JPH0752925A - Method and device for controlling temperature of heat sealer in bag forming machine - Google Patents

Abstract

PURPOSE:To avoid the unevenness of fusion power of a heat seal part by providing a heat sealer with two electric heaters at the upper and lower parts thereof in order that the temperature of the seal edge of a heat sealer for heat sealing the bag strip material consisting of thermoplastic film, tube, etc., may be made nearly uniform all through the operation time and the sealing length. CONSTITUTION:A heat sealer body 10 is provided with electric heaters in two tiers and a first heater 15 disposed close to a heat seal edge 11 is normally energized and a second heater 16 is turned on and off by a thermostat to minimize the unevenness of the temperature of the heat seal edge 11, whereby the fusion power of bag strip material can be imparted to each bag throughout the length of its heat seal part to attain a constant fusion of the heat seal parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention relates to a thermoplastic film band,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sealer temperature control method and apparatus in a bag making machine for manufacturing bags from a bag material band made of a tube band.

[0002]

2. Description of the Related Art In a conventional heat sealer, an electric heating type heater is embedded in a longitudinal direction of the heat sealer, and a sealing edge of the heat sealer is usually a narrow width with a slight width or a knife edge shape with a slight roundness ( For example, the actual Kaihei 2-15337
Issue). A temperature sensor for controlling this temperature is attached to the heat sealer main body part which is slightly apart from the seal edge.

Thus, the temperature of the entire heat sealer is controlled so as to fall within a predetermined temperature range by the ON / OFF signal of the sensor. However, using this heat sealer, when the thermoplastic bag material film band is sequentially heat-sealed, the film is welded, so that the heat-sealing edge is momentarily radiated, and the heat-sealer main body heats up until the next welding. The seal edge should return to its original temperature. However, in reality, the heat radiated is not constant over the entire length of the seal edge, and the supply of heat from the heater does not match the cycle of bag-making work with the above-mentioned off / on control.

Since the sensor is attached to the main body of the heat sealer, there is a considerable time lag from the temperature of the heat seal edge. Therefore, when the heater is off and the sealing work is performed twice or more continuously, the temperature of the heat-seal edge rapidly decreases, and conversely, if there is no sealing work during the on-time, the temperature of the heat-seal edge is decreased. The temperature of the edge of the heat seal will not be constant during the entire sealing work due to excessive rise.

As an example, when the allowable temperature range by the sensor is within 2 ° C. and the set temperature is 230 ° C., the temperature difference between the temperature and the time of the heat-sealing edge during the work is The current situation is that the temperature reaches 30 ° C to 40 ° C.

Therefore, if the welding operation is continued in such a state, the portion having a low temperature is incompletely welded. Further, the temperature sensor which is generally commercially available at the time of this application usually has a diameter of about 10 mm, and due to its size, it cannot be mounted in the vicinity of the seal portion. On the contrary, the temperature may be non-uniform.

There is also an external heat line type sensor that measures the temperature of the seal edge without contact, but it is extremely expensive, and since the heat sealer repeatedly moves up and down, the temperature only at a specific position of the sensor can be measured. Ancillary control or a device such as measurement is required, and the cost is high, which is not practical.

Further, since the heat sealer itself is an elongated plate material and its length is limited, a large capacity heater cannot be provided in the case of an electrothermal type heater. Therefore, since high voltage current is supplied to the low capacity heater to heat it, the life of the heater is shortened and the heater itself is damaged in a relatively short time.
The labor cost and the cost of replacing this increase the work cost. Also, receiving a high-power heater in a narrow space shortens its life.

[0009]

SUMMARY OF THE INVENTION The present invention provides the market with a method and apparatus for minimizing the temperature unevenness of the seal edge of the heat sealer as described above or the temperature unevenness depending on the location. This is to enable reliable heat sealing work. Another object of the present invention is to extend the life of the heater, reduce the number of steps in the work due to damage to the heater, reduce the decrease in operating efficiency due to replacement work, and reduce the cost. .

[0010]

In order to achieve the above object, the present invention is a method for heating a heat sealer in which at least one edge of a plate-shaped heat seal member is a heat seal edge. A method of constantly heating with an electric heater that is embedded in the vicinity in the lengthwise direction, and a temperature sensor that measures the temperature of the heat sealer main body. Furthermore, the temperature control method of the heat sealer in the bag making machine comprises a method of selecting non-heating and heating by a separate electrothermal heater.

