Device for measuring photocuring adhesive

Abstract

The utility model relates to the technical field of optical fiber sensing, in particular to a device for measuring photocuring glue, which comprises an optical fiber grating component and a light-transmitting sleeve component. The fiber bragg grating assembly penetrates through the light-transmitting sleeve assembly, and a grating array of the fiber bragg grating assembly is located in the light-transmitting sleeve assembly; the interior of the light-transmitting sleeve assembly is used for containing light curing glue. And the fiber grating assembly is used for receiving incident light and reflecting the incident light so as to measure the curing process of the photocuring adhesive through the change of the wavelength of the reflected light. According to the embodiment of the invention, the light-transmitting sleeve is used as a container for bearing the contact between the photocuring adhesive and the fiber grating component, so that the photocuring adhesive can receive light in real time, the fiber grating component can reflect light in real time, and the curing process of the photocuring adhesive can be measured in real time through the wavelength change of the reflected light.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of optical fiber sensing technology especially relates to a device for measuring light curing glue. BACKGROUND

[0002] Precise optical coupling technology and high-performance light curing glue are widely used in the optical device and optical module industry. An important parameter of high-performance light curing glue is the strain or curing shrinkage rate during the light curing process. This directly relates to the amount of optical path deviation caused by light curing glue after ultraviolet irradiation. The optical device and optical module industry allow very small optical path deviation, and many precise coupling scenarios allow a deviation of 0.5-1.0um@1dB light power drop. The selection of high-performance light curing glue is an important topic. In addition, the strain of a light curing glue varies greatly when using different ultraviolet irradiation intensities or times, and the optimal ultraviolet curing conditions need to be studied.

[0003] The optical device and optical module products have many components and are expensive. Directly using the products for light curing glue selection and experimental exploration of curing conditions is costly and too late. A raw material level development verification device and method are needed. There are two main types of common measurement methods. The first method is to place the liquid light curing glue to be measured in a mold of a specific shape and size, and measure the size of the solid light curing glue after ultraviolet curing. For example, the invention patent with application number CN202311804002.1 uses this method. This method requires the use of a large-size mold for measurement (e.g., 70*10mm), and this measurement method is relatively accurate in applications with large volumes of glue, but it is not accurate in applications with small volumes of glue. However, the high-performance light curing glue in many industries has a very small dispensing volume, approximately 0.01mm 3 order of magnitude, and this method is not suitable for such scenarios. This method can only measure the volume of the adhesive at the initial and final times, and cannot perform real-time measurement. The second method uses a liquid density meter to measure the density of the uncured liquid light curing glue, a solid density meter to measure the density of the cured solid light curing glue, and a precision balance to measure the mass of both, and then calculates the volume change rate. The disadvantage of this method is that it can only measure the volume of the adhesive at the initial and final times, and cannot perform real-time measurement, which makes it difficult to accurately and comprehensively study the curing conditions of the light curing glue. UTILITY MODEL CONTENTS

[0004] The utility model provides a device for measuring light curing glue to overcome the problem that the prior art cannot perform real-time measurement during the light curing process.

[0005] The utility model is implemented as follows:

[0006] The utility model provides a device for measuring light curing adhesive, including fiber grating component 1 and light transmission sleeve component 2,

[0007] The fiber grating component 1 passes through the light transmission sleeve component 2, and the grating array 11 of the fiber grating component 1 is located inside the light transmission sleeve component 2.

[0008] The light transmission sleeve component 2 is used for accommodating light curing adhesive inside.

[0009] The fiber grating component 1 is used for receiving incident light and reflecting light, to measure the curing process of light curing adhesive by the wavelength change of reflected light.

[0010] Preferably, the light transmission sleeve component 2 is provided with a hole 21 penetrating into the inside of the light transmission sleeve component 2, and the hole 21 is aligned with the position of the grating array 11; the hole 21 is used for injecting light curing adhesive into the inside of the light transmission sleeve component 2.

[0011] Preferably, it further includes a coupling component 3, a spectrum analysis component 4 and a light source component 5.

[0012] The exit end of the light source component 5 is connected to the first port of the coupling component 3, one end of the fiber grating component 1 is connected to the second port of the coupling component 3, and the spectrum analysis component 4 is connected to the third port of the coupling component 3.

[0013] The light source component 5 is used for providing incident light for the fiber grating component 1.

[0014] The spectrum analysis component 4 is used for receiving reflected light from the fiber grating component 1 to measure the wavelength of the reflected light.

[0015] Preferably, the nozzle 22 of the light transmission sleeve component 2 is closed by adhesive.

[0016] Preferably, the material of the light transmission sleeve component 2 is one or more of glass, polyetherimide, polymethyl methacrylate, polystyrene and polycarbonate.

[0017] Preferably, the ratio between the inner wall diameter d1 of the light transmission sleeve component 2 and the outer diameter d2 of the fiber grating component 1 is less than 25.

[0018] Preferably, the ratio between the length L1 of the light transmission sleeve component 2 and the length L2 of the grating array 11 is less than 3.

[0019] Preferably, the ratio between the length L1 of the light transmission sleeve component 2 and the length L2 of the grating array 11 is greater than 1.5.

[0020] Preferably, the fiber grating assembly 1 has a reflectivity greater than 10%.

[0021] Preferably, the fiber grating assembly 1 has an initial center wavelength of 1540-1560nm.

[0022] Compared with the prior art, the utility model has the beneficial effects that: the utility model uses the light transmission sleeve as the container that bears the contact of the photocuring glue and the fiber grating assembly, so that the photocuring glue can receive the light in real time, and the fiber grating assembly can reflect the light in real time, and then through the wavelength change of the reflected light, the real-time measurement of the curing process of the photocuring glue can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, below will be to the embodiment or prior art description needed to use the drawing briefly introduced, obviously, the drawing in the following description only some embodiments of the utility model, for those skilled in the art, under the premise of not paying the creative labor, can also obtain other drawings according to these drawings.

[0024] Figure 1 The structural schematic diagram of the device for measuring photocuring glue provided by the embodiment of the utility model is shown in the drawing.

[0025] Figure 2 The structural schematic diagram of the device for measuring photocuring glue provided by the embodiment of the utility model is shown in the drawing.

[0026] Figure 3 The structural schematic diagram of the device for measuring photocuring glue provided by the embodiment of the utility model is shown in the drawing.

[0027] Figure 4 The structural schematic diagram of the device for measuring photocuring glue provided by the embodiment of the utility model is shown in the drawing.

[0028] Figure 5 The curing shrinkage rate schematic diagram of the photocuring glue measured in the actual application scene by the device for measuring photocuring glue provided by the embodiment of the utility model is shown in the drawing.

[0029] Figure 6 The curing shrinkage rate schematic diagram of the photocuring glue measured in the actual application scene by the device for measuring photocuring glue provided by the embodiment of the utility model is shown in the drawing.

[0030] In all drawings, the same reference signs are used to indicate the same elements or structures, wherein:

[0031] 1. Fiber Bragg grating assembly; 11. Grating array; 12. Optical fiber; 2. Transmitting sleeve assembly; 21. Channel; 22. Tube opening; 3. Coupling assembly; 4. Spectral analysis assembly; 5. Light source assembly. Detailed Implementation

[0032] In the description of this utility model, the terms "inner", "outer", "longitudinal", "lateral", "upper", "lower", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not require that this utility model must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0033] In this utility model, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0034] In this application, unless otherwise expressly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium. Furthermore, the term "coupled" can refer to an electrical connection that enables signal transmission.

[0035] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0036] Example 1:

[0037] This utility model provides a device for measuring photocurable adhesives, such as... Figure 1 As shown, the assembly includes a fiber Bragg grating assembly 1 and a light-transmitting sleeve assembly 2. The fiber Bragg grating assembly 1 passes through the light-transmitting sleeve assembly 2, and the grating array 11 of the fiber Bragg grating assembly 1 is located inside the light-transmitting sleeve assembly 2. In practical use, the fiber Bragg grating assembly 1 can be a fiber Bragg grating. The fiber Bragg grating assembly 1 includes a grating array 11 and optical fibers 12. Both ends of the optical fibers 12 pass through the light-transmitting sleeve assembly 2 to receive incident light and emit reflected light.

[0038] The light-transmitting sleeve assembly 2 is internally used for accommodating light-curing glue, and receiving external light, and the light is guided into the light-transmitting sleeve assembly 2 to solidify the light-curing glue. The fiber grating assembly 1 is used for receiving incident light and reflecting light, so as to measure the solidification process of the light-curing glue by the change of the wavelength of the reflected light.

[0039] The material of the light-transmitting sleeve assembly 2 is one or more of glass, polyetherimide, polymethyl methacrylate, polystyrene and polycarbonate. It can be understood that any material having a relatively high transmittance to the wavelength of light capable of solidifying the glue can be used to manufacture the light-transmitting sleeve assembly 2. For example, when the light-transmitting sleeve assembly 2 is made of glass, a glass thickness greater than 0.80@10mm can be used.

[0040] In the solidification process of the light-curing glue, a three-dimensional network structure is usually formed, and the volume is generally shrunk, accompanied by stress. The fiber grating is sensitive to stress, and the change of the stress received by the fiber grating is reflected on the center wavelength of the reflected light. Therefore, the fiber grating assembly 1 is used as a stress sensor in the embodiment, and the change of the center wavelength of the reflected light is used to determine the stress received by the fiber grating assembly 1, so as to measure the solidification process of the light-curing glue, such as the change of the solidification shrinkage rate of the light-curing glue with time.

[0041] In addition, the light-transmitting sleeve is used as a container for bearing the light-curing glue in contact with the fiber grating assembly 1, so that the light-curing glue can receive light in real time, and the fiber grating assembly can reflect light in real time, and the change of the wavelength of the reflected light can be used to realize the real-time measurement of the solidification process of the light-curing glue.

[0042] In actual use, it is relatively difficult to inject the light-curing glue into the light-transmitting sleeve assembly 2 due to the fact that the light-transmitting sleeve assembly 2 is closed on all sides. Therefore, the embodiment further provides a preferred embodiment, as shown in Figure 2 The outer wall of the light-transmitting sleeve assembly 2 is provided with a hole 21 penetrating into the light-transmitting sleeve assembly 2, and the hole 21 is aligned with the position of the grating array 11. The hole 21 is used for injecting the light-curing glue into the light-transmitting sleeve assembly 2. In an alternative embodiment, the diameter of the hole 21 can be 1-2mm, and more specifically, 1.5mm.

[0043] In an alternative embodiment, in order to prevent the light-curing glue from leaking and to fix the position of the light-transmitting sleeve and the fiber grating assembly 1, as shown in Figure 3 The pipe opening 22 of the light-transmitting sleeve assembly 2 is closed by adhesive. The outer wall of the light-transmitting sleeve assembly 2 corresponding to the position of the pipe opening 22 of the light-transmitting sleeve assembly 2 through which the optical fiber 12 passes is also glued to fix the position of the light-transmitting sleeve assembly 2.

[0044] In this optional embodiment, the present embodiment also has a further technical effect, which is analyzed as follows:

[0045] In the prior art, although there are a small number of research devices using fiber gratings for light curing measurement, in the prior art, the material to be measured (i.e. the light curing glue) often diffuses in multiple directions during the curing process, which on the one hand disperses the stress generated by the curing of the material to be measured, resulting in a large attenuation of the force acting on the fiber grating, thereby reducing the sensitivity of the curing measurement, and on the other hand, the stress direction received by the fiber grating is complex, making it difficult to accurately analyze the stress and the curing process. In the present embodiment, since the periphery of the light-transmitting sleeve (i.e. the pipe opening 22) is closed, it can be understood as a long cylindrical container, which limits the light curing glue in this long cylindrical container, so that it can only have radial displacement and stress (i.e. in the direction of the fiber grating assembly), and cannot have axial flow, thereby concentrating the stress generated by the curing of the curing glue on the radial direction of the fiber grating, reducing the dispersion of the stress acting on the fiber grating, and at the same time, fixing the direction of the stress, thereby reducing the difficulty of analyzing the stress and the curing process, and improving the measurement sensitivity. It should be noted that in the present embodiment, the radial direction and the axial direction are described with reference to the fiber grating assembly as the reference body, the axial direction refers to the direction towards the two ends of the optical fiber, and the radial direction refers to the direction perpendicular to the line connecting the two ends of the optical fiber.

[0046] In one practical application scenario, as shown in Figure 4 The device further comprises a coupling assembly 3, a spectrum analysis assembly 4 and a light source assembly 5; the exit end of the light source assembly 5 is connected to the first port of the coupling assembly 3, one end of the fiber grating assembly 1 is connected to the second port of the coupling assembly 3, and the spectrum analysis assembly 4 is connected to the third port of the coupling assembly 3; the light source assembly 5 is used to provide incident light for the fiber grating assembly 1; the coupling assembly 3 is used to transmit the incident light to the fiber grating and receive the reflected light from the fiber grating, so as to return the reflected light to the spectrum analysis assembly 4. The spectrum analysis assembly 4 is used to receive the reflected light from the fiber grating assembly 1 to measure the wavelength of the reflected light. In actual use, the spectrum analysis assembly 4 can be a spectrum analyzer, and the coupling assembly 3 can be a coupler.

[0047] In order to obtain better measurement sensitivity, the present embodiment also experimentally obtains a set of more optimal applicable sizes, which are as follows:

[0048] The inner wall diameter d1 of the light-transmitting sleeve assembly 2 is greater than the outer diameter d2 of the fiber grating assembly 1. The ratio between the inner wall diameter d1 of the light-transmitting sleeve assembly 2 and the outer diameter d2 of the fiber grating assembly 1 is less than 25. That is, d1:d2>1 and d1:d2<25. Under this size condition, the curing glue can be well limited, and the stress is concentrated in the radial direction of the fiber grating.

[0049] The ratio between the length L1 of the light-transmitting sleeve assembly 2 and the length L2 of the grating array 11 is less than 3. The ratio between the length L1 of the light-transmitting sleeve assembly 2 and the length L2 of the grating array 11 is greater than 1.5. That is, L1:L2<3 and L1:L2>1.5.

[0050] In a preferred embodiment, the reflectivity of the fiber grating assembly 1 is greater than 10%. The initial center wavelength of the fiber grating assembly 1 is 1540-1560 nm. The initial center wavelength is the center wavelength of the fiber grating when it is not stressed.

[0051] In a specific application scenario, the strain sensitivity coefficient of the device is 10.70-10.80 pm / (nm*με).

[0052] In combination with a specific manufacturing process, the embodiment also provides a more specific embodiment: the length L of the grating array 11 of the fiber grating is 3-6 mm, for example, the length of the grating array 11 is 4 mm, and the length of the light-transmitting sleeve assembly 2 is 8 mm. The outer diameter of the fiber grating is 250 um. The inner diameter of the light-transmitting sleeve assembly 2 is 3 mm. grating For example, the length of the grating array 11 is 4 mm, and the length of the light-transmitting sleeve assembly 2 is 8 mm. The outer diameter of the fiber grating is 250 um. The inner diameter of the light-transmitting sleeve assembly 2 is 3 mm.

[0053] Embodiment 2:

[0054] The utility model is based on the method described in embodiment 1, combined with specific application scenarios, and the implementation process in the characteristic scene of the utility model is described by the technical description in the related scene.

[0055] In this embodiment, the light-curing glue is ultraviolet glue that can be cured by 365 nm ultraviolet light, and glass sleeve is used as the light-transmitting sleeve assembly 2. For example, the length of the grating array 11 is 4 mm, and the length of the light-transmitting sleeve assembly 2 is 8 mm. The outer diameter of the fiber grating is 250 um. The inner diameter of the light-transmitting sleeve assembly 2 is 3 mm. Figure 3As shown, the device for measuring photocurable adhesives provided in this embodiment includes: a fiber optic grating and glass sleeve assembly, a 3dB coupler (i.e., coupling assembly 3), a C-band broadband light source (i.e., light source assembly 5), and a spectrometer (i.e., spectrometer analysis assembly 4). The fiber optic grating and glass sleeve assembly consists of a fiber optic grating (i.e., fiber optic grating assembly 1), a glass sleeve (i.e., light-transmitting sleeve assembly 2), side adhesive, a 1mm optical fiber (i.e., an optical fiber connected to the outside of the glass sleeve), and an optical fiber connector. The fiber optic grating consists of a grating array 11 and two 250um optical fibers 12. The glass sleeve includes a central hollow region and a dispensing channel 21.

[0056] Based on the principle of fiber Bragg grating sensing and through experimental exploration, it was found that in order to obtain a relatively large strain sensitivity coefficient, the ratio β of the diameter of the glass sleeve surrounding the fiber Bragg grating to the diameter of the fiber Bragg grating needs to be less than 25. The ratio γ of the length of the UV-coated cylinder to be tested surrounding the fiber Bragg grating to the length of the fiber Bragg grating needs to be less than 3.

[0057] In some embodiments, the center wavelength of the fiber Bragg grating is 1540–1560 nm. The reflectivity of the fiber Bragg grating is >10%. The length L of the fiber Bragg grating array 11 is... grating It is 3-6mm.

[0058] In a more preferred embodiment, the center wavelength of the fiber Bragg grating is 1548–1562 nm. The reflectivity of the fiber Bragg grating is >30%. The coating type is acrylate or polyimide. grating The length L of the glass sleeve encasing the fiber Bragg grating is 4mm. tube =γ·L grating Considering process adaptability, 1.5 < γ < 3. In some embodiments, γ = 2, i.e., L tube =2·L grating =8mm.

[0059] The fiber grating has a diameter of 250 μm. The diameter of the plastic sheath area of ​​the fiber is 1 mm, hence it is called a 1 mm fiber. The outer diameter of the fiber optic connector is 2.5 mm. The inner diameter of the glass sleeve encasing the fiber grating needs to be larger than the outer diameter of the fiber optic connector to allow the fiber grating to be placed inside the glass sleeve. The inner diameter d of the glass sleeve encasing the fiber grating is... cube The diameter of the fiber Bragg grating needs to be less than 25 times, i.e., 6.25 mm. In some embodiments, d cube =3mm.

[0060] The length of the fiber Bragg grating needs to be slightly greater than the length L of the glass sleeve surrounding the fiber Bragg grating. tube This leaves some space for applying adhesive to both ends of the glass sleeve.

[0061] Considering the actual process and material cost, the outer diameter D of the glass sleeve cube The size is d cube +4mm<D cube <d cube +10mm. In some embodiments, D cube =10mm.

[0062] The material of the glass sleeve needs to have a large transmittance to 365nm ultraviolet light, such as greater than 0.80@10mm glass thickness. The glass material can be FK5HTi, N-FK5, N-FK58, N-PK51, N-BK7, etc.

[0063] The glass sleeve has a glue hole (i.e. hole 21). Considering the viscosity of the precision coupling ultraviolet glue commonly used in the optical module and optical device industry is 100-100000mPa·s, on the one hand to ensure smooth dispensing, on the other hand the diameter of the glue hole should not be too large relative to the inner diameter of the center hollow area of the glass sleeve. The diameter of the glue hole is 1-2mm. The diameter of the glue hole can be 1.5mm.

[0064] After the 250um optical fiber 12 is put into the glass sleeve, the 250um optical fiber 12 and the glass sleeve need to be glued and fixed to form a side adhesive and block the gaps at both ends of the glass sleeve to prevent the outflow of the internal ultraviolet glue to be tested. The ultraviolet glue used for filling and fixing needs to be relatively thick, with a viscosity of 30000-200000mPa·s. It can be UV cured alone.

[0065] The common end of the 3dB coupler is connected to the fiber grating assembly 1. One branch end of the 3dB coupler is connected to a C-band broadband light source. The other branch end of the 3dB coupler is connected to a spectrum analyzer. The light emitted by the C-band broadband light source enters the fiber grating and glass sleeve assembly after passing through the 3dB coupler, and enters the spectrum analyzer from the other branch end of the 3dB coupler after being reflected by the grating array 11.

[0066] The wavelength of the light emitted by the C-band broadband light source needs to cover the range of 1540-1560nm to match the characteristic reflection wavelength of the fiber grating.

[0067] The wavelength measurement accuracy of the spectrum analyzer needs to be ≤10pm. The wavelength measurement accuracy of 10pm is the accuracy level of conventional spectrum analyzers on the market.

[0068] The principle of measuring the curing process based on the device for measuring the light curing glue provided in the embodiment is as follows:

[0069] The fiber grating reflects incident light of a specific wavelength (λ B ).

[0070] λ B = 2n eff Λ (1)

[0071] where n eff is the effective refractive index of the grating, and Λ is the intrinsic period of the grating. The Bragg reflection center wavelength λ B of the fiber grating varies with n eff and Λ. Stress affects the reflection center wavelength through the photoelastic effect and the change of grating period. Temperature affects the reflection center wavelength through the thermo-optic effect and thermal expansion.

[0072] When the fiber grating is only subjected to stress, the effective refractive index and the period of the fiber grating change, causing the shift of the reflection center wavelength:

[0073]

[0074] The change of the refractive index of the grating when subjected to stress is:

[0075]

[0076] where ε is the axial stress, μ is the Poisson's ratio of the core material, P 11 , P 12 are the radial and axial photoelastic coefficients, and P e is the effective photoelastic coefficient.

[0077] It is assumed that the fiber grating is absolutely uniform, i.e., the relative change rate of the period of the grating is consistent with the relative change rate of the physical length of the grating:

[0078]

[0079] The formula for calculating the change rate of the reflection center wavelength of the bare fiber grating is obtained by combining (2), (3), and (4):

[0080]

[0081] In the curing process of the measured material using the device for measuring light-cured glue described in the embodiment, the measured material will wrap the grating. After the measured material receives an external force, the force transmitted to the grating area is greatly attenuated and the direction is complex. The overall effect on the change of the reflection center wavelength is represented by the strain sensitivity coefficient κ ε . The corresponding formula is:

[0082]

[0083] Wherein, the uncured ultraviolet adhesive is liquid, with fluidity, containing a large number of small molecular monomer resin, photoinitiator, filler, diluent, catalyst. When ultraviolet light irradiation, monomer resin and photoinitiator crosslinking chemical reaction occurs with the aid of catalyst, forming a three-dimensional network structure, the process will have volume shrinkage, accompanied by stress. The cured ultraviolet adhesive is solid.

[0084] In order to accurately match the stress of the ultraviolet adhesive under ultraviolet light irradiation and the stress of the ultraviolet adhesive on the fiber grating, the position change of the ultraviolet adhesive needs to be constrained. It is limited in a narrow cylindrical container, so that it can only have radial displacement and stress, and cannot have axial flow.

[0085] Using the device described in this embodiment, a standard adhesive sample with a known linear curing shrinkage rate (0.75%) is measured, and the initial Bragg reflection center wavelength is 1549.73 nm. After irradiation with 500 mW / cm 2 of 365 nm ultraviolet light for 55 s, the Bragg reflection center wavelength no longer drifts and stabilizes at 1549.60 nm. The sampling time interval for recording wavelength data is 5 s. The strain sensitivity coefficient of the device is calculated to be 0.0003 nm / mW / cm

[0086]

[0087] Using the device, the Bragg reflection center wavelength drift of an ultraviolet adhesive under three ultraviolet irradiation conditions is measured, which is -0.13 nm@500 mW / cm 2 , -0.18 nm@1000 mW / cm 2 , -0.37 nm@2000 mW / cm 2 . The data results are shown in Figure 5 . According to this, the curing shrinkage rates of the adhesive under the three ultraviolet irradiation conditions are calculated to be 0.74%, 1.14%, and 2.23%, respectively. The change trend of the curing shrinkage rate with time can also be clearly seen, and the shortest time required for the ultraviolet adhesive to complete curing is known. Therefore, the device can realize real-time monitoring and measurement of the linear curing shrinkage rate of trace ultraviolet adhesive, and can explore the optimal ultraviolet curing conditions of a specific ultraviolet adhesive quickly and accurately at low cost.

[0088] Using the device, the Bragg reflection center wavelengths of three ultraviolet adhesives under one ultraviolet irradiation condition are measured, which are -0.13 nm, -0.17 nm, and -0.08 nm, respectively. The data results are shown in Figure 6 . According to this, the curing shrinkage rates of the three ultraviolet adhesives under the ultraviolet irradiation condition of 500 mW / cm 2The curing shrinkage rates under the condition of ultraviolet light irradiation are 0.74%, 0.98% and 0.51% respectively. The change trend of the curing shrinkage rate with time can be clearly seen, and the shortest time required for the ultraviolet glue to end curing is known. Therefore, the device can be used for the performance comparison of different ultraviolet glues and the selection of high-performance ultraviolet glue at low cost, quickly and accurately. In the case that the wavelength measurement accuracy of the spectrum analyzer is 10pm, the measurement accuracy of the linear curing shrinkage rate of the ultraviolet glue by the device reaches 60ppm.

[0089] The device can realize the real-time monitoring and measurement of the linear curing shrinkage rate of trace ultraviolet glue, and can compare the performance of different ultraviolet glues and explore the best ultraviolet curing conditions of a specific ultraviolet glue at low cost, quickly and accurately.

[0090] The above only describes the preferred embodiments of the utility model, and does not limit the utility model, and any modification, equivalent replacement, improvement, etc. within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. An apparatus for measuring light-cured glue, characterized by, The fiber grating assembly (1) and the light-transmitting sleeve assembly (2) are provided. The fiber grating assembly (1) passes through the light-transmitting sleeve assembly (2), and a grating array (11) of the fiber grating assembly (1) is located inside the light-transmitting sleeve assembly (2). The light-transmitting sleeve assembly (2) is internally provided with a space for accommodating light-curing glue. The fiber grating assembly (1) is used for receiving incident light and reflecting the light, so as to measure the curing process of the light-curing glue through the change of the wavelength of the reflected light.

2. The apparatus for measuring light-cured glue according to claim 1, wherein, The outer wall of the light-transmitting sleeve assembly (2) is provided with a hole (21) penetrating into the inside of the light-transmitting sleeve assembly (2), and the hole (21) is aligned with the position of the grating array (11); the hole (21) is used for injecting light-curing glue into the inside of the light-transmitting sleeve assembly (2).

3. The apparatus for measuring light-cured glue according to claim 1, wherein, The coupling assembly (3), the spectrum analysis assembly (4) and the light source assembly (5) are further provided. An exit end of the light source assembly (5) is connected to a first port of the coupling assembly (3), one end of the fiber grating assembly (1) is connected to a second port of the coupling assembly (3), and the spectrum analysis assembly (4) is connected to a third port of the coupling assembly (3). The light source assembly (5) is used for providing incident light for the fiber grating assembly (1). The spectrum analysis assembly (4) is used for receiving reflected light from the fiber grating assembly (1) to measure the wavelength of the reflected light.

4. The apparatus for measuring light-cured glue according to claim 1, wherein, The tube opening (22) of the light-transmitting sleeve assembly (2) is closed by using glue.

5. The apparatus for measuring light-cured glue according to claim 1, wherein, The material of the light-transmitting sleeve assembly (2) is one or more of glass, polyetherimide, polymethyl methacrylate, polystyrene and polycarbonate.

6. The apparatus for measuring light-cured glue according to claim 1, wherein, The ratio between the inner wall diameter d1 of the light-transmitting sleeve assembly (2) and the outer diameter d2 of the fiber grating assembly (1) is less than 25.

7. The apparatus for measuring light-cured glue according to claim 1, wherein, The ratio between the length L1 of the light-transmitting sleeve assembly (2) and the length L2 of the grating array (11) is less than 3.

8. The apparatus for measuring light-cured glue according to claim 1, wherein, The ratio between the length L1 of the light-transmitting sleeve assembly (2) and the length L2 of the grating array (11) is greater than 1.

5.

9. The apparatus for measuring light-cured glue according to claim 1, wherein, The reflectivity of the fiber grating assembly (1) is greater than 10%.

10. The apparatus for measuring light-cured glue according to claim 1, wherein, The initial center wavelength of the fiber grating assembly (1) is 1540-1560 nm.

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