JP2003031342A - Heater unit and its production method and seal holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater unit optimum for resin film seal of a packaging device by realizing even temperature distribution in longitudinal direction of the welding surface to the utmost so as to enable use of an inexpensive film with retaining high sealability. SOLUTION: For the heater unit H, groove 1A is formed on the surface of base part 1 made of highly heat conductive metal. Heating element 2 that consists of a band plate type member forming wavy regular curves widthwise along the longitudinal direction is arranged in the groove 1A. The plate height is shorter than the depth of the groove. The space 1S around the heating element 2 in the groove 1A is filled with filler 8 without leaving any gap.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heater unit optimal as a heater unit for sealing a resin film of a packaging device, a manufacturing method thereof, and a seal holder for mounting the heater unit (a sealing device attached to the packaging device. Refers to a substrate).

[0002]

2. Description of the Related Art In recent years, various products are often stored, transported, or sold after being packaged with a resin film for protection and the like.

[0003] In such packaging, the resin film is generally wrapped around the outer periphery of the product with a resin film wound in a coil shape, and the resin film is sealed by a sealing device having a seal holder with a heater unit built in at a required position. It is packaged by partially melting and sealing. For example, a seal holder Sh as shown in FIG. 6A is currently used. This seal holder S
h is a portion in the vicinity of the welding surface 11 of the metal base 1,
A hole 1R is formed in the base 1 along the welding surface, and the hole 1R is formed.
The heater unit H (see the alternate long and two short dashes line) having a cylindrical outer periphery is inserted therein.

However, in the case of the seal holder having such a structure, firstly, the heater unit itself has a different temperature distribution in each position in the longitudinal direction in the heat generating state. In addition, between the heater unit and the hole for inserting the heater unit of the seal holder, in a strict sense, the shape of the hole and that of the heater unit are slightly different, and an abutting portion and a gap are appropriately provided between them. The heat transfer state from the heater unit to the seal holder is different in each part due to the formation of the heat exchanger. That is, specifically speaking, the difference in the temperature distribution at each position in the longitudinal direction of the heater unit H is that the winding density (pitch) of the nichrome wire spirally wound around the outer periphery of the core material is different in each longitudinal direction. Due to the subtle differences in the parts, the temperature distribution differs at each position in the longitudinal direction (see the arrow X direction in FIG. 6). Regarding the heat transfer from the heater unit to the seal holder, the heat transfer is good at the portion where the heater unit H is in contact with the inner peripheral wall surface of the hole 1R of the seal holder Sh, and the seal holder Sh has good heat transfer properties.
At that portion of the seal holder Sh, on the other hand, the temperature becomes high, and at the portion where there is a gap between the heater unit H and the inner peripheral surface of the hole 1R of the seal holder Sh, heat transfer is low at that portion of the seal holder Sh. The temperature will drop. Therefore, in the case of the conventional seal holder, the temperature distribution in each part in the longitudinal direction of the welding surface of the seal holder is different.

Therefore, when the conventional seal holder is used to seal the resin film, the entire weld surface of the seal holder is slightly elevated so that the resin film can be welded even at a location where the temperature distribution is low. The temperature was set so that the resin film was welded. When the present inventor measures the temperature distribution of each part in the longitudinal direction of the seal holder of the conventional sealing device illustrated in FIG. 6A, for example, when welding a resin film having an appropriate sealing temperature of 150 ° C., The temperature of the seal holder is 150 ℃ at the lowest temperature, but it is about 1 at the highest temperature.
It was 70 ° C to 180 ° C. Therefore, in the case of a resin film having a narrow permissible sealing temperature range, there are many cases in which the resin film is melted and has a hole at a high temperature and thus cannot be sealed. Therefore, at present, the price is high and the seal welding temperature range is wide, for example, 150 ° C to 1
It was obligatory to use a resin film at 80 ° C. Alternatively, for sealing work that is not required to be completely sealed, by setting the lowest temperature point of the seal holder below the sealable temperature, the sealing work is partially incomplete. Was.

By the way, the structure of the above-mentioned conventional heater unit will be described with reference to FIG. 6 (b). A heating element formed of a thin wire (a thin wire of about 0.05 mm) around a cylindrical material (ceramic) 20. 22 is wound in a spiral shape so that the winding pitch is close, and the heater unit H
Cylindrical casing member 2 made of stainless steel that becomes the outer cover of
4, a space 21S inside the casing member formed by the insertion is filled with a fine spherical filler (not shown), and finally one end of the casing member 24 is covered with a lid 25. It was Since the casing member 24 is formed by a high-pressure press, a drawing process, or a general roll forming process, in a precise sense, the entire casing is distorted. For this reason, the hole 1R (see FIG. 6A) in which the heater unit of the seal holder is installed is made considerably larger than the outer diameter of the heater unit. Therefore, as described above, there is a problem that heat is not evenly transferred from the entire circumference of the heater unit to the base side of the seal holder.

The present invention has been made in view of the above circumstances, and the temperature distribution is as much as possible in the longitudinal direction of the welding surface so that an inexpensive resin film can be used while maintaining a high sealing property. An object of the present invention is to provide a heater unit that is uniform as a heater unit for a resin film sealing device of a packaging device, a manufacturing method thereof, and a seal holder excellent in maintainability for mounting the heater unit. To do.

[0008]

A heater unit according to the first aspect of the present invention forms a space for accommodating a heating element in a metal base having high heat conductivity, and the heating element and the heating element are provided in the space. In a heater unit in which a filler that fills a gap between a body and a base is arranged, the heating element is composed of a strip plate member that is repeatedly curved in a wavy shape in the longitudinal direction.

According to the heater unit thus constructed, however, since the heating element is a strip-shaped member, the current-carrying cross-sectional area is larger than that of the conventional thin nichrome wire, and moreover, in the groove. Since it is repeatedly curved in a wavy shape, it is possible to obtain a large amount of heat generation, which is many times that of the conventional one. Therefore, there is a margin in heat capacity, and stable temperature distribution and temperature management are facilitated for the entire heater unit. Also, the heating element itself is deformed due to temperature changes,
By repeatedly bending in the wavy shape, the influence of expansion and contraction of the heating element is minimized.

In the heater unit according to the second aspect of the present invention, a groove is formed on the surface of a metal base having high heat conductivity, and the plate height is lower than the depth of the groove and the plate width direction is within the groove. A heating element composed of a strip-shaped member which is repeatedly curved in a wavy shape along the longitudinal direction, and the space around the heating element in the groove is filled with a filler without any gap. Is characterized by.

According to the heater unit having such a structure, the same effect as that of the first aspect of the invention can be obtained, and in addition, the heating element is filled with the filler in the groove of the base portion so that there is no gap. Since they are arranged in a state, the heat generated from the heating element is evenly transferred to each part of the base through the filler. Therefore, the temperature distribution of the entire heater unit can be made uniform.

In the heater unit, the base is made of an aluminum material, at least the groove surface of the base has a non-conductive structure, and a heat-resistant inorganic filler is used as the filler. Then, the heater unit is easy to process and is preferable in terms of performance.

Further, in the heater unit, the non-conductive structure forms a hard alumite coating on the aluminum on the groove surface, and the porous structure formed on the aluminum surface by the formation of the hard alumite coating. When it is formed by impregnating the inside with a tetrafluoride resin, it can be insulated with high reliability without impairing the heat conduction performance, and it is a preferable heater unit with excellent performance.

Further, in the heater unit, when the heater unit is a heater unit for a resin film sealing device, a sealing device having excellent sealing performance and capable of using an inexpensive resin film having a narrow temperature range is realized. it can.

In the heater unit manufacturing method according to the third aspect of the present invention, a hard alumite coating is formed on at least the groove surface of a metal base having a groove formed on the surface thereof, and the hard alumite coating is formed. The porous tissue formed on the surface of the aluminum was impregnated with tetrafluororesin, and then, in the groove, the plate height was lower than the groove depth, and wavy in the plate width direction repeatedly along the longitudinal direction. A heating element composed of a curved strip-shaped member is inserted, and subsequently, in the space around the heating element in the groove, the inorganic filler is divided into a plurality of times with respect to the entire groove depth. Sequentially filling the filled inorganic filler until a semi-dry state,
Finally, the inorganic filler is filled up from the upper end of the groove to a slightly raised state, and then the inorganic filler in the groove is dried until the conductivity disappears.

Thus, the heater unit according to the second aspect of the present invention can be manufactured by manufacturing through the above steps.

Further, in the method of manufacturing the heater unit, after the drying is completed, the portion rising from the upper end of the groove is cut off to be flush with the surface around the groove, so that the heater unit is mounted on the seal holder side. When this is done, heat is evenly transferred at each position in the longitudinal direction of the seal holder, and a heater unit with a more uniform temperature distribution can be realized.

Further, the seal holder according to the fourth aspect of the present invention is attached to a packaging device, and is provided with a heater unit for melting and sealing the resin film by heat on a welding surface formed on one surface, A seal holder serving as a base material of a sealing device, wherein the seal holder has a concave groove for mounting the heater unit, which is open in the passing direction, on at least one surface orthogonal to the passing direction of the member to be sealed. It is characterized by being formed.