In order to achieve the above object, at least one edge of the plate or rod-shaped heat seal member of the present invention is a heat seal edge, and the heat seal member has a position close to the heat seal edge and a heat seal edge. Electrothermal first heaters and second heaters are embedded in layers independently of each other along the length direction of the heat-sealing member in the middle part of the main body of the member. The first heater closer to the heater is a constant heating type, and a temperature sensor is provided in the heat sealer main body near the second heater in the middle section, and the measured temperature value of this temperature sensor is above or below the set temperature or set temperature range. The temperature of the heat sealer in the bag making machine is characterized in that a control device for turning the second heater on and off is provided, and the set temperature is variable. The control device.

In order to achieve the above object, it is preferable that the supply voltage to the first heater of the temperature controller for the heat sealer in the bag making machine is of a changeable type.

[0013]

The operation of the invention according to claims 2 to 3 which is an apparatus invention for carrying out the method invention of claim 1 will be described.

In the invention according to claim 2, when the power of the heat sealer is turned on, the first heater and the second heater are both energized, and the entire heat sealer is heated by these heaters to set or set the temperature of the temperature control device. When the temperature exceeds the temperature range, the second heater is turned off, and the heat sealer is continuously heated only by the first heater.

In this state, when the heat-sealing work is started, heat is taken from the heat-sealing edge each time the bag material band made of the thermoplastic synthetic resin film is heat-sealed, but the heat from the first heater near the heat-sealing edge is removed. Supply will recover rapidly. However, the temperature of the entire heat sealer gradually decreases, and when the temperature falls below the set temperature or set temperature range, the second heater is turned on again to heat the entire heat sealer, and when the set temperature or set temperature range is reached, Turns off.

This operation is repeated thereafter. That is, claim 1
The described method invention is practiced. Since the above-mentioned heat sealer is heated by the two heaters of the first and second heaters, the temperature unevenness depending on the location is averaged as compared with the case of heating by one heater.
The decrease in the temperature of the heat-sealing edge for each heat-sealing operation serves to recover the temperature to the almost required temperature by the first heater which is always on.

In the invention described in claim 3, claim 2
In addition to the operation of the invention described above, since the supply voltage of the first heater is variable, the supply voltage is changed according to the weather conditions of the workplace, the material of the bag material strip to be supplied, the thickness, etc. Adjust the edge temperature to the optimum temperature before use.

[0018]

【Example】

Example 1 An example including the inventions of claims 2 and 3,
An apparatus capable of implementing the method of claim 2. In FIGS. 1 and 2, reference numeral 10 denotes a heat sealer main body made of a metal having a good thermal conductivity, which is usually a plate shape, and one edge thereof is a heat seal edge 11, which is formed by fitting a hard metal plate 12 therein. The heat sealer main body 10 is provided with two holes 13 and 14 from one end, and a first heater 15 and a second heater 16 which are close to the heat seal edge 11 are embedded therein. In the above example, the holes 13 and 14 are provided from the end surface of the heat sealer main body 10, and the first heater 15 and the second heater 16 are inserted into the holes 13, 14, but the first heater 15 and the second heater 16 are heat sealers. Even if the main body 10 is equipped so as to be held on the side surface, it is included in the embodiment of the present invention. Numeral 20 is a variable pressure type transformer which is usually called a slidac, which is usually equipped in a part of the machine frame of the bag making machine, the primary side of which is connected to a 200V power source, and the secondary side of which. Voltage output terminals 21a, 21 of
The first heater 15 is connected to b. In the embodiment, the supply voltage of the first heater 15 is 30V to 70V, and the supply voltage to the second heater 16 is about 200V.

The output wattage of the first heater 15 and the second heater 16 may be the same, but the output wattage of the first heater 15 may be larger than that of the second heater 15.
For example, the first heater 15 is 3KW, the second heater 16 is 1K
W. The wattage itself does not have a limiting meaning in the present invention. Further, high voltage output terminals 22a and 22b on the secondary side of the transformer 20 are connected via a relay switch 23 for turning on and off the second heater 16.
These voltage values themselves have no limiting meaning in the present invention. The relay switch 23 may be an electromagnetic type or an electronic contactless relay, and its type is not limited. One terminal 21b of the low voltage output terminals and the high voltage output terminal 22b are both connected to the first and second sliding terminals 24a and 24b of the transformer 20.

Reference numeral 25 denotes a temperature sensor embedded in the heat sealer main body 10, which emits a signal for turning off the relay switch when a signal detected by the temperature sensor exceeds a set range temperature (for example, 230 ° C. ± 1 ° C.). A temperature control device 26 is provided which outputs a signal to turn on the relay switch when the temperature falls below a set range temperature. In the temperature control device 26, the set temperature can be input to an arbitrary value using the input unit 27. Further, for the convenience of the circuit of the control device 26, a circuit which obtains the same effect by reversing the OFF / ON signals by the vertical movement of the temperature sensor 25 is also included in the embodiment of the present invention. 28 is a main switch provided on the primary side of the transformer 21. The temperature sensor 25 is not particularly limited in its type such as thermocouple type, resistance type, thermistor type.

