JP2005305865A - Fusion bonding method and fusion bonding apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fusion bonding method and an apparatus for a synthetic resin product which can accurately bring the temperature of a seal member within a specified range during continuous operation, and even when an operating condition and a waiting condition are switched, can make the temperature of a heater reach more quickly a specified temperature. <P>SOLUTION: In the fusion bonding method, the synthetic resin products 2 and 2 are fusion-bonded while the temperature of the heater 3a is controlled by PID controlling. In the operating condition wherein the seal members 3 and 3 heated by the heater 3a are brought into contact with the products 2 and 2 to continuously or intermittently heat the products 2 and 2, and in the waiting condition for waiting without heating the products 2 and 2, an electric power obtained by operating a gain of the electric power of an electric power source 4 supplied at a time of the PID controlling is set so that it becomes smaller under the waiting condition in comparison with the operating condition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fusion bonding method and apparatus used for fusion bonding a synthetic resin product such as a packaging film.

When bonding synthetic resin products, fusion bonding is often used because reliable bonding strength can be obtained with a simple operation. For example, in order to wrap contents such as liquids, powders, granules, etc., when sealing a synthetic resin molded container with a lid with a sealant, manufacturing a packaging bag or packaging the above-mentioned contents into a bag. 2. Description of the Related Art Heat sealing devices that repeatedly heat-seal long films (sheets, tubes, etc.) conveyed in the longitudinal direction continuously or intermittently are widely used. In this type of heat sealing device, the sealing member heated by the heater is brought into contact with the synthetic resin product so that the synthetic resin product is heat sealed and the required portions are fusion-bonded. Various proposals have been made to control the temperature of the seal member within a certain range when joining is performed (see, for example, Patent Document 1).
For example, Patent Document 1 discloses that a thermistor (surface temperature detecting means) detects the surface temperature of a heat roller (thermal fusion member), and a signal voltage generated by the thermistor upon detection of the surface temperature of the heat roller is generated in a comparator. A technique is disclosed in which the input to the heat source of the heat roller is controlled by opening and closing a relay in accordance with a comparator output obtained as a result of comparison with a reference voltage.
In addition, in order to keep the temperature of the seal member during continuous operation within a predetermined range, it has been studied to control the heater by PID (proportional integral derivative) control.
JP 2000-318715 A

In a synthetic resin product, for example, a film heat sealing apparatus, when a sealing member heated continuously or intermittently and heated by a heater is in contact with the film to heat the film (operating state) More heat is released from the heater than when the seal member is waiting away from the film (standby state). In other words, when switching from the standby state to the operating state, the temperature of the sealing member is greatly reduced by increasing the temperature of the film, melting the synthetic resin, or absorbing the heat of the contents. Need to supply. On the other hand, when it is released from the operating state and switched to the standby state, the temperature of the seal member rises because there is nothing to remove heat. For example, if a problem occurs during operation or the operation is interrupted due to change of setup, a large temperature change occurs when switching from the standby state to the operation state again. Operation is performed to lower the temperature of the seal member. Most of the film and contents used during this period are discarded as defective products.
By the way, as described above, in order to keep the temperature of the seal member within a predetermined range during continuous operation, it is conceivable to control the heater by PID control, but PID control sets the temperature of the seal member during continuous operation to a predetermined value. Even if it is effective when the amount of change is relatively small, such as being within a range, but when there is a large change in the control amount, such as switching between the operating state and the standby state, the temperature of the seal member is limited by the PID constant. It had the disadvantage that it took a relatively long time to converge. For this reason, when waiting for the temperature of the seal member to converge, the waiting time becomes longer and the productivity decreases. In order to avoid this, if the temperature range of the seal member during continuous operation is set wide, adjustment of the seal member temperature may be insufficient, and heat seal failure may occur due to insufficient heating or overheating, resulting in a decrease in yield. May decrease.
Therefore, it is difficult to use the PID control when the temperature of the heater reaches the predetermined temperature faster when the operation state and the standby state are switched.
As a means for overcoming such a difficulty, for example, Japanese Patent Application Laid-Open No. 7-219646 discloses a temperature control device in which two PID controllers forming a master controller and a slave controller are cascaded to cope with a large change amount. Has been proposed. However, since the invention described in this publication deals with uncertain disturbances such as entry / exit furnaces and burning in a diffusion furnace for semiconductor heat treatment, the configuration of the control device is complicated by having two PID controllers. In addition, there are problems such as increased costs for installation and operation.

  The present invention has been made in view of the above circumstances, and it is possible to accurately keep the temperature of the seal member within a predetermined range during continuous operation, and even when the operation state and the standby state are switched, It is an object of the present invention to provide a method and an apparatus for fusion-bonding synthetic resin products that can cause a temperature to reach a predetermined temperature more quickly.

As a result of intensive investigations by the inventors of the present invention in order to solve the above-mentioned problems, the PID control is based on a function in contrast to the common sense that temperature control can be performed in an optimum state only by PID control, and therefore only continuous control can be performed. The problem, that is, the problem that the output to the heater cannot be raised or lowered at once, can be switched stepwise by switching the amount of power supplied during PID control according to the state. Since it is continuous when viewed from the regulator, it has been made by obtaining the knowledge that the temperature of the heater can reach the predetermined temperature faster without causing any problems in the PID control itself.
That is, the present invention is a fusion bonding method in which a synthetic resin product is fusion bonded while controlling the temperature of the heater by PID control, and a seal member heated by the heater comes into contact with the product to The power obtained by manipulating the gain of the power source power supplied in the PID control in the operation state in which the product is continuously or intermittently heated and in the standby state in which the product is not heated is in the operation state. Provided is a fusion splicing method characterized in that it is set to be smaller in the standby state than in the case.
In this fusion bonding method, the gain of the power source power can be manipulated when switching between the operation state and the standby state.
For the gain operation of the power source power, a method of energizing and controlling the AC power source with the phase angle of the AC waveform can be adopted.
It is also possible to employ a method in which the power obtained by operating the gain of the power source power supplied during the PID control in the operating state is 100% of the power source power.
Examples of the synthetic resin product include packaging films.

Further, the present invention is a fusion bonding apparatus for fusion-bonding synthetic resin products while controlling the temperature of the heater with a PID control apparatus, wherein the fusion bonding apparatus includes a seal member heated by the heater, A power source that supplies power to the heater of the seal member and an electric power obtained by operating the gain of the power source are in an operating state where the seal member abuts the product and heats the product continuously or intermittently. Compared to the case, the power control means that is set to be smaller in the standby state where the product waits without being heated, and the power supplied to the heater via the power control means by performing PID control. And a temperature control means for performing on / off of the fusion bonding apparatus.
In this fusion bonding apparatus, it is also possible to adopt a configuration in which the power control means operates the gain of the power source power based on a signal instructing the operation state start or standby state start of the fusion bonding apparatus. Is possible.

According to the fusion splicing method of the present invention, the gain of the power supplied from the power source (the gain of the power source power) is smaller than the amount of power obtained by the gain in the standby state than the amount of power obtained by the gain in the operating state. Therefore, the required power amount of the heater due to the change in the heat radiation amount from the seal member can be switched in a stepped manner, and the time required for PID control can be shortened. In addition, the switching of the power supply power gain may be performed manually so as to be optimal according to the environment to which the present invention is applied, and automatically in conjunction with the switching of the heater state based on the operation signal sent from the operation control means. It can also be performed. Accordingly, it is possible to shorten the waiting time for temperature adjustment and improve the operation rate and productivity of the apparatus, and it is possible to improve the yield by suppressing the heat seal failure of the film.
The power gain switching operation is preferably performed at the same time when the operating state and the standby state of the seal member are switched. In this case, setting the power gain so that the amount of power in the standby state is smaller than the amount of power in the operating state can be easily and reliably linked with the change in state.
When a method of conducting energization control of an AC power source at the phase angle of the AC waveform is adopted as the gain operation of the power source power, smooth and fine control can be performed.
In the operating state, when the power obtained by operating the gain of the power source power supplied in the PID control is 100% of the power source power, the heater capacity can be utilized to the maximum, It can converge quickly.

The present invention will be described below with reference to the drawings based on the best mode.
The fusion bonding apparatus 1 in this embodiment is a heat sealing apparatus for heat-sealing the film 2 as a synthetic resin product. In the following description, the fusion bonding apparatus is described as a heat sealing apparatus.
As shown in FIGS. 1 and 2, the heat sealing apparatus 1 of this embodiment includes a sealing member 3 for heat sealing the film 2, a power supply 4 for supplying power to the heater 3 a of the sealing member 3, and an operation signal. An operation control means 5 for sending to the power control means 6, a power control means 6 for switching the gain of power supplied from the power source based on an operation signal sent from the operation control means, and the heater 3a There are provided temperature control means 7 for switching on and off the power supplied to the heater 3a via the power control means 6 by PID control of the temperature, and transport means 8 for transporting the film 2.

  Film 2 is a long film that can be heat-sealed. For example, a single-layer plastic film, a laminated film in which multilayer plastics are laminated by coextrusion, a metal foil such as an aluminum foil, or paper is laminated with plastic. The laminated film etc. which were made can be used. As an aspect of the film, for example, one or a plurality of sheets, a tube, a bag having an opening, and the like can be exemplified.

The film 2 is continuously or intermittently moved by the conveying means 8, and the film 2 can be continuously or repeatedly heat-sealed to form a packaging bag, a package, or the like sequentially.
When manufacturing a packaging body in which contents such as liquid and powder are filled in a packaging container formed from the film 2, the filling of the contents is performed alternately with a sealing process of the packaging bag by heat sealing, for example. Can do. In addition, bags can be made on the line where filling and sealing are performed, and packaging is carried out by sequentially feeding and moving films such as tubes while filling the contents without interruption, and heat-sealing the films at predetermined intervals. The body can also be manufactured.

The seal member 3 is, for example, a rod-shaped (bar) or cylindrical (roll) member, and a configuration in which two are used in combination is often used. At least one of the sealing members 3 and 3 includes a heater (H1) 3a for heating the film 2. The heat sealing of the film 2 can be performed by sandwiching the film 2 between the sealing members 3 while the heater 3a is heated.
The seal member 3 is provided with a thermocouple (T 1) 9, and the thermocouple 9 can measure the temperature of the seal member 3.

  The sealing members 3 and 3 are driven by a driving means (not shown) so that an operation state in which the film 2 is in contact with the film 2 and the film 2 is heated and a standby state in which the seal member 3 and 3 are separated from the film 2 can be taken. It has become. The driving of the seal members 3 and 3 is controlled by an operation signal sent from the operation control means 5.

A power control means (G1) 6 and a relay (R1) 10 (for example, a semiconductor relay) are connected in series in this order between the power source 4 and the heater 3a.
An operation signal for controlling the heater 3a by the operation control means 5 is sent to the power control means 6 (power controller) in synchronization with the movement of the heater 3a. The power control means 6 is the power obtained by manipulating the gain of the power of the power source 4 (here, the power sent from the power control means 6 to the relay 10; hereinafter also referred to as the power after operation). The gain of the electric power is switched and controlled based on the operation signal so as to be lower in the standby state than in the case of. As the gain control method, for example, a phase control method in which power adjustment is performed by energizing the AC waveform of the power supply 4 in an arbitrary phase angle range can be employed. This is preferable because smooth and fine control can be performed. In addition, it is also possible to employ a zero cross control method in which power adjustment is performed by opening and closing the circuit when the power supply voltage becomes zero volts.

Further, the power supplied from the power source 4 to the heater 3a via the power control means 6 is feedback controlled by the temperature control means (F1) 7. The temperature control means 7 (temperature controller) opens and closes (on / off) the relay 10 installed between the power control means 6 and the heater 3a by PID-controlling the temperature of the seal member 3 measured by the thermocouple 9. Thus, the heater 3a is controlled, and the temperature of the seal member 3 is controlled within a predetermined range.
That is, the electric power after the operation is an input for the feedback control of the temperature control means 7, that is, the electric power supplied during the PID control of the temperature control means 7.
The power after the operation during operation may be lower than the power of the power source 4 as long as it is set higher than the power after the operation during standby. However, in order to make full use of the capacity of the heater, it is preferable that the power after the operation during operation is 100% of the power supply power (equal to the power supply power), in which case the temperature converges faster. Can be made.

The operation of the heat seal device 1 of this embodiment will be described.
The heater 3a has a relatively small heat release amount H0 (see FIG. 2) in the standby state, and requires less power to keep the temperature constant. On the other hand, in the operating state, since heat is absorbed by the film and contents, the heat radiation amount H1 from the heater 3a is larger than the heat radiation amount H0 during standby, and the power for keeping the temperature constant is More are needed than in the standby state. The change between the heat radiation amounts H0 and H1 is large in order to cope with the PID control of the temperature control means, and it takes time to converge the temperature.
When the power supply gain is set to a relatively large value suitable for converging the temperature of the seal member 3 in the operating state, it is long to converge the temperature of the seal member 3 when shifting from the operating state to the standby state. It takes time.
Therefore, if the power supply gain is set to a relatively small value that is suitable for converging the temperature of the seal member 3 in the standby state, the temperature of the seal member 3 is converged when shifting from the standby state to the operating state. It takes a long time.

When a synthetic resin product is heated continuously or intermittently, the heat radiation amount H1 during operation and the heat radiation amount H0 during standby depends on the purpose of heat sealing, the object, the temperature at which heat sealing is performed, the working speed, etc. However, when a specific synthetic resin product is heat-sealed under conditions with relatively little fluctuation, it can be predicted to some extent, and in accordance with this, roughly the operating gain G1 and standby Gain G0 can be determined. Even if the initial gains G0 and G1 are slightly out of sight, the results will not be worse than if the gains are not switched unless G0 is significantly lowered. Based on the result, the values of the gains G0 and G1 can be corrected to the optimum values.
Further, for example, the optimum values of G0 and G1 may be obtained by experiments. That is, following the examples described later, for the time being, G1 is set to 100%, G0 is sequentially decreased, the temperature of the seal member when the state transitions from standby to operation is recorded, and the temperature of the obtained seal member is recorded. The optimum G0 is determined from the data of G1, and it is confirmed that there is no problem when G1 is 100%. Since the lowering of the temperature of the seal member due to resumption of operation can be recovered more quickly as the heater capacity is larger, normally G1 is 100% and there is no problem, but when the heater capacity is extremely large, the temperature of the seal member Therefore, if 100% is too large, G1 is lowered and the experiment is performed again. Once G0 and G1 are determined, record the temperature of the seal member when the state transitions from operation to standby, and confirm that there is no problem with the determined G0 and G1 from the obtained seal member temperature data . In this way, by determining the power gain corresponding to the temperature change, the operating gain G1 and the standby gain G0 can be determined prior to the actual operation.

In the case of the heat seal device 1 of this embodiment, the power control means 6 sets the power gain to the standby gain based on the operation signal for controlling the state of the seal member 3 regardless of the temperature change of the heater and the result of PID control. Since G0 and operating gain G1 are set in advance and can be switched according to the state, the power gain is applied when shifting from standby to operating and when shifting from operating to standby. Can be switched instantly. Thereby, it is set as the gain of power supply power suitable for converging the temperature of the sealing member 3 in each state, and the control amount of the temperature control means can be reduced. As a result, the operating time and productivity of the apparatus can be improved by shortening the waiting time for temperature adjustment. Moreover, it becomes possible to improve the yield by suppressing the heat seal failure of the film.
And since the structure of the heat seal device of this embodiment is simple, it can be easily modified from the conventional device already installed, and the operation is easy, so that it can be installed and operated at low cost.

Hereinafter, in order to verify the temperature control method used in the present invention, a temperature control circuit as shown in FIG. 2 is configured, and a disturbance that lowers the temperature of the heater 3a (in this experiment, blown by a fan) The temperature variation of the heater 3a was measured while giving In this verification experiment, the time when the disturbance is applied to the heater 3a corresponds to the operation according to the present invention, and the time when the heater 3a is released from the disturbance corresponds to the standby time according to the present invention.
Regardless of the presence of the power control means 6, 100% of the power is supplied to the relay 10 as a gain of the power source power suitable for converging the temperature of the heater 3a in the operation state, and the presence of the power control means 6 in the standby state. Thus, the gain was manipulated so as to supply the relay 10 with 40% to 100% of the operating state. The power source power gain in the standby state was reduced to 40%, 50%, 60%, and 85% as examples, and the case of 100% without power reduction as a comparative example.
FIG. 3 shows changes in temperature over time when the standby state is switched to the operating state. Further, FIG. 4 shows a change in temperature with time when the operation state is switched to the standby state.
3 and 4, the graph lines include a two-dot chain line when the standby power is 40%, a one-dot chain line when the power is 50%, a solid line when the power is 60%, a broken line when the power is 85%, and 100%. In each case, dotted lines were used.

As shown in FIG. 3, the time for which the temperature of the heater 3a is converged when the heater is switched from the standby state to the operation state becomes shorter as the gain of the power supply during standby is smaller, and the convergence time is less than 100%. In this example, it was possible to converge to a predetermined temperature in a short time.
When the power supply gain during standby was 50% or 60%, the convergence of the temperature of the heater 3a could be accelerated. When the power supply gain during standby was set to 40% of that during operation, hunting occurred and convergence was somewhat unstable.

As shown in FIG. 4, the time for which the temperature of the heater 3a is converged when the heater is switched from the operating state to the standby state becomes shorter as the standby power is smaller. It was able to converge to a predetermined temperature in a short time.
In particular, when the power supply power gain during standby was 60%, the temperature converged quickly and could be controlled stably. When the standby power was 40% or 50%, hunting occurred and the convergence became somewhat unstable.

  From the above results, in this embodiment, when the power supplied during standby is set to 60% of the power supplied during operation, it is possible to realize control excellent in temperature convergence of the heater 3a.

  The purpose of the present invention is to fuse and bond synthetic resin products, for example, to make a packaging bag, or to fill a packaging bag or a synthetic resin molded container with contents such as liquid, powder, granule, etc. It can be used for purposes such as heat-sealing or bag-filling packaging in which a packaging container is formed from a film.

It is a schematic block diagram which shows an example of the heat seal apparatus of this invention. It is a block diagram explaining the effect | action of the heat seal apparatus of FIG. It is a graph which shows the example of the temperature change at the time of switching to a driving | running state from a standby state. It is a graph which shows the example of the temperature change at the time of switching from an operation state to a standby state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Heat seal apparatus (fusion joining apparatus), 2 ... Film (synthetic resin product), 3 ... Seal member, 3a ... Heater, 4 ... Power supply, 5 ... Operation control means (temperature controller), 6 ... Power control means (Power controller), 7 ... Temperature control means.

Claims (7)

A fusion bonding method for fusion bonding of synthetic resin products while controlling the temperature of the heater by PID control,
Supplied in the PID control in the operation state in which the seal member heated by the heater contacts the product and heats the product continuously or intermittently and in the standby state in which the product waits without heating. A fusion splicing method characterized in that the power obtained by manipulating the gain of the power supply is set to be smaller in the standby state than in the operation state.   The fusion splicing method according to claim 1, wherein the power gain is manipulated when switching between the operation state and the standby state.   The fusion splicing method according to claim 1 or 2, wherein the gain operation of the power supply power controls energization of the AC power supply with the phase angle of the AC waveform.   The fusion splicing method according to any one of claims 1 to 3, wherein, in the operating state, the power obtained by operating the gain of the power source power supplied in the PID control is 100% of the power source power.   The fusion-bonding method according to claim 1, wherein the synthetic resin product is a packaging film. A fusion bonding apparatus for fusion bonding of synthetic resin products while controlling the temperature of the heater with a PID control apparatus,
The fusion splicer is
A sealing member heated by a heater;
A power source for supplying power to the heater of the seal member;
The electric power obtained by manipulating the gain of the power supply does not heat the product as compared with the operation state in which the product is continuously or intermittently heated when the seal member contacts the product. Power control means for setting so as to be small when in a standby state of waiting;
And a temperature control means for turning on and off the power supplied to the heater via the power control means by performing PID control.   The fusion bonding apparatus according to claim 6, wherein the power control means operates the gain of the power supply power based on a signal instructing the operation state start or standby state start of the fusion bonding apparatus.

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