JP2011224493A - Method of forming cylindrical or columnar member with coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of forming a cylindrical or columnar member with a coating film by using an annular nozzle with an annular manifold inside and applying a flowable resin material to the external surface of a cylindrical or columnar base material, which prevents stagnation of the flowable resin material with an efficiently and unevenly dispersed carrier fluid and which improves quality of a formed article.SOLUTION: The annular manifold 3 arranged inside the annular nozzle 2 provides a plurality of inlets 7a and 7b, wherein branch pipes 5a and 5b are respectively connected to the inlets 7a and 7b. The supply rate of the flowable resin material from the inlets 7a and 7b to the manifold 3 is changed every time when the predetermined number of cylindrical or columnar members to be formed with coating films are formed.

Description

  The present invention relates to a method for forming a cylindrical or columnar member having a coating film of a fluid resin material on the outer surface of a cylindrical or columnar substrate.

  When forming a cylindrical or columnar member having a coating film of a fluid resin material on the outer surface of a cylindrical or columnar substrate, an annular nozzle is used. In the annular nozzle, an annular manifold provided in the annular main body and an annular discharge port opened in the inner wall surface are communicated with each other via a circular throttle, and a supply port for supplying a fluid resin material is provided in the annular manifold. Is provided.

  The fluid resin material supplied to the annular manifold from the supply port spreads along the annular shape of the annular manifold, and the fluid resin material collides from the left and right on the opposite side of the supply port. Since the position at this time is the farthest position from the supply port, the opposite side of the supply port is the slowest flow velocity region. When the fluid resin material collides with the left and right sides on the opposite side of the supply port in the annular manifold, a retention portion is generated, and the dispersion medium contained in the fluid resin material loses the flow velocity and precipitates in the retention portion.

  There is a limit in the staying part, and when the capacity of the staying part is exceeded, a substance containing a large amount of dispersion medium is placed on the flow rate of the fluid resin material, passes through the restrictor, flows out from the annular discharge port, and does not enter this part. If it appears as continuous or continuous streaks, it will be defective.

  On the other hand, Patent Document 1 discloses that a fluid resin material having a certain quality is always discharged by always discharging a fluid resin material containing a large amount of material in which a solidified or dispersion medium is unevenly distributed in a staying portion in an annular manifold. A method of forming a coating film by the above is disclosed.

  Further, Patent Document 2 discloses a fluid resin material that prevents a part of the fluid resin material from solidifying or uneven distribution of the fluid resin material by stirring with a stirring mechanism disposed at a staying portion in the annular manifold. A coating method for re-stirring just before discharging is disclosed.

Japanese Patent No. 1377135 Japanese Patent No. 2930748

  However, in the invention disclosed in Patent Document 1, since the quality is made constant by always discharging the staying portion of the fluid resin material from the resin discharge port, the fluid resin material must always be used more than necessary. Don't be. In the invention disclosed in Patent Document 2, since the rotation mechanism is built in the annular manifold and the drive portion is installed outside or inside the annular nozzle, the structure inside the annular manifold in the annular nozzle becomes complicated. Furthermore, since the diameter of the annular manifold in the annular nozzle is reduced in the formation of small-diameter parts, there is a problem that it is difficult to install a rotation mechanism in the annular manifold and to install a drive part outside or inside the annular nozzle. is there.

  The present invention is a method for applying a flowable resin material to the outer surface of a cylindrical or columnar substrate by an annular nozzle having an annular manifold inside, and more effectively prevents the stagnation of the material in which the dispersion medium is unevenly distributed. The purpose is to improve the quality of molded products.

  In order to achieve the above object, a method for forming a cylindrical or columnar member having a coating film according to the present invention comprises an annular nozzle having an inner wall surface that surrounds an outer surface of a cylindrical or columnar substrate with a fluid resin material. In the method of forming a coating film on the outer surface of a cylindrical or columnar substrate by supplying to an annular manifold provided in the interior and discharging from an annular discharge port opening in the inner wall surface, A plurality of inlets for supplying the fluid resin material is provided, and a cylindrical or columnar member having a coating film in which a ratio of the amount of the fluid resin material supplied from each inlet to the annular manifold is set in advance is formed. It is characterized in that it is changed every time the number is formed.

  According to the present invention, the position phase of the material in which the dispersion medium is unevenly distributed in the staying portion is not limited to one place by changing the ratio of the supply amount of the fluid resin material supplied into the annular manifold from the plurality of inlets. be able to.

  Furthermore, by changing the ratio of the supply amount of the fluid resin material supplied from each inflow port, the flow rate of the low speed region, which is the material in which the dispersion medium settles and is unevenly distributed in the staying portion inside the annular manifold, is changed. It becomes possible to change the flowable resin material to a high speed flow rate.

  As a result, the material in which the dispersion medium in the staying portion existing in one place is unevenly placed is put on the flow rate of the fluid resin material, and the dispersion medium in the staying portion is settled and the unevenly-distributed material disappears. Stable formation that does not appear is possible.

It is a model front view which shows an example of the coating device used for implementation of this invention. The annular nozzle in 1st Embodiment is shown, (a) is a schematic top view, (b) is a schematic cross section along the AA line of (a). The annular nozzle in 2nd Embodiment is shown, (a) is a schematic top view, (b) is a schematic cross section along the AA line of (a). The annular nozzle in 3rd Embodiment is shown, (a) is a schematic top view, (b) is a schematic cross section along the AA line of (a). In 3rd Embodiment, it is a graph which shows the resin supply amount supplied from each material supply pipe | tube. It is sectional drawing which shows the state of the annular manifold in 3rd Embodiment. The annular nozzle in 4th Embodiment is shown, (a) is a schematic top view, (b) is a schematic cross section along the AA line of (a). In 4th Embodiment, it is a graph which shows the resin supply amount supplied from each material supply pipe | tube.

(First embodiment)
FIG. 1 is a schematic side view showing the entire coating apparatus used for carrying out the present invention. 2A and 2B show an annular nozzle in the coating apparatus shown in FIG. 1, wherein FIG. 2A is a schematic top view, and FIG. 2B is a schematic cross-sectional view taken along line AA in FIG.

  The annular nozzle 2 forms a coating film by applying a fluid resin material to the outer surface of the cylindrical substrate 1. The annular nozzle 2 has an inner wall surface that surrounds the outer surface of the cylindrical or columnar substrate 1, and communicates with an annular manifold 3 that has an annular discharge port 9 a that opens in the inner wall surface. The annular manifold 3 is provided with a plurality (two in the drawing) of inlets 7a and 7b for supplying a fluid resin material. And the annular manifold 3 and the 1st and 2nd branch pipes 5a and 5b of fluid resin material are connected by 180 degree phase from 2 directions.

  One end of the material supply pipe 14 communicates with the material supply apparatus 20, and the other end of the material supply pipe 14 is branched into the first and second branch pipes 5 a and 5 b via the two-way diverter 4. Yes. On-off valves 6a and 6b are interposed in the branched first and second branch pipes 5a and 5b, respectively. The branch pipes 5 a and 5 b are connected to each other at a pair of inflow ports 7 a and 7 b of the annular manifold 3.

  The cylindrical base material 1 is fixed by a pair of upper and lower holding portions 8a and 8b and is attached to the linear motion guide 10 of the coating device E. A ball screw portion 12 that is rotationally driven by the drive portion 11 is connected to the linear guide 10.

  In the fluid resin material supply device 20, a ball screw portion 22 that is rotationally driven by a drive portion 21 is connected to a linear motion guide 23. The linear motion guide 23 is connected to the movement shaft 24 of the material supply device 20, and the movement shaft 24 moves integrally with the linear motion guide 23 to supply the fluid resin material to the material supply pipe 14.

  The cylindrical base material 1 is fixed by one holding portion 8a and the other holding portion 8b of the coating device E and is attached to the linear motion guide 10, and by rotating the ball screw portion 12 by the driving portion 11, Move from bottom to top in the figure. When the linear motion guide 10 moves, the ball screw portion 12 of the material supply device 20 is rotated in the application region of the cylindrical base material 1 to move the moving shaft 24. At the same time, one of the first and second on-off valves 6a and 6b is opened to supply the fluid resin material to the annular manifold 3 and discharged from the annular discharge port 9a to be the outer surface of the cylindrical substrate 1 A coating film 13 is applied to the substrate.

  Next, a method for setting the switching timing of the open / close valves 6a and 6b will be described.

  Liquid silicone rubber coating material A (XE15-B9236A / B: manufactured by Momentive Performance Materials Japan GK, viscosity 250 Pa · s, specific gravity 2.6) was used as the fluid resin material to be applied. A coating film having a coating film thickness of 2 mm and a coating length of 240 mm is formed on the outer surface of a cylindrical base material having an outer diameter of 8 mm and a length of 260 mm by the coating material A.

  Only the first opening / closing valve 6a was opened, and continuous coating was started on the cylindrical substrate 1 while supplying the coating material A from the opened first inlet 7a. Then, after the 60th coating operation, streaks and defects were formed due to uneven distribution of filler in the coating film on the side opposite to the first inlet 7a. This is presumably because the dispersion medium settled and the unevenly distributed material stayed and applied in the merging zone where the materials in the annular manifold collide.

  Therefore, at the 50th point from the start of application, the first on-off valve 6a is closed to close the first inflow port, and instead the second on-off valve 6b is opened to apply from the opened second inflow port 7b. Continuous application was carried out while feeding material A. Then, even after the 60th application, no formation of streaks or irregularities in the coating film occurred.

  However, when 60 pieces are continuously applied from the open / close valve 6b, and the 110th piece is continuously applied, the formation of streaks and irregularities due to the uneven distribution of the filler on the coating film on the side opposite to the second inlet 7b is still observed. Occurred. Therefore, the coating material A was supplied continuously for 50th, 100th, 150th, and every 50 coatings while alternately opening and closing the first on-off valve 6a and the second on-off valve 6b. .

  That is, each time the number of cylindrical or columnar members having a preset coating film is formed (number of coatings), the ratio of the amount of flowable resin material supplied from each inlet to the annular manifold is changed. The formation defects such as streaks and bumps did not occur in the coating film.

  Next, as a flowable resin material to be applied, liquid silicone rubber coating material B (DY35-561A / B: 100 parts by weight manufactured by Toray Dow Corning Silicone Co., Ltd., Glass Bubbles Filler (K15: manufactured by Sumitomo 3M Co., Ltd.)): 10 parts by weight was added and dispersed). Similarly to the above, a coating film having a coating film thickness of 2 mm and a coating length of 240 mm was formed on the outer surface of a cylindrical base material having an outer diameter of 8 mm and a length of 260 mm using the coating material B.

  When only the first opening / closing valve 6a is opened and the coating material B is supplied from the first inflow port 7a and continuous coating is started on the cylindrical base material 1, the coating material B has the eight In the coating film on the opposite side, streaks and irregularities were formed due to uneven distribution of filler.

  Therefore, the first on-off valve 6a is closed at the fifth time from the start of application, and then the second on-off valve 6b is opened to supply the coating material B from the second inflow port 7b. It was. As a result, no streaks or defects were formed on the coating film even after the eighth coating. Thereafter, when the continuous application is continued while the first opening / closing valve 6a and the second opening / closing valve 6b are alternately opened / closed every 5 coatings, no defects such as streaks / spots occur in the coating film. It was.

  As described above, by appropriately adjusting the switching timing of the open / close valves 6a and 6b according to the characteristics of the coating material, the material in which the dispersion medium is unevenly distributed is retained and applied in the merged area where the materials in the annular manifold collide. A coating film with a stable quality could be formed continuously.

(Second Embodiment)
The second embodiment of the present invention will be described below with reference to the drawings.

  3A and 3B show a coating apparatus according to a second embodiment of the present invention, in which FIG. 3A is a top sectional view of a cylindrical member of the coating apparatus, and FIG. 3B is a side sectional view of the coating apparatus.

  The flowable resin material supplied from the material supply device 20 is supplied to the material supply pipe 14 and is branched into the first to third branch pipes 5a, 5b, and 5c by the two-way diverter 4. The branched first to third branch pipes 5a, 5b, and 5c are provided with opening and closing valve portions 6a, 6b, and 6c, respectively. The material supply pipes 5 a, 5 b and 5 c are connected to the annular manifold 3 at the inlets 7 a, 7 b and 7 c of the annular manifold 3.

