A UV varnish printing system, UV printer and use method thereof

Abstract

The invention discloses a UV varnish printing system, a UV printer and a method of using the same, belonging to the technical field of UV varnish printing, comprising a nozzle, a first ultraviolet ray emitting device and a second ultraviolet ray emitting device, the nozzle being used to print UV varnish on a printing object and forming a printing area; the first ultraviolet ray emitting device being used to emit ultraviolet rays and irradiate the printing object and form a first irradiation area, the second ultraviolet ray emitting device being used to emit ultraviolet rays and irradiate the printing object and form a second irradiation area, the first irradiation area and the second irradiation area being spaced apart in the front-to-back direction and the first irradiation area being located in front of the second irradiation area, the first irradiation area overlapping the printing area and the total width of the overlapping part in the front-to-back direction accounting for 5%-80% of the width of the printing area in the front-to-back direction; the second irradiation area not overlapping the printing area. The UV varnish printing system of the invention can ensure the smoothness of the pattern while improving the printing thickness.

Description

Technical Field

[0001] The invention belongs to the technical field of UV varnish printing, and in particular relates to a UV varnish printing system, a UV printer and a use method thereof. Background Art

[0002] The existing UV varnish printing technology generally has the following two methods:

[0003] 1. The UV lamp is staggered with the nozzle along the paper feeding direction. The purpose is to make the irradiation range of the UV lamp not overlap with the printing area. This method can make the printed pattern smoother, but the cost is that the printing thickness cannot be too high, otherwise the varnish will overflow, thus affecting the printing quality;

[0004] 2. The UV lamp is not offset from the nozzle along the paper feeding direction and the irradiation range of the UV lamp covers the entire printing area. This method can quickly cure the entire pattern, allowing printing with a greater thickness. However, in this method, due to the fast curing speed, the UV varnish is completely cured before it is leveled, resulting in a low smoothness of the pattern and the surface of the pattern is often pitted, which also affects the printing quality.

[0005] Therefore, the current UV varnish printing technology cannot take into account both thickness and smoothness, that is, it cannot ensure the smoothness of the pattern while increasing the printing thickness.

[0006] Therefore, the existing technology needs to be improved and developed. Summary of the invention

[0007] The object of the present invention is to provide a UV varnish printing system, a UV printer and a method of using the same, which can improve the printing thickness while ensuring the smoothness of the pattern.

[0008] In a first aspect, the present invention provides a UV varnish printing system, comprising a nozzle and a first ultraviolet emitting device, wherein the nozzle is used to print the UV varnish on a printing object and form a printing area;

[0009] The UV varnish printing system also includes a second ultraviolet ray emitting device; the first ultraviolet ray emitting device is used to emit ultraviolet rays and irradiate the printing object to form a first irradiation area, the second ultraviolet ray emitting device is used to emit ultraviolet rays and irradiate the printing object to form a second irradiation area, the first irradiation area and the second irradiation area are spaced apart in the front-to-back direction and the first irradiation area is located in front of the second irradiation area, the first irradiation area overlaps with the printing area and the total width of the overlapping part in the front-to-back direction accounts for 5%-80% of the width of the printing area in the front-to-back direction; the second irradiation area does not overlap with the printing area.

[0010] In the UV varnish printing system provided by the present invention, the first ultraviolet emitting device and the second ultraviolet emitting device are arranged at intervals and the irradiation range of the first ultraviolet emitting device does not completely cover the entire printing area, so that the various local parts of the pattern are cured in sequence, and full use is made of the characteristics that when the pattern is semi-cured, the UV varnish is locally limited and the UV varnish can flow locally, so as to achieve a balance between the thickness and smoothness of the pattern and greatly improve the printing quality of the pattern.

[0011] Furthermore, the total width of the overlapping portion along the front-to-back direction accounts for 10%-20% of the width of the printing area along the front-to-back direction.

[0012] Controlling the ratio between 10% and 20% is conducive to printing smoother patterns.

[0013] Furthermore, the first irradiation area and the printing area have only one continuous overlapping portion, and the overlapping portion covers the front end of the printing area.

[0014] Furthermore, the first irradiation area and the printing area have only one continuous overlapping portion, and the overlapping portion does not cover the front end of the printing area.

[0015] The first irradiation area covers the front end of the printing area and conforms to the paper feeding direction of the printing object from front to back, which is more in line with the actual printing process.

[0016] Furthermore, the first irradiation area and the printing area have a plurality of overlapping portions spaced apart along the front-to-back direction, and one of the overlapping portions covers the front end of the printing area.

[0017] Furthermore, the first irradiation area and the printing area have a plurality of overlapping portions spaced apart along the front-to-back direction, and all the overlapping portions do not cover the front end of the printing area.

[0018] In a second aspect, the present invention provides a UV printer, comprising the above-mentioned UV varnish printing system.

[0019] Furthermore, it also includes a guide rail and a moving platform, the moving platform is slidably set on the guide rail and can reciprocate in the left and right directions, the nozzle, the first ultraviolet emitting device and the second ultraviolet emitting device are all installed on the moving platform and move with the moving platform, the first ultraviolet emitting device is slidably set on the moving platform and can adjust its relative position with the nozzle in the front-to-back direction to adjust the proportion of the total width of the overlapping part in the front-to-back direction to the width of the printing area in the front-to-back direction.

[0020] Furthermore, it also includes a carrying device, which is used to carry the printing object and can drive the printing object to move backward.

[0021] In a third aspect, the present invention provides a method for using the above-mentioned UV printer, comprising the steps of:

[0022] S1. Obtaining the radiation intensity of ultraviolet rays emitted by the first ultraviolet emitting device;

[0023] S2. Determine the curing speed of the UV varnish used for printing according to the radiation intensity;

[0024] S3. Determine the target proportion of the total width of the overlapping portion along the front-to-back direction to the width of the printing area along the front-to-back direction according to the curing speed;

[0025] S4. Adjusting the relative position of the first ultraviolet emitting device and the nozzle along the front-to-back direction according to the target proportion.

[0026] It also takes into account the thickness and smoothness of the pattern, and effectively prevents UV varnish from overflowing, greatly improving the printing quality.

[0027] From the above, it can be seen that the UV varnish printing system of the present invention controls the irradiation range of the first ultraviolet ray emitting device to ensure that it does not completely cover the entire printing area, thereby causing the printed pattern to be partially cured, thereby limiting the flow range of the UV varnish, thereby avoiding varnish overflow after the printing thickness increases, and then curing the entire pattern through the second ultraviolet ray emitting device. Since the uncured part is delayed in curing, the UV varnish in this part still has fluidity. During the delayed curing period, the UV varnish in this part can make the entire pattern smoother, thereby achieving control of the curing timing of the pattern from a spatial position, taking into account both the thickness and smoothness of the pattern, and greatly improving the printing quality of the pattern.

[0028] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or be understood by implementing the embodiments of the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A top view of a UV printer including a UV varnish printing system provided in an embodiment of the present invention.

[0030] Figure 2 This is a diagram showing changes in the cross section of a pattern printed twice during the printing process in an embodiment of the present invention.

[0031] Figure 3 This is a diagram showing the first change in the cross section of a pattern that is printed three times during the printing process in an embodiment of the present invention.

[0032] Figure 4This is a second variation diagram of the cross section of a pattern printed three times during the printing process in an embodiment of the present invention.

[0033] Figure 5 This is a printing effect diagram of Experiment 1 in an embodiment of the present invention.

[0034] Figure 6 This is a printing effect diagram of Experiment 2 in an embodiment of the present invention.

[0035] Figure 7 This is a printing effect diagram of Experiment 3 in an embodiment of the present invention.

[0036] Figure 8 This is a printing effect diagram of Experiment 4 in the embodiment of the present invention.

[0037] Fig. 9 This is the second arrangement method of the overlapping part in the embodiment of the present invention.

[0038] Fig.10 This is the third arrangement method of the overlapping part in the embodiment of the present invention.

[0039] Fig.11 This is the fourth arrangement method of the overlapping part in the embodiment of the present invention.

[0040] Fig.12 A flow chart of a method of use provided by an embodiment of the present invention.

[0041] Description of labels:

[0042] 100, nozzle; 200, first ultraviolet emitting device; 210, first irradiation area; 300, printing object; 310, printing area; 320, overlapping part; 400, second ultraviolet emitting device; 410, second irradiation area; 500, first layer pattern; 510, the second half of the first layer pattern; 520, the first half of the first layer pattern; 600, second layer pattern; 610, the second half of the second layer pattern; 620, the first half of the second layer pattern; 700, third layer pattern; 800, guide rail; 900, moving platform; 1000, carrying device. DETAILED DESCRIPTION

[0043] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0044] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and 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 orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0045] In the description of the present invention, it should be noted 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, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0047] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can appreciate the application of other processes and / or the use of other materials.

[0048] It should be noted that the “front-rear direction”, “left-right direction” and “up-down direction” mentioned in this document are as follows: Figure 1 , Attachment Figure 2 , Attachment Figure 3 and attached Figure 4 The arrows marked in FIG. 3 are used as reference. In addition, during the printing process, the printed object 300 is fed in a direction from front to back.

[0049] Reference Figure 1 , the present invention provides a UV varnish printing system, comprising a nozzle 100 and a first ultraviolet ray emitting device 200, the nozzle 100 is used to print the UV varnish on a printing object 300 and form a printing area 310;

[0050] The UV varnish printing system also includes a second ultraviolet ray emitting device 400; the first ultraviolet ray emitting device 200 is used to emit ultraviolet rays and irradiate the printing object 300 to form a first irradiation area 210, and the second ultraviolet ray emitting device 400 is used to emit ultraviolet rays and irradiate the printing object 300 to form a second irradiation area 410. The first irradiation area 210 and the second irradiation area 410 are spaced apart in the front-to-back direction and the first irradiation area 210 is located in front of the second irradiation area 410. The first irradiation area 210 overlaps with the printing area 310 and the total width of the overlapping part 320 in the front-to-back direction accounts for 5%-80% of the width of the printing area 310 in the front-to-back direction; the second irradiation area 410 does not overlap with the printing area 310.

[0051] In this embodiment, the printing area 310 refers to the effective printing range of the nozzle 100. For example, if the nozzle 100 is driven to move in a straight line in the left and right directions, a rectangular effective printing range can be formed, and the nozzle 100 will only print a pattern within the rectangular range each time it moves. In actual application, the complete pattern is printed in a stacked and covered manner, for example, the nozzle 100 is controlled to move and print the first layer of pattern 500 on the printing object 300, and then the printing object 300 is controlled to move backward and the nozzle 100 is controlled to print again. At this time, the upper surface of the first layer of pattern 500 will print the second layer of pattern 600, and so on and so forth until the complete pattern is printed.

[0052] Therefore, a complete pattern needs to be printed at least twice (ie, at least one covering is completed), but the number of printings is not limited to two times, and may also be, for example, 4 times, 8 times, 12 times, 18 times, etc.

[0053] Take the pattern printed twice as an example to explain:

[0054] Reference Figure 2 During the first printing, the nozzle 100 prints the second half 510 of the first layer pattern in the printing area 310. Since the second half 510 of the first layer pattern is located in the first irradiation area 210, the second half 510 of the first layer pattern will be irradiated and cured by the ultraviolet rays emitted by the first ultraviolet emitting device 200. Thereafter, the printing object 300 is controlled to move backward. During the second printing, the nozzle 100 prints the first half 520 of the first layer pattern and the second layer pattern 600 covering the upper surface of the second half 510 of the first layer pattern in the printing area 310. Since the first half 520 of the first layer pattern is located in the first irradiation area 210, the first half 520 of the first layer pattern will be irradiated and cured by the ultraviolet rays emitted by the first ultraviolet emitting device 200. At this time, the printing of the complete pattern is completed.

[0055] Among them, since the second half 510 of the first layer pattern has been finalized, its shape structure limits the flow range of the UV varnish of the second layer pattern 600, thereby preventing the UV varnish from overflowing while increasing the pattern thickness.

[0056] In addition, after the pattern printing is completed, before the pattern enters the second irradiation area 410, the UV varnish of the second layer pattern 600 is still fluid. Since the UV varnish has a leveling property, the UV varnish of the second layer pattern 600 will gradually flow forward to the front half 520 of the first layer pattern. Similarly, since the front half 520 of the first layer pattern has been finalized, the UV varnish of the second layer pattern 600 will not overflow. As a result, the UV varnish of the second layer pattern 600 evenly covers the entire upper surface of the first layer pattern 500, obtaining a pattern with a certain thickness and a smooth surface.

[0057] It should be noted that when printing the same pattern as in the above embodiment, the second layer pattern 600 can also be printed multiple times in segments like the first layer pattern 500. For example, a pattern printed three times is used as an example for explanation:

[0058] Reference Figure 3During the first printing, the second half 510 of the first layer pattern is printed and cured by the first ultraviolet emitting device 200, the printing object 300 is controlled to move backward and during the second printing, the first half 520 of the first layer pattern is printed and cured by the first ultraviolet emitting device 200, and at the same time, the second half 610 of the second layer pattern covering the upper surface of the second half 510 of the first layer pattern is printed, and during the third printing, the first half 620 of the second layer pattern covering the upper surface of the first half 520 of the first layer pattern is printed, and finally the second half 610 of the second layer pattern and the first half 620 of the second layer pattern are cured by the second ultraviolet emitting device 400.

[0059] For further information, see Attachment Figure 4 During the third printing, in addition to printing the first half 620 of the second layer pattern covering the upper surface of the first half 520 of the first layer pattern, the third layer pattern 700 can also continue to cover the upper surface of the second half 610 of the second layer pattern.

[0060] It should be noted that, in terms of the printing steps, the complete pattern is printed three times (i.e., covered twice), but since the first half 620 of the second layer pattern, the second half 610 of the second layer pattern, and the third layer pattern 700 are not cured, the UV varnish of these three parts will merge into one and flow smoothly, which actually manifests as a layer of UV varnish covering the upper surface of the first layer pattern 500. However, there is no doubt that each covering with UV varnish will increase the overall thickness of the pattern and all the covered UV varnishes will be delayed in curing. During the delayed curing period (i.e., before moving to the second irradiation area 410), all the covered UV varnishes have enough time to flow smoothly, and after flow smoothly, they are cured by the second ultraviolet emitting device 400, so that a pattern with a greater thickness and a smoother surface can be obtained.

[0061] In this embodiment, since the first irradiation area 210 does not completely cover the entire printing area 310 and the second irradiation area 410 does not overlap with the printing area 310, the covered UV varnish is delayed in curing, thereby achieving control of the curing timing of the pattern from a spatial position, taking into account the thickness and smoothness of the pattern, and greatly improving the printing quality of the pattern.

[0062] To prove the effect of the present invention, the present invention conducted the following experiments and obtained the following experimental results:

[0063] Experiment 1: Adjust the relative position of the first ultraviolet emitting device 200 and the nozzle 100 in the front-to-back direction so that the first irradiation area 210 does not overlap with the printing area 310, and use UV varnish to print a pattern in the printing area 310 with a width of 33.899 mm according to a predetermined thickness, refer to the attached Figure 5 , it can be seen that the UV varnish in the pattern overflows.

