An illumination optical fiber and a method of making the same

Abstract

The application discloses an illuminating optical fiber and a preparation method thereof. The illuminating optical fiber is prepared by heating and drawing a preform rod, and cooling to prepare glass fibers. The glass fibers are a plurality of single glass fibers which do not cross and contact each other. Then, the glass fibers are coated to form glass optical fibers. The glass optical fibers are bundled and sheathed to obtain the illuminating optical fiber. The illuminating optical fiber provided by the application obviously reduces the problem of breakage of the existing glass fiber optical fiber, avoids cutting processing caused by the breakage, and especially ensures that the illuminating optical fiber emits light without breakage after being installed in an automobile or after being installed on an external lamp, so that the application is facilitated.

Description

Technical Field

[0001] This invention relates to flexible lighting technology, and mainly to a glass fiber lighting material, specifically a lighting optical fiber and its preparation method. Background Technology

[0002] One important application of optical fiber for lighting is influencing the ambiance and enhancing the interior's sophistication. Typically installed in concealed areas, its slender shape necessitates high standards for uniform light emission, brightness, and color accuracy. Optical fiber guides light through side emission, offering advantages such as flexibility, high design freedom, and the elimination of complex optical designs, reducing mold costs. Based on materials, lighting optical fibers are categorized into glass optical fibers and polymer optical fibers. Glass lighting optical fibers consist of bundles of numerous glass fibers forming a flexible light guide, offering advantages over polymer optical fibers such as robustness, durability, and high brightness, while also eliminating the yellowing issue. Currently, the industrial supply of glass optical fibers is limited, primarily relying on a single foreign supplier.

[0003] DE10013482C2 describes a method for manufacturing an optical fiber guide, the optical fiber guide comprising a bundle of optical fibers that is contracted in a glass sleeve at a suitable temperature before being introduced into a tube, wherein the glass sleeve is removed from the fiber bundle after fiber contraction and before the fibers are introduced into the tube, and wherein an interlayer is introduced between the fiber bundle and the glass sleeve before contraction, such that the glass sleeve is better removed from the fiber bundle after contraction. DE19703515C1 describes an optical fiber guide composed of a fiber bundle, the fiber bundle being insertable into a predetermined tube at at least one end and subjected to optically efficient processing. It is specified that the end insertable into the predetermined tube is contracted before being introduced into the glass sleeve and the glass sleeve has been removed before that end is introduced into the predetermined tube.

[0004] Currently, a problem with optical fibers used for lighting, especially for automotive interior lighting, is the presence of breaks in the fiber optic cable. This results in material waste in some cases, and rework after the interior trim is installed in others. Given these shortcomings, reducing or even eliminating the breakage problem in optical fibers without affecting lighting performance is a key focus of research in this field. Summary of the Invention

[0005] This invention provides an optical fiber for illumination and its fabrication method, which has excellent applications in automotive interior and exterior lighting. The invention involves heating and drawing a preform into glass fibers, which are then cooled to obtain a plurality of individual glass fibers that do not cross or contact each other. These glass fibers are then coated to form glass optical fibers. After bundling and sheathing, the glass optical fibers are obtained as the illumination optical fiber. The illumination optical fiber provided by this invention significantly reduces the problem of fiber breakage in existing glass fibers, avoiding the need for cutting due to breakage. In particular, it ensures that the illumination optical fiber emits light without breaks after installation in automotive interiors or as external lights, which is beneficial for its widespread application.

[0006] The present invention adopts the following technical solution.

[0007] An optical fiber for illumination includes a bundle of glass fibers; the bundle of glass fibers includes a plurality of glass fibers; the glass fibers include glass fibers and a coating layer; the glass fibers are prepared by heating, drawing, and cooling a preform.

[0008] In this invention, the illumination optical fiber has a glass fiber bundle as its core and also includes a sleeve; the sleeve is sleeved on the outer wall of the glass fiber bundle, and the specific sleeved method is a conventional technique.