  Next, the switching timing of each on-off valve part 6a, 6b, 6c will be described. Liquid silicone rubber coating material A (XE15-B9236A / B: manufactured by Momentive Performance Materials Japan GK, viscosity 250 Pa · s, specific gravity 2.6) is used as the fluid resin material to be applied. A coating film having a coating film thickness of 2 mm and a coating length of 240 mm is formed on the outer peripheral surface of a cylindrical substrate having an outer diameter of 8 mm and a length of 260 mm using the coating material A.

  First, only the first opening / closing valve 6a was opened, and continuous coating on the cylindrical substrate was started while supplying the coating material from the opened first inlet 7a. As a result, after the 60th coating operation, streaks and defects were formed due to uneven distribution of filler as a dispersion medium in the coating film opposite to the inlet. This is presumably because the material in which the dispersion medium is unevenly distributed stays in the merging area where the materials in the annular manifold collide and is applied.

  Therefore, at the 50th point from the start of application, the first on-off valve 6a is closed to close the first inflow port 7a, then the second on-off valve 6b is opened, and the coating material A is opened from the opened inflow port 7b. Then, continuous coating was performed while feeding. As a result, even after the 60th application, no streak or irregularity occurred in the coating film. Next, in the 100th, the second on-off valve 6b is closed to close the second inflow port, and then the third on-off valve 6c is opened to supply the coating material from the opened third inflow port 7c. Then, continuous coating was performed. As a result, no streaks or defects occurred in the coating film until the 150th coating. Thereafter, when 150 lines were completed, the third opening / closing valve 6c was closed, the first opening / closing valve 6a was opened again, and the coating material A was supplied from the opened first inlet 7a to apply up to 200 lines. In this way, continuous coating was continued while opening and closing the first to third on-off valves 6a, 6b, and 6c for every 50 continuous coatings.

  That is, each time the number of cylindrical or columnar members having a coating film set in advance (the number of times of coating) is formed, one of the plurality of inlets is opened to each annular manifold. The ratio of the supply amount of the fluid resin material is changed. There were no defects such as streaks or irregularities in the coating film.

(Third embodiment)
Hereinafter, a third embodiment of the present invention will be described with reference to FIGS. 4, 5, and 6. 4A and 4B show a coating apparatus according to a third embodiment of the present invention, in which FIG. 4A is a schematic top view of a cylindrical member of the coating apparatus, and FIG. 4B is a side sectional view taken along line AA in FIG. is there.

  In the third embodiment, the flow rate of the flowable resin material is not switched between the branch pipes 5a and 5b as in the first embodiment, but the ratio of the supply amount from the branch pipes 5a and 5b is changed. It is changing continuously. A throttle valve is used for the ratio of the supply amount. A servo motor (not shown) is connected to the throttle valve. The ratio of the supply amount by the throttle valve is continuously changed by phase control of a servo motor (not shown). Furthermore, the operation of the servo motor (not shown) is controlled by electrical control of a driver (not shown), a driver controller (not shown), a sequencer of the coating apparatus, and the like. In the coating apparatus of FIG. 4, the branch pipes 5a and 5b are connected in 180 degrees from two directions, and the throttle valves 22a and 22b are connected and arranged at two locations. The throttle valves 22a and 22b are connected to the inlets 7a and 7b. The inflow ports 7 a and 7 b are connected to the annular manifold 3. The operation of the two servo motors (not shown) is electrically controlled to continuously change the supply amount ratio of the two throttle valves. At that time, the thickness of the coating film 13 becomes uniform by controlling the total supply amount to be always constant.

  FIG. 5 shows the supply amount of the fluid resin material supplied from the respective inlets 7a and 7b. FIG. 5A shows a temporal change in the supply amount of the fluid resin material at the inlet 7a, and FIG. 5B shows a temporal change in the supply amount of the fluid resin material at the inlet 7b. FIG. 5C shows a temporal change in the total amount of the fluid resin material applied to the cylindrical substrate 1.

