JPH0471593B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an improvement in moisture content control of a coating device when changing speed due to changes in production volume or the like.

<Prior art> An outline of a coating apparatus for a double-sided coating process will be explained based on FIG. A indicates a top surface coating process, and B indicates a back surface coating process. The base paper 2 set in the unwinder 1 is coated with the first applicator roll 5 ₁ whose lower part is immersed in the first fountain 4 ₁ containing the paint 3, and then transferred to the first bagging roll 6 ₁ and the first It is led to a second coating line via an air dryer 7 ₁ and a first cylinder dryer 8 ₁ , where the back side is coated through a similar process and wound onto a reel 9 .

Elements 4 ₂ to 8 ₂ of the second step are element 4 of the first step
₁ to 8 are the same components corresponding to ₁ .

In the first and second steps, the coating amount is adjusted by manipulating the pressing force or angle of blades 10 ₁ and 10 ₂ which are operating ends disposed opposite to the backing roll.

11 ₀ is the B/M meter installed on the upstream side of the first process,
11 ₁ is the downstream side of the first process (upstream side of the second process)
11 ₂ is the B/M meter installed downstream of the second process, BD ₀ , BD ₁ , BD ₂ are the bone dry basis weight measurements of these B/M meters, _MP0 , _MP1 ,
MP ₂ is the moisture content measurement value of these B/M meters,
These measured values are input to the control device 12, and the coated amount measured values and moisture content measured values of the first step and the second step are calculated.

The operation of the control device 12 at steady line speed will be explained. Regarding the coating amount, in the first coating process, the speed-type manipulated output ΔW _cw1 is operated by calculating the deviation between the measured value CW _pv1 calculated from the difference between the measured values BD ₀ and BD ₁ and the set value CW _sv1 . Blade 10 which is the end
Send a call to ₁ .

Similarly, in the second coating process, the measured value BD ₁ and
Measured value CW _pv2 calculated from the difference between BD ₂ and set value
Speed type manipulated output ΔW _cw2 calculated by deviation from CW _su2
is transmitted to blade ₁₀₂ .

Regarding moisture content, in the first coating process, the measured value
A moisture content measurement value MP _pv1 is calculated from the difference between MP ₀ and MP ₁ , and a speed-type operation output ΔW _cw1 , which is the calculated deviation from the set value MP _pv1 , is transmitted to the first air dryer operation end 13 ₁ . In the second coating process, the measured moisture content
The moisture content measurement value MP _pv2 on the back side is calculated from the difference between MP ₁ and MP ₂ , and the speed-type operation output ΔW _cw2 , which is the deviation from the moisture content setting value MP _su2 on the back side, is sent to the second air dryer operation end 13 ₂ . do.

The air dryer operating ends 13 ₁ and 13 ₂ are damper valves that control the air flow rate, and the opening degree of the valves is controlled by the speed-type operating outputs ΔW _np1 and ΔW _np2 from the control device 12.

Reference numeral 14 is an operating end that controls the line speed SP by changing the rotational speed of the cylinder dryer, and a speed-type operating output that is sent from the control device as a result of control calculation based on the deviation between the measured speed value SP _pv and the set value SP _sv . ΔSP is sent to the line speed control end 14.

Reference numeral 15 denotes a man-machine interface means for exchanging information with the control device 12, and has a function of providing the various setting values described above to the control device 12.

<Problems to be Solved by the Invention> In such a configuration, when changing the line speed SP in order to change the production amount, the change is made in stages as shown in FIG. 3A.

In this case, the stepwise changing operation is performed intermittently and at constant steps ΔSP _sv so as not to affect the coating amount CW shown in B.

However, the moisture content MP is more susceptible to the line speed than the coating amount, and as shown in C, there is a problem that it fluctuates following the line speed with a time delay τ.

The present invention aims to solve such problems and provide a control method in which the moisture content does not fluctuate even when the line speed changes.

<Means for Solving the Problems> The present invention achieves the above object by measuring the measured values of basis weight moisture content measuring devices (hereinafter referred to as B/M meters) disposed on the upstream and downstream sides of the coating device. When changing the line speed of a coating device in which the coating amount and moisture content are controlled by operating the coating amount control end and moisture content control end using the At the same time, control is performed in the following cases.

First, when the moisture content deviation is within the set limit, the line speed is changed by the stepwise setting amount, and the first interference amount to the moisture content related to this stepwise speed change amount and the above coating are changed. Predicting and calculating the second interference amount to the moisture content due to amount manipulation,
This is added to the moisture content deviation as a feed forward signal to calculate the moisture content manipulation output.

Next, when the moisture content deviation is outside the set limit, the line speed is inhibited from changing, the first interference amount is set to zero, and the second interference amount to the moisture content by the coating amount operation is set to zero. is predicted and added to the moisture content deviation as a feed forward signal to calculate the moisture content manipulation output.

Here, the set limit is a threshold value at which it is recognized that the interference to the moisture content caused by a change in line speed is greater than the moisture content fluctuation caused by other disturbance factors.

<Function> According to the present invention, if the deviation in moisture content is within the limit when changing the line speed, the line speed is changed by a predetermined step, and the first adjustment to the moisture content accompanying this speed change is performed. The amount of interference and the second amount of interference related to the operation of the coating amount are predictively calculated and reflected in the operation amount calculation of the moisture content in a feed forward compensatory manner.

If the moisture content deviation is greater than the limit,
Since the influence of disturbance is greater than the influence of line speed, compensation using the first interference amount is omitted, and the manipulated variable of moisture content is calculated by compensating only the second interference amount, and at the same time, the current line speed postpone the change and wait for the disturbance to subside.

<Example> The hardware configuration is the same as that in Fig. 1,
Since the feature of the present invention lies in the signal processing method within the control device 12, an embodiment will be described based on the flowchart shown in FIG. For simplicity, the second step will be explained as a representative.

Steps (1) to (3) are the steps to calculate the operation output ΔW _cw of the coating amount, and the deviation e _o and the previous deviation e _{o-1
Calculate the} operating _end output of the coating amount based on the _moving average _{deviation E o based} on . Here, P ₁ , k ₁ , and K ₂ are constants.

Steps (4) to (11) are steps for calculating the manipulated output ΔW _np of the moisture content, and in step (5), the second interference amount MP _cw and the moisture content ΔMP resulting from the coating amount manipulation are calculated. , MP _cw = K ₃ · ΔW _cw (2) ΔMP = MP _sv − MP _pv (3) Calculated as follows.

In step (6), it is determined whether the moisture content deviation is within the limit. This condition is effective when the disturbance factors to the moisture content other than the interference caused by changing the line speed are small, so this control is postponed when other large disturbance factors are present. In this case, the main control is started after removing other large disturbances on the operation side. Therefore, the limit is that interference with the moisture content due to line speed changes is
This serves as a threshold value for determining whether the moisture content fluctuation is large compared to other disturbances. Further, even while this control is being executed, if the moisture content deviation increases compared to the set limit, this control is stopped as described later. If within the limit, step (7)
Calculate the line speed operation output ΔSP in step (8), and if this operation output is smaller than the speed change set value ΔSP _sv , set ΔSP = ΔSP _sv , and then in step (9) calculate the change in moisture content due to the speed change. 1
The interference MP _sp is predicted and calculated as MP _sp = K ₄ · ΔSP (4). Here K ₄ is a constant.

Next, in step (10), the deviation e _o =ΔMP+MP _sp +K ₅ ·MP _cw (5) is calculated based on the moisture content deviation and the first and second interference amounts. Here K ₅ is a constant.

Based on the moving average E _o of this deviation e _o , the step
In (11), the operating output ΔW _np of the moisture content is calculated as ΔW _np = 100 {P ₂ (E _o −E _o-1 ) + K ₇ E _o }/K ₆ (6) and is output. Here, P ₂ , K ₆ , K ₇
is a constant.

After the moisture content operation output is sent, a timer is activated in step (11), and after a certain time delay, the speed change operation output calculated in step (7) is output in step (13).

In step (6), if the moisture content deviation ΔMP exceeds the set limit, step
In (14), the first interference amount MP _sp calculated in step (9) is set to zero, and this interference amount is not referenced in the calculation of deviation e _o in step (20). Then, in step (11), the operating output ΔW _np of the moisture content is calculated using equation (6) and output. The process ends without issuing the speed ΔSP change command in step (13).

As described above, in the present invention, the deviation with reference to both or one of the first interference amount and the second interference amount is calculated in step (10) according to the state of the moisture content deviation, and the moisture content is calculated based on this deviation. By calculating the operation amount of
As shown in MP _pv ′, it is possible to maintain it constant.

Although the above explanation was about the second coating process, it goes without saying that the same control is possible in the first coating process as well, and can be similarly applied to coating equipment that only performs one process. Nor.

<Effects of the Invention> As explained above, according to the present invention, it is possible to maintain the coating amount and moisture content at the same values as before changing the speed by changing the line speed due to changes in production volume. A coating control device can be easily realized. In addition, the control mode is selected depending on whether the moisture content deviation limit is within or outside the range, so when it is within the limit, the above effect can be obtained, and when it is outside the limit, the speed change is suppressed and the moisture content is adjusted. By waiting until the deviation converges within the limit, stable line speed change control can be performed without paper waste.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment to which the method of the present invention is applied, and FIGS. 2 and 3 are a flowchart and characteristic diagram for explaining its operation. 2... Base paper, 4... Fountain, 6... Bucking roll, 7... Air dryer, 8... Cylinder dryer, 10... Blade, 11... B/M
meter, 12...control device, 13...moisture content control end,
14...Line speed control end, 15...Man-machine interface.

Claims (1)

[Claims] 1. A coating amount control end and a moisture content control end are determined using the measured values of basis weight moisture content measuring devices (hereinafter referred to as B/M meters) disposed on the upstream and downstream sides of the coating device. When changing the line speed of coating equipment that operates to control coating amount and moisture content,
In addition to setting the speed change amount in stages, when the deviation of the moisture content above is within the set limit, the line speed is changed by the step setting amount above, and the moisture content related to this stepwise speed change amount is changed. The first interference amount and the second interference amount to the moisture content due to the above coating amount manipulation are predicted and calculated, and this is added to the moisture content deviation as a feed forward signal to calculate the moisture content manipulation output. When the rate deviation is outside the set limit, line speed changes are inhibited and
The first interference amount is set to zero, and the second interference amount to the moisture content due to the coating amount manipulation is predicted and calculated, and this is added to the moisture content deviation as a feed forward signal to calculate the moisture content manipulation output. and a coating device characterized in that the set limit is a threshold value at which it is recognized that interference with the moisture content caused by a change in line speed is greater than moisture content fluctuations caused by other disturbance factors. Method for controlling moisture content.