According to the seal holder thus constructed, however, in the packaging device, a continuous space for passing the sealed member is always ensured in the direction in which the sealed member passes. Therefore, by utilizing this space, the heater unit can be inspected or the heater unit can be replaced without removing other parts or the like of the packaging device. Therefore, it is possible to realize a seal holder having excellent maintainability.

Further, in the seal holder, the seal holder is provided with attachment portions which are attached to the frame on the packaging device side at both ends, and the intermediate positions of the both ends are also located at respective longitudinal positions. If a heat radiating portion having the same size as the attaching portion is formed so as to radiate heat evenly, the heat is radiated substantially uniformly over the entire longitudinal direction of the seal holder, and heat is generated at each position in the longitudinal direction. In combination with the uniformity of the above, a seal holder having a temperature distribution as uniform as possible can be realized. In particular, when used in a place where the ambient temperature is low, such as in winter, the seal holder has a temperature distribution that is as uniform as possible over the entire length of the seal holder as compared with the conventional seal holder. .

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a heater unit according to an embodiment of the present invention, a heating element used therein, and a method for manufacturing the heating element will be specifically described with reference to the drawings.

FIG. 1 is a perspective view of the entire heater unit according to the present embodiment, FIG. 2 is an overall perspective view of the base portion of the heater unit in which a heating element is not yet arranged, and a partially omitted perspective view, and FIG. 3 is a base portion. FIG. 4 is a partially enlarged perspective view showing a state in which a heating element is arranged in the groove formed in FIG. 4, and FIG. 4 is a perspective view showing the configuration of the seal holder according to the present embodiment to which the heater unit shown in FIG. 1 is attached.

In FIG. 1, reference numeral 1 is a base portion of the heater unit H, and the base portion 1 is made of an aluminum metal. In particular, in this embodiment, an aluminum represented by a metal symbol "A5050" is used. However, the metal symbol "A5
There may be an aluminum "052". As shown in FIG. 2, a groove 1 </ b> A having a rectangular cross section and a substantially “μ” shape in a plan view is formed on the surface of the base 1. The outer peripheral surface of the base 1 including the groove 1A is provided with electrical insulation performance. That is, the base 1 forms a hard alumite film after forming the groove 1A, and impregnates a tetrafluoride resin into the porous tissue formed on the aluminum surface by the formation of the hard alumite film, Electrical insulation performance is imparted to the entire outer peripheral surface of the base 1. Instead of the series of treatments, other electrical insulation treatments may be performed. For example, the electrical insulation treatment may be applied only by so-called “alumite” treatment. Or, in practice, the so-called "Toughram (" TU
FRAM ": registered trademark of General Magnaplate Corporation, USA" treatment may be applied to provide an electrical insulation treatment.

In the groove 1A, as shown in a partially enlarged view in FIG. 3, a heating element 2 made of a strip-shaped member curved repeatedly in a wavy shape in the longitudinal direction is provided with a wavy top 2a. And the bottom portion 2b are in contact with the inner wall surfaces 1f on both sides of the groove 1A, and the upper end 2u of the heating element 2 is located slightly lower than the upper end surface 1u of the groove 1A.

Further, the groove 1A in which the heating element 2 is arranged
The inner space 1S is filled with an inorganic filler 8, for example, a so-called “ceramic bond”. This "ceramic bond" is filled with the space 1S (inorganic filler 8) after the filling.
The inside is designed so that there are no air bubbles. Specifically, the base portion 1 in which the heating element 2 is arranged in the groove 1 </ b> A is set to 50 ° C. to 70 ° C. before filling the “ceramic bond”.
After preheating to about 60 ° C., preferably about 60 ° C., the “ceramic bond” is filled to a depth of about ½ of the depth of the groove 1A. In this embodiment, the depth of the groove 1A is about half the depth of the groove 1A, but the depth may be less than the depth of the depth of the groove 1A. Is. Next, the "ceramic bond" is dried in a drying oven or the like to a dry state (a dry state in which a cut layer is not formed between the filler to be filled next), and then again in the groove 1A. Fill with "ceramic bond". At the time of this second filling, the "ceramic bond" is filled so as to rise from the upper end surface of the groove 1A,
Again, it is dried in a drying oven or the like until the “ceramic bond” is completely dried. "Ceramic bond" protruding from above the groove 1A with a knife etc. after the drying is completed.
If the heater unit H as shown in FIG. 1 is viewed from the surface, the heater unit H in which the heating element 2 (see FIG. 3) in the groove 1A is covered with the inorganic filler 8 is completed.
In addition, lead wires 1 for energizing are previously provided at both ends of the heating element 2.
It is desirable that 3 is connected. Further, the "ceramic bond" is such that air bubbles do not exist therein after being dried, and it can absorb expansion and contraction of the heating element 2 due to a temperature difference to some extent, that is, it has elasticity after drying. Select a "ceramic bond".
Specifically, the trade name "Q750" of Nippon Special Ceramics Co., Ltd. (head office: Suita City, Osaka Prefecture) is used. Of course, it is needless to say that an equivalent to this "ceramic bond" can be used.

The heater unit H manufactured as shown in FIG. 1 is attached to a seal holder Sh as shown in FIG. 4 when it is used in a sealing device of a packaging device. That is, as shown in FIG. 4, the seal holder Sh according to the present embodiment passes through the surface 12 orthogonal to the direction (see arrow Y in FIG. 4) through which the member to be sealed (item to be packaged) passes. Has a concave groove 5 opened in the direction,
In the groove 5, the heater unit H is connected to the heating element 2
The side (upper surface side in FIG. 1) in which is embedded is the bottom surface 5 of the groove 5.
It is attached to the bolt hole 5d by a bolt (not shown) so as to come into contact with b. Therefore, when the heater unit H is attached to the grooves 5 on both sides of the seal holder Sh in this way,
Even if the heater unit H breaks down, simply by stopping the packaging line, a bolt (not shown) whose tip is screwed into the bolt hole 5d from a continuous space through which the member to be sealed passes is installed. Remove the heater unit H
Can be easily removed from the seal holder Sh. Further, the seal holder Sh is attached to the packaging device side (not shown) via the attachment portions 6 at both ends,
The heat tends to be transferred from the attachment portion 6 to the packaging device side (upper side in FIG. 4), but in this embodiment, this portion is prevented by attaching the heat insulating material to the packaging device side. At the same time, a heat radiating portion 7 having substantially the same size as the attaching portion 6 is formed at an intermediate portion between both ends of the seal holder Sh, and the amount of heat radiated from the attaching portion 6 itself is almost the same. Is also radiated from the heat radiating portion 7 in the middle portion. A welding surface 11 is formed on the surface opposite to the attachment portion 6 and the heat radiation portion 7. Further, in FIG. 4, a slit 9 is formed in the center in the width direction over substantially the entire area in the longitudinal direction. Since the slit 9 passes through a cutting blade (not shown) for cutting performed almost at the same time as the sealing work. belongs to.

However, the heater unit H according to the present embodiment configured as described above operates as follows. That is, as described above, the heating element 2 having a large heating capacity and curved in a wave shape is arranged in the groove 1A, and the groove 1A and the heating element 2 are arranged.
Since the ceramic bond “Q750”, which is an inorganic filler, is filled in the space 1S with and without the inclusion of air bubbles, the heating element 2 expands and contracts in the energized state and the energized state stopped. However, since it has the above-mentioned wavy shape, it hardly changes in the longitudinal direction, and the ceramic bond “Q750” changes correspondingly to the minute expansion and contraction of the heating element 2. Absorb it,
It does not cause internal stress enough to break the heating element 2 itself. In addition, since the top portion 2a and the bottom portion 2b of the heating element 2 are in contact with the groove 1A and the heat is efficiently transferred to the base portion 1 through the inorganic filler 8, the heating element 2 of the heating element 2 is connected to the base portion 1. Heat is transferred effectively and as evenly as possible in all positions. Then, if the surface of the base portion 1 of the heater unit H is machined to have a flatness as high as possible in advance, the groove 5 of the seal holder Sh is obtained.
In the state where the heater unit H is attached inside, the heater unit H is in close contact with the seal holder Sh, and it is possible to uniformly heat the seal holder Sh at each position in the longitudinal direction.

Also, in the seal holder Sh itself, as shown in FIG. 4, since the heat radiating portion 7 is formed so that the amount of heat radiated in each part in the longitudinal direction is substantially equal, the main heater unit H is formed. The attached seal holder Sh exhibits a uniform temperature distribution in a strict sense at each position in the longitudinal direction. In fact, according to the temperature measurement by the present inventor, when the set desired temperature was 150 ° C., the temperature difference at each position in the longitudinal direction was 1 ° C.
This means that the seal holder in which the conventional heater unit shown in FIG. 6 is arranged has a temperature difference of 20 to 30 ° C. at each position in the longitudinal direction with respect to 150 ° C. It is clear that there is a marked difference in.