  FIG. 6 is a cross-sectional view showing the state of the annular manifold 3 during the molding time 0 to 6t. FIG. 6A is a cross-sectional view showing the state of the annular manifold 3 at molding times 0 and 4t. FIG. 6B is a cross-sectional view showing the state of the annular manifold 3 at the molding times 1t, 3t, and 5t. FIG. 6C is a cross-sectional view showing the state of the annular manifold 3 at the molding times 2t and 6t. At any time, the amount of resin discharged from the annular discharge port is constant, and the relative movement speed v between the annular nozzle and the cylindrical substrate 1 is kept constant, so that the resin is discharged onto the cylindrical substrate 1. A coating film 13 is formed.

  In the same manner as in Example 3, a liquid silicone rubber coating material A (XE15-B9236A / B: manufactured by Momentive Performance Materials Japan GK, viscosity 250 Pa · s, specific gravity 2.6) is used. A coating film having a coating film thickness of 2 mm and a coating length of 240 mm is formed on the outer peripheral surface of a cylindrical substrate having an outer diameter of 8 mm and a length of 260 mm using the coating material A.

  First, the first throttle valve 22a was fully opened, and continuous coating on the cylindrical base material was started while supplying the coating material from the opened first throttle valve 22a. Then, after the 60th coating operation, streaks and defects were formed due to uneven distribution of filler as a dispersion medium in the coating film opposite to the inlet.

  Therefore, continuous application was started on the cylindrical substrate 1 while continuously changing the supply amount of the fluid resin material supplied from the throttle valves 22a and 22b from the start of application.

  FIG. 5A shows the change in the supply amount of the fluid resin material of the first throttle valve 22a, FIG. 5B shows the change in the supply amount of the fluid resin material of the second throttle valve 22b, and FIG. FIG. 5C shows a change in the total amount of the fluid resin material applied to the material 1.

  The state of the coating film 13 was confirmed at the time of the 60th, 70th, and 80th continuous coating operations while continuously changing the supply amount of the fluid resin material supplied from each of the throttle valves 22a and 22b. In any of the coating films 13, no streak or unevenness due to uneven distribution of the filler as a dispersion medium was observed, and a stable surface state was confirmed.

  Further, the continuous application was continued up to the 100th while changing the supply amount continuously. Occurrence of streaks and irregularities in the 100th coating film 13 was not confirmed, and a stable surface state was confirmed.

  Furthermore, since the supply amount from each of the throttle valves 22a and 22b is continuously changing, the state in the annular manifold 3 in the process of forming the coating film 13 is the merging region 2m of the fluid resin material as the formation time elapses. Is moving. Since the merging region 2m moves during the formation of the coating film 13, local material retention with time does not occur in the annular manifold 3, and discharge in a stable material state over the entire circumference is possible. It becomes possible.

(Fourth embodiment)
The fourth embodiment of the present invention will be described below with reference to FIGS.

  In the fourth embodiment, instead of switching the branch pipes 5a, 5b, and 5c as in the second embodiment, the ratio of the supply amount from the throttle valves 22a, 22b, and 22c is continuously changed. Yes.

  A throttle valve is used for the ratio of the supply amount. A servo motor (not shown) is connected to the throttle valve. The ratio of the supply amount by the throttle valve is continuously changed by phase control of a servo motor (not shown). Furthermore, the operation of the servo motor (not shown) is controlled by electrical control of a driver (not shown), a driver controller (not shown), a coating device sequencer, and the like.

  In the coating apparatus of FIG. 7, the branch pipes 5a, 5b, and 5c are connected at a phase of 120 degrees from the three directions, and the throttle valves 22a, 22b, and 22c are connected and arranged at three locations. The throttle valves 22a, 22b, and 22c are connected to the inflow ports 7a, 7b, and 7c. The inlets 7 a, 7 b, 7 c are connected to the annular manifold 3.

  The operations of the three servo motors (not shown) are electrically controlled to continuously change the supply amount ratios of the three throttle valves. At that time, the thickness of the coating film 13 becomes uniform by controlling the total supply amount to be always constant.

  FIG. 8 shows a change in the supply amount of the fluid resin material supplied from the inflow ports 7a, 7b, and 7c in the fourth embodiment. FIG. 8A shows a change in the supply amount of the fluid resin material at the first inlet 7a, and FIG. 8B shows a change in the supply amount of the fluid resin material at the second inlet 7b. FIG. 8C shows a change in the supply amount of the fluid resin material from the second inlet 7c. FIG. 8D shows a change in the total amount of the fluid resin material applied to the cylindrical substrate 1.