[0009] This invention discloses a method for preparing the above-mentioned lighting optical fiber, comprising the following steps: heating, drawing, and cooling a preform to prepare glass fiber, wherein the preform consists of multiple preforms and the glass fiber consists of multiple single glass fibers that do not cross or contact each other; then coating the glass fibers to form a glass optical fiber; and then bundling and sheathing the glass optical fibers to obtain the lighting optical fiber.

[0010] This invention discloses a glass fiber bundle comprising a plurality of glass optical fibers; the glass optical fibers include glass fibers and a coating layer; the glass fibers are prepared by heating, drawing, and cooling a preform.

[0011] This invention discloses a method for preparing the above-mentioned glass fiber bundle, comprising the following steps: preparing glass fibers by heating and drawing a preform rod and cooling it, wherein the glass fibers are multiple single glass fibers that do not cross or contact each other; then coating the glass fibers to form glass optical fibers; and then bundling the glass optical fibers to obtain a glass fiber bundle.

[0012] This invention discloses a glass optical fiber, comprising glass fiber and a coating layer; the glass fiber is prepared by heating, drawing and cooling a preform.

[0013] This invention discloses a method for preparing the above-mentioned glass optical fiber, which includes the following steps: heating and drawing a preform into glass fibers and cooling them to prepare glass fibers, wherein the glass fibers are multiple single glass fibers that do not cross or contact each other; and then coating and curing the glass fibers to form glass optical fibers.

[0014] In this invention, the apparatus used for producing glass fibers (glass optical fibers, glass optical fiber bundles, and lighting optical fibers) is all conventional equipment, briefly described as follows: A preform is introduced into the heating bushing of a fiber furnace for heating, and the glass fibers are drawn so that they do not cross or contact each other. The glass fibers are then annealed and cooled downstream of the fiber furnace. Next, the glass fibers are passed through a coating liquid, and a coating layer is formed after impregnation. The glass optical fibers are then conveyed to a bundling assembly device, bundled, and conventionally sleeved to obtain the lighting optical fiber. The preform is an existing product, a glass material rod with a predetermined diameter.

[0015] In this invention, the temperature during heating and drawing is 800-2100℃; preferably, the temperature during heating and drawing is 800-1200℃ or 1800-2100℃, depending on the material of the preform.

[0016] In this invention, the wire drawing speed is 50-500 m / min; preferably, the wire drawing speed is 80-400 m / min; more preferably, the wire drawing speed is 100-300 m / min; and even more preferably, the wire drawing speed is 150-250 m / min.

[0017] In this invention, cooling is performed by means of cooling and / or natural air cooling; preferably, the cooling is performed in multiple stages, such as two-stage cooling, three-stage cooling, four-stage cooling, etc.

[0018] In this invention, the diameter of the glass fiber is 40-100 micrometers; preferably, the diameter of the glass fiber is 50-90 micrometers; more preferably, the diameter of the glass fiber is 60-80 micrometers, such as 65 micrometers, 70 micrometers, 75 micrometers or any data within the range.

[0019] In this invention, an impregnation method is used to coat glass fibers. The glass fibers are passed through a coating liquid to achieve impregnation, and a coating layer is formed on the surface of the glass fibers. The product is a glass optical fiber.

[0020] In this invention, the thickness of the coating layer is 0.1-20 micrometers; preferably, the thickness of the coating layer is 0.2-10 micrometers; more preferably, the thickness of the coating layer is 0.2-5 micrometers.

[0021] In this invention, the coating material is one or more olefin polymers. Preferably, the coating material is a polyolefin elastomer, such as POE.

