CN111468369A

CN111468369A - Optical plate coating system

Info

Publication number: CN111468369A
Application number: CN202010391588.3A
Authority: CN
Inventors: 张景春; 司家林
Original assignee: Anhui Fulang Optical Materials Co ltd
Current assignee: Anhui Fulang Optical Materials Co ltd
Priority date: 2020-05-11
Filing date: 2020-05-11
Publication date: 2020-07-31

Abstract

The invention relates to an optical plate coating system, which comprises a conveying mechanism, a plate feeding device, a film tearing device, a cleaning device, a dust adhering device, a slit extrusion die head, an air knife coating head, a curing device and a film coating device, wherein the conveying mechanism comprises a first part, a second part and a third part, a first gap is formed between the first part and the second part, a second gap is formed between the second part and the third part, the slit extrusion die head is positioned above the first gap, the air knife coating head is positioned above the second gap, and the slit extrusion die head and the air knife coating head are cooperatively coated, wherein the slit extrusion die head has the advantage of uniform coating, the excessive coating liquid blown off by the air knife coating head is used for realizing the control of the thickness of the coating, the excessive coating falls and is recycled from the first gap and the second gap, so that the high-precision rapid coating requirement is realized, and the slit extrusion die head allows the excessive coating to be extruded, therefore, the thickness of the optical plate is not limited, and the thickness tolerance change of the optical plate does not need to be considered.

Description

Optical plate coating system

Technical Field

The invention relates to the field of processing and manufacturing of optical plates, in particular to an optical plate coating system.

Background

Optical resin plates have been widely used in the fields of construction, medical treatment, semiconductors, electronic manufacturing, and the like, but the actual application requirements cannot be met due to low surface hardness and poor wear resistance of raw materials. Therefore, the surface of the material needs to be subjected to functional coating treatment.

The functional coating mainly comprises multiple types of hardening, self-cleaning, wear resistance, anti-glare, anti-static and the like. The coating modes mainly comprise curtain coating, roller coating, spray coating and the like, but the coating modes have respective advantages and disadvantages, for example, the curtain coating process can realize the coating of products with various specifications and different sizes, and is convenient and flexible, but the coating thickness is not uniform, the coating is wasted, and the pollution is serious; the curtain coating process is not limited by the size of the product, but the coating is generally thicker, cannot realize thin coating, and has higher requirements on the viscosity and the leveling property of the coating; the coating thickness can be controlled by a roller coating mode, but the quality of a coating surface is poor, coating marks exist on the surface of the coating, and the optical performance requirement cannot be met; the spraying mode has low efficiency, and large-scale production cannot be realized. The optical resin plate has the characteristic of large thickness tolerance, and the traditional coating mode cannot meet the requirements of coating thickness control and quick coating, namely cannot meet the requirements of high-efficiency and high-precision coating.

Disclosure of Invention

Therefore, it is necessary to provide an optical sheet coating system to solve the problem that the conventional coating method satisfies the requirement of coating optical sheets with high efficiency and high precision.

An optical sheet coating system includes a conveying mechanism for conveying an optical sheet to be coated, the conveying mechanism including a first portion, a second portion, and a third portion arranged in a conveying direction, the first portion and the second portion having a first gap therebetween, the second portion and the third portion having a second gap therebetween; set gradually along the direction of transfer: the device comprises a plate feeding device, a film tearing device, a cleaning device, a dust sticking device, a slit extrusion die head, an air knife coating head, an oven, curing equipment and a film coating device, wherein the plate feeding device is used for transferring the optical plate to be coated to the conveying mechanism; the film tearing device is used for tearing off the film paper on the surface of the optical plate to be coated so as to expose the surface; the cleaning device is used for cleaning the surface of the optical plate to be coated; the dust adhering device is used for further cleaning the surface of the optical plate to be coated after the cleaning device; the slot extrusion die head is used for extruding and forming curtain-shaped coating, and the slot extrusion die head is positioned above the first gap; the air knife coating head is used for spraying gas so as to adjust the coating amount of the coating on the surface of the optical plate to be coated, and the air knife coating head is positioned above the second gap; the curing equipment is used for curing the coating on the surface of the optical plate to be coated so as to obtain the optical plate with the coating; the film covering device is used for covering a protective film on the surface of the coating; the automatic feeding device comprises a recovery tank, a material barrel and a feeding pump, wherein the recovery tank is communicated with the material barrel and is arranged below the first gap and the second gap, and the feeding pump is communicated with the material barrel and the slit extrusion die head.

