Laser etching production process of signboard

Abstract

The invention discloses a laser etching production process of a signboard. The laser etching production process comprises the following steps: S1) manufacturing a light-transmitting surface shell; s2) spraying primer on the outer surface of the light-transmitting surface shell to form a primer layer; s3) colored paint is sprayed based on the primer layer to form a colored paint layer; s4, the middle ring laser etching area is subjected to laser etching, the laser etching depth is smaller than or equal to the thickness of the colored paint layer, and the laser etching depth gradually changes in a reciprocating mode in the first direction; s5) performing laser etching on the secondary outer ring laser etching area and the secondary inner ring laser etching area until the laser etching depth reaches the outer surface of the light-transmitting surface shell; according to the laser etching method, the colored paint layers which are stacked in multiple layers and gradually changed in color are matched with the gradually-changed laser etching depth, the gradually-changed color effect is achieved, and the layering sense, the stereoscopic impression and the diversity of laser etching patterns are improved.

Description

Technical Field

[0001] The invention relates to the technical field of laser engraving, and in particular to a laser engraving production process for a signboard. Background Art

[0002] Laser engraving is a surface treatment process that instantly converts light energy into heat energy, causing the surface material to melt or even vaporize instantly to form a mark.

[0003] The defects of the prior art are: on the one hand, CN112647100B discloses an ultra-environmentally friendly interior graphic display process, which forms a logo on the automobile interior by laser engraving after painting. The depth of the laser engraving always remains consistent, and the laser engraving pattern lacks three-dimensionality and layering, and the visual effect is single; on the other hand, the existing laser engraving pattern has a single color, lacks layering, and especially lacks a three-dimensional visual effect of color gradient.

[0004] Therefore, the prior art is in urgent need of a laser engraving production process for a signboard that can produce a color gradient. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects in the prior art, provide a laser engraving production process for identification plates, and increase the layering, three-dimensional effect and diversity of the laser engraving patterns.

[0006] In order to achieve the above technical effects, the technical solution of the present invention is: a laser engraving production process for a signboard, comprising the following steps: S1: manufacturing a light-transmitting shell, wherein the light-transmitting shell has an outer surface and an inner surface opposite to each other; S2: spraying a primer on the outer surface in S1, and curing the primer layer to form a primer layer; S3: spraying colored paint on the primer layer of the light-transmitting shell obtained in S2, and curing to form a colored paint layer, wherein the colored paint layer includes a first colored paint layer, a second colored paint layer and an Nth colored paint layer of different colors stacked one by one, N≥3; and the colors of two adjacent layers from the first colored paint layer to the Nth colored paint layer gradually transition; S4: The outer surface of the light-transmitting surface shell obtained in S3 is provided with a laser engraving area, and the laser engraving area is divided into an outer ring laser engraving area, a sub-outer ring laser engraving area, a middle ring laser engraving area, a sub-inner ring laser engraving area and an inner ring laser engraving area from the outside to the center; the middle ring laser engraving area is laser engraved, and the laser engraving depth is less than or equal to the thickness of the color paint layer, and the laser engraving depth changes gradually back and forth along a first direction; the first direction is the closed loop direction of the middle ring laser engraving area; S5: laser engraving the sub-outer ring laser engraving area and the sub-inner ring laser engraving area in S4, and the laser engraving depth reaches the outer surface of the light-transmitting surface shell; S6: laser engraving the outer ring laser engraving area and the inner ring laser engraving area in S4, and the laser engraving depth reaches the primer layer or the color paint layer; S7: spraying varnish on the light-transmitting surface shell after laser engraving in S6, and curing to form a varnish layer.

[0007] According to a preferred technical solution, the color paint layer consists of a dark layer and a light layer, and the depth of the laser engraving gradually changes back and forth between the dark layer and the light layer.

[0008] A preferred technical solution is that the middle ring laser engraving area along the second direction is formed by laser engraving a plurality of concentric laser engraving loops with different radii, the laser engraving loop is a closed loop in S4 in which the laser engraving depth gradually changes back and forth along the first direction, and the second direction is the radial direction of the laser engraving area; the laser engraving depth of the middle ring laser engraving area along the second direction is the same.

