JP2799625B2 - Coating amount measuring device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a coating amount measuring device for measuring an operation state of a coating machine used in the papermaking industry, and particularly to improvement of measurement accuracy.

<Prior Art> A coating machine is used in the papermaking industry, and is a device that improves the gloss and the like by applying paint to paper. The coating machine control device is disclosed in Japanese Patent Application Laid-Open Nos. 2-31,858 to 31,860 according to the proposal of the present applicant.
Japanese Patent Application Publication No. 63-181,162 to 181,164. In such a control device, a coating amount measuring device is required in order to grasp the operating state of the coating machine, for example, a gravimeter that measures the weight of paper per unit area, or a water content contained in paper. A moisture meter for measuring the rate is used as a coating amount measuring device.

FIG. 5 is an explanatory view of a conventional apparatus. In the figure, the base paper is coated with a paint by a coating machine to form a coated paper. The grammage meters (or moisture meters) # 1 and # 2 are provided before and after the coating machine, and the amount of coating is grasped from a change in the grammage.

<Problem to be Solved by the Invention> However, the coating amount to be applied is around 10 g / m ^2, which is a small value compared to the base paper weight of 200 to 300 g / m ² . Further, since the accuracy of the grammage meter is defined by the absolute weight, there has been a problem that when the weight of the base paper is increased and the coating weight / base paper weight ratio is reduced, the measurement accuracy of the coating weight is reduced.

The same applies to the case where the base paper has a small basis weight and the coating density is low and the absolute dry coating amount is small. Further, even when measuring the amount of coating based on the amount of water, correction corresponding to fluctuations in the water content of the base paper is required. Accordingly, there has been a demand for accurately measuring the amount of coating even in the case described above.

The present invention has solved such a problem, and the coating amount /
It is an object of the present invention to provide a coating amount measuring device capable of accurately measuring a coating amount even when a base paper weight ratio is small.

<Means for Solving the Problems> FIG. 1 is a configuration block diagram for explaining the present invention that achieves the above object. In the drawing, in the paper making process, a coating machine 10 for applying a coating material to a base paper and a dryer 15 for drying the coated paper after the coating are provided.

The coating measurement device includes a base paper sensor 20 provided before the coating machine 10 for measuring the moisture content of the base paper before coating, and a coating machine.
The reflection type moisture meter 30 for measuring the moisture content of the coated paper surface after the coating provided after 10 and the reflection type moisture meter 30 for the moisture content of the base paper measured by the β-ray type base paper sensor 20 A moisture content calculating means 40 for calculating the moisture content of the coating layer from the surface moisture percentage obtained,
It is characterized by comprising a coating amount calculating means 60 for calculating the coating amount applied to the base paper from the concentration of the paint applied by the coating machine 10 and the water amount measured by the water amount calculating means 40.

Preferably, the coating density is measured using a coating densitometer 50, and the calculation result of the coating amount calculation means 60 is displayed on a CRT or the like.

<Operation> Each component of the present invention performs the following operation. The base paper sensor 20 measures the moisture content of the base paper before coating, and the reflection type moisture meter 30 measures the moisture content of the base paper surface after coating, and the moisture content calculating means 40 calculates the moisture content of the coating layer. The coating amount calculation means 60 calculates the coating amount based on the paint concentration obtained by the coating densitometer 50 and the like and the calculated water content of the coating layer. That is, the coating amount is evaluated using the moisture percentage, and the coating amount is obtained indirectly. Because it is not affected by the basis weight of the base paper, it can measure with higher accuracy than before.

<Example> Hereinafter, the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 3 is a perspective view of an apparatus for specifically configuring them.
In the figure, the base paper sensor 20 has a so-called β-ray
It is equipped with a moisture content meter 22, and measures at least the moisture content of the base paper before coating by the coating machine 10. The grammage / moisture meter 22 reciprocates along the frame 24 to measure the width of the base paper in the paper width direction. The station 26 processes the data measured by the grammage / moisture content meter 22 for each scan, and the data y _{n, i} (where n is the number of scans provided corresponding to the base paper being manufactured) I is provided for determining the position in the width direction of the paper,
For example, it is assumed that 1 ≦ i ≦ 360 is a natural number. This relationship will be described later with reference to FIG. 4). The base paper sensor 20 includes, for example, Japanese Patent Publication No. 62-25984 as a moisture meter, Japanese Patent Publication No. 1-18375 for reciprocation, and Japanese Patent Publication No. 62-37159 for profile control using data of one scan. It is described in.

The reflection type moisture meter 30 measures the surface moisture content of the paper coated by the coating machine 10, and for example, a reflection type moisture meter is used. The frame 32 is a support for moving the reflection type moisture meter 30 in the width direction of the paper. The station 34 obtains the scanning information of the grammage / moisture meter 22 of the station 26 and scans the reflective moisture meter 30 so as to trace the position measured by the grammage / moisture meter 2. The measured data of the reflection type water type 30 is stored as surface water content data Y _{n, i} for each scan. The station 34 also has a function as a water content calculating means 40 and a coating amount calculating means 60. It is in the water amount calculation means 40, sent from the station 26 coating before moisture content data yn, i and the surface moisture content data Y _n, with the _i,
Perform the following operation.

y _{n, i} ⁻ = Y _{n, i} −α (yn _{, i−} β) (1) Here, the constants α and β are predetermined according to the brand of paper to be manufactured. This formula is called a synchronous calculation, and the position on the base paper at which the moisture content is measured by the reflective moisture meter 30 at the position where the base paper sensor 20 measures the moisture content is matched.

