JPH0240257A - Gravure coater - Google Patents

Abstract

PURPOSE:To allow the administration of a coated amt. with high accuracy by nipping a base material just before a coating point, providing a reference for the traveling speed of the base material, electrically or mechanically control ling the surface speed of a gravure roll with respect to the base material speed and controlling the coated amt. without exchanging the gravure roll. CONSTITUTION:The base material 5 supplied from an un-winding shaft 8 is nipped by a reference roll 10 and a rubber roll 11 near the inlet of a coating section and the traveling speed of the line is maintained by revolution of the roll 10. While the gravure roll 1 is rotated, the roll is passed through a paint supplying section 2 where paint is stuck on the roll. The paint except in engrav ing grooves 1a is scraped off when the surface of the roll 1 passes along a doctor blade 3. The approximately uniform paint is stuck to the grooves on the roll 1 surface by the shapes of the grooves having a peak width (g), groove width (a) and depth (G) The base material 1 is then pressed by a rubber roll 4 to transfer the paint in the grooves 1a from the roll 1 to the base material. The transferred paint is finished to a smooth surface by a smoother 6 at need so that the uniformly coated film is obtd. The base material is guided by a guide roll 7 and is taken up on a take-up shaft 9.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a manufacturing device for uniformly applying paint to a base material, and is used for manufacturing coated products such as magnetic tapes, floppy disks, and printer ink ribbons. Can be used for manufacturing, etc.

(Prior Art) Conventionally, the most common method for producing a uniform coating film is the "gravure method."

FIG. 4 shows a schematic diagram of the gravure method.

A paint supply section 2 supplies paint to a gravure roll l whose surface is engraved into a predetermined shape according to the amount of coating, and a blade 3 regulates the paint on the engraving section 1&. These series of movements are performed as the gravure roll l rotates.

The base material 5 is pressed by a rubber roll 4 against a gravure roll 1 rotating in the same direction as the running direction of the base material 5, and the paint is transferred to the base material 5. The surface of the paint transferred to the engraved pattern is smoothed by a smoother 6 if necessary, so that a uniform coating film can be obtained.

[Problem to be solved by the invention]

The amount of coating is determined by the shape engraved on the surface of the gravure roll l, making it easy to obtain a uniform coating, and is particularly excellent for thin film coating. Also, from the equipment point of view, the structure is simple, relatively inexpensive, and can be made larger.

However, when considering the adjustment of the coating amount, it is determined by the transfer rate change due to the groove shape engraved on the surface of the gravure roll and the rheology of the paint. There is no choice but to replace it, which has the disadvantage of becoming difficult to manage as the requirement for coating amount accuracy increases. In addition, there is a reverse roll bandai method that allows the amount of coating to be adjusted from the equipment perspective, but in order to achieve uniform coating, the gap between the applicator roll 12 and the metering roll 13 shown in Fig. 5 is important. Extremely high-precision processing, design, and maintenance are required in terms of accuracy such as cylindricity, roundness, surface quality, bearings, mechanical accuracy, vibration, etc., and equipment is expensive and difficult to increase in size.

[Means to solve the problem]

In order to solve the above-mentioned drawbacks and to make it possible to easily adjust the amount of coating with a gravure coating machine, the present invention provides a reference roll 10 and a rubber roll 11 immediately before the coating point (gravure roll l).
By nipping the base material and setting a standard for the base material running speed, the surface speed of the gravure coating device is electrically or mechanically controlled with respect to this base material speed, and the change is adjustable. The amount of coating is adjusted by changing the number of engravings passed through the gravure roll per length.

[Effect]

The present invention has a structure in which the gravure roll 1 can have a speed difference with respect to the base material 5 due to the above configuration, so even if the engraving portion 1a of the gravure roll 1 selected depending on the coating amount is not optimal, By attaching a control device that changes the circumferential speed of the gravure roll relative to the substrate, the optimum coating amount can be easily obtained. Furthermore, even if environmental changes or changes in coating fluid rheology occur during coating, the amount of coating can be controlled with high precision through interlocking control with an in-line film thickness meter.

The present invention allows existing gravure coating machines to be modified at relatively low cost.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawing of FIG.

The base material 5 fed from the unwinding shaft 8 is nipped by a reference roll lO and a rubber roll 11 near the entrance of the coating section, and the running speed of the line is maintained by the rotational drive of the reference roll lO. While rotating, the gravure roll 1 passes through a paint supply section 2 to which paint is applied. When the surface of the gravure roll l passes a doctor blade 3, paint other than the engraving grooves l is scraped off. As shown in the enlarged view of FIG. 2, on the surface of the gravure roll 1, approximately uniform paint is adhered to the grooves according to the shape of the grooves represented by the groove width a, the groove width a, and the groove depth C. Next, the base material 5 is pressed by the rubber roll 4, and the paint in the grooves from the gravure roll 1 is transferred onto the base material. The surface of the transferred paint is smoothed by a smoother 6 as necessary to obtain a uniform coating film, and then transferred to a guide roll 7.
and is guided by the winding shaft 9 and wound up by the winding shaft 9. At this time, if the speed of the gravure roll 1 is increased or decreased, the amount of paint transferred per unit film length increases or decreases.

FIG. 3 shows an example of the data implemented by this device.

Line speed of 100 m/min due to rotation of reference roll lO,
The paint is a magnetic paint used for floppy disks and the like.

In gravure roll A, b/a is large, and the gravure roll circumferential speed ratio relative to the base material 5 is controlled, and the coating amount can be controlled approximately linearly.In gravure roll B, b/a is small, and as the speed ratio is increased, clipping occurs. Although it was a little rough, I was able to control the amount of application. Almost the same results were obtained at line speeds of 20 to 150 m/min.

〔Effect of the invention〕

As shown in Figure 3, it is possible to easily adjust minute changes in the coating amount on one gravure roll, and the coating amount can be adjusted without replacing the gravure roll, making it possible to control the coating amount with high precision. The effect was great.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a gravure coating device according to the present invention, Fig. 2 is an enlarged view showing the shape of the groove, Fig. 3 is implementation data using gravure rolls A and B, and Fig. 4 is a diagram of a conventional gravure coating device. The side sectional view, FIG. 5, is a sectional view of the reverse coating device. l...Gravure roll 2...Paint supply 3...
Doctor blade 4.11...Rubber roll 5...
Base material 6... Smoother 7... Guide roll 8... Unwinding shaft 9... Winding shaft. Figure 2 Figure 3 Figure 3 Tooth diagram

Claims (1)

[Claims] A gravure coating device has a roll that serves as a reference for running the base material, and is equipped with a control device that rotates the gravure roll engraved in a groove shape at a constant speed ratio to the speed of the base material to control the coating amount. A gravure coating device with the following features: