JP2005342549A - Uv curing method and apparatus for uv-curable coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent thermal deformation without applying excessive heat to the molded article, to uniformly cure a UV-curable coating even in the molded article of a complex shape, to apply UV to a dark area to cure it and to further realize space-saving and cost reduction of a device. <P>SOLUTION: The UV-curable coating of the molded article is uniformly irradiated with UV from a UV lamp by moving the molded article A comprising a polymer material deposited with the UV-curable coating and also moving the UV lamp 62. A UV curing device 50 used for the curing is provided with a UV curing tank 55; molded article movement devices 72, 73, 74 for moving the molded article A in the UV curing tank; the UV lamp 62; and a lamp movement device 63. A first floor part of a box body 51 with two-floor structure is made to the UV curing tank 55 and an inert gas feed device 56 for purging the inside of the UV curing tank with carbon dioxide is provided. Further, a reflection plate 65 for reflecting UV is arranged. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for curing an ultraviolet (UV) curable coating material adhering to a molded article by UV irradiation.

  Conventionally, most paints applied to molded products made of a polymer material are thermosetting. There are also ultraviolet (UV) curable paints, but these have hardly been used for molded products that are exposed to sunlight such as automobile exterior products. Because, first, when UV is radiated to UV curable paint, the UV of the molded product is irradiated for a long time so that UV reaches each part of the molded product. This is because there is a risk of thermal deformation. Second, in order to provide weather resistance to UV curable paints, it is necessary to add a UV absorber, and then the UV absorber absorbs ultraviolet rays that act on the photopolymerization initiator compounded for UV curing. This is because the UV absorber cannot be blended after all because it hinders curing. However, since the second problem is that the absorption wavelength region of the UV absorber and the excitation wavelength region of the photopolymerization initiator overlap, it is possible to mix the UV absorber by shifting both wavelength regions. Therefore, there is an example in which the use of a UV curable coating material has been studied for automobile exterior products. For example, Patent Document 1 discloses a spindle holder on which a resin molded product such as an automotive headlamp is placed, a UV coating device that applies a UV curable paint to the resin molded product, and a solvent in the UV curable paint is volatilized. There is disclosed a coating film applying apparatus including a drying apparatus that performs the above and a UV irradiation apparatus that cures the UV curable paint by UV irradiation.

In this Patent Document 1, in order to uniformly irradiate UV to the entire outer peripheral surface of a resin molded product having a large number of box-types, first, the inside of the apparatus is first described. Divide into at least two areas (4 chambers in the embodiment) and install a plurality of UV lamps in each area. Also, install a spindle reversing device in the middle of both areas to place the resin molded product together with the spindle type holder. It is described that the surface is turned 90 degrees and the second area irradiates a surface that has not been sufficiently irradiated with UV in the first area.
JP-A-4-341360

  However, the UV irradiation apparatus described in Patent Document 1 requires an area of, for example, four rooms arranged in the horizontal direction, and requires a large installation space. In addition, since UV irradiation is continuously performed by a plurality of UV lamps installed in the four chambers, the temperature of the resin molded product rises to, for example, 120 ° C. or more, which may cause thermal deformation. In addition, if the resin molded product is turned 90 degrees with a spindle holder, it is difficult to irradiate the entire resin molded product with a complex shape, so it will inevitably flow slowly into each area. The risk of thermal deformation increases and the curing tact time becomes longer. Moreover, since a large number of UV lamps are required in total, the equipment cost is high.

  The object of the present invention is to solve the above-mentioned problems, prevent thermal deformation without applying excessive heat to the molded product, and uniformly cure the UV curable paint even for a molded product having a complicated shape. It is an object of the present invention to provide a curing method and curing apparatus for a UV curable coating material that can be cured by applying UV to a dark area, and further, can reduce the space and cost of the apparatus.

The method for curing a UV curable paint according to the present invention employs the following means [1] to [3].
[1] A UV curing method for a UV curable coating that uniformly UV-irradiates the UV curable coating of the molded product from the UV lamp by moving a molded product made of a polymer material to which an ultraviolet (UV) curable coating is adhered. .
[2] A UV curable type that uniformly irradiates UV from the UV lamp to the UV curable coating of the molded product by moving the UV lamp on the molded product made of a polymer material to which an ultraviolet (UV) curable coating is adhered. UV curing method for paint.
[3] UV curing for uniformly irradiating UV from the UV lamp to the UV curable coating of the molded product by moving a molded product made of a polymer material to which an ultraviolet (UV) curable coating is adhered and moving the UV lamp. UV curing method for mold paint.