[0022] Typically, optical fibers are coated with a protective layer. Generally, the optical fiber is provided with a polymerizable coating composition. Prior art describes a coating that may contain silanes, such as polyalkoxysilanes and polyhalosilanes, or halides, such as chlorides or fluorides; furthermore, it may contain polyether-urethane-acrylate as a main component. Prior art describes a UV-curable coating containing photopolymerizable compounds, such as caprolactone (meth)acrylate or 4-hydroxybutyl (meth)acrylate. It also contains a photoinitiator, such as 1-hydroxycyclohexylphenyl ketone or 2,2-dimethoxy-2-phenylacetophenone. In the prior art, such coating compositions typically contain acrylates, methacrylates, and other polymerizable components; however, conventional coatings have limited ability to improve the breakage resistance of glass optical fibers. Therefore, there is a need for improved coating materials to enhance the breakage resistance of glass optical fibers. The coating combined with the sheath of this invention has a long service life and good bending strength, which is beneficial for improving the breakage problem of glass optical fibers.

[0023] In this invention, the clustering and sheathing are existing technologies and do not affect the understanding of the technological advancements of this invention by those skilled in the art.

[0024] This invention discloses the application of the above-mentioned lighting optical fiber or glass optical fiber bundle, glass optical fiber, and glass fiber in light-emitting devices.

[0025] This invention discloses the application of the above-mentioned lighting optical fiber or glass optical fiber bundle, glass optical fiber, and glass fiber in automotive lighting devices.

[0026] This invention discloses the application of the above-mentioned lighting optical fiber or glass optical fiber bundle, glass optical fiber, and glass fiber in automotive decorative lighting devices.

[0027] In this invention, automotive decoration includes interior trim, exterior trim, existing decorative positions, and components.

[0028] The present invention discloses an illumination device, including the above-mentioned illumination optical fiber.

[0029] This invention discloses an automotive trim component, including the aforementioned optical fiber for lighting.

[0030] The fabrication of optical fibers from glass preforms has been reported for some time. Currently, the market supply of glass optical fibers is mainly from a single foreign supplier, which enjoys a good market reputation. However, a problem exists in practical applications: the breakage defect in glass optical fibers. This is especially true for automotive decorative lights that require longer dimensions or bending, where the breakage problem needs to be addressed and resolved. This invention offers the following advantages: Existing technologies for addressing glass optical fiber breakage mostly employ cutting methods, leading to high costs and significant waste. Furthermore, once the decorative finish is complete, rework and scrap costs increase dramatically. This invention begins with the preparation of glass fibers through heating, drawing, and annealing, combined with coating to form a coating layer, followed by conventional bundling and sheathing, resulting in a new type of lighting optical fiber. This unexpectedly alleviates the breakage problem in glass optical fibers, exhibiting good breakage resistance in both finished products and bending tests. Simultaneously, its wide applicability facilitates scientific research and large-scale production. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of an illumination fiber optic cable.

[0032] Figure 2 This is a photograph of a glass fiber bundle.

[0033] Figure 3 This is a photograph of the actual lighting optical fiber of the present invention.

[0034] Figure 4 This invention relates to a test of the color temperature performance of the lighting optical fiber before and after aging.

[0035] Figure 5 This is a diagram showing the optical flux measurement of the lighting fiber optic cable according to the present invention.

[0036] Figure 6 This is a photograph of the optical fiber after it has been lit up according to the present invention.

[0037] Figure 7 The results are for the fiber optic break point test, which is a control example.

[0038] Figure 8 The results of the fiber optic bending test are shown in this invention.

[0039] Figure 9 Photographs of existing POF illumination fiber bending tests. Detailed Implementation

[0040] Currently, glass fiber is used as a light guide due to its advantages, such as in automotive interiors. However, a problem exists: breakage points. This invention prepares glass fibers by heating, drawing, and cooling preforms. The glass fibers obtained from multiple preforms are multiple individual glass fibers that do not cross or contact each other. These glass fibers are then coated to form glass optical fibers. After bundling and sheathing, the glass optical fibers are obtained as lighting optical fibers. The lighting optical fiber provided by this invention significantly reduces the breakage problem of existing glass fiber optical fibers, avoiding cutting processes caused by breakage points. In particular, it ensures that the lighting optical fiber emits light without breakage points after installation in automotive interiors or as external lights, which is beneficial for its widespread application.

[0041] Specifically, this invention involves heating, drawing, and cooling a preform to prepare glass fibers. The glass fibers consist of multiple individual glass fibers that do not cross or contact each other. These glass fibers are then coated to form glass optical fibers. The glass optical fibers are then bundled and sheathed to obtain illumination optical fibers. (See [link to previous section]). Figure 1 The diagram shows its structure. When in use, optical coupling terminals are typically installed.

[0042] Compared to traditional single-fiber drawing technology, this invention draws multiple preforms to obtain multiple individual glass fibers, thus improving fiber production efficiency. For example, drawing 80 fiber preforms simultaneously increases efficiency by approximately 10 times. Furthermore, it ensures the performance consistency of different glass fibers. Multi-preform drawing significantly reduces fiber surface defects and breakage rates caused by multiple fiber bundling processes. Existing technologies using single-preform drawing (ultimately producing 80 fibers) have a breakage rate as high as 17.9 / km. Moreover, multi-preform drawing saves 80% of effective cleanroom space, and a centralized drawing furnace energy management system solves 90% of energy consumption issues (taking 80 fibers as an example).

[0043] The following examples are used to illustrate this application, but are not intended to limit the scope of this application.

[0044] Specific embodiments of this application will now be described in more detail. These embodiments are provided to provide a thorough understanding of this application and to fully convey its scope to those skilled in the art. The scope of protection of this application shall be determined by the appended claims.

[0045] The reagents and raw materials used in this invention are all existing products. The specific preparation operations and performance tests are all conventional techniques, meeting the conventional requirements for optical fiber fabrication. The coating and sheath materials are consistent, both being polyolefin elastomers, specifically POE (POE 5101). In this invention, the apparatus used to produce glass fibers (glass optical fibers, glass optical fiber bundles, lighting optical fibers) is all conventional equipment, briefly described as follows: A preform is introduced into the heating bushing of a fiber furnace for heating, and the glass fibers are drawn without crossing or contacting each other. The glass fibers are then annealed and cooled downstream of the fiber furnace. Next, the glass fibers are passed through a coating liquid to impregnate and form a coating layer. The glass optical fibers are then transferred to a bundling assembly device, and after bundling, conventional extrusion (POE sheath) is performed to obtain the lighting optical fiber. The preform is an existing product, a glass material rod with a predetermined diameter, a commercially available product (Heraeste). During production, those skilled in the art can also prepare it according to conventional methods (PCVD, MCVD, etc.), selecting the drawing temperature based on the material.

[0046] Fiber optic bundle trays can be made by extruding a 0.1-0.5mm thick plastic sheath layer, such as POE material, onto the outside of the fiber optic sheathing equipment. Specifically, there are 5-20 fiber optic bundle trays, which are installed sequentially on the sheathing equipment. The fiber bundles on each tray are then guided to the take-up tray by guide wheels and sheath molds. The sheath molds can be adjusted to different diameter molds according to actual needs, which can produce optical guides with different outer diameter sheaths.

[0047] Breakpoint detection: Connecting the glass fiber or lighting fiber to the LED light source is a standard technique. After illumination, visually inspect for breaks. Generally, finished fiber rolls (usually 600 meters) are cut into 50-meter segments or other lengths, and terminals are added. Breakpoints are then measured using a fiber breakpoint tester. The total number of breaks is divided by the length of the fiber roll to obtain the number of breaks per meter, which is then converted to the conventional kilometer value in this field.

[0048] Example 1 A method for fabricating an illumination optical fiber includes the following steps: (1) 90 optical fiber preforms (silica-based) are fixedly installed in the drawing tower and in the heating bushing of the fiber furnace; (2) Heat the preform at 1950℃ and draw glass fibers at a speed of 200m / min; (3) The drawn glass fiber enters the annealing zone and is subjected to three-stage annealing temperature control at 1100℃-1000℃-900℃ (one meter each), and then is naturally cooled in the air; (4) After annealing, the glass fiber is passed through the coating liquid (POE melt) and then naturally cooled in the air to be coated, resulting in glass optical fiber with a fiber diameter of 65±1 micrometers and a coating thickness of 2 micrometers. (5) After coating, the glass fiber is pulled by the traction wheel and passes through the torque wheel and multi-stage bundler in sequence to form a glass fiber bundle, which is then wound onto the take-up reel. See the product fiber bundle photo. Figure 2 This is a standard technique.