[0064] Experiment 2: Adjust the first ultraviolet emitting device 200 to be 4-5 mm closer to the nozzle 100 in the front-to-back direction, so that the first irradiation area 210 overlaps with the printing area 310 and the total width of the overlapping portion 320 in the front-to-back direction accounts for 11.800%-14.750% of the width of the printing area 310 in the front-to-back direction. Use the same UV varnish to print a pattern in the printing area 310 of the same width according to the same predetermined thickness, refer to the attached Figure 6 It can be seen that there is no UV varnish overflow in the pattern, there are no pitting defects on the pattern surface, and the pattern as a whole is very smooth.

[0065] Experiment 3: Adjust the first ultraviolet emitting device 200 to be 14mm-15mm closer to the nozzle 100 in the front-to-back direction, so that the first irradiation area 210 overlaps with the printing area 310 and the total width of the overlapping portion 320 in the front-to-back direction accounts for 41.299%-44.249% of the width of the printing area 310 in the front-to-back direction. Use the same UV varnish to print patterns in the printing area 310 of the same width according to the same predetermined thickness. Refer to the attached Figure 7 It can be seen that there is no UV varnish overflow in the pattern, there are only a few pitting defects on the pattern surface, and the pattern is relatively smooth overall.

[0066] Experiment 4: Adjust the relative position of the first ultraviolet emitting device 200 and the nozzle 100 in the front-to-back direction so that the first irradiation area 210 and the printing area 310 completely overlap, and use the same UV varnish to print the pattern in the printing area 310 of the same width with the same predetermined thickness, refer to the attached Figure 8 It can be seen that there is no UV varnish overflow in the pattern, but there are a lot of pitting defects on the surface of the pattern, and the overall pattern is very rough.

[0067] It should be noted that the ratio of the total width of the overlapping portion 320 to the width of the printing area 310 is a theoretical value. Since the ultraviolet light source has a scattering characteristic, the actual ratio will be larger.

[0068] In some preferred embodiments, the total width of the overlapping portion along the front-to-back direction accounts for 10%-20% of the width of the printing area 310 along the front-to-back direction.

[0069] In this embodiment, it can be seen from the above experimental results that when the total width of the overlapping portion 320 accounts for 10%-20% of the width of the printing area 310, a very smooth pattern can be printed.

[0070] In certain embodiments, referring to Figure 2The second setting method of the overlapping part is: the first irradiation area 210 and the printing area 310 have only one continuous overlapping part 320, and the overlapping part 320 does not cover the front end of the printing area 310. The overlapping part 320 can be set between the front and rear ends of the printing area 310, or set at the rear end of the covering printing area 310.

[0071] It should be noted that, in this embodiment, the total width of the overlapping portion 320 is equal to the width of the overlapping portion 320 itself.

[0072] In certain preferred embodiments, reference is made to the attached Figure 1 The first setting mode of the overlapping part is: the first irradiation area 210 and the printing area 310 have only one continuous overlapping part 320, the overlapping part 320 covers the front end of the printing area 310, the position of the first irradiation area 210 is located in front of the second irradiation area 410, and the first irradiation area 210 covers the front end of the printing area 310 in accordance with the paper feeding direction of the printing object 300 from front to back, which is more in line with the actual printing process.

[0073] In certain embodiments, referring to Fig.10 The third setting method of the overlapping part is: the first irradiation area 210 and the printing area 310 have multiple overlapping parts 320 arranged at intervals along the front-to-back direction, and all overlapping parts 320 do not cover the front end of the printing area 310. All overlapping parts 320 can be arranged between the front and rear ends of the printing area 310, or one of the overlapping parts 320 covers the rear end of the printing area 310.

[0074] It should be noted that, in this embodiment, the total width of the overlapping portion 320 is equal to the sum of the widths of the plurality of overlapping portions 320 .

[0075] In certain preferred embodiments, Fig.11 The fourth setting mode of the overlapping part is: the first irradiation area 210 and the printing area 310 have a plurality of overlapping parts 320 arranged at intervals along the front-to-back direction, one of the overlapping parts 320 covers the front end of the printing area 310, the position of the first irradiation area 210 is located in front of the second irradiation area 410, and the first irradiation area 210 covers the front end of the printing area 310 in accordance with the paper feeding direction of the printing object 300 from front to back, which is more in line with the actual printing process.

[0076] Reference Figure 1 The present invention provides a UV printer, including the UV varnish printing system of the above embodiment.

[0077] In some embodiments, the UV printer also includes a guide rail 800 and a moving platform 900, the moving platform 900 is slidably set on the guide rail 800 and can reciprocate in the left and right directions, the nozzle 100, the first ultraviolet emitting device 200 and the second ultraviolet emitting device 400 are all installed on the moving platform 900 and move with the moving platform 900, the first ultraviolet emitting device 200 is slidably set on the moving platform 900 and can adjust its relative position with the nozzle 100 in the front-to-back direction to adjust the proportion of the total width of the overlapping part 320 in the front-to-back direction to the width of the printing area 310 in the front-to-back direction.

[0078] In this embodiment, the nozzle 100, the first ultraviolet emitting device 200 and the second ultraviolet emitting device 400 are integrated on the same moving platform 900 for synchronous movement. In actual application, after the user adjusts the relative position of the first ultraviolet emitting device 200 and the nozzle 100, the first ultraviolet emitting device 200 is fixed on the moving platform 900. When the nozzle 100 moves in the left and right directions, the ultraviolet rays emitted by the first ultraviolet emitting device 200 can irradiate part of the pattern, thereby fixing the shape of the pattern and limiting the flow range of the UV varnish covered during the next printing, thereby avoiding overflow of the UV varnish due to increased thickness, until after the printing is completed, all the covered UV varnish is leveled during the delayed curing period, and then the entire pattern is fully cured by the second ultraviolet emitting device 400, and finally a pattern with a certain thickness and a smooth surface is obtained.

[0079] Furthermore, the UV printer also includes a carrying device 1000, which is used to carry the printing object 300 and can drive the printing object 300 to move backward.

[0080] Reference Fig.12 The present invention provides a method for using the UV printer as described in the above embodiment, comprising the steps of:

[0081] S1. Obtaining the radiation intensity of ultraviolet rays emitted by the first ultraviolet emitting device;

[0082] S2. Determine the curing speed of the UV varnish used for printing according to the radiation intensity;

[0083] S3. Determine the target proportion of the total width of the overlapping portion along the front-to-back direction in the width of the printing area along the front-to-back direction according to the curing speed;

[0084] S4. Adjust the relative position of the first ultraviolet emitting device and the nozzle along the front-to-back direction according to the target proportion.

[0085] In this embodiment, the key to increasing the pattern thickness while preventing the UV varnish from overflowing is that the UV varnish has been completely cured after passing through the overlapping part. However, different UV varnishes have different curing speeds under ultraviolet rays of different radiation intensities. Therefore, it is necessary to determine the curing speed of the UV varnish according to the radiation intensity of the ultraviolet rays (which can be obtained through experiments), and then determine the target ratio according to the curing speed of the UV varnish, thereby ensuring that the UV varnish is completely cured after passing through the overlapping part.

[0086] In addition, the key to ensuring a smooth pattern surface is to have enough time for the UV varnish to level, and the UV varnish leveling process occurs during delayed curing, so its essence is to control the length of delayed curing according to the target ratio.

[0087] Specific examples include:

[0088] 1. UV varnish has a fast curing speed. UV varnish can be completely cured with only one irradiation. The width of the overlapping part along the front-to-back direction can be designed to be narrower (at least 5% of the width of the printing area along the front-to-back direction). Conversely, the part of the printing area that does not overlap with the first irradiation area is wider (at most 95% of the width of the printing area along the front-to-back direction).