Here, the movement of the molded article preferably includes at least any two of swinging, reversing, rotation, back and forth movement, left and right movement, and vertical movement, and more preferably including at least any three. Most preferably, all six are included. An example of how to determine this movement is as follows.
1. The basic movement of the molded product is determined according to the size and shape of the molded product.
2. If the dimensions of the molded product are particularly large: Invert in addition to. This is because the internal volume of the UV curing tank is made as small as possible in consideration of the use efficiency of the inert gas to be purged.
3. For example, a molded product having a complicated three-dimensional shape, such as a radiator grill of an automobile, which does not easily reach the back, is swung and irradiated with UV to the back.
4). For example, circular parts such as wheel caps of automobiles and small items are rotated (spindle rotated) to uniformly irradiate UV.

  In addition, the movement of the UV lamp preferably includes at least any two of a change in the light source distance from the molded product, a left / right turn, a vertical / horizontal tilt, a change in an elevation angle, a vertical / horizontal movement, and a left / right movement. It is more preferable to include three, and it is most preferable to include all six. If priority movement is selected in view of the importance of movement, it is preferable to include at least any two of light source distance change, left / right turn, vertical / horizontal tilt, and elevation angle change, including all four. Is more preferable, and it is most preferable to add vertical movement and horizontal movement thereto. Even with the movement of the UV lamp, the UV can be uniformly irradiated onto the molded product. However, the movement of the UV lamp can be added to the movement of the molded product to irradiate the molded product more uniformly.

The UV curing paint curing device according to the present invention employs the following means [4].
[4] A UV curing tank, a molded article moving device for moving a molded article made of a polymer material to which an ultraviolet (UV) curable coating material is attached, in the UV curing tank, and a UV lamp provided in the UV curing tank And a UV curing device for UV curing paint, comprising a lamp moving device for moving the UV lamp.

  Here, it is preferable that a first floor portion of a two-story structure housing communicated with a communication port provided at a central height is the UV curing tank. Moreover, it is preferable to provide an inert gas supply device that purges the inside of the UV curing tank with an inert gas. The inert gas is preferably carbon dioxide.

  In addition, it is preferable to arrange a reflector that reflects UV irradiated from the UV lamp on one side of the molded product to the molded product from the other side of the molded product.

  The UV curable paint includes a solvent type containing a solvent (this is general) and a solventless type containing no solvent, and any of them may be used. However, it is preferable to use a substantially solvent-free type in that a solvent volatilization step after application is unnecessary and adjustment of the solvent in the recovered paint is unnecessary. The term “substantially solvent-free” means not only those that do not contain any solvent, but also those that contain a trace amount of solvent (to the extent that adjustment of the solvent in the recovered paint is unnecessary).

  The UV curable paint includes a colored color paint and a transparent clear paint, and any of them may be used. However, it is preferable to use a clear paint because there is no inconvenience such as correction of color mixing and color variation.

  According to the method and apparatus for curing a UV curable coating material according to the present invention, it is possible to prevent thermal deformation without applying excessive heat to the molded product, and even a complex-shaped molded product is capable of preventing UV curable coating material. Can be cured uniformly, UV can be applied to the dark area, and further, space saving and cost reduction of the apparatus can be achieved.

  By moving the molded article (A) made of the polymer material to which the UV curable paint is adhered and moving the UV lamp (62), the UV curable paint of the molded article is uniformly irradiated with UV. The movement of the molded product is rocking, reversing and rotating, and the movement of the UV lamp is changing the light source distance from the molded product, turning left and right, vertically and horizontally tilting, changing the elevation angle, and adjusting up and down. The apparatus used for this curing is a UV curing tank (55) and a molded article moving apparatus (72, 73, 74) for moving a molded article (A) made of a polymer material to which a UV curable coating is adhered in the UV curing tank. And a UV lamp (62) provided in the UV curing tank, and a lamp moving device for moving the UV lamp. An inert gas supply device that purges the interior of the UV curing tank with carbon dioxide gas as an inert gas, using the first floor portion of the case (51) of the second floor structure communicated with the communication port provided at the center height. (56) is provided. Further, there is disposed a reflector that reflects the UV irradiated from the UV lamp on one side of the molded product to the molded product from the other side of the molded product.

The curing device and curing method for the UV curable paint of Example 1 will be described with reference to FIGS.
<Painting equipment for molded products>
1 and 2 schematically show a molding apparatus 1 in a molding equipment for a molded product and an entire painting equipment including a paint curing apparatus according to the first embodiment. Prior to the painting facility, the molding apparatus 1 will be briefly described. The molding apparatus 1 is for molding the molded product A with a polymer material. Illustrated in FIGS. 1 and 2 is a molding apparatus 1 that performs injection molding with a synthetic resin, and includes a fixed mold 2 and a movable mold 3 that opens and closes in the lateral direction. Here, as an example of the molded product A, it is assumed that the molds 2 and 3 for molding the radiator grille having the lattice-shaped portion a having a complicated shape among the automobile exterior products are provided. The molding tact by the molding apparatus 1 is, for example, about 1.5 minutes (1 to 2 minutes). The molding apparatus 1 is not limited to this example, and the molding method may be, for example, casting, blow, slash or the like, the polymer material may be rubber or elastomer, and the molded product is, for example, protector molding, lamp Various automobile exterior products such as covers and emblems may be used.