[0049] When the above-mentioned glass fiber bundle is connected to an LED light source, it is observed with the naked eye at a distance of 50cm that there are no bright spots, i.e., no breaks. (6) Extrude a POE sheath (0.2 mm) onto the glass fiber bundle to obtain the illumination fiber, see [reference]. Figure 3 This is a standard technique.

[0050] As is common knowledge, the feed unit controls the feed speed of the optical fiber preform, and the wire diameter control unit monitors the drawn wire diameter in real time. This is a conventional technology, and all relevant performance tests have been passed, meeting application requirements. Specifically, half-light attenuation reaches 750mm, color temperature drift is as low as 140K / m, and VOC / FOG emissions, xenon lamp testing, and flame retardancy all meet the requirements of this field. This invention reduces optical fiber surface stress, lowers Rayleigh scattering, improves optical fiber transmission performance, and enhances optical fiber fracture toughness (the fracture stress of glass optical fiber reaches 1.31N). Figure 4 The above-mentioned optical fiber was tested for color performance before and after conventional thermal aging. Figure 5 The above diagram shows the optical fiber flux measurement for illumination.

[0051] Comparison Example The commercially available lighting optical fibers used in automotive interior ambient lighting and electrical equipment are made of glass fiber and are currently the best-reputed products on the market, sourced from foreign companies.

[0052] Test Implementation Examples Breakpoints were detected in the illumination fiber of the present invention and the illumination fiber of the comparative example; the present invention showed no breakpoints. See [link to relevant documentation]. Figure 6 The control example has 3.3 breakpoints / km. See [reference needed]. Figure 7 Currently, the automotive and consumer electronics industries have placed demands on uninterrupted lighting optical fibers.

[0053] The lighting optical fiber also needs to have good bending performance. The lighting optical fiber of the present invention and the lighting optical fiber of the comparative example were bent respectively ( Figure 8 The amplitude was measured, with 10 bends per segment; then, breakpoints were detected. The control example showed 8.3 breakpoints / km; unexpectedly, this invention showed no breakpoints. (See [reference]). Figure 8 The results are from the bending test of the lighting optical fiber of this invention.

[0054] Existing technologies for developing plastic optical fibers aim to improve bending performance, but they suffer from light spot problems. Taking POF optical fiber, which is currently widely used in production, as an example... Figure 9The photographs of existing lighting optical fibers after bending show bright spots; however, the present invention does not show bright spots. It is evident that the present invention also improves the problem of light spots when existing commercially available lighting optical fibers are bent.

[0055] Example 2 The number of optical fiber preforms is 40, 80 or 120. Referring to Example 1, an illumination optical fiber is obtained, and no breaks are found during testing.

[0056] Example 3 Sixty multi-component glass fiber preforms were selected. The preforms were heated to 950°C and the glass fibers were drawn. The preforms were then subjected to three-stage annealing with temperature control at 700-600-500°C (one meter each). The fibers were then allowed to cool naturally in the air. Following the example in Example 1, the illumination fiber was obtained, and no breaks were found during testing.

[0057] Example 4 The number of optical fiber preforms is 105. Referring to Example 3, an illumination optical fiber was obtained, and no breaks were found during testing.

[0058] Example 5 Referring to Example 1, the difference lies in the drawing speed being 50m / min, 100m / min, or 300m / min, to obtain an illumination fiber. The test showed no breaks, and the test after bending showed no breaks.

[0059] Example 6 Referring to Example 1, the difference is that the drawing speed is 500m / min, resulting in an illumination fiber. The test showed no breaks, but after bending, 1.7 breaks per km were detected.

