of the central area of the 3 as the first horizontal cut;
• 10 a detailed view of the central area of the 3 as a second horizontal cut; and
• 11 the representation of 5 with a pulsed mode of operation of all UV LEDs of both curing units;
• 12 the representation of 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;
• 13 the representation of 5 with opposite UV-LEDs off and pulsed on both curing units;
• 14 the representation of 5 with mutually offset switched off and pulsed UV LEDs of both curing units;
• 15 the representation of 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;
• 16 the representation of 5 with pulsed and continuously operated UV LEDs opposite one another and offset UV LEDs of both curing units that are switched off; and
• 17 the representation of 5 with opposing pulsed or continuously operated and switched off UV LEDs of both curing units.

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

A curing device 1, 2 according to the invention for coating glass fibers 4 has a first curing unit 1 and a second curing unit 2, which are of identical 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 space 11, 21, through which a coated glass fiber 4 can be guided in the vertical direction Z from top to bottom in a movement direction A as part of a manufacturing process. In addition to the two curing units 1, 2, the curing device 1, 2 according to the invention also has rails 3, various fluid and protective 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 for the sake of clarity and clarity of the figures.

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 provided with a coating of plastic such as polyamide, acrylic or silicone or . To cure the coating of the glass fiber 4 using UV light, the coated glass fiber 4 is guided through the receiving space 11, 21 of the curing device 1, 2 and is irradiated using UV light, as will be described in more detail below. The coated glass fiber 4 can then be rolled up with the hardened coating.

As already mentioned above, the two curing units 1, 2 are of identical design, so that the first curing unit 1 is essentially described in detail below and this applies correspondingly to the second curing unit 2.

The first curing unit 1 has a housing 10 which closes off the first curing unit 1 on the outside and which essentially accommodates its elements on the inside. The housing 10 is essentially cuboid and has a semi-circular indentation facing the second curing unit 2 in the transverse direction Y, which forms a first receiving half-space 11 of the first curing unit 1 . 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 the cylindrical receiving space 11, 21 of the curing device 1, 2 in the closed state Glass fiber 4 along the longitudinal axis or central axis (not labeled) of the cylindrical receiving space 11, 21 out through this in the vertical direction Z from top to bottom.

A plurality of UV radiation sources 12 in the form of UV LEDs 12 are arranged linearly one above the other in the vertical direction Z in the middle of the semicircular arc-shaped first recording half-space 11, which can therefore also be referred to as a UV LED row 12. The corresponding UV LEDs 22 of the second curing unit 2 are diametrically opposed to the UV LEDs 12 of the first curing unit 1 with respect to the coated glass fiber 4 or to the longitudinal axis of the cylindrical receiving space 11 , 21 . In this way, the coating of the glass fiber 4 can be irradiated from both sides with UV light as the primary radiation B and thereby hardened. The speed of movement of the coated glass fiber 4 can be matched to the number or the power of the UV LEDs 12, 22 in the vertical direction Z in such a way that the coated glass fiber 4 when exiting the receiving space 11, 21 of the curing device 1, 2 has a fully cured coating.

Compared to known curing devices 1, 2 for coating glass fibers 4, there is no need to adjust the coated glass fiber 4 relative to the usually tubular UV radiation sources, which means that the effort involved in adjustment or adjustment and the errors caused thereby can be avoided. The advantageous properties of UV LEDs 12, 22 such as comparatively low energy consumption, comparatively low heat loss, comparatively small installation space, comparatively little heating of the coating of the coated glass fiber 4 and/or a comparatively long service life can also be used.

In order to be able to operate the UV LEDs 12, 22 of the two curing units 1, 2 during operation at a predetermined temperature and at least to protect them from overheating, the curing device 1, 2 according to the invention has two fluid lines running in the vertical direction Z per curing unit 1, 2 13a, 23a 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 in each case formed by a particularly good thermally conductive material in order to transfer the heat away from the UV LEDs 12, 22 into the area of the To favor fluid lines 13a, 23a, or vice versa.

The cooling water lines 13a, 23a each have fluid connections 13 in the form of cooling water connections 13, 23 at their ends. The total of eight cooling water connections 13, 23 are each connected to flexible hoses. Cooling water can be fed to the two curing units 1 , 2 as a fluid via half of the cooling water connections 13 , 23 . About the other half of the cooling water Connections 13, 23 allow the cooling water to be discharged from the respective curing unit 1, 2 after it has flowed through it and, if necessary, cooled down or tempered again. The cooling water can be supplied or removed from the curing device 1, 2 by means of appropriate pumps, hoses and heat exchangers and the like (not shown).

In the simplest case, the heat generated by the UV LEDs 12, 22 during operation can be dissipated to a certain extent in this way via the cooling water in order to increase the longevity of the UV LEDs 12, 22 or to avoid overheating of the UV LEDs 12, 22, 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, at least a certain stable operating point can be achieved during the operation of the curing device 1, 2 or during the manufacturing process of the coated glass fiber 4.

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

In addition, this relationship between the wavelength of the primary radiation B emitted by the UV LEDs 12, 22 and its operating temperature can be used to keep the UV LEDs 12, 22 within a certain range by controlling the temperature of the cooling water to a predetermined temperature to operate with a predetermined wavelength. For this purpose, a temperature sensor 15, 25 is arranged immediately next to each UV LED 12, 22 of both curing units 1, 2, so that a temperature in the immediate vicinity of each UV LED 12, 22 can be detected by sensors via the temperature sensors 15, 25 , Which of the respective UV-LED 12, 22 can be attributed. By means of a control unit (not shown) of the curing device 1, 2, the temperatures of all UV LEDs 12, 22 can be detected and in relation to a predetermined temperature, which corresponds to a predetermined wavelength of the primary radiation B, for controlling the temperature and/or the Flow rate of the cooling water can be used. The temperature of the cooling water can therefore also be comparatively high and for this purpose the cooling water can even be heated by the curing device 1, 2 in order to be able to set the predetermined wavelength of the primary radiation B. Correspondingly, instead of cooling the UV LEDs 12, 22, one can also speak of temperature control of the UV LEDs 12, 22, since the cooling water or the fluid can also be heated.

This can make it possible to influence the wavelength of the primary radiation B in a predetermined manner solely by controlling the temperature of the fluid or the cooling water. As a result, the UV LEDs 12, 22 can be operated to a certain extent with different predetermined wavelengths of the primary radiation B, so that different coatings of the glass fiber 4 can be used and cured effectively by means of the UV light of the primary radiation B.

The two curing units 1, 2 also each have two protective gas lines 14a, 24a, which can also receive or release a protective gas at both ends via protective gas connections 14, 24. The total of 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 is made available from a source such as a tank (not shown) and by means of at least one Pump (not shown) half of the protective gas lines 14a, 24a can be supplied by funding. In comparison, the other half of the protective gas lines 14a, 24a lead via hoses to at least one pump (not shown), which sucks in the protective gas and can discharge it into a reservoir (not shown).

The total of four protective gas lines 14a, 24a run in the vertical direction Z parallel to the respective receiving half-space 11, 21 of the respective curing unit 1, 2. Two protective gas branches 14b, 24b in a straight line or radially away from the respective protective gas lines 14a, 24a and each open out in the form of a protective gas opening 14c, 24c into the respective receiving half-space 11, 21. If the corresponding protective gas line 14a, 24a is supplied with the protective gas, the protective gas can flow through all the protective gas openings 14c , 24c, which are connected to this protective gas line 14a, 24a via the protective gas branches 14b, 24b, reach the corresponding receiving half-space 11, 21. These inert gas openings 14c, 24c can correspondingly be referred to as inert gas openings 14c, 24c for inflow or as inert gas inlets 14c, 24c. If the protective gas via the corresponding protective gas line 14a, 24a discharged or sucked out of the corresponding receiving half-space 11, 21, these inert gas openings 14c, 24c can accordingly be referred to as inert gas openings 14c, 24c for escaping or as inert gas outlets 14c, 24c.

