Glass processing method for fragment identification and tracing

Abstract

The invention discloses a glass processing method for fragment identification and tracing. The method comprises the following steps: determining a plurality of laser code depths in the thickness direction of a glass raw material according to linear cutting requirements and laser code requirements; a laser is adopted to form invisible codes with unique codes and consistent code point sizes at all depths in the direction from the bottom surface to the top surface through laser; reading and associating all invisible code information; carrying out linear cutting to obtain a plurality of glass sheets; and in the back-end process, reading the invisible code, and binding the invisible code with the production quality data to realize full-life-cycle tracing. Through the multi-layer depth coding and intelligent code reading strategy, it is ensured that the invisible code can still be stably recognized after being subjected to ink preparation and other back-end processes, the influence on the glass strength is small, the problems that a traditional identifier is prone to being lost and is difficult to track in a fragmented mode are solved, and the method is suitable for intelligent manufacturing and automatic tracing scenes of ultra-thin glass.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of glass processing, in particular to a glass processing method for piece identification and traceability. BACKGROUND

[0002] In the glass manufacturing process, it is often necessary to cut large-size raw materials into multiple small-size glass pieces through a wire cutting process, and then enter subsequent processes such as coating, silk printing, and bonding. In this context, how to realize the independent identity identification and full life cycle traceability of each glass piece has become a key link to improve production yield and realize quality closed-loop management. Currently, the commonly used glass identification methods in the industry mainly include surface code spraying, label pasting, and laser surface etching. However, these traditional identification technologies have exposed problems such as inability to support piece traceability, easy damage or obstruction of identification, affecting appearance and function, and poor tamper resistance when applied to ultra-thin glass, especially in scenarios that go through multiple post-processes.

[0003] To solve the above problems, in recent years, a technology based on femtosecond or picosecond laser-induced micro-modification in transparent materials has emerged, i.e., the "invisible code" technology. However, existing invisible code technologies mostly use a single-layer coding scheme, i.e., only one coding layer is set in the entire thickness direction of the glass. This structure still has obvious limitations when facing multiple piece cutting scenarios, and cannot assign independent identities to different sub-pieces on the same raw material. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a glass processing method for piece identification and traceability in view of the above defects of the prior art.

[0005] To achieve the above purpose, the present application provides a glass processing method for piece identification and traceability, which comprises the following steps: Step S1: determining multiple radium code depths in the thickness direction of the glass raw material according to the wire cutting requirements and the radium code requirements, and cutting the glass raw material into multiple glass pieces along the thickness direction by the wire cutting process; Step S2: using a laser to form invisible codes at the radium code depths in the direction from the bottom surface to the top surface of the glass raw material, the invisible codes being invisible to the naked eye and identifiable by an optical camera under the irradiation of a specific light source; the invisible codes at each depth have a unique code value; when forming the invisible codes at each depth, if the laser light output mode is a point mode, the laser marking frequency and single-point action time are kept constant; for the coding layers at different depths, the laser output power is adjusted so that the larger the depth, the higher the laser power, and the invisible code point sizes at each depth are consistent; Step S3: reading and recording each invisible code, and establishing a data association between all invisible codes in the same glass raw material; Step S4: cutting the glass raw material according to the wire cutting process to obtain a plurality of independent glass sheets; Step S5: performing post-process treatment on the independent glass sheet, and reading the internal invisible code before and after the treatment, binding the production information and quality data of the independent glass sheet with the invisible code; By iteratively optimizing the laser machining parameters, it is ensured that the invisible code is not visible to the naked eye, can be stably read after laser and after the post-process treatment, and the impact on the strength of the glass body is within the preset range; the post-process includes preparing a light-colored ink layer or a dark-colored ink layer on the glass surface.

[0006] In the glass processing method for slice identification and traceability of the application, in step S1, the method for determining a plurality of radium code depths in the thickness direction of the glass raw material according to the wire cutting requirements and the radium code requirements comprises: According to the wire cutting wire consumption, the target glass sheet thickness, and the preset position of the invisible code in the glass sheet, the absolute depth position of each invisible code in the thickness direction of the glass raw material is calculated.