When a commercially available thermostat is used as the temperature control device 26, the allowable temperature range is 1 ° C. in advance.
It is defined before and after, and when this is used, this allowable range cannot be input each time the device of the present invention is operated. Excluding the economical aspect, the temperature control device 26 may be capable of setting the magnitude of the above-mentioned allowable range.

Operation of Embodiment 1 An embodiment of the method invention of claim 1 will be described together with the operation of Embodiment 1. First, the supply voltage of the first heater 15 is set to the transformer 20.
The mover 24a is moved to set the target voltage. Next, the set temperature of the temperature control device 26 is set to a temperature range corresponding to the purpose. When the main switch 28 is closed, the ON signal is output because the temperature sensor 25 detects a low temperature, and the relay switch 23 is in the closed state, so the first heater 15 and the second heater 15 are closed. Both 16 are energized to generate heat, and the heat seal body 10 and the heat seal edge 11 are heated.

When these temperatures gradually increase, the temperature sensor 25 detects a temperature exceeding the set temperature or the set temperature range, and the temperature control device 26 issues an output signal of OFF, the relay switch 23 is turned on. It is turned off, and the second heater 16 is de-energized. However, since the first heater 15 remains as it is, it continues to generate heat. If the temperature of the heat sealer body 10 falls below a set value or set temperature range, the temperature sensor 25 detects this temperature, the temperature control device 26 issues an ON signal, the relay switch 23 is closed again, and the second heater 16 regenerates heat. To do.

In this state, the heat-sealing work is started, and the heat-sealing edge 11 absorbs heat by the work each time by the bag material band and the pedestal, so that the temperature momentarily drops, but the heat-sealing always continues. The heat is directly replenished by the first heater 15 that is in operation, and the fluctuation of the heat of the entire heat sealer body 10 is allowed by turning on / off the relay switch 16 by the temperature detection signal from the temperature sensor 25 described above. The temperature of the heat sealer body 10 is kept within the range.

In this embodiment, one terminal 21b of the first heater 15 is connected to the moving element 24a, and one terminal 22b of the second heater 16 is connected to the moving element 24b. Then, the amount of heat generated by the first heater 15 and the second heater 16 is adjusted to a value suitable for the purpose. If the voltage of the second heater 16 is fixed, only the supply voltage of the first heater 15 is adjusted.

Embodiment 2 This is an embodiment of the apparatus invention according to claims 2 and 3 as shown in FIGS. 3 and 4, and by operating this, one embodiment of the method invention of claim 1 is obtained. Become.

The first heater 1 is different from the first embodiment.
5, first heater 16 temperature sensor 25 and temperature control device 2
6 are also provided on the right and left sides, respectively, and two sets are provided respectively, and this is mainly performed when the heat seal main body 10 is long.

As for the electric wiring, as shown in FIG. 4, the first heater 15 and the second heater 16 are heaters of the same manufacturer and have the same output. Even when the same voltage is applied, the left and right heaters generate the same heat. The input voltage of the first heater 15 is independently variable by the mover 24a of the transformer 20, which is a sliderac, and these are adjusted to obtain the same heat generation. Is obtained. The input unit 27 of the set temperature of the control device 26 can input the same value to both control devices 26 at the same time by a single input operation.
The individual control structures on the left or right are the same as in Example 1,
Do the same.

Further, in this embodiment, both the high voltage and the low voltage can be slightly changed by the mover, so that these temperatures themselves can be determined by the temperature, the material of the bag material band, the thickness, the working conditions, the weather in the workplace. The optimum value is set according to.

[0030]

According to the method of the present invention, the heat seal member is constantly heated by the heater near one heat seal edge. Therefore, the heat seal work is performed. The temperature drop at the heat seal edge is immediately supplied with heat and does not cause a significant temperature drop, and the entire heat seal member is measured by a temperature sensor and the temperature exceeds or exceeds the set temperature or set range. Depending on the temperature, the heating is stopped or the heating is stopped and the temperature is maintained at a substantially set temperature. The heat seal edge temperature has little temperature unevenness and local temperature unevenness. Can be done.

In the apparatus invention according to the second aspect, the above-mentioned method invention can be carried out, and the first heater and the second heater are provided on the upper and lower sides in the heat seal member, and the first heater near the heat seal edge is provided. And a second heater is provided,
Since the first heater in the vicinity of the heat-sealing edge is a constant heating type, the heat of the heat-sealing edge is taken away by the bag material band and the pedestal each time the heat-sealing work is performed. The temperature of the edge of the heat seal returns to a temperature suitable for heat sealing, and the temperature of the entire heat seal member is controlled by energizing and de-energizing the second heater by the temperature control device to keep the temperature within the set temperature or set temperature range. Therefore, the temperature of the heat-seal edge is extremely small in terms of temperature even in part of the place, and the size of the temperature sensor cannot be made very small in the present technology. Even if the temperature sensor is not provided in the vicinity of the heat seal edge, the temperature obtained by averaging the heat seal edge in terms of location and time can be obtained as described above.

By providing the first heater and the second heater, one heater is not turned on and off,
These heaters can be used at a voltage within a sufficiently permissible range without applying a voltage that is full of the capacity of one heater. Especially, since the first heater is not energized, its life is long and the whole of conventional heaters can be used. The life of the heater is significantly longer than that of one.

Further, since the upper and lower first heaters and the second heater are used for heating, even if the total output is the same as that of the conventional type of heating by the one-stage heater, in the present invention, the output of each heater is The wattage may be low, and even if the first heater is turned off and turned on, this rarely causes a wire breakage fault, which significantly extends the life.

In the third aspect of the invention, since the heating temperature of the first heater is the variable voltage of the first heater, the working conditions at that time, that is, the weather in the workplace, the thickness of the supplied bag material band, Alternatively, the supply voltage can be changed so that the temperature of the heat seal edge becomes the optimum temperature for this material.

Effects of the Embodiment In the first embodiment, it is possible to supply a voltage of about 40 V to 70 V to the outer first heater which achieves the effects of the second and third aspects, and 180 V to the second heater. Two
Since the voltage of 00V can be supplied, when the set temperature is set to 230 ° C., the heat seal edge 11
The temperature is within the range of 5 ° C in terms of the entire length and time difference, and there is no significant heat fluctuation of about 30 ° C to 40 ° C as in the prior art, and heat sealing is not necessary in the heat sealing work of the bag material band. There is no danger of being complete. The second embodiment also has the same effect as that of the first embodiment. Particularly, even a long heat sealer can perform substantially uniform heating over the entire length and is suitable for heat sealing a wide bag material band. In both of the above-described two embodiments, the first heater 15 (15a, 1a, which is a heater in the upper and lower two stages).
5b) and the second heater (16a, 16b) heats the heat sealer, so that it is not necessary to use a large output wattage of each heater, and the second heater 16 (16a, 16b) is temporarily turned off, Even with ON control, the output is low, so the life until disconnection is much shorter than that with high output.

[Brief description of drawings]

FIG. 1 is a perspective view of a heat sealer according to a first embodiment.

FIG. 2 is a wiring diagram showing an example of the electric wiring of FIG.

FIG. 3 is a front view of a heat sealer according to a second embodiment.

FIG. 4 is a wiring diagram of a second embodiment.

[Explanation of symbols]

 10 Heat Sealer 11 Heat Seal Edge 15 First Heater 16 Second Heater 20 Transformer 25 Temperature Sensor

Claims (3)

[Claims] 1. A method of heating a heat sealer in which at least one edge of a plate-shaped heat seal member is a heat seal edge, which is an electrothermal type in which the vicinity of the heat seal edge is embedded in the longitudinal direction. A method of constantly heating with a heater, and measuring the temperature of the heat sealer body with a temperature sensor,
A method of controlling the temperature of a heat sealer in a bag making machine, comprising a method of selecting non-heating or heating by a separate electrothermal type heater above the constant heating temperature depending on whether the temperature is above or below a set temperature or above. 2. A plate or rod-shaped heat-sealing member has at least one edge as a heat-sealing edge, and the heat-sealing member has a heat-sealing member at both a position close to the heat-sealing edge and a middle portion of the main body of the heat-sealing member. An electrothermal first heater and a second heater are provided along the length direction of the seal member.
The first heater near the edge of the heat seal is a constant heating type, and the temperature sensor is provided in the heat sealer body near the second heater in the middle section. When the measured temperature value of the temperature sensor exceeds or falls below a set temperature or set temperature range, the second off signal is issued, the on and off signals are issued, and the second heater is turned off and on by the on signal. A temperature controller for a heat sealer in a bag making machine, characterized in that a controller is provided and the set temperature is variable. 3. The heat sealer for a bag making machine according to claim 2, wherein the supply voltage to the first heater is of a changeable type.