  Now, in order from the molding device 1, the coating equipment sequentially takes out the molded device A from the molding device 1, the BC coating device 20 that applies a base coat (BC) coating to the molded product A, and the BC coating by heating. The BC drying device 30 for drying, the UV coating device 40 for applying a substantially solvent-free UV curable coating material to the molded product A, and the UV curing device 50 for curing the UV curable coating material by UV irradiation, These devices 10, 20, 30, 40, and 50 are also arranged without using an inventory storage area. A UV curable paint recovery device 400 is connected to the UV coating device 40. In addition, the coating equipment is provided with a transport device 70 for automatically transporting the molded product A between the devices 10, 20, 30, 40, and 50.

[Taking device 10]
The take-out device 10 is manufactured as a unit having a substantially rectangular parallelepiped housing 11, and a molded product inlet 12 is opened on the lower surface of the housing 11, and a molded product outlet 13 is opened on one side surface (the right side surface in FIG. 1). Yes. The take-out device 10 is attached to the second floor portion of the next BC coating device 20 so as to be positioned above the molding device 1, and the molded product inlet 12 faces the opening of the molds 2 and 3 of the molding device 1. Inside the housing 11, there is a chuck 14 for gripping a molded product, and a moving device (illustrated) for moving the chuck 14 between the opening portions of the molds 2 and 3 and a movable receiving device 74 of a transfer device 70 described later. Abbreviation).

[BC coating apparatus 20]
The BC coating device 20 is manufactured as a unit having a substantially rectangular parallelepiped casing 21, and the casing 21 has a two-story structure of a second floor part and a first floor part by a partition plate provided at a central height. In the second floor portion, a molded product inlet 22 is opened on one side surface (left side surface in FIG. 1) of the housing 21, and a molded product outlet 23 is opened on the other side surface (right side surface in FIG. 1). A known robot 24 having a three-dimensional drive arm connected and supported by a plurality of joints is provided inside the second floor portion. The robot 24 is provided with a spray nozzle 25 that sprays BC paint on the molded product A. Inside the first floor portion, there is provided a paint supply device comprising a BC paint tank 26, a pump 27, a BC paint heating device 28, an electromagnetic valve 29, and a control device (not shown), and a BC paint nozzle is provided on the spray nozzle 25. It is designed to supply paint. The BC paint is not particularly limited, but is preferably a lacquer containing a highly volatile solvent. The radiator grill, which is the molded product A, only needs to be coated with BC paint only on the part visible from the front side, so it is sprayed only from the front side, but a small amount of BC also wraps around the back of the radiator grille. Paint mist inevitably adheres. The BC coating tact by the BC coating apparatus 20 can be substantially synchronized with the molding tact by using the robot 24, and is, for example, about 1 minute (0.5 to 1.5 minutes).

  The casing 21 is connected to a BC paint recovery device 200 that recovers BC paint that has not adhered to the molded product A, and an exhaust device 210. It is arbitrary whether the BC paint collected by the BC paint collection apparatus 200 is discarded or used as a secondary material of the paint (reuse as pure BC paint is difficult).

[BC dryer 30]
The BC drying device 30 is manufactured as a unit having a substantially rectangular parallelepiped casing 31. The casing 31 has a two-story structure of a second floor part and a first floor part by a partition plate provided at a central height. In the second floor portion, a molded product inlet 32 is opened on one side surface (left side surface in FIG. 1) of the housing 31, and a molded product outlet 33 is opened on the other side surface (right side surface in FIG. 1). In this BC drying, the solvent in the BC paint may be volatilized sufficiently. Therefore, an IR (infrared) lamp 34 is used as a heating source in the second floor portion and is arranged in parallel as follows. As described above, the BC paint is not only attached to the radiator grill as the molded product A from the front side, but also unavoidably attached to the back side, so it is necessary to heat and dry both sides uniformly. . Moreover, in order to achieve the BC drying tact described below, quick drying is necessary. Therefore, the IR lamp 34 includes a group of lamps in which a plurality of (e.g., seven) horizontally long lamps are arranged in parallel so as to face the front of the radiator grill, and a horizontally long lamp that faces the back of the radiator grill. It has a two-group configuration with a plurality of lamp groups (for example, six) arranged vertically. In addition, the lamps in the two groups are arranged in a staggered manner in which the heights are alternately shifted. A control power supply 35 is provided inside the first floor portion so that power is controlled and supplied to the IR lamp 34. The BC drying tact by the BC drying apparatus 30 can be substantially synchronized with the above-described forming tact by the above-described device, for example, about 1.5 minutes (0.5 to 2 minutes).

[UV coating device 40]
The UV coating device 40 is manufactured as a unit having a substantially rectangular parallelepiped casing 41, and the casing 41 has a two-story structure of a second floor part and a first floor part by a partition plate provided at a central height. In the second floor portion, a molded product inlet 42 is opened on one side surface (left side surface in FIG. 1) of the casing 41, and a molded product outlet 43 is opened on the other side surface (right side surface in FIG. 1). A known robot 44 having a three-dimensional drive arm connected and supported by a plurality of joints is provided inside the second floor portion. The robot 44 is provided with a spray nozzle 45 for spraying the UV curable paint 5 onto the molded product A. The interior of the first floor is provided with a paint supply device comprising a UV curable paint tank 46, a pump 47, a UV curable paint heating device 48, a solenoid valve 49 and a control device (not shown) for spraying. The UV curable paint 5 is supplied to the nozzle 45.

  As the UV curable paint 5, a solventless clear paint is used. The solventless UV curable coating material has advantages such as omitting the drying step for solvent volatilization before UV curing, which is required for the solvent type UV curable coating material. However, since the solvent-free UV curable paint is expensive, a UV curable paint recovery apparatus 400 that recovers in a reusable state is provided as described later. The UV curable coating material 5 is blended with a photopolymerization initiator for UV curing and a UV absorber for imparting weather resistance, and the former absorption wavelength region and the latter excitation wavelength region are shifted at least at the peak wavelength. The one is selected. When the viscosity of the UV curable paint is high, the viscosity is lowered by heating with the heating device 48.

  For the same reason as the BC coating, the radiator grill as the molded product A is spray-coated with the UV curable paint 5 only from the front side. Inevitably adhere. The UV coating tact by the UV coating device 40 can be substantially synchronized with the molding tact by using the robot 44, and is about 1 minute (0.5 to 2 minutes), for example.

[UV curable paint recovery device 400]
The UV curable paint 5 has a property of not curing unless UV is applied. Therefore, in the UV coating device 40, an atmosphere in which outside light including UV does not enter the housing 41 is formed. Specifically, the housing 41 is formed so as to be a dark room, and an outside air inlet 420 is provided on a side surface (front side surface in the illustrated example) of the housing 41, but the outside air inlet 420 is outside light. It is made of a breathable material or structure that does not pass through. Then, the UV curing that recovers the mist-like UV curable coating 5 that has not adhered to the molded article A, which is the object to be coated, in an uncured state that can be reused as a UV curable coating by spray application in the atmosphere. A mold paint recovery device 400 is provided. As shown in FIGS. 3 and 4, the UV curable coating material recovery apparatus 400 includes, for example, a cylindrical housing 401 connected to one side surface (tapered rear side surface in the illustrated example) of the housing 41, and the housing 401, a plurality of eliminators 402 that are arranged in parallel with each other at an interval, a rotary drive unit 403 that rotates the eliminator 402 together with the shaft, and a UV attached to the surface of each eliminator 402 in the form of a film. A plurality of scrapers 404 for scraping and removing the curable paint 5, a collection container 405 under the housing 401 for storing and collecting the scraped UV curable paint 5, and an air flow from the molded product A to the eliminator 402. And an exhaust device 410. Of course, an atmosphere in which external light including UV does not enter is also formed in the housing 401 of the apparatus 400.

  As shown in FIGS. 4 to 6, the eliminator 402 is formed in a disk shape that substantially closes the inner cross section of the housing 401, and a large number of vent holes 406 are formed in a distributed manner. Since the vent holes 406 are arranged in a zigzag manner so that they are not arranged in the axial direction of the vent holes 406 between the adjacent eliminators 402, the UV curable paint 5 that has passed through the vent holes 406 together with the air of the adjacent eliminator 402 It is easy to collect by colliding with the surface. Further, since the inner edge of the vent hole 406 is processed obliquely (FIG. 6), the UV curable paint 5 attached to the inner edge is likely to sag. The diameter of the eliminator 402 is, for example, 800 to 1000 mm, the interval between the eliminators 402 is, for example, 10 to 50 mm, the diameter of the vent holes 406 is, for example, 20 to 40 mm, and the number of the vent holes 406 in each eliminator 402 is, for example, 100 to 200 It is. In this numerical range, the collection rate of the UV curable paint 5 by one eliminator 402 is about 40 to 60%. Therefore, for example, the collection rate of the UV curable paint 5 by four eliminators 402 is 87. It is about -98%. In the case of this example, 3 to 6 eliminators 402 are appropriate. In addition, this collection rate is a number which changes by the change of the said numerical value.

  The scraper 404 is in the shape of a long spatula that extends and contacts the front surface (the side facing the molded product A) and the rear surface (the opposite side) of each eliminator 402 in the radial direction. The scraper 404 itself is fixedly provided, and the UV curable paint adhered to both surfaces of the eliminator 402 is scraped off by the scraper 404 by the rotation of the eliminator 402 and stored and collected in the recovery container 405. Is done. The material or surface treatment of the eliminator 402 and the scraper 404 is an important factor for smoothly scraping off the UV curable paint, and the use of a material or surface treatment excellent in a low friction coefficient, wear resistance, corrosion resistance, etc. preferable. In this example, the eliminator 402 is formed of SS (JIS: rolled steel for general structure), and is further nickel-plated. The scraper 404 is made of NC nylon resin.