[0007] In the glass processing method for slice identification and traceability of the application, in step S2, an ultraviolet picosecond laser is used for invisible code laser processing.

[0008] In the glass processing method for slice identification and traceability of the application, the thickness of the glass raw material is not more than 5 mm.

[0009] In the glass processing method for slice identification and traceability of the application, in step S3, the optical detection system for reading the invisible code comprises: A blue ring light source arranged below the glass raw material, and an optical camera arranged above the glass raw material, with the lens directly facing the blue ring light source.

[0010] In the glass processing method for slice identification and traceability of the application, in step S5, after the light-colored ink layer is formed on the surface of the glass sheet, the invisible code is read in the following way: An optical camera is arranged above the opposite side of the light-colored ink layer, and a white parallel light source is arranged on one side of the camera lens, which is obliquely irradiated on the surface of the glass sheet to realize high-contrast imaging.

[0011] In the glass processing method for slice identification and traceability of the application, in step S5, after the dark-colored ink layer is formed on the surface of the glass sheet, the invisible code is read in the following way: An optical camera is arranged above the opposite side of the dark-colored ink layer, and a red ring light source is arranged on both sides of the camera lens, and the image signal-to-noise ratio of the invisible code is improved by synchronous side illumination on both sides.

[0012] The glass processing method for slice identification and traceability provided by the present application adopts a two-dimensional matrix code or Data Matrix code format for the invisible code, and the encoded information includes a glass batch number, a glass slice number, process parameters, and a timestamp.

[0013] The present application has the following advantages: the present application realizes independent identification of each glass slice after cutting by arranging multiple invisible codes in the thickness direction of the glass raw material. The unique coding and data association mechanism supports accurate traceability after slicing. Iterative optimization of laser parameters ensures that the invisible code can be read before and after the subsequent process without affecting the mechanical strength of the glass. Compared with the traditional surface inkjet coding or label method, the present application has the advantages of strong anti-interference, non-tamperability, and compatibility with automatic production lines, significantly improving the intelligence and traceability of the glass manufacturing process. BRIEF DESCRIPTION OF DRAWINGS

[0014] The accompanying drawings, which are included to provide a further understanding of the present application, form a part of the present application and help to explain the present application together with the specification. The illustrative embodiments described herein and their descriptions serve to explain the present application and do not limit the present application in any manner. In the drawings: Figure 1 The present application provides a glass processing method for slice identification and traceability. DETAILED DESCRIPTION

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in detail with reference to the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0016] The embodiments of the present application will be described in further detail below with reference to the accompanying drawings of the present application. It should be understood that the described embodiments are only used to illustrate and explain the present application, and are not used to limit the present application.

[0017] As shown in the drawings, Figure 1 The present application provides a glass processing method for slice identification and traceability, which comprises the following steps: Step S1: determining multiple invisible code depths in the thickness direction of the glass raw material according to the wire cutting requirements and the invisible code requirements, wherein the wire cutting process cuts the glass raw material into multiple glass slices along the thickness direction.

[0018] The method for determining multiple invisible code depths in the thickness direction of the glass raw material according to the wire cutting requirements and the invisible code requirements comprises: According to the wire cutting before the amount of wire, the cutting line diameter consumption, the target glass sheet thickness and the preset position of the invisible code in the glass sheet, the absolute depth position of each invisible code in the glass raw material thickness direction is calculated.

[0019] The present application has no special restriction on the laser code requirement of the glass sheet. In some embodiments of the present application, the glass raw material is cut into a plurality of glass sheets, and a laser invisible code is required on each glass sheet. In other embodiments of the present application, the glass raw material is cut into a plurality of glass sheets, and a laser invisible code is required on part of the glass sheets and no laser invisible code is required on part of the glass sheets.

[0020] The present application also has no special restriction on the number of invisible codes on the same glass sheet. In some embodiments of the present application, only one invisible code is required on each glass sheet requiring a laser code. In other embodiments of the present application, one invisible code is required on part of the glass sheets and multiple invisible codes are required on part of the glass sheets.

[0021] The present application has no special restriction on the depth of the invisible code in the glass sheet. In order to prevent affecting the performance of the glass sheet, the invisible code is as far away from the surface of the glass sheet as possible, and the position of the invisible code at each depth is avoided to overlap with the functional area. In some embodiments of the present application, the position of the invisible code is the center position in the thickness direction of each glass sheet.

[0022] In the embodiments of the present application, after the wire cutting requirement and the laser code requirement are determined, the absolute depth position of each invisible code in the thickness direction of the glass raw material is calculated according to the wire cutting before the amount of wire, the cutting line diameter consumption, the target glass sheet thickness and the preset position of the invisible code in each glass sheet. By comprehensively considering the factors such as the amount of wire, the wire cutting loss and the target thickness, the depth position of each invisible code is accurately calculated to ensure that the invisible code in each glass sheet after cutting is located in the preset area, avoid the encoding missing or offset caused by cutting deviation, and improve the encoding availability and reading success rate. For example, the thickness of the glass raw material is 3.95mm, before wire cutting, the amount of wire on both surfaces of the glass raw material is 0.18mm, the glass raw material needs to be cut three times in the thickness direction to divide the glass raw material into four glass sheets, and the wire cutting consumption is 0.1mm. From the top surface to the bottom surface of the glass raw material, the thickness of the front three glass sheets is 0.7mm, and the invisible code needs to be laser on the front three glass sheets. The lowest glass sheet does not need to be laser invisible. Assuming that the invisible code is in the center position in the thickness direction of each glass sheet, the laser code depth corresponding to the three glass sheets from top to bottom can be calculated as 0.53mm, 1.33mm and 2.13mm respectively.

[0023] Step S2: using a laser to form a hidden code at each depth from the bottom surface to the top surface of the glass raw material, the hidden code is invisible to the naked eye and can be recognized by an optical camera under the irradiation of a specific light source; the hidden code at each depth has a unique code value; when forming the hidden code at each depth, if the laser light output mode is a point mode, the laser marking frequency and single-point action time are kept constant; for different depth code layers, the laser output power is adjusted so that the deeper the depth, the higher the laser power, and the code point size of each depth is consistent.

[0024] In the embodiment of the present application, in step S2, an ultraviolet picosecond laser is used for hidden code laser processing. The wavelength of the ultraviolet picosecond laser is 355 nm, the effective focal depth is short, the thermal zone is <1 µm, ordinary glass has a certain absorption to 355 nm, and combined with nonlinear multi-photon absorption, energy can be deposited instantaneously at the internal focusing point to form a burst cavity. Compared with 532 nm or 1064 nm, the threshold energy required by the ultraviolet band is lower, the single-point energy can be reduced, the risk of micro-cracks is reduced, and the "hidden code" with extremely thin, extremely shallow and no cracks is suitable.

[0025] In some embodiments of the present application, the thickness of the glass raw material is not more than 5 mm. The maximum power of the ultraviolet picosecond laser is small, and the full power is only 2 W. The energy loss of the laser in the glass will increase with the increase of the thickness of the glass. If the glass raw material is too thick, the refractive and scattering energy loss will be too large after the laser reaches a certain depth, and the hidden code cannot be laser marked.

[0026] In the embodiment of the present application, when laser marking at each depth, if the laser light output mode is a point mode, the laser marking frequency and single-point action time are kept constant; for different depth code layers, the laser output power is adjusted so that the deeper the depth, the higher the laser power, to compensate for the attenuation of the optical path and ensure the consistency of the code point quality of each layer, thereby improving the reading consistency and identification accuracy of multi-layer coding. For example, if the code depths are 0.53 mm, 1.33 mm and 2.13 mm respectively, the laser light output mode at each depth is a point mode, the marking frequency is 400 KHz, and the single-point action time (i.e. dot marking time) is 0.03 ms. The laser power at a depth of 0.53 mm is 0.28 W, the laser power at a depth of 1.33 mm is 0.38 W, and the laser power at a depth of 2.13 mm is 0.45 W. In the embodiment of the present application, the size of the code point is measured by a code depth machine.