According to the optical plate coating system, the slit extrusion die head and the air knife coating head are cooperatively coated, wherein the slit extrusion die head has the advantage of uniform coating, the air knife coating head is used for blowing off redundant coating liquid to realize coating thickness control, so that high-precision and rapid coating requirements are realized, and the slit extrusion die head is allowed to be farther away from a plate and to extrude redundant coating, so that the thickness of the optical plate is not limited, and the thickness tolerance change of the optical plate does not need to be considered.

In one embodiment, the two conveying mechanisms are arranged side by side, wherein a first conveying mechanism is provided with a turning frame at the downstream of the film laminating device, the turning frame is used for turning over the optical plate covered with the protective film and placing the optical plate on a second conveying mechanism, the tail end of the first conveying mechanism is close to the front end of the second conveying mechanism, and the front end of the first conveying mechanism is close to the tail end of the second conveying mechanism; the two conveying mechanisms share one automatic feeding device or are respectively provided with the automatic feeding devices.

In one embodiment, the slot gap of the slot extrusion die is 0.2mm to 2 mm.

In one embodiment, the air amount of the air knife coating head is 50m³/H-2000m³H, the distance between the air knife and the optical plate to be sprayed is 2-20 mm, and the angle between the air knife and the optical plate to be sprayed is 0-90 degrees.

In one embodiment, the automatic feeding device further comprises a feeding barrel, a feeding pump, a concentration sensor and a control system, wherein the feeding pump is communicated with the feeding barrel and the feeding barrel, the concentration sensor is arranged in the feeding barrel, the control system is electrically connected with the concentration sensor and the feeding pump, and the control system controls the feeding pump to work according to a feedback signal of the concentration sensor.

In one embodiment, the automatic feeding device further comprises at least two groups of filter units, at least two groups of filter units are sequentially arranged between the feeding pump and the slit extrusion die head, the pore sizes of the filter elements of different filter units are different, and the pore size range is 0.22um-15 um. In one embodiment, the sheet feeder comprises a mechanical suction cup and a transfer rail, one end of which is engaged with the first part of the transfer mechanism.

In one embodiment, the dust-binding device comprises a pneumatic pressure unit and a rubber dust-binding roller, the rubber dust-binding roller is connected to the pneumatic pressure unit, and the rubber dust-binding roller is positioned above the first part.

In one embodiment, the curing device comprises an oven and a UV curing device, wherein the oven is configured to pass through the conveying mechanism for drying the coating on the surface of the optical plate to be coated; and the UV curing device is used for curing the coating on the surface of the optical plate to be coated so as to obtain the optical plate with the coating.

In one embodiment, the UV curing apparatus is one of an L ED lamp, an electrodeless lamp, and a high pressure mercury lamp.

Drawings

FIG. 1 is a schematic side view of an optical sheet coating system according to one embodiment of the present invention.

Fig. 2 is a schematic top view of the arrangement of the conveying mechanism when two conveying mechanisms are provided in the optical sheet coating system according to an embodiment of the present invention, wherein only the arrangement of the plurality of plasma generators is shown, and the illustration of the sheet feeding device and other elements is omitted.

