JPS6146285B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for adjusting the thickness of an asbestos cement board in a paper manufacturing method.

Asbestos-cement boards are sometimes manufactured by the paper-making method, and one cycle of the production consists of the process of forming an asbestos-cement thin film from the asbestos-cement slurry in a vat using a paper-making cylinder, and the process of forming an asbestos-cement thin film on the paper-making cylinder. The process of transferring the thin film onto a rotating felt belt in contact with a cylinder, the process of winding the thin film on the felt belt with a making roll that is rotating in contact with the belt, and the process of winding the thin film on the making roll until it reaches a predetermined thickness. Then, the wire-type cutter in the making roll (a groove spanning the entire width of the making roll is provided at one point on the circumference of the making roll, a tension wire is placed in the entire length of the groove, and this wire is moved in and out using a hydraulic cylinder) is activated to cut the winding. This cycle is repeated, including the process of cutting the thin film to be taken and the process of transferring the cut thin film to the receiving conveyor behind the making roll as the making roll rotates.

By the way, the thin film wound on the above-mentioned making roll is cut when the number of wound layers reaches a predetermined number, but the thickness of the thin film may change each time the cycle changes. The winding thickness of a predetermined number of layers is measured, and if the thickness deviates from the specified value, the above-mentioned papermaking process is controlled in advance for the next cycle, and the thin film winding thickness is changed in the next cycle. It is necessary to adjust it to a predetermined value.

As for such an adjustment method, when the number of thin film layers wound on the making roll reaches a predetermined number in the previous cycle, the thickness of the wound film is measured using a thickness measuring device.
It is conceivable to control the traveling speed of the felt belt according to the measured value.

However, in order to measure the thickness of the above-mentioned thin film roll, it is necessary to bring the attachment of the thickness measuring device into contact with the surface of the roll with a predetermined pressure. To,
There are inconveniences such as contact marks from the attachments and remaining on the surface of the asbestos cement board.

The board thickness adjustment method in the paper manufacturing method for asbestos cement boards according to the present invention is a method that can eliminate the above-mentioned inconveniences, and is a method in which the asbestos cement thin film extracted by the paper making cylinder is transferred to a belt, and the thin film on the belt is made. In a paper manufacturing method for asbestos cement boards, which involves winding up a thin film with a roll and then cutting the wound thin film and peeling it off from the making roll when the wound thickness reaches a predetermined thickness, the final thickness of the wound thin film is set as above. This method is characterized in that the thickness is measured using a contact type thickness measuring device only in the vicinity of the cutting position, and the running speed of the belt is adjusted according to the measured value.

The present invention will be explained below with reference to the drawings.

In FIG. 1, 1 is a vat filled with asbestos-cement slurry, and 2 is a papermaking cylinder. 3 is a felt-like belt that can be rotated in contact with the papermaking cylinder 2; 4 is the drive unit that is the rotation source;
1A and 2B respectively indicate control units of the drive unit 4. A making roll 6 is in contact with the felt belt 3 and is equipped with a wire cutter 61. 7
is a thickness measuring device for the thin film P wound on the making roll; This thickness measuring device 7
Although not shown, the wire type cutter 61
A measurement start command is issued by a phototube or a limit switch that detects the position of the making roll 6, and then a timer that changes according to the circumferential speed of the making roll 6 measures the thickness only during a certain angle α. Only the attachment 71 is brought into contact with the outer surface of the wound thin film under a predetermined pressure. Of course, there is a built-in correction circuit for the amount of biting under this contact pressure.

FIG. 2 shows the drive mechanism and thickness measuring device 7 for the making roll 6, and the making roll 6 is driven by a commutator motor 8 via a transmission belt 9 and a speed reducer 10. 11 is a speed changer (brush movement) of the commutator motor 8, 12 is a speed changer position detector, and 13 is a speed detector, and these detection signals are sent to the control unit 5 of the felt belt drive unit. The making roll and the felt belt are kept in synchronization, and the measurement time during the thickness measurement period is set in correlation with the angle α.

To carry out the present invention, immediately after the number of thin film layers on the making roll 6 reaches a predetermined number and the wire cutter 61 of the making roll 6 passes through the thickness measuring device 7, the attachment of the thickness measuring device 7 is removed. 71 to automatically contact the thin film winding body,
After the making roll is rotated by a slight angle α° (within 15°), the attachment 71
is automatically detached from the thin film roll, and the thickness of the thin film roll is measured until this time of detachment. Therefore, this thickness measurement is performed only in the vicinity of the cutting position of the thin film roll.

The above thickness measurement value is sent to the drive control unit 5 for the felt belt 3, and when the thickness deviates from the standard value (for example, ±5% or more), the speed of the felt belt 3 is adjusted. Ru. As a result of this adjustment, in the next cycle described above, the thin film can be wound to a predetermined thickness on the making roll.

The board thickness adjustment method in the paper manufacturing method for asbestos cement boards according to the present invention is the method described above, and the board thickness can be easily made to a predetermined thickness only by adjusting the speed of the felt belt. Since the thickness measurement of the thin film wound body on the making roll, which is necessary for the adjustment, is carried out only near the cutting position of the wound body, the adhesion of thickness measurement traces can be kept to a very small extent. As most of the parts with traces are cut (the cut surface of the wire-type cutter is not neat and is ultimately cut with a knife-type cutter with a certain edge width), the asbestos has almost no traces of thickness measurement. You can get cement board.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an asbestos-cement board paper manufacturing apparatus used in the present invention, and FIG. 2 is an explanatory diagram showing a driving mechanism for a making roll used in the present invention. In the figure, 2 is a papermaking cylinder, 3 is a belt, 6 is a making roll, 61 is a wire cutter, and 7 is a thickness measuring device.

Claims (1)

[Claims] 1. Transfer the asbestos-cement thin film that has been made into a papermaking cylinder to a belt, wind up the thin film on the belt with a making roll, and when the rolled thickness reaches a predetermined thickness, cut the wound thin film and transfer it to a making roll. In the paper manufacturing method of asbestos cement board that is peeled off from the sheet, the final thickness of the wound thin film is measured with a contact thickness measuring device only in the vicinity of the cutting position,
A method for adjusting plate thickness in a paper manufacturing method for asbestos cement plates, characterized in that the running speed of the belt is adjusted according to the measured value.