The configuration of the two curing units 1, 2 with regard to the protective gas openings 14c, 24c, which are used to flow in and suck off the protective gas into the receiving space 11, 21 of the curing device 1, 2, can be done quickly and easily by connecting the hoses for guiding the protective gas be made or changed. For example, per curing unit 1, 2, one protective gas line 14a, 24a can be used for the inflow and the other protective gas line 14a, 24a for the protective gas to escape. This can be done crosswise in the horizontal X, Y, for example, so that, viewed in the circumferential direction around the coated glass fiber 4, the protective gas openings 14c, 24c for inflow and the protective gas openings 14c, 24c for escaping alternate.

In this way, according to the invention, the protective gas can be distributed as evenly as possible over the entire receiving space 11, 21 of the curing device 1, 2, both in the vertical direction Z and within the horizontal planes X, Y, and fed to the coated glass fiber 4 in order to facilitate the curing of the To be able to coat the glass fiber 4 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, the protective gas, including the noxious vapors that may arise during the process of curing the coating of the glass fiber 4, can be prevented from escaping, discharging or sucking off the protective gas from the receiving space 11, 21 into the surroundings of the curing units 1, 2 can.

In addition, the temperature of the protective gas inside the receiving space 11, 21 can also be detected by means of the temperature sensors 15, 25 described above. On the part of the curing device 1, 2, the protective gas can be heated to a predetermined temperature before it flows into the receiving space 11, 21, which can promote the curing of the coating of the glass fiber 4. As a result, the reaction speed or the polymerization speed of the coating of the glass fiber 4 can be influenced and, in particular, increased by an increased temperature. This can make it possible to increase the speed of drawing the glass fiber 4 from the preform and thereby the production speed of the coated glass fiber 4, which can lead to increased productivity of the entire manufacturing process and thus to reduced production costs for the coated glass fiber 4.

To operate the two curing units 1, 2, they can be connected via control lines (not shown) to control connections 16, 26 of their housings 10, 20 with the control unit of the curing device 1, 2 in a signal-transmitting manner. As a result, at least the temperature sensors 15, 25 and the UV LEDs 12, 22 can be operated and controlled. The two curing units 1, 2 can also be connected via electrical supply lines (not shown) to the control unit of the curing device 1, 2 or to another electrical energy supply source via corresponding electrical supply connections 17, 27 in order to at least LEDs 12, 22 to be able to supply electricity.

Furthermore, the curing device 1, 2 according to the invention is based on the knowledge that the heating of the coated glass fiber, i. H. both the material of the glass fiber coating and the material of the glass fiber core itself, can be reduced or regulated in that the UV LEDs 12, 22 are not operated continuously but are pulsed or not operated. These three operating modes of pulsed operation, continuous operation and the switched-off state or non-operation can be used for individual UV LEDs 12, 22 and for pairs or groups of UV LEDs 12, 22 both along the direction of movement A as well as 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 from the UV LEDs 12, 22 and at the same time to reduce the thermal load on the material or materials of the coated glass fiber 4 to be kept low or to avoid thermal overload. These operating modes or operating modes of the UV LEDs 12, 22 can be implemented or undertaken by the previously mentioned control unit of the curing device 1, 2 according to the invention.

This is how it shows 11 a representation of 5 , in which all UV LEDs 12, 22 of both curing units 1, 2 are operated in a pulsed manner, so that all pulses are present at the same time and thus act simultaneously on the coated glass fiber 4, i.e. the UV LEDs 12 of the first curing unit 1 and the UV LEDs 22 the second curing unit 2 are operated synchronously pulsed. The pulses of all UV LEDs 12, 22 are thus synchronized with one another, so that the switched-on and switched-off phases are of the same length and take place in parallel or simultaneously. This allows a reduced but the still comparatively high curing by means of UV radiation and thus a further comparatively rapid curing with nevertheless at least somewhat reduced heating of the coated glass fiber 4.

the 12 shows a representation of the 5 , in which only the UV LEDs 22 of the second curing unit 2 are operated in a pulsed manner and the UV LEDs 12 of the first curing unit 1 are switched off. As a result, the effective UV radiation can be significantly reduced, with the side of the coated glass fiber 4 opposite the UV LEDs 22 of the second curing unit 2 being able to be reached by UV radiation from the UV LEDs 22 of the second curing unit 2, which is transmitted from the inner surface of the first receiving space 11 of the first curing unit 1 can be reflected. In order to promote this, the two receiving spaces 11, 21 can be provided with a reflective coating.

the 12 can also be a representation for 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 configured phases are not at the same time and in particular are exactly offset from one another, see above 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 enables asynchronous operation of the UV LEDs 12 of the first curing unit 1 and of the UV LEDs 22 of the second curing unit 2 represents. This represents a comparable process as using the 11 described, wherein 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 slows down the curing but also reduces the thermal load.

the 13 shows a representation of the 5 , in which the upper and lower UV LEDs 12, 22 of the two curing units 1, 2 in the vertical direction Z are operated in a synchronously pulsed manner and the middle UV LEDs 12, 22 lying in between along the direction of movement A are switched off. As a result, the material or materials of the coated glass fiber 4 can cool down again during the movement in the direction of movement A through the receiving space 11, 21 in its central area before the lower UV LEDs 12, 22 of the two curing units 1, 2 can act on the coated glass fiber 4 in a pulsed manner.

the 13 can also be a representation of pulsed operation both of the UV LEDs 12 of the first curing unit 1 and of the UV LEDs 22 of the second curing unit 2, in which the switched-on and switched-off phases are not at the same time but between the upper and lower groups of UV LEDs 12, 22 and the intermediate middle group of UV LEDs 12, 22 are offset from one another 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 to the respective middle UV LEDs 12, 22, which can lead to comparatively rapid curing with comparatively high heating, which, however, is less than before are known.

the 14 shows a representation of the 5 , in which the pulsed-operated UV LEDs 12, 22 of the two curing units 1, 2 are exactly offset from one another in the direction of movement A and the corresponding opposite UV LEDs 12, 22 in the transverse direction Y are switched off. As a result, both sides of the coated glass fiber 4 can be alternately pulsed and cured.

the 14 can also be a representation of pulsed operation both of the UV LEDs 12 of the first curing unit 1 and of the UV LEDs 22 of the second curing unit, in which the switched-on switched-off phases are not at the same time but alternate along the direction of movement A with the first Curing unit 1 or the second curing unit 2 are present, so that alternately 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 in the switched-on phase, or vice versa, ie operated asynchronously. This allows compared to the operation according to the 13 curing is slowed down but at the same time the thermal load is reduced.

the 15 shows a representation of the 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. As a result, the right side of the coated glass fiber 4 in the transverse direction Y can be cured and heated continuously with UV radiation, while the opposite left side of the coated glass fiber 4 in the transverse direction Y is cured and heated in a pulsed manner.

the 16 and 17 show more representations of 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 with completely out switched UV LEDs 12, 22 of the two curing units 1, 2 are combined.

In any case, by using the 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 Movement direction A is achieved and at the same time the thermal load is reduced, since at least in 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 load or avoid thermal overload, which can be of great importance in particular for coated glass fibers 4 with a comparatively low melting point of the material of the coating and/or the fiber core. Overall, due to the numerous combination and variation options, 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, the design options for curing and heating the coated glass fiber 4 can be clearly compared the hitherto known purely continuous operation of the UV radiation source or all UV radiation sources.

In order to be able to make the receiving space 11, 21 of the curing device 1, 2 more easily accessible, the two curing units 1, 2 are each movably arranged on a common pair of rails 3, which extends horizontally in the transverse direction Y. The rails 3 can be arranged in a stationary manner on a frame of the fiber drawing tower, so that the two curing units 1, 2 each extend outwards in the transverse direction Y away from the longitudinal axis of the coated glass fiber 4, relative to the longitudinal axis of the coated glass fiber 4 running in the vertical direction Z, or can be proceeded towards this. The two curing units 1, 2 can be moved by electric drives of the curing units 1, 2, which can also be operated and controlled or electrically supplied by the control unit of the curing device 1, 2, as described above. However, such electrical drives can be provided on the side of the rails 3 in order to keep the effort and the weight of the two curing units 1, 2 low.

If the two curing units 1, 2 are moved towards the longitudinal axis of the coated glass fiber 4, the receiving space 11, 21 can be closed as a result. In this position, the two curing units 1, 2 can also be secured mechanically on the outside of their housings 10, 20 (not shown). In this state, the manufacturing process of the coated glass fiber can be carried out as described above. Gas-tight sealing of the closed receiving space 11, 21 in the longitudinal direction X can be ensured by seals made of rubber, for example, running in the vertical direction Z.

If the two curing units 1, 2 are moved away from one another in the transverse direction Y, the receiving space 11, 21 can be opened as a result. The two receiving half-spaces 11, 21 of the two curing units 1, 2 are sufficiently spaced apart from one another in the transverse direction Y, so that a coated glass fiber 4 can be positioned in the longitudinal direction X between the two receiving half-spaces 11, 21 of the two curing units 1, 2. In this way it can be avoided that a coated glass fiber 4 has to be introduced in the vertical direction Z from above into a permanently closed receiving space of a known curing device, which can be comparatively costly and complicated.

reference list

A

direction of movement; drag direction

B

primary radiation

X

longitudinal direction; Depth; length

Y

transverse direction; Broad

Z

vertical direction; Height

X, Y

Horizontal; horizontal plane

pulsed mode

continuous mode of operation

switched off; no operation

1, 2

Curing device for coatings of glass fibers 4

11, 21

recording room

1

first curing unit; first curing module

10

Housing

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 pipes

14

shielding gas connections

14a

protective gas lines

14b

inert gas branches

14c

protective gas openings; protective gas inlets; shielding gas outlets

15

temperature sensors

16

control connections

17

electrical supply connections

2

second curing unit; second curing module

20

Housing

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 pipes

24

shielding gas connections

24a

protective gas lines

24b

inert gas branches

24c

protective gas openings; protective gas inlets; shielding gas outlets

25

temperature sensors

26

control connections

27

electrical supply connections

3

rails

4

coated fiberglass

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US4710638A [0007]
• US 6419749 B1 [0008]
• US9132448B2 [0009]
• US8604448B2 [0015]
• EP 2388239 B1 [0016, 0022, 0023, 0037]

Claims (14)

Curing device (1, 2) for coatings of glass fibers (4) with a receiving space (11, 21) for guiding a coated glass fiber (4) through in a direction of movement (A), the receiving space (11, 21) having a plurality of UV radiation sources (12, 22) which are designed to cure the coating of the glass fiber (4) by means of UV light, characterized in that the UV radiation sources (12, 22) are UV LEDs (12, 22), the curing device (1, 2), preferably a control unit of the curing device (1, 2), at least one UV LED (12, 22), preferably several UV LEDs (12, 22) at the same time, particularly preferably all UV LEDs (12, 22) to be operated at the same time in a pulsed manner. Curing device (1, 2) after claim 1 , characterized in that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is designed to have at least one UV LED (12, 22), preferably several UV LEDs (12, 22) at the same time, particularly preferably to operate all UV LEDs (12, 22) at the same time, alternatively continuously. Curing device (1, 2) after claim 1 or 2 , characterized in that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is designed to have at least one UV LED (12, 22), preferably several UV LEDs (12, 22) at the same time, particularly preferably all UV LEDs (12, 22) at the same time, alternatively not to be operated. Curing device (1, 2) according to one of the preceding claims, characterized in that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is designed to have at least one UV LED (12, 22), preferably to operate several UV LEDs (12, 22) at the same time, particularly preferably all UV LEDs (12, 22) at the same time, with such a pulse repetition rate and with such a pulse-pause ratio, so that the pulse duration is shorter than the thermal relaxation time of the material of the fiberglass coating and/or the fiberglass. Curing device (1, 2) according to one of the preceding claims, characterized in that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is designed to have at least one UV LED (12, 22), preferably to operate several UV LEDs (12, 22) at the same time, particularly preferably all UV LEDs (12, 22) at the same time, with the maximum operating current of continuous operation. Curing device (1, 2) according to one of Claims 1 until 4 , characterized in that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is designed to have at least one UV LED (12, 22), preferably several UV LEDs (12, 22) at the same time, particularly preferably to operate all UV LEDs (12, 22) at the same time with an operating current which is preferably at least 25%, particularly preferably at least 50%, greater than a maximum operating current of continuous operation. Curing device (1, 2) according to any one of the preceding claims, characterized in that the UV LEDs (12, 22), preferably precisely, as a first plurality of UV LEDs (12), preferably the first curing unit (1), and as second plurality of UV LEDs (22), preferably of the second curing unit (2), wherein the two plurality of UV LEDs (12, 22) each extend linearly in the direction of movement (A) of the coated glass fiber (4). and/or wherein the two pluralities of UV LEDs (12, 22) are arranged diametrically opposite one another perpendicularly to the direction of movement (A) of the coated glass fiber (4). Curing device (1, 2) after claim 7 , characterized in that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is designed to pulse at least one UV LED (12) of the first plurality of UV LEDs (12) and at the same time at least one UV-LED (22) of the second plurality of UV-LEDs (22) to be operated in a pulsed manner, the two UV-LEDs (12, 22) • in the direction of movement (A) of the coated glass fiber (4), preferably immediately adjacent to one another offset or • perpendicular to the direction of movement (A) of the coated glass fiber (4) are arranged diametrically opposite one another. Curing device (1, 2) after claim 7 or 8th , characterized in that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is designed to pulse at least one UV LED (12) of the first plurality of UV LEDs (12) and at the same time at least one operate UV-LED (22) of the second plurality of UV-LEDs (22) continuously, the two UV LEDs (12, 22) • in the direction of movement (A) of the coated glass fiber (4), preferably immediately adjacent, offset from one another or • perpendicular to the direction of movement (A) of the coated glass fiber (4) are arranged diametrically opposite one another . Curing device (1, 2) according to one of Claims 7 until 9 , characterized in that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is designed to pulse at least one UV LED (12) of the first plurality of UV LEDs (12) and at the same time at least one UV-LED (22) of the second plurality of UV-LEDs (22) not to be operated, the two UV-LEDs (12, 22) • in the direction of movement (A) of the coated glass fiber (4), preferably immediately adjacent to one another offset or • perpendicular to the direction of movement (A) of the coated glass fiber (4) are arranged diametrically opposite one another. Curing device (1, 2) according to one of Claims 7 until 10 , characterized in that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is formed, 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) to be operated continuously, the two UV-LEDs (12, 22) • in the direction of movement (A) of the coated glass fiber (4), preferably immediately adjacent to one another offset or • perpendicular to the direction of movement (A) of the coated glass fiber (4) are arranged diametrically opposite one another. Curing device (1, 2) according to one of Claims 7 until 11 , characterized in that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is formed, 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) not to be operated, the two UV-LEDs (12, 22) • in the direction of movement (A) of the coated glass fiber (4), preferably immediately adjacent to one another offset or • perpendicular to the direction of movement (A) of the coated glass fiber (4) are arranged diametrically opposite one another. Curing device (1, 2) according to one of Claims 7 until 12 , characterized in that the curing device (1, 2), preferably the control unit of the curing device (1, 2), is designed to have at least one UV LED (12) of the first plurality of UV LEDs (12) and at the same time at least one UV-LED (22) of the second plurality of UV-LEDs (22) not to be operated, the two UV-LEDs (12, 22) • in the direction of movement (A) of the coated glass fiber (4), preferably immediately adjacent to one another offset or • perpendicular to the direction of movement (A) of the coated glass fiber (4) are arranged diametrically opposite one another. Curing device (1, 2) according to one of the preceding claims, characterized in that the curing device (1, 2) has 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 half-receiving space (11) of the first curing unit (1) and the second half-receiving space (21) of the second hardening unit (2) are designed to jointly form the receiving space (11, 21) of the hardening device (1, 2), and wherein the first curing unit (1) and the second curing unit (2) are designed to be movable relative to one another, preferably translationally, in order to open and close the receiving space (11, 21) of the curing device (1, 2).

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