  At any time during the molding times 0, 1t, 2t, and 3t, the resin discharge amount from the annular discharge port is constant, and the relative moving speed v between the annular nozzle and the cylindrical substrate 1 is kept constant. Thus, the coating film 13 is formed on the cylindrical substrate 1.

  Similarly to Example 2, a liquid silicone rubber coating material A (XE15-B9236A / B: manufactured by Momentive Performance Materials Japan GK, viscosity 250 Pa · s, specific gravity 2.6) is used. A coating film having a coating film thickness of 2 mm and a coating length of 240 mm is formed on the outer peripheral surface of a cylindrical substrate having an outer diameter of 8 mm and a length of 260 mm using the coating material A.

  First, the first throttle valve 22a was fully opened, and continuous coating on the cylindrical base material was started while supplying the coating material from the opened first throttle valve 22a. Then, after the 60th coating operation, streaks and defects were formed due to uneven distribution of filler as a dispersion medium in the coating film opposite to the inlet.

  Therefore, continuous application to the cylindrical substrate 1 is started while continuously changing the supply amount of the fluid resin material supplied from the throttle valves 22a, 22b, and 22c from the start of application as shown in FIG. did. The state of the coating film 13 was confirmed at the time of the 80th continuous coating, while continuously changing the supply amount of the fluid resin material supplied from each of the throttle valves 22a, 22b, and 22c. In the coating film 13, no streak or unevenness due to uneven distribution of the filler as a dispersion medium was observed, and a stable surface state was confirmed. Further, the continuous application was continued up to the 100th while changing the supply amount continuously. Occurrence of streaks and irregularities in the 100th coating film 13 was not confirmed, and a stable surface state was confirmed.

  Since the supply amounts from the throttle valves 22a, 22b and 22c connected to the respective inlets 7a, 7b and 7c are continuously changed, the fluidity in the annular manifold 3 in the process of forming the coating film 13 A joining region (not shown) of the resin material always moves. Accordingly, local stagnation of the fluid resin inside the annular manifold 3 is suppressed, and discharge in a stable material state can be continuously performed over the entire circumference.

  In the above embodiment, in order to make the explanation simple and easy to understand, an example of forming a coating film on the outer surface of a cylindrical base material is given as an example, and a case where the coating film thickness is uniform over the discharge longitudinal direction is illustrated. . However, the present invention is not limited to the above-described embodiment. For example, when the thickness of the coating film is changed, the total amount of supply from each branch pipe is changed. Moreover, a fluid-like resin material is apply | coated to the outer surface of a cylindrical base material, and the cylindrical member which has a coating film can be formed.

  The present invention is effective even when the number of supply ports of the annular nozzle is two or more, and in the case of extrusion molding in which the resin material discharged in a cylindrical shape from the annular nozzle is directly formed as a resin cylindrical member. Needless to say.

DESCRIPTION OF SYMBOLS 1 Cylindrical base material 2 Annular nozzle 3 Annular manifold 4 Bidirectional branch part 5a, 5b, 5c Branch pipe 6a, 6b, 6c On-off valve 7a, 7b, 7c Inlet 8a, 8b Holding part 13 Coating film 14 Material supply pipe 20 Material supply device 21 Drive unit 22 Throttle valve

Claims (3)

A fluid resin material is supplied to an annular manifold provided inside an annular nozzle having an inner wall surface that surrounds the outer surface of a cylindrical or columnar base material, and is discharged from an annular discharge port that opens on the inner wall surface. In a method for forming a coating film on the outer surface of a cylindrical or cylindrical substrate,
The annular manifold is provided with a plurality of inlets for supplying the fluid resin material, and the ratio of the amount of fluid resin material supplied from each inlet to the annular manifold is a cylindrical shape having a preset coating film or A method for forming a cylindrical or columnar member having a coating film, wherein the number of columnar members is changed each time the number is formed.   The method for forming a cylindrical or columnar member having a coating film according to claim 1, wherein the ratio of the supply amount is changed by opening any one of the plurality of inlets.   The method for forming a cylindrical or columnar member having a coating film according to claim 1, wherein the ratio of the supply amount is changed by closing any one of the plurality of inlets.

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