Subsequently, the coating amount calculating means 60 performs the following calculation from the water content data y _{n, i} ⁻ obtained by the equation (1) and the paint concentration γ obtained by the coating densitometer 50 or the like. Data y _{n, i} ″.

y _{n, i} ″ = y _{n, i} ⁻ · γ (2) The coating densitometer 50 measures the density γ of the paint applied to the base paper by the coating machine 10, and is usually substantially equal to the density γ. There is a correlation between the water content data y _{n, i} which is the water content of the paint.If the density γ can be considered substantially constant, this value is used instead of the measured value of the coating densitometer 50. It may be a value.

The display unit 70 is in charge of the man-machine interface, and is referred to herein as BOSC.
Is connected via a communication line to exchange information such as coating amount data y _{n, i} ″. Brand management information (for example, constants α and β in equation (1)) is also included. In addition to being managed by BOSC, a screen such as a CRT displays profile data (data representing the distribution of basis weight, moisture percentage, etc. in the width direction of the paper, and the contents are usually updated every scan). The BPCS is installed on the field side and controls the coating machine 10, and uses a controller 80 as an internal instrument in response to an instruction sent from the BOSC via a communication line. The total 80 is the coating amount data y via the communication line.
_{n, i} ″ is received as a measurement sheet, and an operation signal is sent to the coating machine 10 or the dryer 15 so that this value matches the set value.

The operation of the device configured as described above will now be described. Water amount calculation means 40 receives the coating before the moisture content data y _n, the _i from the station 26 receives the surface moisture content data Y _{n, i} from the reflection type moisture meter 30, executes the Synchronous operation (1) To obtain water content data y _{n, i} ⁻ . Coating amount calculation means 60 water content data y _n from moisture amount calculation means _{40, i} ^- receive, from the coating concentration meter 50 to give a concentration γ running (2), the coating amount data y _{n, i} ″ is obtained. The coating amount data y _{n, i} ″ is sent to the BOSC via a communication line, used for displaying profile data, and sent to the BPCS to control the coating machine 10, Make a paper with a coat weight that matches the brand being manufactured.

FIG. 4 is an explanatory diagram of a measurement state of the base paper sensor 20 and the reflection type moisture meter 30. The base paper flows at a high speed to the coating machine 10 and has a considerable width. Since it is not practical in terms of cost to provide a grammage / moisture meter 22 or a reflection type moisture meter 30 for simultaneously measuring such a wide width, the frames 24, 32
And reciprocally scan in the width direction to measure the moisture content. Therefore, the distribution of the measurement points on the base paper has a zigzag polygonal line shape as shown in the figure. This relationship is expressed using the subscripts n and i of each data.

The water amount data y _n using the time constant α and β were determined experimentally (1) in the above _{embodiments, i} ^- and coated amount data y _n, but seeking _i "or the like, the The invention is not limited to this, and may be another polynomial or an expression using a constant.

<Effects of the Invention> As described above, according to the present invention, since the amount of coating is determined using the amount of water in the coating layer applied to the lunar paper, the measurement accuracy of the amount of coating increases. By controlling the coating amount, the quality of the coating amount is precisely controlled, and the required quality paper can be manufactured at low cost. Further, the profile control of the coating amount becomes easier.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating the configuration of the present invention, FIG. 2 is a block diagram illustrating an embodiment of the present invention, FIG. 3 is a perspective view of an apparatus that specifically configures the components, and FIG. FIG. 3 is an explanatory diagram of a measurement state of a sensor for use 20 and a reflection type moisture meter 30. FIG. 5 is an explanatory view of a conventional apparatus. 10 ... Coating machine, 20 ... Sensor for base paper, 30 ... Reflective moisture meter, 40 ... Moisture content calculating means, 50 ... Coating densitometer, 60 ...
Coating amount calculation means.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Katsuyuki Miyauchi 1-26-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Chino Co., Ltd. (72) Katsutoshi Uchiyama 2-9-132 Nakamachi, Musashino-shi, Tokyo Inside Kawa Electric Co., Ltd. (72) Inventor Kazushi Takano 2-9-132 Nakamachi, Musashino City, Tokyo Yokogawa Electric Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) D21H 11/00- 27/42

Claims (1)

(57) [Claims] 1. A base paper sensor for measuring a moisture content of a base paper before coating provided before the coating machine for a coating machine for coating a base paper with a coating material, and provided after the coating machine. A reflection-type moisture meter for measuring the moisture content of the coated paper surface after coating, and the moisture content of the coating layer from the moisture content of the base paper measured by the sensor for the base paper and the surface moisture content measured by the moisture meter. And a coating amount calculating means for calculating the coating amount applied to the base paper from the concentration of the paint to be applied by the coating machine and the water amount measured by the water amount calculating means. A coating amount measuring device, comprising: