JP2008222311A - Heat-sealing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-sealing device capable of hot melt-bonding a packaging sheet while detecting a surface temperature of a hot melt-bonding member to keep the surface temperature in a predetermined temperature range. <P>SOLUTION: The heat-sealing device has a heat roller and hot melt-bonds the packaging sheet by pressing the surface of the heat roller to the packaging sheet wherein there are mounted a surface temperature detecting means for detecting the surface temperature of the heat roller, the surface temperature detecting means being a non-contact type thermometer, and a temperature controlling means for maintaining the surface temperature in a predetermined range from the detected result by the surface temperature detecting means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat sealing device for a heat-fusible packaging sheet of a packaging machine that packages, for example, drugs.

  In general, in a heat sealing apparatus of a packaging machine that performs packaging of a medicine, etc., the medicine is packaged using a heat-fusible packaging sheet. As this type of heat sealing apparatus, for example, the one described in Japanese Patent Application Laid-Open No. 8-23032 is known.

  In such a heat sealing apparatus, a heat roller or the like for performing heat fusion of the packaging sheet 101 is used. FIG. 6 is an explanatory view schematically showing a main part of a conventional heat sealing apparatus, and shows only one heat roller 102 of a pair of heat rollers.

  FIG. 7 schematically shows the relationship between the heating element portion 105 of the heat roller 102 and the welded portion of the packaging sheet from the side surface of the heat roller 102 when the packaging sheet 101 is heat sealed.

  The heat roller 102 is a pair of rollers having a heating source therein, and the surface thereof is heated and soaked (lateral heating body 103, vertical heating body 104, axial heating body 105, circular heating surface 107). In this state, the heating roller 102 itself is rotated by the rotation mechanisms 112 and 113 to feed the packaging sheet 101 in which a medicine or the like (not shown) is introduced from the chute 111 and is packaged. It is configured to be sealed by one package 102a for each rotation.

  For this reason, the heat roller 102 has a cylindrical roller surface that can contact the surface of the heat roller 102 only when the portion 101b to be welded of the packaging sheet 101 comes to a position between the heat roller pair. The non-contact surface 106 is formed by cutting away the other surface portion while leaving the portion to be contacted by the portion 101b to be welded. And the perforation blade 134 for forming the perforation in the sealed packaging sheet is provided in the roller surface part which should contact | abut the packaging sheet 101b.

  In order to maintain the temperature of such a heat roller in a predetermined range, the heating source is an electric heater, and a temperature detection means is disposed inside the heat roller to detect the temperature at a position as close as possible to the electric heater, While detecting the temperature of the heating source, the voltage of a power source for energizing the heating source is set or turned on and off to maintain the temperature of the heating source within a predetermined range.

  However, according to such a method, it is difficult to reliably capture the temperature of the heating source. That is, even if the temperature detecting means is provided, the heat roller is a rotating body and the output wiring for detecting output from the temperature detecting means is always twisted by rotation. This is because it can be implemented only with an unstable structure.

  In addition to such a structural problem, there is a problem of grasping the actual fusion temperature. That is, normally, for a packaging sheet of a material that is frequently used, the fusion temperature range corresponding to this can be grasped empirically, and the temperature of the heating source can be set correspondingly, but a high temperature outside this temperature range can be set. It is impossible to grasp what the fusing temperature is relative to the temperature of the heating source in the region and the low temperature region.

  However, the surface temperature of the heat roller is energized due to the difference in the local environment of the place where the heat sealing device of the packaging machine is installed and the seasonal or temporal difference in the timing of operating the heat sealing device. It is not always quantitatively captured with respect to the current, and actually a considerable temperature difference occurs. Therefore, when shipping the heat seal device, it must be adjusted so that a predetermined current can be applied once, but the person in charge or the user must make fine adjustments according to the circumstances at the time of delivery, which is very troublesome. There is a problem.

  The present invention has been made in view of the above-described problems. While detecting the temperature of the surface of the heat-sealing member of the packaging machine, the surface temperature is maintained within a predetermined temperature range to heat-melt the packaging sheet. It is an object of the present invention to provide a heat seal device capable of wearing.

  In order to solve the above-described problems, the present invention provides a configuration in which the surface temperature of a heat-sealing member of a packaging machine is measured and controlled so that the surface temperature becomes an optimum temperature for heat-sealing a packaging sheet.

  For this reason, the heat sealing apparatus according to claim 1 of the present invention is a heat sealing apparatus that includes a heat roller and heat-bonds the packaging sheet by bringing the surface of the heat roller into contact with the packaging sheet. A surface temperature detecting means for detecting the surface temperature of the heat roller, and a temperature control means for controlling the surface temperature to be maintained within a predetermined range based on a detection result of the surface temperature detecting means, The surface temperature detecting means is a non-contact type temperature measuring body.

  In particular, it is preferable that the surface temperature detecting means is in contact with a portion of the surface of the heat roller opposite to the portion that is in contact with the packaging sheet.

  The surface temperature of the heat-sealing member can be controlled over a wide temperature range without the need to monitor the surface temperature, so that the predetermined heat sealing can be performed without wasting power consumption, and the surface temperature at a position where it is difficult to contact the heat roller can be detected. Alternatively, the surface temperature can be detected even when the surface conditions are not good.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows a heat seal device 50 according to the present invention, and conceptually shows a configuration of a main part of the heat seal device 50 provided with a contact type thermistor TH as a surface temperature detecting means. As an example of the sheet heating element 12 (12a and 12b) serving as a heat-sealing member of the heat seal device 50, an example in which each roller of the roller pair 10 includes a heat source EH will be described. In FIG. 1, only one of the heat rollers 10a is illustrated in the same manner as in FIG. 6, and the portions other than those related to the measurement and control of the surface temperature are illustrated simply or omitted. FIG. 2 is a schematic block diagram showing surface temperature detection means and temperature control means according to the present embodiment.

  The heat seal device 50 according to the present embodiment is provided with a surface temperature detection means for detecting the surface temperature of the heat roller 10, a temperature control means, and a detection control circuit 14 related to both means. Is measured, and the packaging sheet 20 is heat sealed while maintaining the surface temperature within a predetermined range.

  In addition to the conventional configuration, the configuration other than the above configuration includes a heat roller pair 10 including a heat source EH, a frame (not shown) for fixing the heat roller pair 10, and a driving device 13 related to the rotation of the heat roller. , A control device 15 for the entire heat sealing device, a power supply 16 related to heat generation of the heat roller, a conveying device (not shown) related to supply of the packaging sheet 20 to the heat roller pair 10, and the like. Hereinafter, the configuration that is not particularly described is the same as the conventional one.

  Hereinafter, the heat roller pair 10, the surface temperature detection means, and the temperature control means, which are the main components of the present embodiment, will be described. In the following description, the heat roller pair 10 is described with respect to one roller 10a, but also corresponds to the roller 10b.

  First, the heat roller pair 10 has the same shape and structure as a conventional one. For example, a steel cylinder of about 20Φ × 60L (mm) is used as a sheet for thermal welding of a packaging sheet as described above. The shape is such that a non-contact surface is formed by cutting away the surface portion other than the heating body portion.

  The heat roller pair 10 accommodates a heat generation source EH, and the heat generation source EH is preferably, for example, an electric resistance heating with a nichrome wire of about 50 W to 100 W because the heat generation temperature can be easily controlled. Thus, according to the roller-shaped heat sealing member, a steady operation without intermittent stop can be performed, and the surface temperature can be easily stabilized because the heat roller is kept in contact with the packaging sheet.

  Next, the surface temperature detecting means detects the surface temperature by bringing it into contact with the surface of the heat roller 10a. For example, the thermistor having a shape in which the temperature sensing part is coated with thin glass and covered with a resin tape or the like. TH is used. As will be described later, the thermistor TH can obtain an accurate and highly sensitive electric signal with respect to temperature, and is controlled by a normal circuit element together with a control circuit such as a heat source EH. The surface temperature can be adapted to the fusing conditions of the packaging sheet 20, and it is small in size and has few failures, so that the device cost is low.

  The thermistor TH is attached to the surface of the sheet heating body 12 so that a suitable pressure is applied from the surface of the sheet heating body 12 of the heat roller 10a so that the thermosensitive portion can sense its temperature. In FIG. 1, the example attached to the position on the opposite side of the part which the packaging sheet 20 contact | abuts among the sheet | seat heating bodies 12 parts of the heat roller 10a was shown.

  The appropriate pressure in this case is set by bringing the thermistor TH into pressure contact with the heat roller 10a from a position close to the heat roller 10a, and adjusting and fixing the pressure so as not to hinder the rotation of the heat roller 10a. To do. In this case, the glass thin plate has wear resistance, and since the wear does not continue when the glass thin plate and the iron-made heat roller 10a are in contact with each other, the wear of the temperature sensing portion is small, This is preferable because a stable contact state can be obtained. Therefore, the thermistor has few failures and has a long life.

  The mounting position of the thermistor TH is preferably near the heat source as close as possible, for example, the surface of the sheet heating body 12 or the surface or side surface of the heat roller 10a. And as mentioned above, since it attaches so that abrasion of a temperature sensing part hardly arises, while being able to detect surface temperature correctly, a lifetime is long and a failure is very few.

  Other than the thermistor TH, a platinum resistance temperature sensor, a thermocouple, or the like may be attached to the heat roller 10a as in the case of the thermistor. According to these contact-type surface temperature measuring means, the surface temperature of the heat roller 10a can be accurately detected, and the heat source can be controlled so that the surface temperature exactly matches the fusing condition of the packaging sheet. Therefore, the surface temperature of the heat roller 10a can be accurately detected and controlled over a wide temperature range.

  By the way, the packaging sheet 20 is provided by applying a thin film of synthetic resin such as polyethylene on the surface of a normal paper material such as glassine paper or cellophane polyethylene paper, and imparting heat-sealing property by this film. is there. In addition to this, for example, (1) glassine paper with aluminum deposited on the inside in consideration of moisture resistance for a long period of dosing, and (2) Japanese paper with polyethylene coated inside to wrap herbal medicines such as Chinese medicine There is.

  For these packaging sheets, the heat seal device according to the present embodiment can accurately cope with the surface temperature of the heat roller 10a up to a temperature range lower than the conventional one. Although the wearing conditions are slightly different, any type of packaging sheet can be set to a temperature of approximately 50 to 300 degrees Celsius and fused to each other at that temperature. For example, ordinary synthetic resin-coated glassine paper or aluminum-deposited glassine paper is welded in the range of 120 to 140 degrees Celsius. Depending on the setting time of the welding time in the heat sealing apparatus, the Japanese paper (2) is welded at about 300 degrees Celsius, while the synthetic resin-coated packaging sheet having a low melting point is about 100 degrees Celsius. It is welded at the following temperature. The glassine paper becomes thin when pressure is applied, and can be made almost transparent.

  Therefore, when the surface temperature of the heat roller 10a is set in the range of 120 to 140 degrees Celsius, it is possible to heat-weld the glass paper or cellophane polyethylene paper with low temperature fluctuation and heat efficiency. Moreover, when set in the range of 50 to 300 degrees Celsius, it is relatively high like a glassine paper of (1) and Japanese paper of (2), or a packaging sheet of a synthetic resin film having a low melting point. Even for low-temperature types, it can be set to suit various cases according to each material and processing quantity.

  Next, the temperature control means will be described. The temperature control means includes a first comparator (first comparator) CM1, a first constant voltage power source (first constant voltage power source), and a relay. In order to maintain the above-described surface temperature of the heat roller within a predetermined range, the target value of the temperature to be controlled is set as the target temperature, and the signal voltage obtained by the surface temperature detecting means (thermistor) at this target temperature is the heat generation reference voltage. Set as V0.

  Then, the heat generation reference voltage V0 and the signal voltage generated by the surface temperature detecting means detecting the surface temperature of the heat roller 10a are compared in the first comparator CM1, and according to the comparator output obtained as a result, the relay SR And the input to the heat source EH of the heat roller 10a is controlled according to the set value of the heat generation reference voltage V0.

  The voltage of the first constant voltage power supply is set by the resistance means rA with respect to the constant voltage power supply CVS so as to be equal to the heat generation reference voltage V0. As described above, since the predetermined temperature range can be maintained by the normal circuit elements, the predetermined temperature range can be arbitrarily determined and precisely controlled.

  In the present embodiment, since the relay SR is constituted by a semiconductor relay (solid state relay) such as a photo MOS relay, the relay operation is performed in a non-contact state, is small, has almost no failure, is highly reliable, and has low power consumption. Therefore, there is an advantage that the driving device of the heat seal device can be miniaturized and the running cost is low.

  As described above, the heat seal device is configured to maintain the surface temperature of the heat roller 10a within a predetermined range, and thus, manually and empirically while monitoring the current of the heat source EH of the heat roller 10a as in the past. It is not necessary at all to adjust the surface temperature of the heat roller 10a over a wide temperature range, and a predetermined thermal welding can be performed on the packaging sheet to heat-seal the packaging sheet. It does not occur. Furthermore, there is an advantage that there is no waste of power consumption and there is no need to monitor the heat sealing state of the wrapping paper and the current value of the heat source.

  (Embodiment 2) In this embodiment, in addition to the configuration of Embodiment 1, for example, there are two systems of abnormality detection means for detecting abnormal states such as short circuit and disconnection of the thermistor TH which is a temperature detection means, respectively. And the input to the heat source EH is stopped in response to an abnormal state of the thermistor TH. Other configurations are the same as those of the first embodiment. First, the basic principle of providing abnormality detection means will be described.

  FIG. 3 is a block diagram of a main part of a heat sealing apparatus provided with two systems of such abnormality detection means. In the first embodiment, a comparator (first comparator CM1), a resistance means rA, and a constant voltage power source CVS (first constant voltage power source) are provided to set the heat generation reference voltage V0.

  On the other hand, in the second embodiment, the second and third comparators CM2 and CM3 are connected to the output wiring of the temperature detecting means, and at the same time, the constant voltage power supply CVS is used as one common resistor. The second and third voltages (with the heat generation reference voltage V0 of the first embodiment as the first voltage) Vn and Vm are set by means rB and rC, and by this setting, the second and third constant voltage power supplies The connection is equivalent to that provided. The second and third voltages Vn and Vm are determined corresponding to an abnormal state virtual temperature value described below.

  In this way, the abnormality detection means provided in two systems is constituted by the second and third comparators CM2 and CM3, the constant voltage power supply CVS, and the second and third constant voltages Vn and Vm. In order to detect the abnormal state of the thermistor TH described above, a virtual temperature value in each case that should be recognized as an abnormal state when a short circuit or disconnection occurs is defined as an abnormal setting value.

  Then, when the thermistor TH reaches this abnormal state, the signal voltage that the surface temperature detecting means detects and outputs this abnormal state, and the signal that the surface temperature detecting means outputs in the normal operating state The voltages are compared in the second and third comparators CM2 and CM3, respectively, and the comparator outputs obtained at this time are sent to the CPU as the disconnection detection signal eC and the short detection signal eS, respectively, and the CPU inputs the input to the heat source EH. Control to stop.

  While the constant voltage power supply CVS is shared, the voltage of the constant voltage power supply CVS is made using three systems of resistance means rA to rC so as to be equal to the signal voltages Vn and Vm corresponding to the heat generation reference voltage V0 and the abnormal set value, respectively. Is set. A setting procedure for specifically setting the abnormal setting values by the resistance means rA to rC according to a short circuit or disconnection will be described.

  The resistance means rB is set to a voltage slightly lower than the upper limit of the output of the constant voltage power supply CVS because the voltage at the S point reaches the upper limit when the thermistor is disconnected so that the second comparator CM2 is used for disconnection detection. Set. On the other hand, the resistance means rC has a voltage slightly higher than the lower limit of the output of the constant voltage power supply CVS because the voltage at the S point becomes almost zero when the thermistor TH is shorted so that the third comparator CM3 is for short detection. Set to.

  As described above, since the constant voltage power supply CVS is shared and the abnormality setting value is set by the resistance means rA to rC, the power supply cost can be reduced and, for example, the variable in the resistance means such as a variable resistor can be changed. There is an advantage that an easy-to-operate means such as knob adjustment can be used.

  Note that only one system of abnormality detection means may be provided, or three or more systems may be provided. Furthermore, by setting multiple heat generation reference voltages V0, it is possible to set multiple target temperatures in consideration of differences in the type and thickness of the packaging sheet, the number of welding treatments, etc. Can be improved.

  As described above, since the abnormality detection means is provided, it is possible to immediately detect an abnormal state and take measures, and when multiple systems are provided, each of a plurality of types of abnormal states is separately detected, and It is possible to respond appropriately to each.

  Further, when a plurality of temperature detecting means and abnormality detecting means are provided, these may be provided separately for each roller of the heat roller pair 10 so as to eliminate the temperature difference.

  (Embodiment 3) In the present embodiment, when a disconnection detection signal eC or a short detection signal eS is obtained, the input to the heat source can be stopped with a simple configuration as shown in FIG. In addition, a circuit breaker SB is provided in the input path of the heat generation source EH, and the circuit breaker SB is interrupted by receiving the disconnection detection signal eC or the short detection signal eS.

  By comprising in this way, a circuit breaker can be interrupted | blocked by cheap apparatus cost, without passing through CPU. In this embodiment, since the circuit breaker SB is constituted by a switching diode, a thyristor, or the like, which is a semiconductor switch, it can be reduced in size without contact, has high reliability, and has low power consumption. There is an advantage that the driving device of the sealing device can be reduced in size and the running cost is low.

  As described above, since the abnormality detecting means and the circuit breaker are provided, it is possible to immediately detect the abnormal state and stop the input to the heat source to prevent abnormal heating, etc., or prevent secondary damage. In addition, when a plurality of systems are provided, each of a plurality of types of abnormal states can be detected separately, and each can be handled accurately.

  (Embodiment 4) In this embodiment, the temperature detecting means is a non-contact type. Other configurations can be the same as those in any of the first to third embodiments. In the present embodiment, the surface temperature in the above-described temperature range can be detected by using, for example, a radiation thermometer using an infrared fiber that transmits infrared rays as the non-contact type temperature sensor.

  In this way, by using a non-contact temperature sensor, the finished state of the surface of the heat roller can be used in contact with the contact temperature sensor regardless of whether the heat roller is rotating or not. The surface temperature of the heat roller can also be detected when it is not suitable or when detecting the surface temperature at a position that is difficult to contact. Therefore, it is possible to detect the surface temperature regardless of the shape of the heat roller by reducing the design restrictions related to the configuration of the driving device of the sealing device.

  (Embodiment 5) In this embodiment, as a heat-sealing member of a heat-sealing device, as shown in FIG. 6, the packaging sheets have a flat surface in accordance with the shape of the part to be heat-sealed with each other. The packaging sheet 20 is heat-sealed using the formed heat equalizing body 40, the surface temperature of the heat equalizing body 40 is detected and measured, and the input to the heat source EH is controlled. Other configurations can be the same as any one of the first to fourth embodiments. FIG. 6 shows only the positional relationship between the soaking body 40 and the packaging sheet 20 and the position when the thermistor TH, which is a contact-type temperature sensor, is attached as the surface temperature detecting means.

  Thus, by the structure which makes the soaking | uniform-heating body 40 contact | abut to the packaging sheet 20 in a plane, the heat transfer efficiency to the packaging sheet 20 can be improved, and the adhesiveness of the sealing part of the packaging sheet 20 is also good.

  As is clear from the above description, the heat sealing device according to the present invention is not limited to drugs and the like, and can be configured to seal food with a packaging sheet or the like. The same effects as those described are obtained.

  The heat sealing apparatus according to the present invention has a structure in which the surface temperature of the heat-sealing member is measured, and the surface of the heat-sealing member is heat-sealed by maintaining the surface temperature in a predetermined range and heat-sealing the packaging sheet. Since the temperature can be maintained within a predetermined range and the surface temperature of the heat-sealing member can be accurately handled in a wider temperature range than before, current adjustment of the heat source of the heat-sealing member is not required. Therefore, the surface temperature of the heat-sealing member can be controlled over a wide temperature range without the need for monitoring the surface temperature, and predetermined heat sealing can be performed without wasting power consumption.

  Since the heat fusion member can be constituted by a pair of heat rollers and can be packaged by one rotation of the roller, a steady operation can be performed and the surface temperature can be easily stabilized.

  Since the surface temperature detecting means can be composed of a contact-type temperature sensor, the surface temperature can be detected accurately, and the heat source can be controlled so as to accurately match the heat-sealing conditions of the packaging sheet.

