JPH0126751B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating film thickness control device and a coating film thickness control method in a continuous coating line.

In a continuous coating line, it is necessary to maintain a constant coating thickness.

Conventionally, coating film thickness has generally been controlled by manually adjusting the gap of a coater roll.

However, with this method, it is only possible to set a coating thickness of about ±3 microns at most, and the coating thickness is large, and the coating thickness is set on the safe side.
This method has disadvantages in that it consumes a large amount of paint, and in that control is unstable because the coating position and the film thickness measurement position are different.

The present inventors have conducted various studies regarding the above-mentioned automation, and have found that even if the signal from the coating film thickness detector is the same, it may vary depending on paint conditions, original plate conditions, roll conditions, etc.
It was discovered that the coating film thickness changes.

In view of the above facts, the present invention converts the signal from the coating film thickness detector into a function that satisfies the conditions from among functions that have been actually measured and inputted in advance based on paint conditions, original plate conditions, pre-processing conditions, etc. a data processor that selects the
The signal corresponding to the function is controlled for variable waste time, and then calculated by a calculator that extracts the setting output for operation from the function determined based on the actual measurement data of the paint conditions and operating conditions to control the paint film thickness. It is an object of the present invention to provide a coating film thickness control device and a coating film thickness control method in a continuous coating line.

Next, the present invention will be explained according to one embodiment.

FIG. 1 shows a flow sheet of the present invention, and FIG. 2 shows the mechanism of the infrared coating thickness detector 1. The infrared coating film thickness detector 1 irradiates infrared rays from an infrared generator 9 to a painted original plate W that has been dried and is continuously conveyed, and this infrared ray is selectively absorbed depending on the coating thickness and reflected on the surface of the original plate W. The infrared sensor unit 10 measures the amount of attenuation inputted by the infrared ray sensor 10, and extracts a coating film signal.

Next, this coating film signal is linearized by a linearizer 2 and A/D converted. This film thickness signal is then input to the film thickness data processor 3.

A function representing the relationship between a film thickness signal and film thickness based on the type of paint, the type of original plate, preprocessing conditions, etc. is input to the data processor 3 for a large number of conditions. By setting these conditions before starting operation, a function that meets the conditions is selected. Then, when the film thickness signal is input, the true film thickness signal is extracted by correcting or determining a coefficient according to the function.

The central processing unit 4 includes a variable waste time control section 5 and a calculation section 6, which perform variable waste time control on the film thickness signal and calculate the deviation from the set film thickness.

The variable wasted time control unit 5 controls the coater using operation signals, calculates the time required for the coated position under new conditions to reach the measurement unit from the line speed, and sets a variable blank time so that the operation unit is not controlled during that time. When the coating position under new conditions is measured, control is performed by providing a blank time between commands in the same way as described above.

The calculation unit 6 converts the relationship between the film thickness signal and the set output for coater operation into a function based on paint conditions such as paint composition and dilution rate, and operating conditions such as original plate speed and roll hardness. A large number of conditions are entered for each.

Once the paint conditions and operating conditions are set in advance, a function corresponding to the conditions is selected. Then, when a film thickness signal is input, a set output for coater operation is extracted from the selected functional relationship and the deviation from the set film thickness. In this case, it goes without saying that if the operating conditions are not changed, there is no need to change any conditions.

The roll gap or nip pressure driver 7 outputs an output signal for operating a drive mechanism 8 for controlling the roll gap or nip pressure based on the set output. This operation signal is inputted to the nip force or roll gap drive mechanism 8 to accurately numerically control the coater roll rotation speed and roll gap.

As is clear from the above explanation, according to the present invention, the signal from the film thickness detector is not converted into the coater roll rotation speed and roll gap only by feedback, but is converted into the coater roll rotation speed and roll gap based on various factors and The conditions are made to correspond to the feedback values and are used as operation output signals for each drive mechanism. Note that the film thickness data processor, central processing unit, etc. can also be incorporated into one processing unit. However, the variable wasted time control section controls the drive mechanism until the coating position reaches the coating thickness detector under the new conditions.
It has become possible to automatically control the set film thickness with an accuracy of about ±0.5 to 1 micron using simple equipment.

Therefore, the amount of paint used can be reduced and the product can be made more uniform.

[Brief explanation of drawings]

Figure 1 is a flow sheet according to the present invention;
The figure shows an infrared coating thickness detector. 1...Infrared coating thickness detector, 2...Linearizer,
3... Film thickness data processor, 4... Central computing unit, 5... Variable waste time control section, 6... Arithmetic section, 7... Roll gap or nip pressure driver, 8... Drive mechanism.

Claims (1)

[Claims] 1. An infrared coating thickness detector that detects coating thickness by selective absorption and reflection of infrared rays, and a coating signal that is input in advance based on the type of paint, original plate pretreatment conditions, etc. A data processor extracts a film thickness signal from a function obtained by converting the relationship between the film thickness and the film thickness, and performs control to eliminate the time lag between the control position and the painting position by comparing the film thickness signal and the set film thickness. In addition, there is a coater control calculator that outputs a setting output that matches the operating conditions input in advance based on the type of paint, and a control signal that controls the rotation speed of the coater roll and the roll gap or nip pressure based on operation signals from the coater control calculator. A coating film thickness control device for a continuous coating line, characterized by comprising drive mechanisms for numerical adjustment. 2. Input the set film thickness or film thickness into the coater control calculator, take out the roll nip pressure setting output that matches the type of paint currently in operation, original plate pretreatment conditions, etc., and input this setting output into the nip pressure driver. A method for controlling coating film thickness in a continuous coating line, characterized in that the coating thickness is controlled by comparing the actually measured roll nip pressure and numerically controlling a roll nip pressure drive mechanism so that these values match.