JPS63314405A - Printing pitch measuring device for packaging synthetic resin film - Google Patents

Abstract

PURPOSE:To automatically adjust the tensile force of a synthetic resin film in the transfer line to an optimum value, by detecting a printed mark on the moving synthetic resin film and the moving speed of the film. CONSTITUTION:A mask detector 1 generates a detection signal P1 in pulses every time a mark M passes the mark detector 1 in accordance with the movement of a synthetic resin film F. On the other hand, a speed detector 2 generates a detection signal P2 corresponding to the moving speed of the film F. These detection signals P1 and P2 are amplified by an amplifier 3 to be inputted to an operation unit 4 which in turn obtains the continuous average or moving average of the pitch between the adjacent two marks M on the basis of the detection signals P1 and P2. The operation unit 4 further compensates for the inspected value by the use of a predetermined operation formula, in consideration of the slippage between the speed detector 2 and the surface of the resinous film F. Then, the obtained continuous average or moving average is indicated on a display 5, printed out to a printer 6 or stored in a memory 7 as the confirmation data of the extension of the film F. Thus, the tensile force of the film F can be automatically adjusted to an optimum value.

Description

Detailed Description of the Invention [Industrial Application Field] This invention is a method for automatically and continuously measuring the pitch between printed marks on a synthetic resin film for packaging bags that is continuously conveyed along the length direction. The present invention relates to a printing pitch measuring device for synthetic resin film for packaging bags.

[Prior Art] Packaging materials based on synthetic resin films are widely used as packaging bags for foods, medicines, etc., and most of them are subjected to gravure printing or the like.

Generally, such packaging bags are used by a so-called bag-forming and filling method, in which contents are filled while forming the packaging bag.

By the way, in the case of such a bag making and filling method, during the process of printing on the synthetic resin film as a packaging material and during the laminating process to give it thermal adhesive properties, tension is applied to the synthetic resin film while it is being transported. It is fed at a predetermined speed in the length direction in the line. At this time, when the synthetic resin film is stretched by the applied tension,
An error will occur between the repeated printing pitch for each bag making width, which is preset during printing plate manufacturing, and the actual printing pitch. Such errors in printing pitch affect the amount of contents to be filled, so management of the printing pitch has become an important issue in the industry.

Conventionally, the printing pitch has been confirmed by taking a sample from the end of the rolled synthetic resin film at the end of each process, and visually checking the printing pitch on the printed surface of the sample using a scale, etc. I was checking.

[Problem to be solved] As mentioned above, in the past, only a part of the synthetic resin film wound into a roll, that is, only the end, was sampled to check the printing pitch. It was not possible to confirm the printing pitch of the film. In other words, it was not possible to confirm the printing pitch over the entire length of the synthetic resin film.

This invention was made in view of these circumstances, and it is possible to measure and confirm the printing pitch over the entire length of a synthetic resin film, but the measurement results can be effectively utilized to, for example, It is an object of the present invention to provide a printing pitch measuring device for a synthetic resin film for packaging bags, which is capable of automatically and optimally adjusting the tension of the synthetic resin film in a line.

[Means for Solving the Problems] The printing pitch measuring device for a synthetic resin film for packaging bags of the present invention measures a synthetic resin film for packaging bags on which printing marks are attached at predetermined intervals along the length direction. A printing pitch measuring device installed in a conveyance line that conveys continuously in the length direction, and a mark detection device installed at a fixed position on the conveyance line to detect printing marks attached to a synthetic resin film for packaging bags. a speed detector provided at a fixed position on the conveyance line to detect the conveyance speed of the synthetic resin film for packaging bags; a detection signal of the mark detector and a detection signal of the speed detector; The present invention is characterized by comprising a calculation device that continuously calculates the pitch of the color between each printed mark from the detection speed of the speed detector at each interval of detection timing of the mark detector.

[Function] The printing pitch measuring device for synthetic resin film for packaging bags of the present invention detects the printing marks attached to the synthetic resin film for packaging bags moving in the conveyance and feeding line, and also detects the printing pitch of the synthetic resin film for packaging bags as it moves in the conveyance and feeding line. By detecting the speed, the pitch between printed marks is automatically and continuously determined, making it possible to confirm the amount of elongation over the entire length of the synthetic resin film.

[Example] Hereinafter, one embodiment of the present invention will be described based on the drawings.

In Fig. 1, F is a synthetic resin film of the packaging material to be measured, and a mark M called an eye mark is placed on the side or part of the surface in the length direction of the synthetic resin film F. They are attached at regular intervals along the line. One or more marks M are placed at equal intervals for each bag making width, and a series of processing operations such as bag making and filling can be performed at the optimal timing based on the position of this mark M. It has become. Therefore, by measuring the pitch between the marks M, the degree of elongation of the synthetic resin film F can be confirmed.

The synthetic resin film F is continuously fed at a predetermined speed in the conveyance line of each step while tension is applied in the length direction thereof. The conveyance line is, for example, a conveyance line in the process of printing on the synthetic resin film F or the lamination process for imparting thermal adhesive properties, and includes a feed roll,
It is composed of a combination of multiple rolls such as a tension roll and a guide roll. The illustrated conveyance line is configured to continuously feed from the left to the right.

The printing pitch measuring device of this embodiment is installed on such a conveyance line.

Reference numeral 1 denotes a mark detector l, which is provided at a fixed position in the conveyance line so as to face the printed part of the mark M on the synthetic resin film F. The mark detector 2ZI detects the presence or absence of the mark M, that is, it outputs a detection signal when the mark M moves to the opposing position.In this example, the mark detector 1 is a light reflection type. It is an optical sensor. Reference numeral 2 denotes a speed detector, which is installed at the first position in the transport line and detects the transport speed of the synthetic resin film F. In the case of this example, the speed detector 2 is provided so as to sandwich the synthetic resin film F between rollers R constituting the transport line, and while in contact with the synthetic resin film F, the speed detector 2 responds to the transport speed I2. This is a pulse generator that rotates and outputs pulses, and outputs a pulse every time the synthetic resin film F moves a certain amount.

The detection signals of mark detector l and speed detector 2 are sent to amplifier 3.
The signal is input to the arithmetic unit 4 through. The function of the arithmetic unit ξ4 will be described later along with its operation. The arithmetic device 4 includes a display device (
A CRT (CRT) 5, a printer 6, and an analog recorder 7 are connected to display or print out the calculation results.

The printing pitch measuring device of this embodiment configured as described above is made into a movable unit, and can be installed or removed from various conveyance lines as appropriate. There is.

Next, the effect will be explained.

The mark M detector 1 outputs a pulse-like detection signal P1 as shown in FIG. 2(a) every time the mark M passes as the synthetic resin film F moves.

On the other hand, the speed detector 2 outputs a detection signal (FIG. 2(b)) P2 corresponding to the moving speed of the synthetic resin film F.

Since this detection signal P2 is a pulse that is output every time the synthetic resin film F moves by a certain amount, the number of pulses corresponds to the amount of movement of the synthetic resin film F.

These detection signals PI, P2 are amplified by the amplifier 3 and input to the arithmetic unit 4, and the arithmetic unit 4 calculates the continuous average or moving average of the pitch between the marks M from these detection signals PI, P2.

That is, each time the detection signal PI is output a predetermined number of times, the number of pulses of the detection signal P2 during that period is counted. For example, as shown in FIG. 2(c), every time the detection signal pt is output twice, the number of pulses of the detection signal P2 during that period is counted. Since the pulse interval of the detection signal P2 corresponds to a constant moving claw of the synthetic resin film F, the length of the mark M by two pitches can be determined by such counting. The value is divided into two equal parts or the continuous average. Further, as shown in FIG. 2(d), if the pitch is shifted one pitch at a time and the length of every two pitches is determined and divided into two equal parts, this becomes the moving average. When performing such calculations, the calculation device 4 takes into account the slip between the speed detector 2 and the surface of the synthetic resin film F, and compensates the measured value using a predetermined calculation formula.

The continuous average or moving average obtained in this way becomes data for checking the elongation of the synthetic resin film F.
Displayed on display device 5, printed out on printer 6,
Alternatively, it is recorded by an analog recorder 7.

FIG. 3 is a flowchart for explaining the operation of CPIJ that controls the arithmetic unit 4. First, when measuring the pitch, a pitch reference value and the like are initially set using switches (step S1). Then, the data from the switches are read (step S2) and actual measurement is started. First, when the mark detector l is turned on, that is, when the detection signal PI is output,
Proceeding from step S3 to step S4, the count value of the detection signal P2 of the speed detector 2 is read. Then, if a moving average value is to be calculated (step S5), and if a continuous average is to be calculated, the process proceeds from step S6 to step S7, and the continuous average is calculated.

Thereafter, the calculated average value is compared with a preset reference value to determine an error (step 58), and if the average value exceeds the allowable range, an alarm is issued. Then, the calculated average value is converted into digital/analog data and displayed on the analog recorder 7, and is also printed out from the printer 6 (step S9).

By the way, the mark detector l is not limited to the one that detects the mark M called an eye mark, but also detects other printed parts corresponding to the printed part of the eye mark, for example - printing that is repeatedly printed for each bag making width. It may be possible to detect a predetermined location of the part. In this case, the elongation of the synthetic resin film F is confirmed by using the predetermined portions of the printed portion in the same manner as the marks M described above and determining the pitch between the predetermined portions.

Further, the speed detector 2 is not limited to the two types that rotate while in contact with the synthetic resin film F, but for example, the speed detector 2 is in contact with a roller R that rotates as a result of the movement of the synthetic resin film F, and together with that roller R. It may be one that rotates or one that directly detects the rotational speed of the roller R. In short, any device that can detect the moving speed of the synthetic resin film F may be used.

Further, the output of the analog recorder 7, which is the measurement result of the arithmetic device 4, can be effectively used as a detection output for automatically adjusting the tension of the synthetic resin film in the conveyance line to an optimum level, for example.

As explained above, the printing pitch measuring device for synthetic resin film for packaging bags of the present invention detects the printing marks attached to the synthetic resin film for packaging bags moving in the conveyance line, and Since the pitch between printed marks is automatically and continuously determined by detecting the transport speed of the resin film, the elongation m can be confirmed over the entire length of the synthetic resin film. As a result, it is possible to eliminate errors in printing pitch and to accurately fill the amount of contents, thereby improving quality.

[Brief explanation of the drawing]

The drawings are diagrams for explaining one embodiment of the present invention,
FIG. 1 is a schematic block diagram, FIG. 2 is a time chart for explaining the operation, and FIG. 3 is a flow chart for explaining the operation. l... Mark detector, 2... Speed detector, 3... Amplifier, 4... Arithmetic device, 5... Display device , 6...
Printer, 7...Analog recorder, F...Synthetic resin film, M...Mark.

Claims (1)

[Scope of Claims] A printing pitch measuring device that is installed in a conveyance line that continuously conveys a synthetic resin film for packaging bags, which is provided with printing marks at predetermined intervals along its length. A mark detector is provided at a fixed position on the conveyance line to detect the printed mark attached to the synthetic resin film for packaging bags, and a mark detector is provided at a fixed position on the conveyance line to detect the printed mark on the synthetic resin film for packaging bags. A speed detector that detects the conveyance speed, a detection signal of the mark detector, and a detection signal of the speed detector are inputted, and each detection speed is calculated from the detection speed of the speed detector at each interval time of the detection timing of the mark detector. 1. A printing pitch measuring device for synthetic resin film for packaging bags, comprising a calculation device that continuously calculates the pitch between printing marks.