Polymer optical fiber panel and preparation method and application thereof

Abstract

The invention provides a polymer optical fiber panel and a preparation method and application thereof. The method comprises the following steps: obtaining colorless and transparent plastic A monofilaments and plastic B monofilaments with the same filament diameter; the absolute value of the square difference of the refractive indexes of the two monofilaments is greater than or equal Uniformly mixing the two monofilaments at random, arranging the monofilaments in a mold in a densest manner, heating, and preserving heat under a vacuum condition to obtain a prefabricated polymer optical fiber rod; drawing into multifilament; the multifilaments are arranged in a mold in a densest mode, the temperature is increased, heat preservation is conducted under the vacuum condition, and a panel blank section is obtained; and performing post-treatment on the panel blank section to obtain the polymer optical fiber panel. The technical problem to be solved is how to prepare a polymer optical fiber panel, the wire diameter is controlled within several microns, the resolution ratio of the polymer optical fiber panel is improved, and the optical fiber panel has the advantages of electromagnetic interference resistance, irradiation resistance, corrosion resistance and the like of the polymer optical fiber panel, and also has the advantages of low cost and the like. And the polymer optical fiber panel achieves the resolution comparable to that of a glass optical fiber panel, and has excellent image transmission quality.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber panel manufacturing, and in particular to a polymer optical fiber panel and a preparation method and application thereof. Background Art

[0002] The fiber optic panel is an image transmission component, which is made of many optical fibers arranged according to certain rules and prepared by processes such as heating and fusion. Each optical fiber is composed of a core material with a high refractive index and a skin material with a low refractive index. The two ends of the optical fiber are closely arranged in a one-to-one relationship. Each optical fiber transmits an image point and transmits the image from the input end face to the output end face. The fiber optic panel has the characteristics of high numerical aperture, high light collection, high resolution, and true phase transmission. It is widely used in many image transmission fields such as aerospace, national defense, and medical treatment.

[0003] Traditional fiber optic panels are mostly made of glass materials, but glass fiber optic panels are generally small in size and have problems such as glass being fragile, heavy, poor in acid corrosion resistance, poor in biocompatibility, and complex and expensive manufacturing processes. Compared with glass fiber optic panels, polymer fiber optic panels have advantages such as simple manufacturing processes and low costs. They have attracted much attention in recent years and are expected to become a substitute for traditional fiber optic panels; especially their advantages such as anti-electromagnetic interference, radiation resistance, and corrosion resistance can be used in some special occasions.

[0004] In the prior art, the manufacturing process of polymer optical fiber panels is as follows: a high-precision melt spinning machine is used to spin polymer optical fiber monofilaments with a core-skin structure, the monofilaments are arranged regularly, melted into a primary preform rod, and optical fiber multifilaments are drawn; the panels are arranged, and then the multifilaments are made into polymer optical fiber blanks through vacuum melting and pressing in a hot pressing furnace, and finally the polymer optical fiber panels are obtained through optical finishing. However, since the thermal properties of the polymer material itself are different from those of glass, it is easy to deform the internal part of the optical fiber panel during the melting and pressing process, resulting in poor imaging quality of the optical fiber panel, especially the central area of ​​the optical fiber panel cannot be imaged; at the same time, due to the material properties of the polymer itself, it is difficult to be stretched multiple times, resulting in a thicker wire diameter of the polymer optical fiber, making it difficult to obtain a high-resolution plastic optical fiber panel. Summary of the invention

[0005] The main purpose of the present invention is to provide a polymer optical fiber panel and its preparation method and application. The technical problem to be solved is how to prepare a polymer optical fiber panel so that the wire diameter of the plastic optical fiber can be controlled within a few microns, reaching the wire diameter level of the glass optical fiber, and improving the resolution of the polymer optical fiber panel. The optical fiber panel has the advantages of polymer optical fiber panel such as anti-electromagnetic interference, radiation resistance, and corrosion resistance, avoiding the problems of glass optical fiber panel such as small size, fragile glass, heavy weight, poor acid corrosion resistance, poor biocompatibility, and complex preparation process. The polymer optical fiber panel also achieves a resolution comparable to that of a glass optical fiber panel and has excellent image transmission quality, making it more suitable for practical use.

[0006] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. According to a method for preparing a polymer optical fiber panel proposed in the present invention, the method comprises the following steps:

[0007] S11 obtains colorless and transparent plastic A monofilament and plastic B monofilament with the same wire diameter; the absolute value of the square difference of the refractive index of the two monofilaments is ≥ 0.25;

[0008] S12 randomly mixes the two monofilaments uniformly; wherein the amount of the plastic A monofilament accounts for 40 to 60% of the total amount of the two monofilaments;

[0009] S13: arranging the two uniformly mixed monofilaments in the most dense manner in a mold, heating them, and keeping them warm under vacuum conditions to fuse the monofilaments to each other, thereby obtaining a prefabricated polymer optical fiber rod; the monofilaments in the mold are placed in a vertical direction with their axes; and the top of the monofilaments bears a mold cover weight;

[0010] S14 drawing the prefabricated polymer optical fiber rod into a multifilament;

[0011] S15: arranging the multifilaments in the most dense manner in a mold, heating them, and keeping them warm under vacuum conditions to fuse the multifilaments to each other, thereby obtaining a panel blank; the multifilaments in the mold are placed in a vertical direction with their axes; and the top of the multifilaments bears a mold cover weight;

[0012] S16: post-processing the panel blank to obtain a polymer optical fiber panel.