[0009] A preferred technical solution is to spray a PMMA solution on the light-transmitting surface shell after the treatment in S3 and solidify it to form a PMMA coating; in S4, the depth of the laser engraving is less than or equal to the sum of the thickness of the color paint layer and the PMMA coating.

[0010] A preferred technical solution is to spray a PMMA solution on the light-transmitting surface shell after the S4 treatment, and solidify it to form a PMMA coating.

[0011] A preferred technical solution is to spray transparent metallic paint on the light-transmitting surface shell after the S4 treatment, and solidify it to form a metallic paint layer.

[0012] According to a preferred technical solution, the laser engraving loop includes a plurality of grooves, and the groove bottom spacing of the grooves is smaller than the groove opening spacing.

[0013] In a preferred technical solution, the primer layer in S2 is dark in color.

[0014] In a preferred technical solution, the laser engraving depths of the outer ring laser engraving area and the inner ring laser engraving area in S6 are up to the primer layer or the dark layer.

[0015] The advantages and beneficial effects of the present invention are: Through the gradual reciprocating change of the color paint layer with the laser engraving depth, the color change is highly coordinated, and the laser engraving pattern presents a gradient effect at multiple angles, with a sense of layering and three-dimensionality, which increases the eye-catching effect of the sign. The setting of the color paint layer makes the laser engraving pattern present a gradient color and increases the sense of layering; the change of the laser engraving depth increases the three-dimensional sense and layering of the laser engraving pattern.

[0016] The laser engraving pattern is composed of multiple concentric laser engraving loops with different radii. After the colors on the opposite sides of the groove of the laser engraving loop are reflected, in addition to the color of the paint layer itself, the superposition of different light reflected by the paint layer can show more different colors, further increasing the diversity of the laser engraving pattern. The laser engraving pattern is a pattern with a gradient effect presented by reciprocating paint units of different colors. The smaller the area of ​​the paint unit, the denser the arrangement, and the laser engraving pattern presents different colors, further increasing the diversity of the laser engraving pattern. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a process flow chart of the laser engraving production process of the identification plate of the embodiment; Figure 2 2. It is a schematic diagram of the three-dimensional structure of the light-transmitting surface shell; Figure 3 This is a schematic diagram of the three-dimensional structure of the light-transmitting shell after laser engraving; Figure 4 This is a magnified 3D diagram of the laser engraving area after S6 laser engraving process; Figure 5 yes Figure 4 Schematic diagram of the cross-sectional structure of the coating after S7 laser engraving process; Figure 6 is a schematic diagram of the cross-sectional structure of a coating after laser engraving process in another embodiment S7; Figure 7 is a schematic diagram of the cross-sectional structure of a coating after laser engraving process in another embodiment S7; In the figure: 1. translucent surface shell; 11. outer surface; 12. inner surface; 2. primer layer; 3. color paint layer; 31. first color paint layer; 32. second color paint layer; 33. Nth color paint layer; 4. varnish layer; 5. laser engraving area; 51. outer ring laser engraving area; 52. sub-outer ring laser engraving area; 53. middle ring laser engraving area; 54. sub-inner ring laser engraving area; 55. inner ring laser engraving area; 6. laser engraving loop; 61. trough section; 62. peak section; 63. increasing section; 64. decreasing section; 65. groove; 651. groove bottom; 652. notch; 7. laser engraved curved surface; 71. color paint unit; 8. PMMA coating; 9. metallic paint layer. DETAILED DESCRIPTION

[0018] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0019] In the description of the present invention, it should be noted that, unless otherwise specified, “plurality” means more than two; the terms “upper”, “lower”, “left”, “right”, “inside”, “outside”, etc., indicating directions or positional relationships, are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0020] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0021] The first direction: the closed loop direction of the central laser engraving area; the second direction: the radial direction of the laser engraving area.