  The exhaust device 410 includes a housing 411 connected to the end of the housing 401, a filter 412 provided in the housing 411, and an exhaust fan 413 that sucks air in the direction outside the filter 412. This intake air forms an air flow that flows in the order of the outside air inlet 420 → the inside of the casing 41 → the inside of the casing 401 → the inside of the casing 411 → the outside air, and the mist-like UV curable paint that has not adhered to the molded product A is formed. It flows to the eliminator 402 with this air flow.

[UV curing device 50]
The UV curing device 50 is manufactured as a unit having a substantially rectangular parallelepiped casing 51. As shown in FIG. 7, the casing 51 is separated from the second floor portion by a partition plate with a communication port 54 provided at the center height. It has a two-story structure with the floor part. In the second floor portion, a molded product inlet 52 is opened on one side surface (left side surface in FIG. 1) of the casing 51, and a molded product outlet 53 is opened on the other two side surfaces (right side surface and front side surface in FIG. 1). Yes.

  The interior of the second floor portion is hollow, but a power source, a control device (movement control, output control, etc.) for the UV lamp 62 described below may be provided.

  The first floor portion is the main body of the UV curing device 50, and the casing 51 itself of the first floor portion is a UV curing tank 55 that purges (fills) an inert gas. In UV curing, a molded product A made of a heat-sensitive synthetic resin is irradiated with UV so as not to apply an excessive amount of heat, and a radiator grille having a lattice-shaped portion a having a complicated shape is used. The key point is how uniformly UV can be applied to the molded product A even in a dark area where the UV is difficult to hit, such as the back of the lattice-shaped portion a. Therefore, the UV curing device 50 of this example is manufactured by incorporating the following five items.

(1) Dropping method As described above, the casing 51 has a two-story structure, and a dropping method is adopted in which the molded product A is dropped into the UV curing tank 55 on the first floor from the communication port 54 of the partition plate and UV cured. This method is adopted because of the nature of the inert gas used in the purge described later. Further, the drop-in type is effective in preventing UV leakage from the apparatus and process to the previous UV coating apparatus and process. The internal volume of the UV curing tank 55 is about 1 m ³ , and the floor size is about 1 m × about 1.5 m.

(2) Purging with inert gas The presence of oxygen in the atmosphere during UV irradiation inhibits UV curing of the paint and causes uncured parts. Therefore, an inert gas supply device 56 for purging the inside of the UV curing tank 55 with an inert gas is connected to the UV curing tank 55. The inert gas supply device 56 includes an inert gas tank 57, a plurality of electromagnetic valves 58, and discharge ports 59. A part of the discharge ports 59 is opened in the casing 51 and is filled with an inert gas. Further, the other discharge ports 59 are branched and opened to the communication port 54 of the partition plate, and an inert gas is ejected so as to cross the communication port 54 to prevent the inflow of air from the second floor portion. . The UV curing tank 55 is provided with an oxygen sensor 60, and a purge control device 61 that controls opening and closing of the electromagnetic valve 58 so that the oxygen concentration detected thereby becomes a predetermined value or less. In this example, carbon dioxide (carbon dioxide) is used as the inert gas. Since carbon dioxide gas is heavier than air, it has the property that it keeps itself in the UV curing tank 55 and does not easily escape from the upper communication port 54. Therefore, even if it is not constantly supplied, it is sufficient to supply it intermittently. Nitrogen gas is generally used for the purpose of purging, but nitrogen gas is lighter than air and therefore easily escapes from the communication port 54.

(3) UV lamp and lamp moving device In the UV curing tank 55, a UV lamp 62 is provided as follows. As described above, it is necessary to irradiate the UV evenly to the UV curable paint in the dark area where the UV does not hit like the back of the lattice-shaped portion a of the radiator grill. Moreover, in order to achieve the UV curing tact described later, quick curing is necessary. Therefore, for example, two UV lamps 62 face the front of the radiator grill, and one UV lamp 62 looks up the front of the radiator grill from the lower side, for example, in the vertical and horizontal directions. The front surfaces can be irradiated in different irradiation directions. Further, a general electrode-type UV lamp cannot be freely moved, but in this example, an electrodeless UV lamp 62 that can freely move the lamp is used. Specifically, it is an electrodeless lamp of FUSION. Based on this, each UV lamp 62 is attached to a lamp moving device 63, and the lamp moving device 63 changes the light source distance from the molded product A, turns left and right, vertically and horizontally tilts, changes the elevation angle, and moves up and down and left and right. Can be done. The movable range of the UV lamp 62 is, for example, a light source distance of 50 to 200 mm, left and right turn ± 30 degrees, vertical and horizontal tilt ± 45 degrees, elevation angle ± 30 degrees, vertical movement width 500 mm, and horizontal movement width 200 mm. By making the UV lamp 62 movable in this way, the lamp arrangement can be made optimally corresponding to the shape of the molded product A (radiator grill or other molded product) flexibly.

  As shown in FIG. 8, the lamp moving device 63 of this example includes an upper and lower base 602 that moves up and down guided by a guide pole 601 standing in the UV curing tank 55, and the upper and lower base 602 on the front and rear and the left and right. A front and rear left and right base 603 that moves, a movable vertical axis 604 that rotates and tilts with a lower end supported by the front and rear left and right base 603, and a support base 605 that is attached to the upper end of the movable vertical axis 604 and is provided with a UV lamp. A movable horizontal shaft 606 that supports 62 and rotates about the shaft is provided, and each is provided with a drive device (not shown) such as a motor. Then, the UV lamp 62 is moved up and down by the vertical movement of the vertical table 602, the light source distance of the UV lamp 62 is changed by the vertical movement of the front and rear left and right table 603, and the UV lamp 62 is moved right and left by the horizontal movement of the front and rear left and right table 603. The UV lamp 62 is turned left and right by the rotation of the movable vertical axis 604, the UV lamp 62 is tilted vertically and horizontally by the tilt of the movable vertical axis 604, and the elevation angle of the UV lamp 62 is changed by the rotation of the movable horizontal axis 606. It has become.

(4) Movement of molded product A movable receiving device 74 of the transfer device 70 described later enters the UV curing tank 55 while receiving the molded product A. At that time, the molded product A is swung and reversed ( It has the function of rotating, moving back and forth, moving left and right, and moving up and down. With this function, UV is applied to the UV curable paint in the dark area while swinging the molded product A as shown in FIG. Further, as described above, in order to reduce the internal volume of the UV curing tank 55 as much as possible so as to reduce the amount of inert gas necessary for purging, and to use UV efficiently, as shown in FIG. Product A is inverted and rotated so that it is exposed to UV.

(5) Reflector plate As described above, the mist of the UV curable coating 5 inevitably adheres to the back surface of the radiator grill which is the molded product A. Therefore, the back surface needs to be irradiated with UV light. However, the amount of the mist is small, and it is inefficient to provide an expensive UV lamp for curing. Therefore, in order to use the UV from the UV lamp 62 on the front side more efficiently, a reflection plate (mirror) 65 for reflecting the UV is arranged on the back side of the molded product A as shown in FIG. The secondary UV reflected by the plate 65 is used to cure the UV curable paint adhering to the back surface of the molded product A and the dark area. In FIG. 11B, I is a range of the UV curable coating 5 that is cured by direct UV (primary UV) from the UV lamp 62, and II is a UV curable type that is cured by the secondary UV reflected by the reflector 65. The range of the paint 5 is shown.

[Conveying device 70]
A continuous conveying device 70 is provided on the ceiling of each second floor portion of the take-out device 10, the BC coating device 20, the BC drying device 30, the UV coating device 40, and the UV curing device 50. The conveying device 70 includes a continuous rail 71, a moving device 72 that moves along the rail 71, a hanging member 73 that hangs down from the moving device 72, and a movable receiving device that is provided at the lower end of the hanging member 73. 74. The mobile device 72 has a function of moving the drooping member 73 up and down. The movable receiving device 74 has a function of receiving and supporting the molded product A and a function of swinging, reversing, rotating, moving back and forth, moving left and right, and moving up and down as described above. Yes.

[Arrangement of each device]
The devices 10, 20, 30, 40, 50 are arranged and joined in a straight line in that order so that the molded product outlet and molded product inlet are aligned (FIGS. 1 and 13 (a)). )). In each of the devices 10, 20, 30, 40, and 50, one side surface of another unit can be joined to one side surface that can be selected from two or three side surfaces of at least one unit. Accordingly, the planar arrangement of each unit may be changed, such as a planar L-shaped arrangement as shown in FIG. 13B or a planar U-shaped arrangement as shown in FIG.

In addition, since the units of the devices 20, 30, 40, and 50 are assembled so that they can be rearranged, the following three arrangements can be selectively performed.
(1) The BC coating device 20, the BC drying device 30, the UV coating device 40, and the UV curing device 50 are arranged and joined in this order (FIGS. 1 and 13A). The coating method in this case is each process described later, so-called 2-coat 2-bake.
(2) The BC coating device 20 and the BC drying device 30 are omitted, and the UV coating device 40 and the UV curing device 50 are arranged and joined in this order (FIG. 14A). The coating method in this case is a configuration of a UV coating process and a UV curing process, which will be described later, so-called 1 coat 1 bake.
(3) The BC drying device 30 is omitted, and the BC coating device 20, the UV coating device 40, and the UV curing device 50 are arranged and joined in this order (FIG. 14B). The coating method in this case is a BC coating process, a UV coating process, and a UV curing process, which will be described later, a so-called two-coat one-bake. In this case, the BC paint is not subjected to IR drying (adjusting the solvent of the BC paint in advance so that IR drying is unnecessary).