[0013] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0014] Preferably, in the aforementioned preparation method, the two monofilaments are polystyrene monofilaments and polymethyl methacrylate monofilaments respectively.

[0015] Preferably, in the aforementioned preparation method, the polystyrene monofilaments and polymethyl methacrylate monofilaments are prepared by an electrospinning process; the specific steps are as follows:

[0016] S31 dissolving polystyrene and polymethyl methacrylate in a solvent respectively to obtain a spinning solution; the solvent is selected from at least one of acetone, N,N-dimethylacetamide and tetrahydrofuran; the mass concentration of the spinning solution is 2-12%;

[0017] S32 electrospins the spinning solution to obtain polystyrene monofilaments and polymethyl methacrylate monofilaments respectively; the process parameters of the electrospinning are as follows: the power supply voltage is 15-20 kV, and the flow rate of the spinning solution is 0.004-0.01 mL / min.

[0018] Preferably, in the aforementioned preparation method, the process parameters for drawing the multifilament are as follows: drawing temperature 200-300° C., feeding speed 2-6 mm / min, and drawing speed 3-10 r / min.

[0019] Preferably, in the aforementioned preparation method, the diameter of the monofilament is 0.08 to 0.3 mm, and the stretching ratio is 18 to 31; and the diameter of each filament in the polymer optical fiber panel is 5 to 16 μm.

[0020] Preferably, in the aforementioned preparation method, the heating time is ≥2h; the insulation process parameters described in step S13 are as follows: the insulation temperature is 100-220°C, and the insulation time is 4-6h; the insulation process parameters described in step S15 are as follows: the insulation temperature is 100-220°C, and the insulation time is 4-8h.

[0021] Preferably, in the aforementioned preparation method, the mold is a hexagonal mold; the weight of the mold cover is as follows: when the distance between the opposite edges of the prefabricated polymer optical fiber rod or the panel blank segment is less than 20 mm, the weight of the mold cover is 2 to 5 kg; when the distance between the opposite edges of the prefabricated polymer optical fiber rod or the panel blank segment is 20 to 30 mm, the weight of the mold cover is 6 to 10 kg; when the distance between the opposite edges of the prefabricated polymer optical fiber rod or the panel blank segment is greater than 30 mm, the weight of the mold cover is 10 to 15 kg.

[0022] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. A polymer optical fiber panel proposed in the present invention comprises:

[0023] A plurality of polystyrene monofilaments are arranged and connected in a manner that the axes are parallel;

[0024] A plurality of polymethyl methacrylate monofilaments are arranged and connected in a manner of parallel axes; the axes of the polystyrene monofilaments are parallel to those of the polymethyl methacrylate monofilaments, and the two monofilaments are arranged in a highly disordered radial direction; and the diameters of the two monofilaments are 5 to 16 μm.

[0025] Preferably, the aforementioned polymer optical fiber faceplate is prepared by the aforementioned preparation method.

[0026] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions: According to the present invention, a polymer optical fiber panel according to the above is used in the fields of aerospace, national defense, medical treatment or image transmission technology.

[0027] By means of the above technical solution, the polymer optical fiber panel and its preparation method and application proposed by the present invention have at least the following advantages:

[0028] The present invention proposes a polymer optical fiber panel and a preparation method and application thereof. The polymer optical fiber panel is prepared by using two plastic monofilaments. The refractive index relationship of the two plastics is limited to ensure that the optical fiber panel can form an image transmission element through the difference in refractive index; the number ratio and mixing method of the two monofilaments are limited to form an Anderson localized arrangement with a radially highly disordered arrangement, so that the optical fiber image transmission effect can be achieved without a core-skin structure; the melting and pressing process of the optical fiber is optimized to heat and keep the temperature in a vacuum environment, so as to avoid temporary short-term pressure on the monofilament at a local time during the melting and pressing process. Instead, a constant and appropriate weight pressure is given to the monofilament through a mold cover counterweight during the whole process of heating and keeping the temperature, so that the monofilament can match the thermal properties of the polymer, ensuring that the polymer monofilament will not be deformed during the melting and pressing process, and will not affect its image transmission quality; and the vacuum environment can not only avoid defects such as bubbles in the product, but also avoid the quality damage of the plastic material due to oxidation, and also avoid stress concentration problems in the product.

[0029] Furthermore, the present invention optimizes the preparation process of plastic monofilaments and adjusts the mass concentration of the spinning solution, the power supply voltage and the flow rate of the spinning solution to effectively control the diameter of the monofilaments. In conjunction with the subsequent drawing process, the diameter of each optical fiber in the polymer optical fiber panel reaches a level comparable to that of a glass optical fiber, with the diameter being only a few microns, thereby improving the resolution of the polymer optical fiber panel.

[0030] Furthermore, the present invention optimizes the melting and pressing process so that no additional pressure is required during the entire melting and pressing process, thereby enabling it to break away from the constraints of the prior art that optical fiber melting and pressing can only be achieved through a hot pressing furnace; during the melting and pressing process of the present invention, on the one hand, it is necessary to provide a vacuum environment to improve the product quality and avoid the occurrence of bubble defects in the product and the deterioration of the plastic due to oxidation, and on the other hand, the heating rate and the insulation temperature need to be precisely controlled to avoid the damage to the product quality due to temperature instability during the melting and pressing process; and the precise control of vacuum and temperature in the melting and pressing process can be achieved only through a vacuum drying oven in the prior art; on the one hand, as an existing mature industrial product, the vacuum drying oven has a variety of models, is simpler and more convenient to operate, and is easy to move; and the cost is low, for some small enterprises or enterprises with limited funds, it is more practical and easier to buy a vacuum drying oven; on the other hand, it can also make polymer optical fiber panel manufacturers subject to the limitations of the hot pressing furnace in the prior art, without the need to invest in hot pressing furnace equipment with a complex structure and high cost, and can also avoid defects such as plastic oxidation, uneven temperature and bubbles in the product during the hot pressing process.

[0031] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The prefabricated polymer optical fiber rod of the embodiment of the present invention is arranged with 12 monofilaments as the base;

[0033] Figure 2 Schematic diagram of highly disordered arrangement of two plastic monofilaments in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of a polymer optical fiber panel and its preparation method and its specific implementation, structure, features and effects proposed by the present invention in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0035] The present invention provides a method for preparing a polymer optical fiber panel, which comprises the following steps:

[0036] The first step is to obtain colorless and transparent plastic A monofilament and plastic B monofilament with the same wire diameter.

[0037] In this step, the plastic monofilament is limited to colorless and transparent mainly because of its purpose of being used as an optical fiber: the optical fiber is used to transmit optical signals; if the plastic has color, it will absorb and scatter light of a specific wavelength, causing the optical signal to attenuate during transmission; while colorless and transparent plastic can minimize its absorption and scattering of light, ensuring that the optical signal is efficiently transmitted in the optical fiber; at the same time, colored plastic will cause deviation and distortion in the transmission of light, which is not conducive to the accurate transmission of signals, while transparent plastic can ensure the accuracy of light transmission.

[0038] In this step, the two plastic monofilaments are limited to have the same wire diameter. The technical purpose is to enable the two monofilaments to be densely stacked without distinction in the subsequent rod arrangement process.

[0039] The plastic monofilaments in the above steps can be purchased from the market, or can be prepared by themselves. In order to ensure that the diameter and fiber morphology of the monofilaments are uniformly controlled, the present invention preferably prepares the plastic monofilaments by an electrostatic spinning method. By adjusting the parameters in the electrostatic spinning process, such as voltage, solution concentration, flow rate, etc., the diameter of the plastic optical fiber can be accurately controlled, and fibers with different diameters from tens of nanometers to several microns can be prepared to meet the requirements of optical fiber size in different application scenarios.

[0040] The electrospinning process is applicable to a variety of plastic materials, such as polymethyl methacrylate (PMMA), polystyrene (PS), polycarbonate (PC), etc. The present invention selects suitable plastic materials to prepare optical fibers according to the specific application scenario requirements, thereby giving plastic optical fibers different properties. For example, PMMA plastic optical fibers have good optical transparency and biocompatibility, and are suitable for the fields of biomedicine and optical communications; PS plastic optical fibers have a higher refractive index and are suitable for the fields of optical sensing and optical imaging. The present invention preferably uses two monofilaments, polystyrene monofilaments and polymethyl methacrylate monofilaments.

[0041] The specific steps of electrospinning polystyrene monofilament and polymethyl methacrylate monofilament are as follows:

[0042] First, polystyrene and polymethyl methacrylate are dissolved in a solvent respectively to obtain a spinning solution. The spinning solution can be prepared as long as it can ensure the full dissolution of PS and PMMA. In the present invention, the solvent is preferably selected from at least one of acetone, N,N-dimethylacetamide and tetrahydrofuran. In order to ensure the spinnability of the spinning solution and the quality of the obtained single fibers, the present invention preferably has a mass concentration of 2 to 12% of the spinning solution; further preferably, the mass concentration of the spinning solution is 5 to 12%; and further preferably, the mass concentration of the spinning solution is 10%.

[0043] Then, the spinning solutions are electrospun respectively to obtain polystyrene monofilaments and polymethyl methacrylate monofilaments. The electrospinning process parameters are optimized based on a large amount of experimental data as follows: the power supply voltage is 15-20 kV, and the flow rate of the spinning solution is 0.004-0.01 mL / min.

[0044] After obtaining the two plastic monofilaments, the second step is to randomly mix the two monofilaments evenly to make them highly disordered; wherein the absolute value of the square difference of the refractive index of the two monofilaments is ≥0.25; and the number of plastic A monofilaments accounts for 40-60% of the total number of the two monofilaments.

[0045] The polymer optical fiber panel of the present invention is composed of two transparent plastic fibers with different refractive indices arranged in a highly disordered manner in the transverse direction. Factors to be considered in such arrangement include: the refractive index difference of the two plastic materials, the usage ratio of the two plastic materials and the arrangement and distribution state of the two plastic monofilaments.

[0046] The above-mentioned lateral disorder refers to the disordered distribution and arrangement of two plastic monofilaments with different refractive indices on the plane along the cross section / radial direction of the optical fiber; high disorder refers to a high degree of disorder in the distribution; the more disordered the arrangement, the higher the degree of disorder. The purpose of the present invention to select the lateral high disorder setting is to make the diffusion of light waves in the lateral / radial direction highly constrained / inhibited, to achieve the forward transmission of light waves in a highly localized area, and to avoid the problems of image transmission distortion and blurring.

[0047] In the above technical solution, if the difference in refractive index between the two plastics is too small, the Anderson localization phenomenon is not obvious; if the difference in refractive index is too large, the performance difference between the two plastic monofilaments may be too large and not conducive to production operations. In order to ensure that the two plastic monofilaments can form Anderson localization well after being highly disordered, and to ensure that they can transmit images with high quality. The present invention preferably has an absolute value of the square difference in the refractive index of the two plastic monofilaments ≥ 0.25; that is, the numerical aperture of the optical fiber formed by the two plastic monofilaments is ≥ 0.5. The technical solution of the present invention can be implemented by any two plastics whose refractive index difference meets the above requirements, as long as the plastic material can adapt to the subsequent process requirements of the plastic optical fiber.

[0048] For the arrangement of two plastic monofilaments, the disorder is mainly reflected in their arrangement positions. If any one of the plastic monofilaments accounts for too much, such as 99%, then the other plastic monofilament must account for too little. In this case, most of the positions of the plastic monofilaments are the former plastic monofilaments, resulting in a high probability that the monofilaments are continuous or close to each other, which will form an orderly periodic pattern. Therefore, this situation must be avoided. A , the number of plastic B monofilaments is N B According to a large number of experimental tests, the proportion of the two plastic monofilaments is generally N A / (NA +N B )=40%~60%,when N A / (N A +N B )=50%, the maximum disorder can be achieved, which is the best choice. A / (N A +N B ) is lower than 40% or higher than 60%, the Anderson localization effect is not obvious, which may cause the light wave to be significantly diffused and the clarity of the output signal transmitted in the optical fiber panel is poor. For this reason, the present invention preferably uses 40% to 60% of the total amount of the two transparent glass optical fibers.

[0049] The third step is to arrange the two evenly mixed monofilaments in the densest manner in a mold, increase the temperature, and keep the temperature under vacuum conditions to fuse the monofilaments to each other to obtain a prefabricated polymer optical fiber rod; the monofilaments in the mold are placed in a vertical direction with the axis; the top of the monofilament bears the mold cover weight.

[0050] In this step, the two monofilaments are mixed uniformly, which means that the two monofilaments are randomly distributed without any rules, so that they form a highly disordered arrangement structure, such as the attached Figure 2 As shown in the figure, the dark color represents one plastic monofilament, and the light color represents another plastic monofilament. The two plastic monofilaments are mixed irregularly to form Anderson localization without the need for arrangement. Figure 2 The dark-colored monofilaments are only used to show the arrangement of the two monofilaments and do not limit the color of the monofilaments themselves; as mentioned above, the two plastic monofilaments in the present invention are both colorless and transparent plastic monofilaments.

[0051] The most dense arrangement in this step means that the two monofilaments are embedded in each other so that each adjacent monofilament is in contact with each other and arranged closely. Figure 1 The figure shows the arrangement of 12 monofilaments as the base of the prefabricated polymer optical fiber rod in a specific embodiment of the present invention. Figure 1 The middle mold is a hexagonal mold, which is composed of six independent triangular prism mold sliders. A flat surface of each independent triangular prism mold slider abuts against a side surface of the hexagonally arranged single-filament rod, and fixes the six side walls of the hexagonal prefabricated optical fiber rod respectively. It can fix prefabricated optical fiber rods of different sizes, and is very convenient and flexible to disassemble and assemble.

[0052] In actual production, the mold includes not only six independent triangular prism mold sliders, but also a bottom mold and a sleeve mold. In specific operations, the arranged hexagonal monofilament rods are placed on the bottom mold, with one end face of the hexagonal monofilament rod in contact with the bottom mold, and the side of the hexagonal monofilament rod is perpendicular to the bottom mold; then the six independent triangular prism mold sliders are placed around the hexagonal monofilament rod in sequence, so that each mold slider is close to one side of the hexagonal monofilament rod; then the mold sleeve is put on the outside of the mold slider to fix the position of the mold slider so that it can continue to fit tightly to the side of the hexagonal monofilament rod; finally, the upper mold is placed on top of the sleeve mold, and the weight of the sleeve mold and the upper mold is always applied to the top of the hexagonal monofilament rod, that is, the top of the monofilament bears the mold cover weight.

[0053] The present invention always maintains a vacuum state during the melting and pressing process. Except for the mold cover counterweight, no additional pressure is applied to the hexagonal monofilament rod during the whole process. The process setting is mainly considered that the purpose of the present invention is to prepare a polymer optical fiber panel, and the target object is a plastic monofilament. The plastic material has its unique performance characteristics. When additional pressure is applied to the plastic in a heated state, it may cause deformation inside the optical fiber panel, thereby making the imaging quality of the plastic optical fiber panel poor, especially the central area of ​​the plastic optical fiber panel cannot be imaged; in severe cases, improper pressure control may also cause the plastic to overflow the mold, or cause stress concentration inside the product, and stress concentration will make the product more prone to cracks or even breakage during use, reducing the quality and service life of the product. The present invention optimizes the process of the melting and pressing process so that the plastic monofilaments are always kept in a vacuum state during the melting and pressing process. In the whole process, except for the mold cover counterweight, no additional pressure is applied to the hexagonal monofilament rod. That is, the hexagonal monofilament rod of the present invention only bears a constant and stable force of the size of the mold cover counterweight during the whole process of heating and heat preservation, which ensures that the plastic monofilaments can be smoothly fused and connected without any adverse effect on the plastic monofilaments, so that all the plastic monofilaments will not be deformed, thereby ensuring the image transmission quality of the polymer optical fiber panel prepared therefrom.

[0054] The above technical solution does not apply additional pressure to the hexagonal monofilament rod, and not applying additional external force may result in loose fusion between the monofilaments. For this reason, the present invention uses a mold cover of appropriate weight for counterweighting, so that the counterweight can always give the hexagonal monofilament rod a continuous and stable pressure during the entire process of heating and melting, thereby ensuring that the monofilament does not deform. The counterweight of the mold cover is related to the size of the opposite side distance of the prefabricated polymer optical fiber rod. In order to achieve a better balance between fusion and non-deformation, the present invention preferably defines it as follows: when the opposite side distance is less than 20mm, the weight of the mold cover is 2-5kg, when the opposite side distance is 20-30mm, the weight of the mold cover is 6-10kg, and when the opposite side distance is greater than 30mm, the weight of the mold cover is 10-15kg.

[0055] After the hexagonal monofilament rod is installed in the mold, it is heated to fuse and connect with each other. The present invention controls the heating speed to be slowly heated, so that it takes at least two hours to heat up to the preset insulation temperature. The technical purpose of the slow heating setting is: on the one hand, since the monofilament of the present invention is made of plastic material, plastic is a polymer material, which has its own glass transition temperature and melting point range; slow heating can make the plastic monofilament rod heated evenly to avoid excessive local temperature; if the temperature is raised too fast, the local area may reach the melting point or even the decomposition temperature in advance, resulting in material performance degradation, such as local burning, decomposition and bubbles, etc., affecting the quality and appearance of the product; on the other hand, slow heating can allow the molecular chains inside the plastic to have enough time to relax and rearrange; when the temperature gradually rises, the molecular chain segments slowly obtain enough energy and can be arranged more disorderly. This disordered arrangement is conducive to better interlacing and entanglement between the molecular chain segments, thereby helping to improve the physical properties of the melt-pressed product, and the mechanical properties such as strength and toughness will be better. Regarding the control of the heating speed, in the embodiment of the present invention, it is achieved by selecting a vacuum oven of appropriate specifications.

[0056] The present invention is limited to heat preservation under vacuum conditions to make the monofilaments fuse to each other, and its technical purpose is: on the one hand, to prevent the oxidation of plastic materials; heating plastic in air, high temperature conditions will cause the plastic to react with oxygen, resulting in plastic aging, discoloration, and performance degradation; and the vacuum environment can effectively isolate oxygen, avoid the occurrence of oxidation reactions, and ensure the chemical stability and appearance quality of the plastic monofilament rod; on the other hand, it is to eliminate bubbles in the plastic monofilament rod; during the melting and pressing process, the plastic monofilament rod may contain some moisture, low molecular volatiles or mixed air; heat preservation under vacuum can make these gases escape more easily under low pressure environment; if these bubbles are not eliminated, pores will appear inside the product, which will reduce the density and strength of the product and affect its mechanical properties and appearance flatness. The present invention does not specifically limit the specific vacuum range, for example, it can be 90-120kPa, as long as it can maintain a certain vacuum to ensure product quality.

[0057] In the above technical solution, the insulation temperature and insulation time of the plastic monofilament rod under vacuum depend on many factors and can be flexibly adjusted as needed in actual operation. The preferred material of the plastic monofilament rod of the present invention is PS and PMMA. Under the material selection conditions and combined with the target size of the prepared polymer optical fiber panel, the preferred process parameters of the insulation of the plastic monofilament of the present invention are as follows: the insulation temperature is 100 to 220°C and the insulation time is 4 to 6 hours.

[0058] In some specific embodiments of the present invention, the vacuum and heat preservation environment in the above technical solution are realized by a vacuum drying oven. Specifically, the vacuum drying oven can simultaneously provide the process conditions of vacuum and temperature required by the present invention. Compared with the prior art that uses a hot press furnace to melt and press the plastic monofilament rod, the present invention realizes melting and pressing by a vacuum drying oven, and its technical purpose is: first, the vacuum environment of the vacuum drying oven can reduce the boiling point of water and accelerate the evaporation of water, and has a significant effect on removing water from plastics such as PS and PMMA; it can effectively prevent defects such as bubbles and pores caused by water in the plastic monofilament rod during the melting and pressing process, and improve the quality and density of the product; second, the vacuum drying oven can prevent the plastic from being oxidized during the drying process, and for easily oxidized plastics such as PS and PMMA, this helps to maintain its chemical stability and prevent performance degradation; third, the vacuum drying oven is equipped with a precise temperature control system, which can accurately set and control the drying temperature according to the characteristics of PS and PMMA plastics, ensure that the plastic is processed at a suitable temperature, and prepare for subsequent melting and pressing. Fourth, under vacuum conditions, the thermal stress on the plastic monofilament rod is relatively small, which can reduce the stress concentration inside the material and reduce the possibility of deformation, cracking and other problems caused by thermal stress. Fifth, in addition to overcoming the shortcomings of the hot press furnace in the prior art that is prone to material oxidation and temperature uniformity is difficult to ensure, the vacuum drying oven has a complex structure, high manufacturing and maintenance costs, and requires a large equipment investment. As an existing mature industrial product, the vacuum drying oven has a variety of models, is simpler and more convenient to operate, and is easy to move. It is also low-cost. For some small businesses or businesses with limited funds, purchasing a vacuum drying oven would be more practical and easier to achieve.

[0059] The fourth step is to draw the prefabricated polymer optical fiber rod prepared by the above technical solution into a multifilament. The drawing parameters can be flexibly adjusted based on the type of polymer.

[0060] In a specific embodiment of the present invention, the polymers are PS and PMMA. For PS, a PS raw material with a moderate molecular weight should be selected. If the molecular weight is too high, the fluidity is poor and drawing is difficult; if the molecular weight is too low, the strength of the multifilament may be insufficient. For PMMA, attention should be paid to its transparency and molecular weight distribution. High transparency indicates that the raw material quality is good, and uniform molecular weight distribution is conducive to the stability of the drawing process. For the control of the drawing temperature, for PS, the drawing temperature is usually 180-220°C. In this temperature range, PS can be better transformed into a viscous flow state and is easy to stretch. For PMMA, the drawing temperature is slightly higher, generally 220-250°C. Because the glass transition temperature and melting temperature of PMMA are relatively high. The preferred drawing temperature of the present invention is set to 200-300°C so as to take into account the characteristics of both PS and PMMA plastics. For the feeding speed and drawing speed, it is also necessary to take into account the characteristics of both PS and PMMA plastics. In order to ensure that the wire diameter of each single wire is uniform and stable during the drawing process, and that each single wire can better maintain its cross-sectional shape without deformation, based on the experience of a large number of experimental tests, the present invention prefers that the feeding speed of the hexagonal single wire rod is 2-6 mm / min and the drawing speed is 3-10 r / min.

[0061] In order to better balance the performance of subsequent products, the wire diameter of each optical fiber in the final polymer optical fiber panel can reach a level of several microns to ensure the resolution of the polymer optical fiber panel; at the same time, the thermal stretching properties of the two polymers PS and PMMA are combined to avoid excessive stretching and damage to their mechanical properties. The present invention preferably controls the single filament diameter during electrospinning to be controlled at 0.08-0.3mm; such a setting can make the single filament have a thinner wire diameter under the condition of a suitable stretching ratio, thereby ensuring the resolution of the polymer optical fiber panel, while also ensuring that the difficulty of the electrospinning process is not increased.

[0062] In the above technical solution, the stretching multiple of the hexagonal single-filament rod during drawing is 18 to 31; the diameter of each filament in the polymer optical fiber panel is 5 to 16 μm.

[0063] The fifth step is to arrange the drawn multifilaments in the most dense manner in a mold, heat them up, and keep them warm under vacuum conditions to fuse the multifilaments to each other to obtain a panel blank; the multifilaments in the mold are placed in a vertical direction with their axes; the top of the multifilaments bears the mold cover weight.

[0064] The melting and pressing process of hexagonal multifilament rod is similar to that of hexagonal single-filament rod, except that the object to be melted and pressed is changed from hexagonal single-filament rod to hexagonal multifilament rod. The similarities of the melting and pressing processes of the two are not repeated here. The differences are:

[0065] In the above technical scheme, the insulation temperature and insulation time of the plastic monofilament rod under vacuum depend on many factors, and can be flexibly adjusted as needed in actual operation. The preferred materials of the plastic monofilament rod of the present invention are PS and PMMA. Under this material selection condition, and in combination with the target size of the prepared polymer optical fiber panel, the preferred insulation process parameters of the plastic monofilament of the present invention are as follows: the insulation temperature is 100-220°C, and the insulation time is 4-8h; because the polymer has time-temperature equivalence, the use of a higher insulation temperature with a shorter insulation time is basically equivalent to the use of a lower insulation temperature with a longer insulation time. The specific melting and pressing process parameters can be flexibly adjusted according to factors such as the material of the plastic and the specifications of the monofilament and multifilament.

[0066] Finally, the panel blank is post-processed to obtain a polymer optical fiber panel. The operation of this step can be carried out according to conventional operations in the art, and the present invention does not make any specific limitations thereto.

[0067] The present invention also provides a polymer optical fiber panel, which comprises:

[0068] A plurality of polystyrene monofilaments are arranged and connected in a manner that the axes are parallel;

[0069] A plurality of polymethyl methacrylate monofilaments are arranged and connected in a manner of parallel axes; the axes of the polystyrene monofilaments are parallel to those of the polymethyl methacrylate monofilaments, and the two monofilaments are arranged in a highly disordered radial direction; and the diameters of the two monofilaments are 5 to 16 μm.

[0070] The diameter of each single wire in the above-mentioned polymer optical fiber panel is only 5 to 16 μm, which reaches a fineness level comparable to that of the glass optical fiber in the glass optical fiber panel, greatly improving the resolution of the polymer optical fiber panel and having excellent image transmission quality; at the same time, it also has the advantages of polymer optical fiber panel such as anti-electromagnetic interference, radiation resistance, and corrosion resistance, avoiding the problems of glass optical fiber panel such as small size, fragile glass, heavy weight, poor acid corrosion resistance, poor biocompatibility, and complex preparation process.

[0071] The above-mentioned polymer optical fiber panel is prepared by the above-mentioned preparation method.

[0072] The present invention also proposes an application of the aforementioned polymer optical fiber panel in the fields of aerospace, national defense, medical treatment or image transmission technology.

[0073] The present invention will be further described below in conjunction with specific embodiments, but this should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by technicians in this field based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0074] Unless otherwise specified, the materials, reagents, etc. involved below are all commercially available products well known to those skilled in the art; unless otherwise specified, the methods described are all methods well known in the art. Unless otherwise defined, the technical terms or scientific terms used should have the common meanings understood by ordinary technicians in the field to which the present invention belongs.

[0075] Example 1

[0076] This embodiment prepares a polymer optical fiber panel, and the specific steps are as follows:

[0077] PS and PMMA materials were dissolved in tetrahydrofuran to form two textile solutions with a mass concentration of 10% respectively; they were electrospun according to the process parameters of power supply voltage of 15 kV and flow rate of 0.004 mL / min to obtain PS monofilaments and PMMA monofilaments with a wire diameter of 0.1 mm.

[0078] The PS monofilament and the PMMA monofilament are randomly mixed in a ratio of 4:6; the two mixed monofilaments are arranged into a regular hexagon according to the hexagonal closest structure, and the arranged polymer optical fiber rod (opposite sides are 25.91 mm) is assembled into a mold, and the polymer optical fiber plate is surrounded by six triangular prisms, and a mold cover with a weight of 8 kg is placed in a vacuum drying oven, and the heating time is 2 hours, and the temperature is kept at 160°C for 6 hours, and the vacuum degree is 100 kPa, so that the optical fibers are tightly connected to obtain a prefabricated polymer optical fiber rod.

[0079] Step 3: Draw the polymer optical fiber rod into a wire, the drawing temperature is 250°C, the feeding speed is 4mm / min, the drawing speed is controlled at 4.1r / min, and a multifilament with a wire diameter of 1.3mm is obtained.

[0080] Step 4: Arrange the multifilaments obtained in step 3 in a hexagonal stacking manner with 12 bases and opposite sides of 26.27 mm. Assemble the arranged polymer optical fiber board into a mold, cover the mold with a weight of 8 kg, and then place it in a vacuum drying oven. Heat up for 2 hours, keep warm at 100°C for 8 hours, and use a vacuum degree of 100 kPa to tightly connect the multifilaments to obtain a polymer optical fiber panel.

[0081] Step 5: The polymer optical fiber plate obtained in step 6 is subjected to rounding, slicing, grinding and polishing to obtain a finished polymer optical fiber panel.

[0082] After testing, the resolution of the polymer optical fiber panel in this embodiment is 80.6 Lp / mm.

[0083] Embodiments 2 to 8

[0084] Same as Example 1. The differences are shown in Table 1. The resolution test results of the polymer optical fiber panel in this embodiment are shown in Table 1.

[0085] Comparative Example 1

[0086] The steps are the same as those in the embodiment, except that: non-vacuum environment, hot pressing furnace melting and pressing, specific process parameters are shown in Table 1. The resolution test results of the polymer optical fiber panel of this comparative example are shown in Table 1.

[0087] Table 1

[0088]

[0089]

[0090] It can be seen from the test results of the above embodiments and comparative examples that the technical solution of the present invention can be used to prepare a polymer optical fiber panel with excellent performance, whose wire diameter can reach a level of several microns, comparable to the wire diameter of glass optical fiber, greatly improving the resolution of the polymer optical fiber panel, and having excellent image transmission quality, with a resolution of >50Lp / mm, and even reaching 80Lp / mm or more; at the same time, the technical solution of the present invention enables the optical fiber panel to have the advantages of anti-electromagnetic interference, radiation resistance, and corrosion resistance of the polymer optical fiber panel, while avoiding the problems of small size, fragile glass, heavy weight, poor acid corrosion resistance, poor biocompatibility, and complex preparation process of the glass optical fiber panel. In comparative example 1, a hot press furnace was used for melting and pressing in a non-vacuum environment. As can be seen from the test results, the prepared polymer optical fiber panel has poor quality, a resolution of 0, and cannot effectively transmit images.

[0091] The technical features in the claims and / or the specification of the present invention may be combined, and the combination is not limited to the combination obtained by reference in the claims. The technical solution obtained by combining the technical features in the claims and / or the specification is also within the protection scope of the present invention.

[0092] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a polymer optical fiber panel, characterized in that: It includes the following steps: S11 obtains colorless and transparent plastic A monofilament and plastic B monofilament with the same wire diameter; the absolute value of the square difference of the refractive index of the two monofilaments is ≥ 0.25; S12 randomly mixes the two monofilaments uniformly; wherein the amount of the plastic A monofilament accounts for 40 to 60% of the total amount of the two monofilaments; S13: arranging the two uniformly mixed monofilaments in the most dense manner in a mold, heating them, and keeping them warm under vacuum conditions to fuse the monofilaments to each other, thereby obtaining a prefabricated polymer optical fiber rod; the monofilaments in the mold are placed in a vertical direction with their axes; and the top of the monofilaments bears a mold cover weight; S14 drawing the prefabricated polymer optical fiber rod into a multifilament; S15: arranging the multifilaments in the most dense manner in a mold, heating them, and keeping them warm under vacuum conditions to fuse the multifilaments to each other, thereby obtaining a panel blank; the multifilaments in the mold are placed in a vertical direction with their axes; and the top of the multifilaments bears a mold cover weight; S16: post-processing the panel blank to obtain a polymer optical fiber panel.

2. The preparation method according to claim 1, characterized in that: The two monofilaments are polystyrene monofilament and polymethyl methacrylate monofilament.

3. The preparation method according to claim 2, characterized in that: The polystyrene monofilament and the polymethyl methacrylate monofilament are made by an electrospinning process; the specific steps are as follows: S31 dissolving polystyrene and polymethyl methacrylate in a solvent respectively to obtain a spinning solution; the solvent is selected from at least one of acetone, N,N-dimethylacetamide and tetrahydrofuran; the mass concentration of the spinning solution is 2-12%; S32 electrospins the spinning solution to obtain polystyrene monofilaments and polymethyl methacrylate monofilaments respectively; the process parameters of the electrospinning are as follows: the power supply voltage is 15-20 kV, and the flow rate of the spinning solution is 0.004-0.01 mL / min.

4. The preparation method according to claim 2, characterized in that: The process parameters of the multifilament drawing are as follows: drawing temperature 200-300° C., feeding speed 2-6 mm / min, and drawing speed 3-10 r / min.

5. The preparation method according to claim 4, characterized in that: The diameter of the monofilament is 0.08-0.3 mm, and the stretching ratio is 18-31; the diameter of each filament in the polymer optical fiber panel is 5-16 μm.

6. The preparation method according to claim 2, characterized in that: The heating time is ≥2h; the insulation process parameters in step S13 are as follows: the insulation temperature is 100-220°C, and the insulation time is 4-6h; the insulation process parameters in step S15 are as follows: the insulation temperature is 100-220°C, and the insulation time is 4-8h.

7. The preparation method according to claim 2, characterized in that: The mold is a hexagonal mold; the weight of the mold cover is as follows: when the distance between the opposite edges of the prefabricated polymer optical fiber rod or the panel blank is less than 20 mm, the weight of the mold cover is 2 to 5 kg; when the distance between the opposite edges of the prefabricated polymer optical fiber rod or the panel blank is 20 to 30 mm, the weight of the mold cover is 6 to 10 kg; when the distance between the opposite edges of the prefabricated polymer optical fiber rod or the panel blank is greater than 30 mm, the weight of the mold cover is 10 to 15 kg.

8. A polymer optical fiber panel, characterized in that: It includes: A plurality of polystyrene monofilaments are arranged and connected in a manner that the axes are parallel; A plurality of polymethyl methacrylate monofilaments are arranged and connected in a manner of parallel axes; the axes of the polystyrene monofilaments are parallel to those of the polymethyl methacrylate monofilaments, and the two monofilaments are arranged in a highly disordered radial direction; and the diameters of the two monofilaments are 5 to 16 μm.

9. The polymer optical fiber panel according to claim 8, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 7.

10. Application of the polymer optical fiber panel according to claim 8 or 9 in the fields of aerospace, national defense, medical treatment or image transmission technology.

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