JP2008119630A - Doctor roll gap adjusting mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a doctor roll gap adjusting mechanism for adjusting the thickness of a coating film by adjusting the gap between a coating roll and the doctor roll of a reverse roll coater for applying an adhesive or an adhesive agent on a sheet. <P>SOLUTION: In the doctor roll gap adjusting mechanism of the reverse roll coater, the doctor roll is supported by one end of a rotative arm and the gap between the coating roll and the doctor roll is adjusted by the rotation of the arm. The rotatively movable doctor roll is arranged so that the distance between the center of the coating roll and the center of the rotation of the arm is set to be shorter than the sum of the radius of the coating roll and the rotation radius of the arm (including the outer periphery of the doctor roll). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a doctor roll gap adjustment mechanism that adjusts the thickness of a coating film by adjusting a gap between a coating roll and a doctor roll of a reverse roll coater that coats a sheet with an adhesive, an adhesive, or the like.

  In general, a reverse roll coater for applying an adhesive, a pressure-sensitive adhesive, or the like to a sheet has a pair of a movable roll (doctor roll) and a fixed roll (coating roll). And the thickness of a coating film adjusts the clearance gap (gap) between rolls by moving or pressing a doctor roll with respect to a coating roll.

  Also, conventionally, there has been a mechanism for adjusting the gap between the coating roll and doctor roll of the reverse roll coater by mechanically moving the gap as shown in FIG. The thickness of the coating film of the coating roll is adjusted by narrowing or widening the gap.

  As a drive source for the parallel movement, a gap adjusting device (for example, see Patent Document 1) of a coating device of a linear motion mechanism using pneumatic pressure, hydraulic pressure, a motor or the like is known.

  Further, in order to reduce the film thickness of the coating liquid to be applied, the gap between the coating roll and the doctor roll is gradually narrowed. Finally, the film thickness can be made thinner by eliminating the gap between the coating roll and the doctor roll.

  The pressing mechanism for eliminating the gap is performed using the above-described pneumatic pressure, hydraulic pressure, motor, or the like. Further, when the thickness of the coating film is increased, the gap between the coating roll and the doctor roll is gradually widened. In either case, a power source with power is required.

  There has been proposed a method for adjusting a coating thickness by a roll coater that measures a pressing pressure for adjusting the gap between the coating roll and the doctor roll and corresponds to the thickness of the coating film (for example, see Patent Document 2).

  Further, when the doctor roll is rotated, the coating film on the coating roll produces spotted or wavy mottle. This mottle is transferred directly to the coated surface of the substrate. Furthermore, this mottle is eliminated by locking the rotation of the doctor roll.

  And when producing an optical member etc., since the request | requirement is severe with respect to the external appearance of the coated surface and the film thickness of a coating film, it is known to fix and apply a doctor roll. An optical disk manufacturing method for manufacturing an optical disk by this method and an optical disk manufactured by the same method (for example, see Patent Document 3) are known.

Prior art documents are shown below.
Japanese Patent Laid-Open No. 9-299842 JP 58-166959 A JP 2006-79790 A

  The conventional reverse roll coater as described above can be used only when aligning the position of the doctor roll when the gap between the coating roll and the doctor roll is set to 0 mm or more when the adhesive or adhesive material is thickly applied to the sheet. It can be done easily without any load.

  However, when reducing the thickness of the coating liquid to be applied, the gap must be set to 0 mm or less. Then press the coating roll and doctor roll. For this reason, power corresponding to the load is required.

  In addition, a roll coater that coats a coating film with a small thickness is provided with a large doctor roll pressing mechanism that can handle high loads. In particular, in the case of a thin coating roll coater corresponding to a wide sheet, the surface length of the doctor roll becomes wide. And the load for pressing also becomes large. For this reason, a large pressing mechanism is required.

  The present invention has been made in view of the above-described conventional problems, and provides a doctor roll gap adjusting mechanism having a simple mechanism and a pressing mechanism corresponding to a high load without using a power actuator or the like. The purpose is to do.

In order to solve the above problems, the invention according to claim 1 of the present invention provides:
In the doctor roll gap adjustment mechanism of the reverse roll coater, the doctor roll is supported on one end of a rotatable arm, and the rotation of the arm adjusts the gap (gap) between the coating roll and the doctor roll, and the rotational movement The possible doctor rolls must be arranged such that the distance between the center of the coating roll and the center of rotation of the arm is shorter than the sum of the radius of the coating roll and the rotation radius of the arm (including the outer circumference of the doctor roll). It is a doctor roll gap adjustment mechanism characterized by these.

  Since the doctor roll gap adjusting mechanism of the present invention has the above-described configuration, a power actuator or the like is not used when thinly applying an adhesive, an adhesive, or the like to the sheet. And by a simple mechanism, a doctor roll can be pushed into a coating roll, and the design of the apparatus irrespective of a utility is attained at low cost.

  The doctor roll gap adjusting mechanism of the present invention will be described in detail below along the embodiments with reference to the drawings.

  FIG. 1 is an explanatory view showing a side surface of an embodiment of a doctor roll gap adjusting mechanism of the present invention.

  As shown in FIG. 1, the doctor roll gap adjusting mechanism of the present invention is formed of a coating roll 1, a doctor roll 3, an arm 2 and a screw 4. The distance between the center of the coating roll 1 and the center of rotation of the arm 2 of the doctor roll 3 is set shorter than the sum of the radius of the coating roll 1 and the rotation radius of the arm 2 (including the outer periphery of the doctor roll). Yes.

  For this reason, the coating roll 1 interferes with the rotational drive of the doctor roll 3, and the doctor roll 3 is on the coating roll 1. The doctor roll 3 is pressed against the coating roll 1 by its own weight.

  In the above state, the rotation of the doctor roll 3 is locked, and the coating roll 1 is rotated reversely (reversely with respect to the substrate transport direction). The doctor roll 3 tries to rotate counterclockwise due to friction, but the coating roll 1 is fixed on the rotation driving track of the doctor roll 3. For this reason, the doctor roll 3 is pressed against the coating roll 1.

  Next, FIG. 2 is a partial explanatory view showing a part of FIG.

  The phenomenon in which the doctor roll 3 is pressed against the coating roll 1 will be described in detail with reference to FIG.

  When the rotation of the coating roll 1 is reversely rotated while the rotation of the doctor roll 3 is locked, a force is generated on the doctor roll 3 in the tangential direction A at the contact point between the doctor roll 3 and the coating roll 1 by friction. . This force is decomposed into the axial direction B of the arm and the direction C perpendicular to the axial line.

  The force in the axial direction B acts to push out the doctor roll 3, but the reaction force from the rotation center of the arm 2 is applied to the doctor roll 3 and the balance is maintained. Further, the force in the direction C perpendicular to the axis acts to drive the doctor roll 3 counterclockwise. As a result, a phenomenon occurs in which the doctor roll 3 is pressed against the coating roll 1.

  By arranging the doctor roll 3 and the coating roll 1 as described above by using the mechanism for rotating the doctor roll 3, the doctor roll 3 can be pressed against the coating roll 1 without using an actuator.

  In addition, when it is necessary to make the coating film to be coated thinner, a mechanism for driving the doctor roll 3 counterclockwise using an actuator or the like and further pushing it into the coating roll 1 may be added. Can do. In this case, it is possible to perform coating with the same thinness using an actuator with lower power compared to the conventional mechanism for parallel translation shown in FIG.

  In addition, when the coating film to be coated is to be thickened, the arm 2 is rotated clockwise, for example, by pushing the screw 4 from above onto the opposite side of the doctor roll 3 across the rotation center of the arm 2, Widen the gap.

  Next, FIG. 3 is explanatory drawing which shows the side surface of another Example of the doctor roll gap adjustment mechanism of this invention.

  As shown in FIG. 4, the axial end of the doctor roll 3 is rotatably connected to the arm 2, and the rotation of the doctor roll 3 can be locked by a clamp 5 fixed to the arm 2.

The arm 2 is rotatably connected to a cantilever pin 7 fixed to the side plate 6, and the doctor roll 3 rotates around the pin 7 as the arm 2 rotates. A beam 8 is provided between the pair of left and right arms 2 and the side plate 6 for reinforcement. A female screw is screwed to the beam 8 of the side plate. The screw 4 is screwed into the screwed portion.

  The tip of the screw 4 is pressed against the beam 9 of the arm. By loosening or tightening the screw 4, the doctor roll 3 is rotated or pressed against the coating roll 1 to adjust the gap or the pressing pressure. can do. When the screw 4 is loosened and the tip of the screw 4 is separated from the beam 8 of the side plate, the doctor roll 3 is completely on the coating roll 1.

  At this time, the entire weight of the doctor roll 3 is applied to the coating roll 1, and the pressing pressure is maximized. And the screw 4 can adjust finely the gap or pushing pressure of the doctor roll 3 with respect to the coating roll 1 using a fine screw.

  The doctor roll 3 is made of fluororubber, and a flat roll having a Shore hardness of 70 degrees, a diameter of 110 mm, and a surface length of 900 mm is used. The material of the coating roll 1 is SUS304, and a flat roll having a diameter of 150 mm and a surface length of 1400 mm is used. Furthermore, the doctor roll 3 is disposed in a state of being 39 mm higher than the coating roll 1 and in contact with the coating roll 1 when the gap (gap) between the coating roll 1 and the feed roll 10 is 1.7 mm.

  Next, an adhesive was applied to the sheet using the doctor roll gap adjusting mechanism of the present invention shown in FIG. 4 on the reverse roll coater. Although it demonstrates concretely below, it is not limited to it.

  An adhesive having a viscosity of 6000 cP (room temperature) was applied to the sheet at room temperature. The sheet is a plastic sheet and has a size of 648 mm × 1128 mm and a thickness of 1.9 mm.

  Further, when coating, the rotation of the doctor roll 3 was locked, and the doctor roll 3 was completely put on the coating roll 1. And the gap of the coating roll 1 and the feed roll 10 was set to 1.7 mm. Further, the coating roll 1 was rotated at a peripheral speed of 2 m / min, the feed roll 10 was rotated at a peripheral speed of 1.8 m / min, and the coating roll 1 was rotated in the opposite direction with respect to the feed roll 10 to apply an adhesive to the sheet.

  The coated surface of the sheet after coating had no faintness or noticeable coating streaks, and no large coating film defects were found.

  In addition, after applying an adhesive to the sheet, the film was bonded with a laminator to bond the sheet and the film.

  Furthermore, after bonding the sheet and the film, the thickness of the adhesive layer was measured. As a result, the thickness of the adhesive layer was about 15 μm on average. Then, it was confirmed that the coating was sufficiently thin as compared with coating by a normal reverse coater.

  Further, the screw 4 shown in FIG. 3 was tightened, and the pressure of the doctor roll 3 against the coating roll 1 was reduced or the gap was widened to apply the adhesive to the sheet. As a result, it was confirmed that the coating was thicker.

As described above, the reverse roll coater using the doctor roll gap adjusting mechanism of the present invention can be applied to a sheet sufficiently thin without using an actuator. Also,
It is possible to adjust the thickness of the coating film by adjusting the pressure or gap of the doctor roll with respect to the coating roll.

  As described above, the doctor roll gap adjusting mechanism of the present invention includes design changes and the like within a range not departing from the gist.

  For example, in the embodiment described above, beams are passed to the left and right arms 2 and the side plates 6 on the side of the doctor roll 3 across the rotation center of the arm 2, and female screws are screwed to the beams of the side plates. A mechanism is also included in which the screw 4 is screwed and the tip is brought into contact with the beam of the arm.

  Further, by tightening the screw 4, the arm 2 can be rotated counterclockwise to increase the pressing force of the doctor roll 3 against the coating roll 1. And it can be applied even thinner.

  Further, instead of the screw 4, an actuator such as an air cylinder or a hydraulic jack may be used.

  The doctor roll gap adjusting mechanism of the present invention is an excellent invention that can be used not only for coating machines such as a reverse roll coater but also for production lines in the confectionery and bakery fields.

It is explanatory drawing which shows the side surface of one Example of the doctor roll gap adjustment mechanism of this invention. FIG. 2 is a partial explanatory view showing a part of FIG. 1. It is explanatory drawing which shows the side surface of other one Example of the doctor roll gap adjustment mechanism of this invention. It is the schematic of the conventional doctor roll gap adjustment mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Coating roll 2 ... Arm 3 ... Doctor roll 4 ... Screw 5 ... Clamp 6 ... Side plate 7 ... Cantilever pin 8 ... Side plate beam 9 ... Arm beam 10 ... Feed roll A ... In contact point of doctor roll and coating roll Tangent direction B ... Axial direction of arm C ... Direction perpendicular to axis of arm

Claims (1)

  In the doctor roll gap adjustment mechanism of the reverse roll coater, the doctor roll is supported by one end of a rotatable arm, and the arm rotates to adjust the gap (gap) between the coating roll and the doctor roll, and the rotational movement The possible doctor rolls should be arranged such that the distance between the center of the coating roll and the center of rotation of the arm is shorter than the sum of the radius of the coating roll and the rotation radius of the arm (including the outer circumference of the doctor roll). Doctor roll gap adjustment mechanism.

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