The relevant elements in the figure are labeled as follows:

101. a first portion; 102. a second portion; 103. a third portion; 104. a first gap; 105. a second gap; 2. a plate material supply device; 3. a film tearing device; 4. a cleaning device; 401. a plasma generator; 5. a dust-binding device; 6. a slot extrusion die head; 7. coating a head by using an air knife; 8. an oven; 9. a UV curing device; 110. a film winding mechanism; 120. a first composite rubber press roller; 130. a second composite rubber press roller; 140. a tension sensor; 150. a protective film; 11. a roll-over stand; 12. an automatic feeding device; 121. a recovery tank; 122. a charging bucket; 123. a feed pump; 124. a material supplementing barrel; 125. a feed pump; 126. a concentration sensor; 127. a control system; 128. and a filtering unit.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

In the field, the traditional coating methods such as curtain coating, roller coating, spray coating and the like cannot meet the requirement of high-precision and quick coating of optical plates, and aiming at the problems, the invention provides an optical plate coating system which can be used for coating the surface of the optical plate. The optical sheet material mainly refers to an optical resin sheet material, including but not limited to a PVC sheet, a PET sheet, an acrylic sheet, and the like.

The following describes a preferred embodiment of the optical sheet coating system according to the present invention with reference to the accompanying drawings.

Referring to fig. 1, fig. 1 illustrates a composition structure of an optical sheet coating system according to an embodiment of the invention. The optical sheet coating system includes a conveying mechanism (including a first portion 101, a second portion 102, and a third portion 103) having, arranged in order along a conveying direction of the conveying mechanism: the device comprises a plate feeding device 2, a film tearing device 3, a cleaning device 4, a dust adhering device 5, a slit extrusion die head 6, an air knife coating head 7, an oven 8, a UV curing device 9, a film laminating device (comprising a film rolling mechanism 110, a first compound rubber compression roller 120 and a second compound rubber compression roller 130), and an automatic feeding device 12 for providing coating for the slit extrusion die head 6. The oven 8 and the UV curing device 9 together form a curing apparatus for curing the coating on the surface of the optical plate to be coated to obtain the optical plate with a coating, and the oven 8 and the UV curing device 9 may be disposed at the same time or alternatively.

And the conveying mechanism is used for conveying the optical plate to be coated and can continuously convey a plurality of optical plates to be sprayed. The transport mechanism comprises a first section 101, a second section 102 and a third section 103 arranged at intervals in the transport direction such that there is a first gap 104 between the first section 101 and the second section 102 and a second gap 105 between the second section 102 and the third section 103. The transport mechanism is embodied as a conveyor belt, i.e. comprises three conveyor belt sections. Of course, other configurations are possible that enable pipelining.

The plate material supply device 2 is used for transferring the optical plate material to be coated to the conveying mechanism. The type of the sheet material feeder 2 is not limited. In one embodiment, the sheet feeder 2 is a mechanical suction cup that picks up the optical sheet and transfers it to the first portion 101 of the transport mechanism. Further, the sheet feeder 2 further comprises a transfer rail cooperating with the mechanical suction cup, and one end of the transfer rail is engaged with the first portion 101 of the transfer mechanism. The mechanical suction cups pick up the optical sheet and place it on the transfer rail before it is transported to the first part 101 of the transfer mechanism. In a specific embodiment, when the plate material supply adopts a mechanical sucker, the mechanical sucker is provided with 6-8 groups of sucker heads, the working pressure is-1 bar-0.5bar (bar), and the suction weight is not less than 50kg (kilogram).

And the film tearing device 3 is used for tearing off the film paper on the surface of the optical plate to be coated so as to expose the surface. The surface of the coated optical plate is attached with protective film paper, and the film paper is torn off by the film tearing device 3 before coating so as to expose the surface to be sprayed. In a specific implementation mode, the film tearing device 3 comprises a viscosity rubber plate and a film collecting mechanism. The adhesive force between the viscous rubber plate and the film paper on the surface of the optical plate is larger than that between the film paper and the optical plate. When the film tearing device 3 works, the viscous rubber plate is contacted with the film paper, then the film paper is lifted upwards and separated from the optical plate, and the film collecting mechanism is used for coiling the torn film paper into a roll for recycling. Preferably, the difference between the two adhesive forces is greater than 50gf (gram force) in order to rapidly separate the film paper from the optical sheet material.

The cleaning device 4 is used for cleaning the surface of the optical plate to be coated, can effectively remove grease and other organic pollutants on the surface of the plate, and can improve the dyne value of the surface of the plate and improve the adhesive force of the coating to the plate. In a specific embodiment, with reference to fig. 1 and 2, the cleaning device 4 is a plasma cleaning device, and includes 2-4 sets of plasma generators, specifically 3 sets in fig. 2, each set including at least one plasma generator 401. As shown in fig. 2, in the direction perpendicular to the conveying direction of the conveying mechanism, the plurality of sets of plasma generators 401 are arranged at intervals, specifically, the plurality of sets of plasma generators 401 are arranged at intervals of 10mm to 50mm (millimeters) in the width direction of the conveying mechanism, and the plurality of sets of plasma generators 401 are configured to be capable of reciprocating in the width direction of the conveying mechanism of 50m/min to 200m/min (meters/minute). Although the cleaning range covered by each set of plasma generator 401 itself is limited, since it can reciprocate, the cleaning range is expanded, and the number of plasma generators 401 required is reduced on the premise of ensuring the cleaning efficiency. It is to be understood that the plasma generators 401 are not limited to be provided with 4 groups at most, and may be more than 4 groups, and particularly, when the width of the optical sheet material coating system is large, 4 or more groups of plasma generators 401 may be provided. In a specific application, the plasma generator 401 uses dry air for removing moisture as an air source, and the distance between the dry air and the plate to be sprayed is 10mm-50mm (millimeter). In other embodiments, the cleaning device 4 may be a wet cleaning device.

And the dust adhering device 5 is used for further cleaning the surface of the optical plate to be coated after the cleaning device 4. In a particular embodiment, the dust-binding device 5 comprises a pneumatic pressure unit and a rubber dust-binding roller connected to the pneumatic pressure unit, the rubber dust-binding roller being located above the first portion 101. The rubber dusting roller is floating, based on the support of the pneumatic pressure unit. When the dust adhering device 5 is used, the optical plate to be coated passes through the lower part of the rubber dust adhering roller and drives the rubber dust adhering roller to rotate, and the rubber dust adhering roller can remove tiny carbon particles remained on the surface of the optical plate to be coated after plasma cleaning. When the optical plate to be coated passes through the rubber dust-sticking roller, the gap and the pressure can be automatically adjusted by the pneumatic pressure unit.

A slot extrusion die 6 is located above the first gap 104 for extruding the coating and forming a curtain-like coating. The slit extrusion coating has the characteristics of high extrusion amount precision and stability, and can form a uniform coating on the surface of the optical plate to be coated. The slot extrusion die 6 has a cavity and a minute slot communicating with the cavity. When the slot extrusion die head 6 works, the automatic feeding device 12 conveys the coating to the cavity, and the coating is extruded through the micro slot to form a curtain, so that the coating is flatly distributed on the surface of the optical plate to be coated.

The air knife coating head 7 is used for spraying gas to adjust the coating amount of the coating on the surface of the optical plate to be coated, and the air knife coating head 7 is positioned above the second gap 105. Specifically, the air knife coating head 7 sprays pressurized dry air, and the coating amount of the coating is controlled by setting parameters such as reasonable air knife and plate angle, distance, air pressure and the like, so that the coating is smoothed, and a thin uniform coating is obtained.

The oven 8 is configured to pass a transport mechanism for drying the coating on the surface of the optical sheet to be coated. Specifically, the third portion 103 of the transport mechanism passes through the oven 8 to be dried with the coating of the surface of the optical sheet material to be coated by the oven 8. The type of oven 8 is not limited, and may be, for example, an infrared oven or a thermal oven. Drying here does not require complete curing of the coating, which is to be understood as precuring. However, when the curing apparatus is provided with only the oven 8, the coating is directly and completely cured by the oven 8.

A UV curing device 9 is disposed downstream of the oven 8 for curing the coating on the surface of the optical sheet to be coated to obtain a coated optical sheet, the UV curing device 9 is one of L ED lamp, a stepless lamp and a high-pressure mercury lamp, preferably L ED lamp, L ED lamp is a cold light source to avoid deformation of the optical sheet, and the energy intensity of the UV curing device 9 is generally 50W/cm to 300W/cm (Watt/cm).

A coating device is provided downstream of the oven 8 for coating the surface of the coating with a protective film 150. Namely, a protective film 150 for protection is coated on the surface of the coated optical plate. The structure of the film covering device is not limited. In a specific embodiment, the film covering device is provided with a first compound rubber pressing roller 120 and a second compound rubber pressing roller 130, wherein the first compound rubber pressing roller 120 is used for supporting the optical plate from below, and the second compound rubber pressing roller 130 covers the protective film 150 conveyed by the film rolling mechanism 110 to the surface of the coating in a rolling manner. By the means, no air bubbles exist between the protective film 150 and the optical plate after the protective film is compounded by the compounded rubber press roller. The film covering device further includes a tension sensor 140 and an automatic cutting device (not shown), the protective film 150 is wound around the tension sensor 140, so that the tension sensor 140 can feed back the pressure applied to the protective film 150 in real time, and when the pressure is too high, the conveying speed of the film winding device can be increased appropriately to avoid the breakage of the protective film 150.

The automatic feed device 12 includes a recovery tank 121, a barrel 122, and a feed pump 123, wherein the recovery tank 121 communicates with the barrel 122 and is disposed below the first gap 104 and the second gap 105, and the feed pump 123 communicates the barrel 122 with the slot extrusion die 6. The recycling tank 121 is used for recycling the excess coating to the material barrel 122, and is configured in a funnel shape. The type of the feed pump 123 is not limited, and may be, for example, one of a screw pump and a gear pump, and preferably a screw pump is used, and the flow rate is 1kg/min to 20kg/min (kg/min). The screw pump has the advantage of small pulse, and can ensure stable coating supply so as to obtain a stable coating.

In each embodiment of the invention, the coating is one of a solvent-based coating, a water-based coating or a 100% solid-borne coating, and can be a thermosetting coating or a UV curing coating. The viscosity of the coating is less than 1000 cps.

The working process of the optical plate coating device of the embodiment of the invention is briefly described as follows:

a plurality of optical sheets to be coated are continuously supplied to the first part 101 of the transfer mechanism by the sheet supply device 2 while being transferred with a space therebetween. Each optical plate to be coated is subjected to the following treatment procedures in sequence: tearing, plasma cleaning, dust sticking, slit coating, air knife adjustment of coating materials, baking, UV curing and film covering.

Wherein an optical sheet to be coated is transferred from the first part 101 to the second part 102 of the transport mechanism while the optical sheet to be coated is subjected to slot coating, and then the optical sheet to be coated is transferred from the second part 102 to the third part 103 and subjected to a process air knife adjusting coating. Since there is a space between two adjacent optical sheets to be coated, the coating material extruded from the slot extrusion die 6 falls into the recovery groove 121 from the space between two adjacent optical sheets to be coated, between the aforementioned first gaps 104, before the slot extrusion die 6 slot-coats the next optical sheet to be coated. Similarly, since the second gap 105 is provided, when the coating amount is adjusted by the air-knife coating head 7, the excess coating material blown off from the surface of the optical plate material to be coated falls into the recovery groove 121 from the gap between the adjacent two optical plate materials to be coated, between the aforementioned second gaps 105.

By the above means, both the slot extrusion die 6 and the air knife coating head 7 can continuously work, and the coating material can not fall on the conveying mechanism because of the interval between the two adjacent optical plates to be coated. And because the slot extrusion die head 6 and the air knife coating head 7 can work continuously, the coating quality of the two end parts of the optical plate to be coated can be ensured. As will be understood, if the slot extrusion die 6 and the air knife coating head 7 are intermittently operated, it is difficult to control the timing of restarting the two, so that it is impossible to ensure the operations of coating both end portions of the coated optical sheet material and adjusting the coating amount in a timely manner while avoiding the coating material from falling on the conveying mechanism.

In the working process, the slot extrusion die head 6 and the air knife coating head 7 are coated in a coordinated mode, wherein the slot extrusion die head 6 has the advantage of uniform coating, the air knife coating head 7 is used for blowing off redundant coating liquid to control the thickness of the coating liquid, so that the requirement of high-precision and quick coating is met, the slot extrusion die head 6 allows the redundant coating liquid to be extruded, the thickness of an optical plate is not limited, and the thickness tolerance change of the optical plate does not need to be considered.

It will be appreciated that the length of the first gap 104 and the length of the second gap 105 described above both correspond to the width of the transport mechanism, i.e., the optical sheet coating system. In a specific arrangement, the optical sheet coating system has a width of 500mm to 1500mm (millimeters). As shown in fig. 1, the width of the optical sheet material coating system is the width of the transport mechanism in the direction perpendicular to the plane of the drawing, which determines the width of the optical sheet material that can be transported.

The width of the first gap 104 and the width of the second gap 105 may then be adjusted as desired. The width of the first gap 104 and the width of the second gap 105 refer to the dimensions of the first gap 104 and the second gap 105 in the left-right direction in fig. 1. When continuously coating, the width of the space between the plurality of optical plates to be sprayed may be greater than, equal to, or less than the width of the first gap 104 and the width of the second gap 105 described above.

In the conventional slot extrusion die 6, the slot gap is 50um (micrometer). In the case of the slot die 6 for slot coating in use, in order to obtain a thin thickness coating with high accuracy, the distance of the slot die 6 from the surface of the plate needs to be controlled within 0.5mm (millimeters). However, the thickness tolerance of the optical resin plate material may be 1mm (millimeter) or more, and even up to 3mm (millimeter). Therefore, the conventional slot die 6 cannot be applied to continuous coating of an optical sheet because the slot die 6 may touch the optical sheet, and if the distance between the slot die 6 and the sheet is increased, the coating quality cannot be ensured and the advantage of slot coating cannot be exerted.

In order to solve the above technical problem, in the embodiment of the present invention, the slit gap of the slit extrusion die 6 is 0.2mm to 2mm (millimeter), so that the slit extrusion die 6 can extrude excessive coating material under the condition that the conveying mechanism is normally conveyed forward, and the coating material is subsequently adjusted by using the air knife coating head 7, so that the slit coating is performed without considering the influence of the thickness tolerance of the sheet material. The slit gap refers to a width of the slit in the conveying direction of the conveying mechanism.

In a preferred embodiment, the slit gap of the slit extrusion die 6 is 0.2mm to 2mm (mm), and the air amount of the air knife of the air passage coating head is 50m³/H-2000m³The air knife and the optical plate to be sprayed have a distance of 2mm-20mm (millimeter), an angle of 0-90 degrees, and a transmission speed of 5m/min-20m/min (meter/min). Thus, the coating weight can reach 100-1000g/m²(grams per square meter) in an excess state; the thickness of the coating processed by the air knife coating head 7 can be in a thinner state, the range of the coating is 40nm (nanometer) -15um (micrometer), and meanwhile, no excess material exists on the edge of the optical plate processed by the air knife coating head 7. Meanwhile, according to the embodiment, the coating precision of the coating thickness is +/-3 um (micrometer), and the coating method is suitable for high-efficiency and high-precision coating of the optical plate with the thickness tolerance of +/-3 mm (millimeter).

Referring to fig. 2, in a specific application, with reference to fig. 1, two conveying mechanisms are arranged side by side, wherein a first conveying mechanism (located above in fig. 2) is provided with a roll-over stand 11 at a downstream of the film coating device, the roll-over stand 11 is used for turning over the optical plate covered with the protective film 150 and placing the optical plate on a second conveying mechanism (located below in fig. 2), a tail end of the first conveying mechanism is close to a front end of the second conveying mechanism, and a front end of the first conveying mechanism is close to a tail end of the second conveying mechanism; the two transfer mechanisms either share one automatic feed device 12 or are each provided with an automatic feed device 12. That is to say, two transport mechanism parallel arrangement, and crisscross relative head and the tail, the head and the tail pass through roll-over stand 11 and link up.

In the line work, the front end and the rear end are relative, wherein the front end refers to a position closer to the starting point of the workpiece in the conveying direction of the workpiece, and the rear end refers to a position farther from the starting point of the workpiece. Specifically, in the present embodiment, the front end refers to the beginning of the first portion 101, and the rear end refers to the end of the third portion 103.

After the optical sheet is transferred on the first transfer mechanism and the coating is completed, the inverting carriage 11 inverts it over the second transfer mechanism to coat the other surface of the optical sheet. Thus, the two opposite surfaces of the optical plate to be coated can be coated quickly with high precision.

When the coating is continuously carried out, the two conveying mechanisms synchronously operate. The spacing between the two transport mechanisms is between 20mm and 100mm (millimeters) so that there is a safe spacing between the optical sheets to be coated on the two transport mechanisms.

The two transfer mechanisms either share one automatic feed device 12 or are each provided with an automatic feed device 12. When one automatic feeding device 12 is used in common, the recovery tank 121 is sized to recover the excess coating material of both the transfer mechanisms at the same time.

Referring to fig. 1, the automatic feeding device 12 further includes a replenishing barrel 124, a replenishing pump 125, a concentration sensor 126 and a control system 127, wherein the replenishing pump 125 is communicated with the replenishing barrel 124 and the replenishing barrel 122, the concentration sensor 126 is disposed in the replenishing barrel 122, the control system 127 is electrically connected with the concentration sensor 126 and the replenishing pump 125, and the control system 127 controls the operation of the replenishing pump 125 according to a feedback signal of the concentration sensor 126, so that the coating material in the replenishing barrel 124 maintains a sufficient concentration.

The workflow of the automatic feed device 12 is as follows: the feed pump 123 pumps the coating in the barrel 122 and conveys the coating to the slot extrusion die head 6, and the coating recovered by the recovery tank 121 continuously enters the barrel 122 for recycling. The concentration sensor 126 detects the concentration of the coating in the material barrel 122 in real time, when the concentration is insufficient, the concentration sensor 126 feeds back a signal to the control system 127, the control system 127 sends an instruction for starting the material supplementing pump 125, and the material supplementing pump 125 pumps the coating in the material supplementing barrel 124 and supplements the coating in the material barrel 122. By the above manner, continuous coating for a long time can be realized.

On the basis of the above embodiment, the automatic feeding device 12 further includes at least two sets of filter units 128, the at least two sets of filter units 128 are sequentially disposed between the feed pump 123 and the slot extrusion die head 6, and the filter elements of different filter units 128 have different pore sizes, which range from 0.22um (micrometers) to 15um (micrometers). That is, a multi-stage filtering unit 128 is disposed between the feeding pump 123 and the slot extrusion die head 6 to filter impurities with different particle sizes, so that the coating extruded from the slot extrusion die head 6 is relatively pure. The filter element may be a filter cartridge and/or a filter bag.

In the above embodiment, the conveying mechanism is specifically a conveyor belt, wherein the third portion 103 passes through the oven 8, the material of the first portion 101 is the same as that of the second portion 102, and the material of the third portion 103 is different from that of the first portion 101 and the second portion 102. Specifically, the first part 101 and the second part 102 may be a common transmission belt, which is not required to be able to withstand high temperature, while the third part 103 is made of a high temperature resistant material, specifically, is able to withstand a temperature of at least 200 ℃ for a long time.

In the above embodiment, the oven 8 may be an infrared oven or a hot air oven, and the baking temperature is 40-160 ℃. The length of the oven 8 is typically 5-20 meters. Furthermore, the inner wall of the oven 8 is made of stainless steel, so that dust is reduced.