<Method of painting molded products>
Next, a coating method performed using the coating equipment for molded products configured as described above will be described. Prior to the coating method, in the molding apparatus 1, the radiator grill as the molded product A is injection-molded in about 1.5 minutes (0.5 to 2 minutes), and the molds 2 and 3 are opened.

1. Unloading process: The chuck 14 of the unloading device 10 descends between the molds 2 and 3, grips and unloads the molded product A, and rises again. Deliver. This extraction tact is several seconds to several tens of seconds, and is extremely short as compared with the tact of other processes, so that it can be almost ignored when taking synchronization. In addition, when taking out a plurality of molded products in the take-out device 10, after taking out, the gate cut is performed and separated one by one, and then similarly delivered one by one.

2. BC application process: The conveying device 70 conveys the molded product A one by one to the BC coating device 20, and the BC coating device 20 applies BC paint to the molded product A with a spray nozzle 25 attached to the robot 24. Apply in about 1 minute (0.5-1.5 minutes).

3. BC drying process: The conveying device 70 conveys the molded product A after BC application to the BC drying device 30, and the BC drying device 30 applies the BC paint of the molded product A to the BC drying tact for about 1.5 minutes by the IR lamp 34. Dry (1-2 minutes).

4). UV coating process: The transport device 70 transports the BC-dried molded products A one by one to the UV coating device 40, and the UV coating device 40 uses the spray nozzle 45 attached to the robot 44 to remove the solvent from the molded product A. The UV curable paint 5 of the mold is applied in about 1 minute (0.5 to 1.5 minutes) of UV application tact. At this time, the UV coating device 40 does not receive external light including UV or UV from the UV curing device 50. For this reason, the UV curable paint recovery apparatus 400 recovers the UV curable paint 5 that has not adhered to the molded product A in an uncured state that can be reused as the UV curable paint. As a result, it is possible to improve the utilization efficiency of the UV curable paint, reduce the cost, and reduce the waste treatment.

5). UV curing step: The conveyance device 70 conveys the molded product A after UV coating to the UV curing device 50 one by one. In the UV curing device 50, the conveyance device 70 lowers the molded product A, passes the BC drying device 30 in the second floor portion, and further drops it into the UV curing tank 55 in the first floor portion through the communication port 54. When passing through the communication port 54, oxygen attached to the molded product A is blown away by the inert gas discharged from the discharge port 59 provided in the communication port 54. Then, in the UV curing tank 55 purged with an inert gas, the UV curing paint 5 (coating film) of the molded product A is irradiated with UV by the UV lamp 62 as described above, and the UV curing tact time is about 1.5 minutes. Cured in (1-2 minutes). At this time, since the UV curing device 50 irradiates the UV by incorporating the five items as described above, the following effects can be obtained.

A: Since UV irradiation can be performed efficiently in an appropriate UV intensity and in an appropriate short time, excessive heat is not applied to the molded product A and it is difficult to be thermally deformed.
A: Even in the case of a molded product A having a complicated shape, the UV curable paint 5 can be uniformly cured, and UV is also reliably applied to the UV curable paint in the dark area such as the back of the lattice-shaped portion a. It can be cured.
C: By adopting a two-story structure and dropping into the first floor part, it is possible to improve the storage of inert gas and prevent UV leakage to the UV coating device 40.
D: Since the number of UV lamps 62 is small and the size of the UV curing tank 55 is minimized, the space for the UV curing device 50 (reduction in installation area) and cost reduction can be achieved.

6). Discharge process: The conveyance device 70 discharges the molded products A after UV curing one by one from the molded product outlet 52. The operator removes and accommodates the molded product A from the movable receiving device 74 of the conveying device 70. The movable receiving device 74 circulates back toward the take-out device 10.
The above steps are performed sequentially and sequentially, and each step is operating almost always. That is, when one molded product is transported from the BC coating process to the BC drying process, the next one molded product is transported to the BC coating process, and the previous one molded product is transported from the BC drying process. It is conveyed to the UV coating process.

  As described above, the BC coating tact, the BC drying tact, the UV coating tact, and the UV curing tact are each in a range of 0.2 times to 5 times (preferably 0.5 times to 2 times). The range is set to be within the range of 2 times), so that one molded article is made to flow through the BC coating process, the BC drying process, the UV coating process, and the UV curing process one by one in order, and there is no inventory in each process. By doing so, the inventory storage space can be eliminated, the equipment layout space can be made compact, the labor required for inventory storage can be reduced, and the lead time can be shortened, and the tact of each process including the drying tact can be substantially synchronized. In addition, it is possible to realize the flow of one molded product, to make the drying device compact and to improve the efficiency.

  In addition, since each device 20, 30, 40, 50 is manufactured as a unit having a second-floor casing 21, 31, 41, 51, the molded product A smoothly passes through the second floor portion of each device. be able to. Further, as described above, the UV curing device 50 can be easily dropped into the first floor portion. Furthermore, by storing control-related parts and the like in the first floor portion of each device, it is possible to save space for the unit (reduction in installation area).

