JPH06272200A - Method and apparatus for manufacturing security paper for forgery prevention - Google Patents

Abstract

(57) [Summary] [Objective] In the manufacture of paper having a window portion on which a stock is not present on a part of a strip or a thread, the intervals and sizes of the window portions are easily changed. [Structure] On the wire part of the Fourdrinier paper machine, a compressed air nozzle for injecting compressed air into a rotating drum is built in, and a compressed air injection hole for injecting compressed air into a stock suspension layer is opened. A rotary drum having a rotation control mechanism described above is installed, and the stock suspension layer on the strip or the thread previously inserted in the stock suspension layer on the wire is moved by blowing compressed air to the part. A method and apparatus for forming so-called windows where there is no stock.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing a security paper for producing products requiring anti-counterfeiting such as banknotes, securities, admission tickets and the like.

[0002]

2. Description of the Prior Art It is well known in the prior art to insert protective strips or threads of plastic film on banknotes. In particular, as is currently found in sterling tickets, a method of making these protective strips or those having a window free of stock on a portion of the yarn is described in EP0059 filed in Europe and the United States by Portals UK Ltd.
No. 056 and USP 4462866. These are so-called cylinder paper machine manufacturing methods, and when a cylindrical wire mesh (cylinder mold) with a part of the surface processed into an uneven shape rotates in a vat containing a stock suspension. , The strip or thread rotates together while contacting the irregularities of the processed surface, and as a result, the strip or thread that was in contact with the convex portion of the wire mesh surface has It is a manufacturing method that does not exist, that is, a so-called window portion.

[0003]

Heretofore, as a method for producing a paper having a paper-free window on a part of a protective strip or a thread made of a plastic film, EP0059056 of the above-mentioned British Portals Company. In the cylinder net-making method described in U.S. Pat. No. 4,462,866 and U.S. Pat. No. 4,462,866, the machine speed is relatively low due to its mechanism, and the window is formed by processing the wire mesh into a concavo-convex shape. There is a problem that the interval and size cannot be changed. An object of the present invention is to provide a manufacturing method and a manufacturing apparatus capable of easily changing the interval and size of the window portion during the manufacture of the paper.

[0004]

In order to achieve the above object, the present invention has a built-in compressed air nozzle for injecting compressed air on a wire of a Fourdrinier paper machine, and suspends the compressed air. Install a rotary drum with a rotation control mechanism that opens compressed air injection holes for jetting into the liquid layer, and strip the stock suspension layer on the wire or the strip previously inserted into the stock suspension layer on the wire. It is moved by blowing compressed air to form a so-called window portion in which the paper material does not exist. Further, by changing the peripheral speed of the rotary drum that injects the compressed air, the size and interval of the window can be arbitrarily changed.

[0005]

The strip previously inserted into the stock suspension layer by compressed air when water in the stock suspension layer is dehydrated downward from the wire on the Fourdrinier wire to form the paper layer. Alternatively, when the stock suspension layer on the thread is moved toward the peripheral stock suspension layer, the stock suspension layer does not exist above the strip or thread portion, and a window is formed on the paper surface. To do. At this time, the size and the interval of moving the stock suspension layer on the strip or the yarn are compressed at regular intervals on the circumference of the rotating drum facing the tip of the compressed air nozzle for intermittently injecting compressed air. This can be changed by changing the peripheral speed of the rotary drum having the air injection holes.

[0006]

FIG. 1 is a front view of the safety protection paper manufacturing apparatus of the present invention installed on a suction box (not shown) of a wire (9) section of a Fourdrinier paper machine A. In FIG.
(1) is a strip or thread previously inserted in the stock suspension layer (8), and in this state, the rotary drum (2) is rotated in the same direction as the traveling direction of the wire (9), Compressed air having a pressure of 4 to 5 kg / cm ^{2 which} is constantly jetted from the compressed air nozzle (3) of the inside (2) is passed through the compressed air jet holes (4) opened at regular intervals on the circumference of the rotary drum (2). As a result, compressed air is intermittently jetted onto the stock suspension layer (8), and the strips or threads (1) are exposed at regular intervals on the surface of the stock suspension layer (8). 7) is formed. At this time, the size or interval of the window part (7) is the speed of the wire (9), the peripheral speed of the rotary drum (2), and the compressed air injection holes opened at regular intervals on the circumference of the rotary drum (2). It is determined by the pitch of (4). The rotating drum (2) is driven by a drive belt (1
0), the peripheral speed of the rotary drum (2) is controlled by the rotary speed controller (6) of the rotary speed variable motor (5).
It can be changed by adjusting.

FIG. 2 is a cross-sectional view of the rotary drum section, showing the bearing (1) with the compressed air nozzle (3) fixed.
1) shows a mechanism in which only the rotary drum (2) held by the rotary drum rotates, and FIG. 3 shows the positional relationship between the tip of the compressed air nozzle (3) and the compressed air injection hole (4) of the rotary drum (2). It is an explanation expanded sectional view.

When the width of the strip or thread (1) is set to 1 mm, the rotary drum (2) having an outer diameter of 100 mm is provided with compressed air injection holes (4) having a hole diameter of about 0.2 mm at regular intervals, and the wire ( FIG. 4 shows an example of the window portion obtained by adjusting the peripheral speed of the rotating drum (2) to several times the speed of 9). Further, FIG. 5 shows the window portion (7) in the state of FIG. 4 when the peripheral speed of the rotary drum (2) is doubled, and the window portion (7) is changed by changing the peripheral speed of the rotary drum (2). The size and interval of 7) can be freely changed.

[0009]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, it is possible to manufacture a paper having a window portion on which a stock material does not exist on a part of a strip or a thread, which can be manufactured even by using a Fourdrinier paper machine. As a result, it is possible to increase the speed of papermaking as compared with conventional cylinder papermaking, and to further improve the forgery prevention effect by combining various plows by a Fourdrinier paper machine and the above-mentioned window portion. You can In addition, by changing the peripheral speed of the rotary drum for injecting compressed air, it is possible to obtain an arbitrary window size and interval.

[Brief description of drawings]

FIG. 1 is a front view of a safety protection paper manufacturing apparatus installed on a wire portion, part of which is a partial cross-sectional view.

FIG. 2 is a sectional view of a rotary drum unit.

FIG. 3 is an explanatory enlarged cross-sectional view showing a positional relationship between a compressed air nozzle tip portion and a compressed air injection hole of a rotary drum.

FIG. 4 is a state diagram of a window portion when a paper layer is manufactured using the manufacturing apparatus of FIG.

5 is a state diagram of a window when the peripheral speed of the drum under the manufacturing conditions of FIG. 4 is doubled.

[Explanation of symbols]

 1 Strip or Thread 2 Rotating Drum 3 Compressed Air Nozzle 4 Compressed Air Jet Hole 5 Rotation Speed Variable Motor 6 Rotation Speed Controller 7 Window 8 Paper Suspension Layer 9 Wire 10 Drive Belt 11 Bearing

Claims (2)

[Claims] 1. A compressed air is intermittently downwardly maintained at a distance from a vertical direction on a traveling line of a strip or a thread inserted in a substantially middle layer of a stock suspension layer on a running Fourdrinier wire. And then the stock suspension layer existing on the upper part of the strip or thread is moved toward the peripheral stock suspension layer, and the strip or thread of the part sprayed with the compressed air is exposed at intervals in the running direction. A method for producing a security paper for forgery prevention, which comprises: 2. A compressed air nozzle having a tip portion in the lower part in the vertical direction and bent in the horizontal direction from the upper part thereof, and a part from the vertical pipe part to the horizontal pipe part of the compressed air nozzle are built in, The compressed air nozzle is held rotatably with a horizontal pipe part as a fixed shaft, and compressed air injection holes are opened at regular intervals on a circumferential surface facing the compressed air nozzle tip part at the time of rotation, and a rotation speed is provided through a drive mechanism. An apparatus for producing a security paper for forgery prevention, comprising a rotary drum connected to a variable device.