Furthermore, if the oven 8 is dried by hot air, the air entering the oven 8 needs to be filtered by a primary, secondary and high-efficiency filter, reaching at least thousand grades. Therefore, when the oven 8 is a hot air oven, a multistage air filter is further arranged at the air inlet of the oven 8.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An optical sheet coating system, comprising:

the conveying mechanism is used for conveying the optical plate to be coated and comprises a first part, a second part and a third part which are arranged along the conveying direction, wherein a first gap is formed between the first part and the second part, and a second gap is formed between the second part and the third part;

set gradually along the direction of transfer: a plate material feeding device, a film tearing device, a cleaning device, a dust sticking device, a slit extrusion die head, an air knife coating head, a curing device and a film coating device, wherein

The plate feeding device is used for transferring the optical plate to be coated to the conveying mechanism;

the film tearing device is used for tearing off the film paper on the surface of the optical plate to be coated so as to expose the surface;

the cleaning device is used for cleaning the surface of the optical plate to be coated;

the dust adhering device is used for further cleaning the surface of the optical plate to be coated after the cleaning device;

the slot extrusion die head is used for extruding and forming curtain-shaped coating, and the slot extrusion die head is positioned above the first gap;

the air knife coating head is used for spraying gas so as to adjust the coating amount of the coating on the surface of the optical plate to be coated, and the air knife coating head is positioned above the second gap;

the curing equipment is used for curing the coating on the surface of the optical plate to be coated so as to obtain the optical plate with the coating;

the film covering device is used for covering a protective film on the surface of the coating; also comprises

The automatic feeding equipment comprises a recovery tank, a material barrel and a feeding pump, wherein the recovery tank is communicated with the material barrel and is arranged below the first gap and the second gap, and the feeding pump is communicated with the material barrel and the slit extrusion die head.

2. The optical sheet coating system according to claim 1, wherein the two transport mechanisms are arranged side by side, wherein a first transport mechanism is provided with a roll-over stand downstream of the coating device, the roll-over stand being configured to roll over and place the optical sheet coated with the protective film onto a second transport mechanism, a trailing end of the first transport mechanism being close to a leading end of the second transport mechanism, and a leading end of the first transport mechanism being close to a trailing end of the second transport mechanism; the two conveying mechanisms share one automatic feeding device or are respectively provided with the automatic feeding devices.

3. An optical sheet coating system as claimed in claim 1, wherein the slot gap of the slot extrusion die is 0.2mm to 2 mm.

4. The optical sheet coating system as claimed in claim 1, wherein the air amount of the air knife coating head is 50m³/H-2000m³H, the distance between the air knife and the optical plate to be sprayed is 2-20 mm, and the angle between the air knife and the optical plate to be sprayed is 0-90 degrees.

5. The optical plate coating system of claim 1, wherein the automatic feeding device further comprises a feeding barrel, a feeding pump, a concentration sensor and a control system, wherein the feeding pump is connected with the feeding barrel and the feeding barrel, the concentration sensor is disposed in the feeding barrel, the control system is electrically connected with the concentration sensor and the feeding pump, and the control system controls the feeding pump to operate according to a feedback signal of the concentration sensor.

6. The optical sheet coating system according to claim 1, 2 or 5, wherein the automatic feeding device further comprises at least two sets of filter units, at least two sets of filter units are sequentially disposed between the feeding pump and the slot extrusion die head, and the pore sizes of the filter elements of different filter units are different, and the pore size ranges from 0.22um to 15 um.

7. An optical sheet coating system as defined in claim 1, wherein said sheet feeder comprises a mechanical suction cup and a transfer rail, one end of said transfer rail engaging said first portion of said transfer mechanism.

8. The optical sheet coating system according to claim 1, wherein said dust-adhering means comprises a pneumatic pressure unit and a rubber dust-adhering roller, said rubber dust-adhering roller being connected to said pneumatic pressure unit, said rubber dust-adhering roller being located above said first portion.

9. The optical sheet coating system of claim 1 wherein said curing apparatus comprises an oven and a UV curing device, wherein said oven is configured to pass said transport mechanism for drying the coating on the surface of the optical sheet to be coated; and the UV curing device is used for curing the coating on the surface of the optical plate to be coated so as to obtain the optical plate with the coating.

10. The optical sheet coating system according to claim 9, wherein the UV curing device is one of L ED lamp, electrodeless lamp and high pressure mercury lamp.