In addition, this invention is not limited to the said Example, For example, it can also be suitably changed and embodied in the range which does not deviate from the meaning of invention as follows, for example.
(1) Use a solvent type containing a solvent for the UV curable paint 5. In this case, as shown in FIG. 14C, a solvent drying device 30 ′ similar to the BC drying device 30 is added between the UV coating device 40 and the UV curing device 50, and the solvent drying device 30 ′ uses the UV. What is necessary is just to volatilize the solvent in the curable coating material 5. Accordingly, it is possible to obtain the operational effects such as the single sink.

(2) The molded product inlet or molded product outlet of each of the devices 20, 30, 40, 50 and the communication port 54 of the UV curing device 50 are simply opened, but may be of an open / close type equipped with an open / close device. In particular, any opening between the UV coating device 40 and the first floor portion of the UV curing device 50 can be opened and closed, so that UV leakage from the UV lamp 62 to the UV coating device 40 can be reliably blocked. .

(3) The present invention can be implemented even if each device 20, 30, 40, 50 has a first floor structure. In this case, it is preferable to take measures against UV leakage (such as opening and closing of the mouth and installation of a shielding plate) and measures against escape of inert gas (such as opening and closing of the mouth).

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view schematically showing a molding facility and a coating facility including a UV curing apparatus according to a first embodiment of the present invention through a casing. It is a top view which shows schematically the whole said painting equipment through a housing | casing. The UV coating device of the painting facility is shown through the housing, (a) is a plan view and (b) is a side view. It is a longitudinal cross-sectional view of the UV curable paint collection | recovery apparatus connected to the same UV coating device. It is a cross-sectional view of the same UV curable paint recovery apparatus. It is sectional drawing which shows the effect | action of the same UV curable coating material collection | recovery apparatus. It is a perspective view which shows the UV curing device of the painting facility through the casing. It is a perspective view which shows the lamp moving apparatus of the UV curing device. It is a perspective view which shows the effect | action by the same UV curing device. It is a perspective view which shows another effect | action by the same UV curing device. It is a perspective view which shows another effect | action by the same UV curing device. It is a graph which shows the tact of each process of the painting equipment. It is a schematic plan view which shows the aspect of arrangement | positioning of each apparatus of the coating equipment. It is a schematic plan view which shows the aspect of another arrangement | positioning of each apparatus of the painting facility.

Explanation of symbols

DESCRIPTION OF SYMBOLS 50 UV curing device 51 Case 55 UV curing tank 56 Inert gas supply device 60 Oxygen sensor 62 UV lamp 63 Lamp moving device 65 Reflecting plate 602 Upper and lower base 603 Front and rear base 604 Movable vertical axis 605 Support base 606 Movable horizontal axis 70 Conveyance device 74 Movable receiving device A Molded product

Claims (10)

  A UV curing method for a UV curable coating that uniformly UV-irradiates the UV curable coating of the molded product from the UV lamp by moving a molded product made of a polymer material to which an ultraviolet (UV) curable coating is adhered.   UV of a UV curable coating that uniformly irradiates UV from the UV lamp to the UV curable coating of the molded product by moving the UV lamp on the molded product made of a polymer material to which an ultraviolet (UV) curable coating is adhered. Curing method.   A UV curable coating that uniformly irradiates UV from the UV lamp to the UV curable coating of the molded product by moving a molded product made of a polymer material to which an ultraviolet (UV) curable coating is adhered and moving the UV lamp. UV curing method.   The UV curing method for a UV curable paint according to claim 1 or 3, wherein the movement of the molded article includes at least any one of rocking, reversing, rotation, back and forth movement, left and right movement, and vertical movement.   4. The UV according to claim 2, wherein the movement of the UV lamp includes at least any one of a change in a light source distance from the molded product, a left / right turn, a vertical / horizontal tilt, a change in an elevation angle, a vertical / horizontal movement, and a left / right movement. UV curing method for curable paint.   A UV curing tank, a molded article moving device for moving a molded article made of a polymer material to which an ultraviolet (UV) curable coating material is adhered, in the UV curing tank; a UV lamp provided in the UV curing tank; A UV curing device for UV curing paint, comprising a lamp moving device for moving a UV lamp.   7. The UV curing apparatus for UV curable paint according to claim 6, wherein a first floor portion of a two-story housing communicated with a communication port provided at a central height is used as the UV curing tank.   8. The UV curing device for UV curable paint according to claim 6 or 7, further comprising an inert gas supply device for purging the inside of the UV curing tank with an inert gas.   9. The UV curing apparatus for UV curable paint according to claim 8, wherein the inert gas is carbon dioxide.   The UV curing according to any one of claims 6 to 9, wherein a reflector that reflects UV irradiated from the UV lamp on one side of the molded product to the molded product from the other side of the molded product is disposed. UV curing equipment for mold paint.

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