  Since the thermistor can be employed as the contact-type temperature sensor, temperature detection can be obtained by an electric signal, and the control circuit can be configured with ordinary circuit elements at low cost. Since the thermistor temperature sensor is appropriately pressed on the surface of the sheet heating body and the thermistor is disposed, the temperature sensor is less worn, the surface temperature can be detected accurately, and the thermistor failure is reduced and the service life is reduced. Can be long.

  The temperature control means includes a first comparator, a first constant voltage power source, and a relay. The relay is opened and closed by a first comparator output with reference to the heat generation reference voltage, and the input to the heat source of the heat roller pair is controlled. Therefore, it can be maintained within a predetermined temperature range by ordinary circuit elements. Therefore, the predetermined temperature range can be arbitrarily determined and precisely controlled.

  Since a semiconductor relay can be adopted as the relay, the relay can be reduced in size, with low power consumption and few failures. Therefore, the running cost can be reduced and the reliability is high.

  Since an abnormality detecting means can be further provided to stop the input to the heat generation source in response to the abnormal state of the surface temperature detecting means, the abnormal state can be immediately detected and a countermeasure can be taken.

  The abnormality detection means comprises a second comparator, a second constant voltage power supply and a circuit breaker, the second constant voltage power supply is set to an abnormality detection voltage set corresponding to the abnormal condition, and the output of the thermistor; When there is a second comparator output by comparison with the abnormality detection voltage, the input to the heat source of the heat roller pair is stopped, so that an abnormal state can be detected by a normal circuit element, and abnormal heating or the like is prevented.

  The circuit breaker is provided in the input path to the heat generation source, and the circuit breaker is interrupted by the second comparator output and the input to the heat generation source is stopped, so that an abnormal state is detected and heat is automatically generated. Since the input to the source is stopped, no secondary damage occurs.

  Since a semiconductor switch can be adopted as the circuit breaker, the circuit breaker can be made non-contact, miniaturized, low power consumption and few failures. Therefore, the running cost can be reduced and the reliability is high.

  Since a plurality of the abnormality detection means are provided, each of a plurality of types of abnormal states can be detected separately, and an appropriate countermeasure can be taken for each.

  Since the temperature detecting means can be composed of a non-contact type temperature sensor, the surface temperature at a position where it is difficult to contact the heat roller can be detected, or the surface temperature can be detected even when the surface conditions are not good. Therefore, design restrictions on the configuration of the heat seal apparatus can be reduced.

  As the heat fusion member, a soaking body having a flat surface can be adopted, and the heat soaking body has good heat transfer efficiency and good adhesion at the fused portion of the packaging sheet.

  Since the predetermined range of the surface temperature can be set at 50 to 300 degrees Celsius, heat welding can be performed by adapting to various cases according to each material and processing quantity.

  Since the predetermined range of the surface temperature can be set at 120 to 140 degrees Celsius, variation in the temperature range can be reduced and heat welding can be performed with high efficiency according to the material of a packaging sheet such as ordinary glassine paper.

  A heat sealing device comprising a heat-sealing member and heat-sealing a packaging sheet by the heat-sealing member, the surface temperature detecting means for detecting the surface temperature of the heat-sealing member, and the heat Temperature control means for controlling the temperature of the fusion member, the surface temperature is measured, and the packaging sheet is heat-sealed while the surface temperature is maintained in a predetermined range. A sealing device can be provided.

  With the above-described configuration, the surface temperature of the heat-sealing member can be maintained within a predetermined range. Therefore, it is not necessary to adjust the current of the heat source of the heat-sealing member, and the heat roller pair 10 can be accurately set in a wider temperature range than before. It can correspond to the surface temperature.

  Further, the heat fusion member is preferably a heat roller pair 10 and can be packaged by one rotation of the roller, so that a steady operation can be performed.

  Furthermore, when the surface temperature detecting means is a contact-type temperature sensor, the surface temperature can be accurately detected.

  Further, when the contact-type temperature measuring element is a thermistor TH, temperature detection is obtained by an electrical signal.

  In addition, the temperature sensing portion of the thermistor TH is pressed against the surface of the sheet heating body 12 to heat the surface of the sheet heating body 12 of the heat roller pair 10 and the thermistor TH is disposed, so that the temperature sensing portion is worn. It can be installed with less.

  Furthermore, the temperature control means comprises a first comparator CM1, a first constant voltage power source and a relay SR, and the heat generation reference voltage V0 is set to maintain the surface temperature of the heat roller pair 10 within the predetermined range. The first constant voltage power source is set, and the relay SR is opened and closed by the output of the first comparator CM1 based on the comparison between the output of the thermistor TH and the heat generation reference voltage V0, and according to the set value of the heat generation reference voltage V0. By controlling the input to the heat source EH of the heat roller pair 10, it can be maintained within a predetermined temperature range by a normal circuit element.

  Further, when the relay SR is a semiconductor relay, the relay can be miniaturized, consumes less power and has few failures.

  Furthermore, if an abnormality detection means is further provided to stop the input to the heat generation source EH corresponding to the abnormal state of the surface temperature detection means, the abnormal state can be detected immediately.

  Further, the abnormality detection means includes a second comparator CM2, a second constant voltage power source, and a circuit breaker SB, and the second constant voltage power source is set to an abnormality detection voltage set corresponding to the abnormal state, If there is a configuration in which the input to the heat source EH of the heat roller pair 10 is stopped when there is a second comparator CM2 output by comparing the output of the thermistor TH and the abnormality detection voltage, an abnormal state is caused by a normal circuit element. Can be detected.

  Further, the circuit breaker SB is provided in the input path to the heat generation source EH, the circuit breaker SB is interrupted by the output of the second comparator CM2, and the input to the heat generation source EH is stopped. An abnormal state is detected, and the input to the heat generation source EH is automatically stopped.

  Further, when the circuit breaker SB is a semiconductor switch, the circuit breaker can be miniaturized with no contact, low power consumption and few failures.

  Furthermore, when the abnormality detection means is provided with a plurality of systems, each of a plurality of types of abnormal states can be detected separately.

  Further, since the surface temperature detecting means is a non-contact type temperature sensor, the surface temperature at a position where it is difficult to contact the heat roller can be detected, or the surface temperature can be detected even when the surface conditions are not good.

  In addition, heat transfer efficiency is good when the heat fusion member is a soaking body having a flat surface.

  Further, when the predetermined range of the surface temperature is 50 to 300 degrees Celsius, a packaging sheet of a synthetic resin film having a relatively low melting point that is welded at a relatively low temperature, a Japanese paper (inner synthetic resin film) that is welded at a relatively high temperature, and the like. Also on the packaging sheet, the surface temperature can be maintained within a predetermined temperature range and heat welding can be performed according to the type of material, the processing quantity, and the like.

  Furthermore, when the predetermined range of the surface temperature is 120 to 140 degrees Celsius, thermal welding can be performed with less variation in the temperature range depending on the material of a packaging sheet such as ordinary glassine paper.

Explanatory drawing which shows notionally the principal part of the heat seal apparatus concerning embodiment of this invention. The block diagram of the principal part of the heat seal apparatus concerning Embodiment 1 of this invention. The block diagram of the principal part of the heat seal apparatus concerning Embodiment 2 of this invention. The block diagram of the principal part of the heat seal apparatus concerning Embodiment 2 of this invention. The perspective view of the principal part of the heat seal apparatus concerning Embodiment 5 of this invention. Explanatory drawing which shows notionally the principal part of the conventional heat seal apparatus. (a), (b) is a side surface process figure which shows notionally the process of heat-sealing a packaging sheet according to the rotation state of a heat roller.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Heat roller pair, 12 ... Sheet heating body, 20 ... Packaging sheet, TH ... Thermistor, EH ... Heat generation source, SR ... Semiconductor relay, SB ... Semiconductor switch

Claims (2)

A heat seal device comprising a heat roller, wherein the surface of the heat roller is brought into contact with the packaging sheet to heat-seal the packaging sheet, the surface temperature detecting means for detecting the surface temperature of the heat roller; And a temperature control means for controlling the surface temperature to be maintained within a predetermined range based on the detection result of the surface temperature detection means, and the surface temperature detection means is a non-contact type temperature measuring body. A heat sealing apparatus characterized by the above. The heat seal device according to claim 1, wherein the surface temperature detecting means is in contact with a portion of the surface of the heat roller opposite to a portion that is in contact with the packaging sheet.

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