[0022] like Figure 1-5 As shown in the embodiment, a laser engraving production process of a signboard includes the following steps: S1: manufacturing a light-transmitting shell 1, wherein the light-transmitting shell 1 has an outer surface 11 and an inner surface 12 opposite to each other; S2: spraying primer on the outer surface 11 in S1, and curing to form a primer layer 2; S3: spraying paint on the primer layer 2 of the light-transmitting shell 1 obtained in S2, and curing to form a paint layer 3, wherein the paint layer 3 includes a first paint layer 3, a second paint layer 3 and an Nth paint layer 3 of different colors, which are stacked layer by layer, N≥3; and the colors of two adjacent layers from the first paint layer 31 to the Nth paint layer 33 gradually transition; S4: The outer surface 11 of the light-transmitting surface shell 1 obtained in S3 is provided with a laser engraving area 5, and the laser engraving area 5 is divided into an outer ring laser engraving area 51, a sub-outer ring laser engraving area 52, a middle ring laser engraving area 53, a sub-inner ring laser engraving area 54 and an inner ring laser engraving area 55 from the outside to the center; the middle ring laser engraving area 53 is laser engraved, and the laser engraving depth is less than or equal to the thickness of the color paint layer 3, and the laser engraving depth changes gradually back and forth along a first direction; the first direction is the closed loop direction of the middle ring laser engraving area 53; S5: laser engraving the sub-outer ring laser engraving area 52 and the sub-inner ring laser engraving area 54 in S4, and the laser engraving depth reaches the outer surface 11 of the light-transmitting surface shell 1; S6: laser engraving the outer ring laser engraving area 51 and the inner ring laser engraving area 55 in S4, and the laser engraving depth reaches the primer layer 2 or the color paint layer 3; S7: spray varnish on the light-transmitting surface shell 1 after laser engraving in S6, and solidify it to form a varnish layer 4.

[0023] In this embodiment S3, the first layer of paint 3 is sprayed on the surface of the primer layer 2, and the second layer of paint 3 and the Nth layer of paint 3 are stacked layer by layer in sequence, N≥3; the colors of the paints are different and the colors gradually change from dark to light, from dark to light (or from light to dark, from light to dark), so that the paint layer 3 has a gradient effect along the direction of paint layer stacking.

[0024] At the same time, the depth of laser engraving is set to change gradually in S4. On the one hand, the depth of laser engraving changes, which enhances the three-dimensional and layered sense of the laser engraved pattern. On the other hand, compared with the sudden change of the depth of laser engraving, the depth of laser engraving is set to change gradually, and light and color are superimposed on the two opposite sides to present another color different from the color of the paint layer 3. The laser engraved pattern has diversity under different viewing angles.

[0025] Furthermore, when the color paint layer 3 after laser engraving is dense enough, the color seen by the eyes is another color different from the color of the color paint layer 3 itself, and the laser engraving pattern is diversified; or the color seen is different at different distances from the laser engraved logo plate.

[0026] Specifically, when multiple red and blue blocks alternate densely, the color you see is not red and blue, but purple; this is because the pixels are too small, and the human eye creates an illusion after the red and blue pixels merge. When the distance from the laser engraved sign is far, the color you see is purple, and when you are closer, you can see clear red and blue.

[0027] Specifically, the gradual reciprocating change is a gradual increase or a gradual decrease.

[0028] Specifically, the gradient color takes the spraying of 5 blue colors from deep to light and from dark to bright as an example. In S3, based on the surface of the primer layer 2, the following are sprayed in sequence: dark blue (first color paint layer), royal blue (second color paint layer), indigo (third color paint layer), blue (fourth color paint layer), and cyan (fifth color paint layer). In S4, the color of the laser engraving pattern after laser engraving in the Central Ring Laser Engraving Area 53 gradually changes among the five colors of dark blue, royal blue, indigo, blue, and cyan, or some of them. If the laser engraving depth reaches the first color paint layer 31 at most, the color of the laser engraving pattern will show a gradient effect of dark blue, royal blue, indigo, blue, and cyan; if the laser engraving depth reaches the second color paint layer 32 at most, the color of the laser engraving pattern will show a gradient effect of royal blue, indigo, blue, and cyan, and so on.

[0029] S1 uses a translucent surface shell 1, which is itself translucent, so the sub-outer ring laser engraving area 52 and the sub-inner ring laser engraving area 54 are laser engraved, and the laser engraving depth reaches the translucent surface shell 1, that is, the laser engraving depth is greater than or equal to the sum of the thickness of the primer layer 2 and the color paint layer 3. The sub-outer ring laser engraving area 52 and the sub-inner ring laser engraving area 54 are both translucent. At this time, the visible surface of the middle ring laser engraving area 53 is not only the surface but also the side, further protruding the laser engraving pattern. At night, the light-emitting component set on one side of the inner surface 12 of the car logo plate works, and the light passes through the sub-outer ring laser engraving area 52 and the sub-inner ring laser engraving area 54 to illuminate the outer surface 11 of the logo plate, so that the logo plate can also play a logo effect at night, and the visual effect is more significant.

[0030] At the same time, the middle ring laser engraving area 53 is the main identification area, and the sub-outer ring laser engraving area 52 and the sub-inner ring laser engraving area 54 sandwich the middle ring laser engraving area 53 between them. On the one hand, the surface of the middle ring laser engraving area 53 is illuminated to highlight the identification and improve the eye-catching effect; on the other hand, the side wall of the middle ring laser engraving area 53 is illuminated, and the gradient effect of the middle ring laser engraving area 53 can also be seen from the side. At this point, the visible range of the middle ring laser engraving area 53 is larger, further highlighting its gradient layering and three-dimensional sense.

[0031] Optionally, the laser engraving area 5 is a closed shape such as a circle or a polygon.

[0032] like Figure 1-5 As shown, in another preferred embodiment, the central ring laser engraving area 53 along the second direction is formed by laser engraving a plurality of concentric laser engraving loops 6 with different radii and the laser engraving depths are the same. The laser engraving loop 6 is a closed loop in which the laser engraving depth gradually changes back and forth along the first direction in S4. The second direction is the radial direction of the laser engraving area 5.

[0033] In this embodiment, the laser carving loop 6 is a closed curve, including a peak section 62, a decreasing section 64, a trough section 61 and an increasing section 63. One cycle in the laser carving loop 6 is a peak section 62, a decreasing section 64, a trough section 61 and an increasing section 63 connected in sequence, and multiple cycles are connected in sequence to form a closed laser carving loop 6.

[0034] Furthermore, the depths of the peak sections 62 of different periods of a single laser engraving loop 6 are the same or different, and the depths of the trough sections 61 are the same or different. The depths of the peak sections 62 and the trough sections 61 are determined specifically according to the laser engraving depth.

[0035] Furthermore, a plurality of laser engraving loops 6 are overlapped along the second direction to form a laser engraving curved surface 7 and the laser engraving depths of the middle ring laser engraving area 53 are the same, thereby increasing the three-dimensional sense and layered sense of the laser engraving pattern.

[0036] Furthermore, the difference in laser engraving depth between the crest section 62 and the trough section 61 between different laser engraving loops 6 is different, which further enhances the three-dimensional effect and the sense of layering.

[0037] In another preferred embodiment, the laser engraving loop 6 includes a plurality of grooves 65 , and the spacing between the groove bottoms 651 of the grooves 65 is smaller than the spacing between the groove openings 652 .

[0038] In this embodiment, the laser engraving loop 6 includes a plurality of grooves 65 arranged at intervals, and the groove 65 includes a groove bottom 651 and a groove opening 652, and the width of the groove opening 652 is greater than the width of the groove bottom 651. This arrangement can make the viewing angle of the laser engraving pattern wider, compared with the groove 65 in which the groove opening 652 is narrower than the groove bottom 651 or the groove 65 in which the groove opening 652 is the same width as the groove bottom 651, the blocked area is less, especially the position at the bottom of the groove 65 is not easily blocked, thereby increasing the viewing angle of the logo.

[0039] Furthermore, because the laser engraving loop 6 is a closed curve extending along the first direction, the laser engraving pattern of the middle ring laser engraving area 53 after laser engraving has a laser engraved curved surface 7, and the laser engraved curved surface 7 is divided into multiple color paint units 71 along the second direction; along the direction from the outer edge of the middle ring laser engraving area 53 toward the inner edge, the area of ​​the color paint unit 71 gradually decreases, therefore, the density of the color paint unit 71 is different, and the laser engraving patterns that can be seen on the laser engraved curved surface 7 of the middle ring laser engraving area 53 along the second direction are also different, further increasing the diversity of laser engraving patterns.

[0040] Optionally, the laser carving loop 6 is a sine curve or a cosine curve.

[0041] like Figure 4 Due to the different laser engraving depths and the gradual reciprocating changes, the laser engraving loop 6 takes a sine (or cosine) curve as an example. Along the second direction (specifically from the outer edge to the inner edge of the middle ring laser engraving area 53), the amplitude of the laser engraving loop 6 is the same (the difference between the peak and the trough is the same), and the period gradually decreases.

[0042] like Figure 1-5 As shown, in another preferred embodiment, the paint layer 3 is composed of a dark layer and a light layer, and the laser engraving depth gradually changes back and forth between the dark layer and the light layer.

[0043] The depth of laser engraving changes gradually between the dark layer and the light layer, alternating between dark and light, and the gradient effect is more obvious; if the depth of laser engraving only changes in the dark layer or the light layer, the marking effect is not obvious and the pattern color layering is poor.

[0044] Specifically, the dark layer is a multi-layer paint layer 3, and the light layer is also a multi-layer paint layer 3. Laser engraving is performed back and forth between any dark layer and any light layer along the first direction.

[0045] like Figure 1-5 As shown, in another preferred embodiment, the primer layer 2 has a thickness of 10 μm to 20 μm.

[0046] Preferably, the primer layer 2 in S2 is dark in color.

[0047] The primer layer 2 forms a light shielding layer on the outer surface 11 of the light-transmitting shell 1. By laser engraving a part of the area and the laser engraving depth reaches the outer surface 11 of the light-transmitting shell 1, the part of the area is light-transmitting and the other area is not light-transmitting. When a light assembly is arranged on the side where the inner surface 12 of the light-transmitting shell 1 is located, at night, the light passes through the light-transmitting shell 1 to illuminate the outer surface 11, which plays a marking role in the dark.

[0048] At the same time, the color of the primer layer 2 is set to a dark color, such as black, dark blue, navy blue, etc., to highlight the color of the 53-color paint layer 3 in the central ring laser carving area as the main identification area without distracting the line of sight.

[0049] If the thickness of the primer layer 2 is too thin, it will not have the shading effect; if the thickness is too thick, the drying efficiency will be low, the bonding strength will be poor, and problems such as coating blistering will easily occur.

[0050] like Figure 1-5 As shown, in another preferred embodiment, the thickness of the paint layer 3 is 10 μm to 20 μm.

[0051] The color paint layer 3 is the main part of the central ring laser engraving area 53 to form a gradient effect.

[0052] Preferably, the thickness of each layer among the first color paint layer 31 , the second color paint layer 32 and the Nth color paint layer 33 in the color paint layer 3 is equal.

[0053] like Figure 1-5 As shown, in another preferred embodiment, the thickness of the varnish layer 4 is 30 μm to 40 μm.

[0054] The varnish layer 4 plays a protective role to prevent the surface of the laser engraved pattern from being damaged during use.

[0055] like Figure 1 As shown, in another preferred embodiment, the laser engraving speed is 800-900 mm / s and the laser engraving power is 0-20 W.

[0056] Because the depth of laser engraving changes gradually, the power or speed will also change; according to the different depths of laser engraving, choose the matching laser engraving speed and laser engraving power.

[0057] When the laser engraving speed and power are fixed, adjust the distance between the laser engraving machine laser head and the position to be engraved to achieve the change of laser engraving depth.

[0058] Furthermore, the laser engraving power is 11~19W.

[0059] like Figure 1-5 As shown, in another preferred embodiment, the laser engraving depth of the outer ring laser engraving area 51 and the inner ring laser engraving area 55 in S6 reaches the primer layer 2 or the dark layer.

[0060] The depth of laser engraving is up to the primer layer 2 or the dark layer. The dark color is not conspicuous and not easy to attract attention, especially at night. Compared with bright colors, dark colors are easier to highlight the pattern of the central laser engraving area 53 when light from the translucent area is transmitted.

[0061] like Figure 1-5 As shown, when the laser engraving production process of the sign of the present invention is operated (with specific numerical values): Step 1: Making a light-transmitting surface shell 1 by injection molding; Step 2: spraying a primer on the outer surface 11 of the light-transmitting shell 1, and curing to form a primer layer 2 of 15 μm; Step 3: spraying colored paint to form a 15 μm colored paint layer 3; the colored paint layer 3 includes a 3 μm first colored paint layer 31 (dark blue), a 3 μm second colored paint layer 32 (sapphire blue), a 3 μm third colored paint layer (indigo), a 3 μm fourth colored paint layer (blue), and a 3 μm fifth colored paint layer (turquoise).

[0062] Step 4: Determine a laser engraving area 5 with a radius of 8 cm on the outer surface 11 of the transparent surface shell 1, and divide the laser engraving area 5 into 5 laser engraving areas, namely an inner ring laser engraving area 55 with a radius of 2 cm, a sub-inner ring laser engraving area 54 with a ring width of 1 cm and an outer circle radius of 3 cm, a middle ring laser engraving area 53 with a ring width of 4 cm and an outer circle radius of 7 cm, a sub-outer ring laser engraving area 52 with a ring width of 1 cm and an outer circle radius of 8 cm, and an outer ring laser engraving area 51 with a ring width of 2 cm and an outer circle radius of 10 cm; Fix the positions of the light-transmitting surface shell 1 and the laser engraving machine, and perform laser engraving on the central laser engraving area 53. Set the laser engraving power to 15W and the laser engraving speed to 800mm / s. The laser engraving laser starts to engrave from the outer edge of the central laser engraving area 53. While the laser engraving laser moves along the first direction (the laser circles the outer edge of the central laser engraving area 53 for multiple circles to complete the laser engraving at the outer edge), the distance between the laser engraving machine laser head and the area to be laser engraved is adjusted according to the different settings of the laser engraving depth. After the laser engraving of the outer edge is completed, the laser is offset along the second direction and then moves along the first direction, so as to form a laser engraved curved surface 7 in the central laser engraving area 53.

[0063] Specifically, the laser carving loop 6 is an enclosed cosine function curve, the peak section 62 of the laser carving loop 6 has a laser carving depth of 0 μm (presenting cyan), the laser carving depth of the decreasing section 64 along the first direction gradually increases and the range of 0 μm<laser carving depth<14 μm (presenting cyan, blue, indigo, royal blue and dark blue in sequence), the laser carving depth of the trough section 61 is 14 μm, the laser carving depth of the increasing section 63 along the first direction gradually decreases and the range of 14 μm>laser carving depth>0 μm (presenting dark blue, royal blue, indigo, blue and cyan in sequence); the peak section 62 to the decreasing section 64, then to the trough section 61 and finally to the increasing section 63 is a cycle, and multiple cycles along the first direction are enclosed to form the laser carving loop 6.

[0064] S5: laser engraving is performed on the sub-outer ring laser engraving area 52 and the sub-inner ring laser engraving area 54 in S4, and the laser engraving depth is 30 μm; S6: laser engraving the outer ring laser engraving area 51 and the inner ring laser engraving area 55 in S4, the laser engraving depth of the outer ring laser engraving area 51 is 18 μm (presenting the primer layer 2), and the laser engraving depth of the inner ring laser engraving area 55 is 12 μm (presenting the first color paint layer 31); S7: spray varnish on the transparent surface shell 1 after laser engraving in S6, and solidify it to form a varnish layer 4, and the thickness of the varnish layer 4 is 35 μm.

[0065] like Figure 6 As shown, in another preferred embodiment, PMMA solution is sprayed on the light-transmitting shell 1 after S3 treatment and cured to form PMMA coating 8; the laser engraving depth in S4 is less than or equal to the sum of the thickness of the color paint layer 3 and the PMMA coating 8.

[0066] like Figure 6 As shown, in another preferred embodiment, PMMA solution is sprayed on the light-transmitting surface shell 1 after S4 treatment, and cured to form a PMMA coating 8.

[0067] The PMMA coating 8 has high light transmittance, strong optical properties, low light scattering and refraction, and has the effect of brightness and clarity. In this embodiment, in the presence of light, the setting of the PMMA coating increases the diversity of the laser engraving pattern.

[0068] like Figure 7 As shown, in another preferred embodiment, transparent metallic paint is sprayed on the light-transmitting surface shell 1 after S4 treatment, and then cured to form a metallic paint layer 9.