[0027] In the embodiment of the present application, the laser is equipped with a height measuring probe, which measures the height of the surface of the glass raw material. The central control program calculates the displacement required for the laser focal point to move at different depths, controls the Z-axis to move to the target position, and then triggers the laser to mark the code.

[0028] The laser invisible code in the glass will cause the glass to be metamorphosed, and if the laser is from top to bottom, the metamorphosed glass will block the laser, and the code effect will be poor. Therefore, in the embodiment of the present application, the codes are sequentially radium from the bottom surface to the top surface.

[0029] In the embodiment of the present application, the invisible code adopts a two-dimensional matrix code or a Data Matrix code format, and the encoded information includes a glass batch number, a glass sheet number, a process parameter and a timestamp. In addition, other encoded information can be added as needed. The two-dimensional matrix code or the Data Matrix code is used as the encoding format, has the advantages of high information density, strong error correction capability, fast recognition speed, etc., can integrate multi-dimensional data such as batch number, timestamp, process parameter, etc., and meets the demand for product life cycle management in the industrial 4.0 environment.

[0030] In some embodiments of the present application, the invisible code is in the format of a Data Matrix code, a field lens with a focal length F of 32 mm is used, and when the field lens and the glass raw material are kept fixed during the radium, the processable area is 5 mm*5 mm, the actual processed invisible code size is 0.4 mm*0.4 mm, and the code point size is 1.8 um. If the size of the invisible code to be radium exceeds the processable area, the glass raw material can be moved in the horizontal direction to radium in different areas to splice a large-area invisible code. If multiple codes need to be radium at the same depth in the same glass sheet, the glass raw material can also be moved in the horizontal direction to achieve radium at multiple places.

[0031] In some embodiments of the present application, three invisible codes are radium on each glass raw material, the processing time is 7 s / pcs, 2000 glass raw materials need 4 hours to process, and the yield is 99.99%.

[0032] Step S3: reading and recording each invisible code, and establishing data association between all invisible codes in the same glass raw material. The data association between all invisible codes in the same glass raw material facilitates subsequent tracing of semi-finished products or finished products manufactured from the same glass raw material.

[0033] In the embodiment of the present application, the optical detection system for reading the invisible code in step S3 comprises: A blue annular light source arranged below the glass raw material, and an optical camera arranged above the glass raw material and directly facing the blue annular light source, which captures the scattering light signal of the invisible code by transmission imaging. After the invisible code is radium on the glass raw material, the detection method of using the bottom blue annular light source for transmission illumination and the top camera for acquisition is adopted, the strong scattering characteristic of the invisible code to blue light is utilized, a high-contrast image is formed, and all depth layers of the invisible code can be quickly and stably read before the glass is processed, which provides reliable input for subsequent cutting and data association.

[0034] In the embodiment of the present application, after laser marking all the depth of the invisible code, each invisible code is read and recorded. When reading, it can be read in the order from top to bottom, or in the order from bottom to top. By aligning the focal length of the optical camera to the depth of each invisible code in turn, the reading of the invisible code at each depth can be realized.

[0035] Step S4: cutting the glass raw material according to the wire cutting process to obtain a plurality of independent glass sheets. When cutting, the cutting position and cutting loss amount need to be accurately controlled to ensure that the glass sheet formed after cutting has a predetermined thickness, and the invisible code is at a pre-calculated position.

[0036] Step S5: performing post-process treatment on the independent glass sheet, and reading the internal invisible code before and after the treatment, and binding the production information and quality data of the independent glass sheet with the invisible code.

[0037] By iteratively optimizing the laser marking process parameters, it is ensured that the invisible code is not visible to the naked eye, can be stably read after marking and after experiencing post-process treatment, and the impact on the strength of the glass body is within a predetermined range; the post-process includes preparing a light-colored ink layer or a dark-colored ink layer on the glass surface.