[0089] 2. When the curing speed of UV varnish is slow, since UV varnish needs multiple irradiations to be completely cured, the width of the overlapping part along the front-to-back direction needs to be designed to be wider (accounting for up to 80% of the width of the printing area along the front-to-back direction). Correspondingly, the part of the printing area that does not overlap with the first irradiation area is narrower (accounting for at least 20% of the width of the printing area along the front-to-back direction).

[0090] In this way, adhering to the principle that the UV varnish can be completely cured and there is enough time for the UV varnish to level, the relative position of the first ultraviolet emitting device and the nozzle is adjusted according to the target ratio, so as to achieve both the thickness and smoothness of the pattern and effectively prevent the overflow of UV varnish, thereby greatly improving the printing quality.

[0091] In the description of this specification, the description with reference to the terms "one embodiment", "certain embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0092] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A UV varnish printing system, comprising a nozzle (100) and a first ultraviolet emitting device (200), wherein the nozzle (100) is used to print UV varnish on a printing object (300) and form a printing area (310); It is characterized in that The printing apparatus further comprises a second ultraviolet emitting device (400); the first ultraviolet emitting device (200) is used to emit ultraviolet rays and irradiate the printing object (300) to form a first irradiation area (210); the second ultraviolet emitting device (400) is used to emit ultraviolet rays and irradiate the printing object (300) to form a second irradiation area (410); the first irradiation area (210) and the second irradiation area (410) are spaced apart in the front-to-back direction and the first irradiation area (210) is located in front of the second irradiation area (410); the first irradiation area (210) overlaps with the printing area (310) and the total width of the overlapping portion (320) in the front-to-back direction accounts for 5% to 80% of the width of the printing area (310) in the front-to-back direction; and the second irradiation area (410) does not overlap with the printing area (310); The first irradiation area (210) and the printing area (310) have only one continuous overlapping portion (320), and the overlapping portion (320) is arranged between the front and rear ends of the printing area (310); Or, the first irradiation area (210) and the printing area (310) have a plurality of overlapping portions (320) arranged at intervals along the front-to-back direction, and one of the overlapping portions (320) covers the front end of the printing area (310); Alternatively, the first irradiation area (210) and the printing area (310) have a plurality of overlapping portions (320) arranged at intervals along the front-to-back direction, and all the overlapping portions (320) do not cover the front end of the printing area (310).

2. The UV varnish printing system according to claim 1, characterized in that: The total width of the overlapping portion along the front-to-back direction accounts for 10%-20% of the width of the printing area (310) along the front-to-back direction.

3. A method for using a UV printer, characterized in that: The UV printer comprises a UV varnish printing system as claimed in any one of claims 1 to 2, and further comprises a guide rail (800) and a moving platform (900), wherein the moving platform (900) is slidably arranged on the guide rail (800) and is capable of reciprocating in the left-right direction, the nozzle (100), the first ultraviolet emitting device (200) and the second ultraviolet emitting device (400) are all mounted on the moving platform (900) and move with the moving platform (900), and the first ultraviolet emitting device (200) is slidably arranged on the moving platform (900) and is capable of adjusting a relative position with respect to the nozzle (100) in the front-to-back direction, so as to adjust a proportion of a total width of the overlapping portion (320) in the front-to-back direction to a width of the printing area (310) in the front-to-back direction; The method of use comprises the steps of: S1. Obtaining the radiation intensity of ultraviolet rays emitted by the first ultraviolet emitting device; S2. Determine the curing speed of the UV varnish used for printing according to the radiation intensity; S3. Determine the target proportion of the total width of the overlapping portion along the front-to-back direction to the width of the printing area along the front-to-back direction according to the curing speed; S4. Adjusting the relative position of the first ultraviolet emitting device and the nozzle along the front-to-back direction according to the target proportion.

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