[0069] The metallic paint has a glossy feel, and can reflect light to present a glossy feel, especially at night when the light is weak. Due to the metal particles in the metallic paint, the light presents more diversely when passing through the metallic paint, and thus the metallic paint layer 9 also increases the diversity of the laser engraving pattern.

[0070] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A laser engraving production process for a sign, characterized in that: The following steps are involved: S1: manufacturing a light-transmitting shell (1), wherein the light-transmitting shell (1) has an outer surface (11) and an inner surface (12) that are opposite to each other; S2: spraying a primer on the outer surface (11) in S1, and curing the primer layer (2); S3: spraying a color paint on the primer layer (2) of the light-transmitting shell (1) obtained in S2, and curing the paint to form a color paint layer (3), wherein the color paint layer (3) comprises a first color paint layer (3), a second color paint layer (3) and an Nth color paint layer (3) of different colors, which are stacked layer by layer, N≥3; and the colors of two adjacent layers from the first color paint layer (31) to the Nth color paint layer (33) gradually transition; S4: The outer surface (11) of the light-transmitting surface shell (1) obtained in S3 is provided with a laser engraving area (5), and the laser engraving area (5) is divided into an outer ring laser engraving area (51), a sub-outer ring laser engraving area (52), a middle ring laser engraving area (53), a sub-inner ring laser engraving area (54), and an inner ring laser engraving area (55) from the outside to the center; the middle ring laser engraving area (53) is laser engraved, and the laser engraving depth is less than or equal to the thickness of the color paint layer (3), and the laser engraving depth gradually changes back and forth along a first direction; the first direction is the closed loop direction of the middle ring laser engraving area (53); S5: laser engraving the sub-outer ring laser engraving area (52) and the sub-inner ring laser engraving area (54) in S4, with the laser engraving depth reaching the outer surface (11) of the light-transmitting surface shell (1); S6: laser engraving the outer ring laser engraving area (51) and the inner ring laser engraving area (55) in S4, with the laser engraving depth reaching the primer layer (2) or the color paint layer (3); S7: spraying varnish on the light-transmitting shell (1) after laser engraving in S6, and curing to form a varnish layer (4).

2. The laser engraving production process for identification plates according to claim 1 is characterized in that: The color paint layer (3) consists of a dark layer and a light layer, and the depth of the laser engraving gradually changes back and forth between the dark layer and the light layer.

3. The laser engraving production process for identification plates according to claim 1 is characterized in that: The central ring laser engraving area (53) along the second direction is formed by laser engraving a plurality of concentric laser engraving loops (6) with different radii, wherein the laser engraving loops (6) are closed loops in S4 whose laser engraving depths gradually change back and forth along the first direction, and the second direction is the radial direction of the laser engraving area (5); the laser engraving depths of the central ring laser engraving area (53) along the second direction are the same.

4. The laser engraving production process for identification plates according to claim 1 is characterized in that: The light-transmitting shell (1) treated in S3 is sprayed with a PMMA solution, and cured to form a PMMA coating (8); and in S4, the depth of the laser engraving is less than or equal to the sum of the thicknesses of the color paint layer (3) and the PMMA coating (8).

5. The laser engraving production process for identification plates according to claim 1 is characterized in that: The light-transmitting shell (1) after the S4 treatment is sprayed with a PMMA solution, and then cured to form a PMMA coating (8).

6. The laser engraving production process for identification plates according to claim 1 is characterized in that: The light-transmitting surface shell (1) after the S4 treatment is sprayed with transparent metallic paint, which is cured to form a metallic paint layer (9).

7. The laser engraving production process for identification plates according to claim 3 is characterized in that: The laser engraving loop (6) comprises a plurality of grooves (65), wherein the spacing between groove bottoms (651) of the grooves (65) is smaller than the spacing between groove openings (652).

8. The laser engraving production process for identification plates according to claim 2 is characterized in that: The primer layer (2) in S2 is dark in color.

9. The laser engraving production process for identification plates according to claim 2, characterized in that: The laser engraving depth of the outer ring laser engraving area (51) and the inner ring laser engraving area (55) in S6 reaches the primer layer (2) or the dark layer.

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