[0038] In the embodiment of the present application, to ensure that the invisible code is not visible to the naked eye, can be stably read after marking and after experiencing post-process treatment, and the impact on the strength of the glass body is within a predetermined range, steps S1-S5 need to be repeated, and the laser marking process parameters need to be iteratively optimized so that the invisible code can meet the requirements at each stage. In the embodiment of the present application, the effect of the invisible code is accepted by the following standards, and the laser processing parameters are fixed: (1) The power / pulse width just passes the "threshold value", which can mark small micro-explosion points in the glass, and at the same time, the crack does not extend to the surface, so that the invisible code can not be broken after chemical hardening.

[0039] (2) The position of the invisible code occurs at a specified depth, the adjustment frequency and multi-pulse dotting time are adjusted to allow the specified position to absorb heat without branching up and down.

[0040] (3) The code type has a refractive index difference <0.0001 under visible light, which is not visible to the naked eye, and the contrast between the code point and the background under subsequent processing under lateral or bidirectional illumination is >30%, so that the code reading rate is 100%.

[0041] In the embodiment of the present application, the glass raw material is microcrystalline glass, the laser light output mode is selected as point mode, and a large number of verifications are carried out in the range of marking frequency 200KHz-1000KHz, laser power 0.20W-0.30W, and single-point action time 0.03ms-0.1ms to test the stability and visibility of the invisible code. Since the invisible code is visible in the later stage when the single-point action time is about 0.1ms, the value is excluded. According to the intensity requirement, a batch of parameter values affecting the intensity are excluded, and after a large number of materials are made, it is found that the parameter values of marking frequency 400KHz, laser power 0.28W, and single-point action time 0.03ms have high stability, small influence on the strength of the glass, high code reading rate after the preparation of different ink layers in the later stage process, and invisibility. For different glass materials, different later stage processes, and different code point size requirements, the selected processing parameters may be different. The laser light output mode can also be selected as a circular mode, and in the circular mode, a large number of verification work is also needed to fix the laser processing parameters, and the laser processing parameters that need to be adjusted in the circular mode include marking speed, light-on delay, and light-off delay.

[0042] In some embodiments of the present application, after the shallow ink layer is formed on the surface of the glass sheet in step S5, the invisible code is read in the following manner: An optical camera is arranged above the opposite side of the shallow ink layer, a white parallel light source is arranged on one side of the camera lens, and the white parallel light source is obliquely irradiated on the surface of the glass sheet to laterally illuminate the scattering light of the invisible code and realize high-contrast imaging.

[0043] When the shallow ink layer is formed on the surface of the glass, the white parallel light source is used for lateral illumination, the light is diffusely reflected on the ink, the diffusely reflected image received in the lens barrel is an image with dark code points, the image signal-to-noise ratio is significantly improved, and misreading or missing reading is avoided.

[0044] In some embodiments of the present application, after the deep ink layer is formed on the surface of the glass sheet in step S5, the invisible code is read in the following manner: An optical camera is arranged above the opposite side of the deep ink layer, red ring light sources are arranged on both sides of the camera lens, and the double-side synchronous lateral illumination is used to improve the image signal-to-noise ratio of the invisible code and ensure that the invisible code can be stably recognized in the high-absorption background.

[0045] When the deep ink layer is formed on the surface of the glass, the double-side synchronous lateral illumination of the red ring light sources is used to enhance the local brightness of the invisible code area and overcome the imaging blur problem caused by the background absorption; the red light waveband is selected to reduce the absorption of the ink layer, further improve the penetration ability and recognition stability, and expand the application range of the method in complex processes. When the red light is irradiated on the deep ink layer, the ink absorbs light and the reflected light source at the code point is bright, and the image received in the lens barrel has dark background.

[0046] The present application realizes that each piece of glass can be independently identified after cutting by setting multi-layer invisible code in the thickness direction of the glass raw material. The unique coding and data association mechanism is adopted to support accurate traceability after the glass is cut. The laser parameters are iteratively optimized to ensure that the invisible code can be read before and after the subsequent process, and the mechanical strength of the glass is not affected. Under the premise of keeping the marking frequency and action time constant, the laser power is increased with the increase of the laser depth to compensate for the energy attenuation of the light beam during the propagation in the glass, so as to ensure that the code point morphology and scattering characteristics of each depth layer are consistent, thereby improving the reading consistency and identification accuracy of multi-layer coding. By adapting the illumination scheme for reading the invisible code of different ink layers, the application range of the invisible code is improved. Compared with the traditional surface code spraying or label method, the present method has the advantages of strong anti-interference, non-tamperability, and compatibility with automatic production line, and significantly improves the intelligentization and traceability of the glass manufacturing process.

[0047] The above is only a specific embodiment of the present application, which cannot limit the scope of the present application. The equivalent changes made by the general technical personnel in the technical field according to the present application, and the changes well known by the technical personnel in the field, should still be within the scope covered by the present application.

Claims

1. A glass processing method for piece identification and traceability, characterized in that, The method includes the following steps: Step S1: Determine multiple laser marking depths in the thickness direction of the glass raw material according to the wire cutting requirements and laser marking requirements. The wire cutting process cuts the glass raw material into multiple glass sheets along the thickness direction. Step S2: Using a laser, invisible codes are formed sequentially at each laser depth from the bottom to the top surface of the glass material. These invisible codes are invisible to the naked eye but can be identified by an optical camera under specific light source illumination. Each invisible code at each depth has a unique encoding value. When laser-etching invisible codes at each depth, if the laser output mode is dot mode, the laser marking frequency and single-point action time are kept constant. For coding layers at different depths, the laser output power is adjusted so that the laser power is higher as the depth increases, and the size of the invisible code dots is consistent at each depth. Step S3: Read and record each invisible code, and establish data association between all invisible codes in the same glass material; Step S4: Cut the glass raw material according to the wire cutting process to obtain multiple independent glass sheets; Step S5: Perform post-processing on the independent glass sheet, and read its internal hidden code before and after processing, and bind the production information and quality data of the independent glass sheet with the hidden code; By iteratively optimizing the laser engraving parameters, it is ensured that the invisible code is not visible to the naked eye, can still be stably read after laser engraving and subsequent processing, and has no impact on the strength of the glass body within a preset range; the subsequent processing includes preparing a light-colored ink layer or a dark-colored ink layer on the glass surface.

2. The glass processing method for piece identification and traceability according to claim 1, characterized in that, In step S1, the method for determining multiple laser marking depths in the thickness direction of the glass raw material based on wire cutting requirements and laser marking requirements includes: Based on the amount of wire cut before wire cutting, the amount of wire diameter consumed, the thickness of the target glass sheet, and the preset position of the invisible code in the glass sheet, calculate the absolute depth position of each invisible code in the thickness direction of the glass material.

3. The glass processing method for piece identification and traceability according to claim 1, characterized in that, In step S2, an ultraviolet picosecond laser is used for laser processing of the invisible code.

4. The glass processing method for piece identification and traceability according to claim 3, characterized in that, The thickness of the glass material shall not exceed 5 mm.

5. The glass processing method for piece identification and traceability according to claim 1, characterized in that, In step S3, the optical detection system for reading the invisible code includes: A blue ring light source positioned below the glass material, and an optical camera positioned above the glass material with its lens facing the blue ring light source.

6. The glass processing method for segment identification and traceability according to claim 1, characterized in that, In step S5, after a light-colored ink layer is formed on the surface of the glass slide, the invisible code is read using the following method: An optical camera is positioned above the opposite side of the light-colored ink layer, and a white parallel light source is configured on one side of the camera lens. The white parallel light source illuminates the glass surface at an angle to achieve high-contrast imaging.

7. The glass processing method for piece identification and traceability according to claim 1, characterized in that, In step S5, after a dark ink layer is formed on the surface of the glass slide, the invisible code is read in the following way: An optical camera is positioned above the opposite side of the dark ink layer, with red ring light sources on both sides of the camera lens. The signal-to-noise ratio of the stealth code image is improved by simultaneous side illumination from both sides.

8. The glass processing method for piece identification and traceability according to claim 1, characterized in that, The hidden code adopts a two-dimensional matrix code or Data Matrix code format, and the encoded information includes glass batch number, glass sheet number, process parameters and timestamp.

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