[0060] Example 7 Referring to Example 1, the difference is that the annealing temperature is 1000℃ (3 meters), and the resulting illumination fiber has no breaks. However, after bending, 1.7 breaks per km are detected.

[0061] Example 8 Referring to Example 1, the difference lies in the coating thickness being 1 micrometer or 3 micrometers, resulting in an illumination fiber with no breaks during testing.

[0062] Comparative Example 1 Referring to Example 1, the difference is that the coating is omitted. That is, the glass fiber is pulled by the traction wheel and passes through the torque wheel and multi-stage bundle in sequence to form a glass fiber bundle. The glass fiber bundle is covered with a POE sheath to obtain the illumination fiber. 1.7 breaks / km were detected, and 5 breaks / km were detected after bending.

[0063] Comparative Example 2 Referring to Example 1, the difference is that the classic communication fiber coating DP-1020 with a thickness of 2 micrometers is used to obtain the illumination fiber. The test showed no breaks, but after bending, 3.3 breaks / km were detected.

[0064] Given the shortcomings of existing technologies, improving the anti-breakage capability of glass optical fibers without degrading their optical guiding performance is a key research focus in this field. This invention, based on existing equipment, involves heating and drawing glass fibers from a preform rod under specific drawing parameters and coating conditions. The glass fibers consist of multiple individual fibers that do not cross or contact each other. These fibers are then coated to form glass optical fibers. After bundling and sheathing, the glass optical fibers are obtained as lighting optical fibers, which can be applied in the automotive field: interior and exterior trim, instrument panels, center consoles, pedals, door panels, car logos, grilles, door handles, wheel rims, welcome lights, air conditioning vents, dashboards, center console backlighting areas, roofs, storage boxes, cup holders, speakers, trunks, taillights; flexible lighting for consumer electronics; smart home and carbon-free lighting, etc. This invention offers advantages such as high flexibility, high light utilization, low cost, high safety, and ease of promotion. Solving the glass optical fiber breakage problem will provide crucial support for the sustainable development of the glass optical fiber industry.

[0065] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An illumination optical fiber, comprising a bundle of glass optical fibers, characterized in that, The glass fiber bundle includes a plurality of glass fibers; the glass fiber includes glass fibers and a coating layer; the glass fibers are prepared by heating, drawing, and cooling a preform.

2. A glass fiber bundle comprising a plurality of glass fibers, characterized in that, The glass optical fiber includes glass fibers and a coating layer; the glass fibers are prepared by heating, drawing, and cooling a preform.

3. A glass optical fiber, characterized in that, It includes glass fiber and a coating layer; the glass fiber is prepared by heating, drawing and cooling a preform.

4. The illumination optical fiber according to claim 1, the glass fiber bundle according to claim 2, or the glass optical fiber according to claim 3, characterized in that, The glass fiber has a diameter of 40-100 micrometers and a coating thickness of 0.1-20 micrometers.

5. A method for preparing the lighting optical fiber of claim 1, the glass fiber bundle of claim 2, or the glass optical fiber of claim 3, comprising the following steps: preparing glass fibers by heating and drawing a preform and cooling it; then coating the glass fibers to form a glass optical fiber; and finally bundling and sheathing the glass optical fibers to obtain the lighting optical fiber.

6. The preparation method according to claim 5, characterized in that, The preform consists of multiple strands, and the glass fiber consists of multiple strands; the temperature during heating and drawing is 800-2100℃; the drawing speed is 50-500m / min; during cooling, natural air cooling and / or cooling pipe cooling methods are adopted.

7. The preparation method according to claim 5, characterized in that, During coating, the coating material is one or more of olefin polymers.

8. The application of the lighting optical fiber of claim 1, the glass optical fiber bundle of claim 2, or the glass optical fiber of claim 3 in a light-emitting device.

9. The application of the lighting optical fiber of claim 1, the glass optical fiber bundle of claim 2, or the glass optical fiber of claim 3 in automotive lighting devices.

10. A lighting component or automotive trim component comprising the lighting optical fiber as described in claim 1.

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