Further, according to the heater unit H of the present invention, since the heating element 2 uses the strip-shaped member as described above, the heating unit 2 having a larger conducting cross-sectional area than the conventional one can be used. The rise time to the predetermined temperature is short, and
The temperature is stable against heat dissipation during sealing work. Therefore, it is possible to realize a highly reliable sealing device for a packaging device, which is intended for a member to be sealed that continuously requires a large amount of heat.

In the above-described embodiment, the linear heater unit has been described, but the heater unit is not limited to this, and a "shimeji" or the like is wrapped in a ball shape as shown in FIG. Groove 1A for packaging
The heater unit H may be a circular heater unit having a circular shape. Of course, even in such a case, the heater unit according to the above-described embodiment can be manufactured basically through the same steps.

Further, in the above-described embodiment, the case where the heater unit is exclusively used as the heater unit has been described, but it goes without saying that the heater unit can also be used as other heater units, and the same effect as described above can be obtained.

[0032]

According to the present invention, since the heater unit and the seal holder have extremely uniform temperature distribution at each position in the longitudinal direction, it is possible to strictly set the temperature on the welding surface of the seal holder. Therefore, even an inexpensive resin film having a narrow allowable temperature range can be sealed while maintaining high sealing property.

Further, according to the heater unit manufacturing method of the present invention, the heater unit having excellent performance can be manufactured with high reliability.

Further, according to the seal holder of the present invention, the performance of the heater unit can be pulled out by 100 percent, and a seal holder having a uniform temperature distribution at each position in the longitudinal direction can be realized, and the mounted heater can be realized. It is a seal holder with excellent maintainability that allows you to easily inspect and replace the unit.

[Brief description of drawings]

FIG. 1 is a perspective view of an entire heater unit according to the present embodiment.

FIG. 2 is an overall perspective view, partly omitted, showing a configuration of a base portion of a heater unit before a heating element is arranged.

FIG. 3 is a partially enlarged perspective view showing a state in which a heating element is arranged in a groove formed in a base portion.

FIG. 4 is a perspective view showing a configuration of a seal holder according to the present embodiment to which the heater unit shown in FIG. 1 is attached.

5 is an overall perspective view showing a heater unit of a different form from the heater unit shown in FIG.

6A and 6B are perspective views showing a configuration of a conventional seal holder and a heater unit, FIG. 6A is an overall perspective view of the seal holder, and FIG. 6B is a heater unit in a state of being cut away so that a part of an internal structure can be seen. FIG.

[Explanation of symbols]

1 ... Base 1A ... groove 2 ... Heating element 1S ... space 8: Inorganic filler (filler) H: Heater unit

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3K034 AA12 AA16 AA19 AA21 AA23                       BA06 BA15 BA18 BB02 BB14                       BC03 BC15 FA13 FA33 GA02                       GA10 GA12 HA10 JA02 JA10                 3K092 PP20 QA05 QB02 QB32 QB36                       QB37 QB44 QB45 RF03 RF09                       RF17 RF22 SS17 TT27 VV03                       VV22                 4F211 AJ02 AK09 TA01 TC17 TN29                       TQ13

Claims (9)

[Claims] 1. A heater in which a space for accommodating a heating element is formed in a base made of a metal having high heat conductivity, and a heating element and a filler filling a gap between the heating element and the base are arranged in the space. In the unit, a heater unit is characterized in that the heating element is composed of a strip-shaped member which is repeatedly curved in a wavy shape in a longitudinal direction. 2. A groove is formed on the surface of a metal base having a high heat transfer property, and a plate height is lower than the depth of the groove in the groove, and the groove is repeatedly wavy in the plate width direction and curved along the longitudinal direction. A heater unit comprising: a heating element formed of a strip-shaped member, and a space around the heating element in the groove is filled with a filler without a gap. 3. The base is made of an aluminum material,
The heater unit according to claim 2, wherein at least the groove surface of the base has a non-conductive structure, and a heat-resistant inorganic filler is used as the filler. 4. The non-conductive structure forms a hard alumite film on the aluminum on the groove surface, and tetrafluoride is formed in the porous tissue formed on the aluminum surface by the formation of the hard alumite film. It is formed by impregnating a resin.
The heater unit described. 5. The heater unit according to claim 1, wherein the heater unit is a resin film sealing heater unit. 6. A hard alumite film is formed on at least the groove surface of a metal base having a groove formed on the surface thereof, and a hard anodized film is formed in the porous structure formed on the aluminum surface by the formation of the hard alumite film. Impregnate with fluorinated resin,
Next, in the groove, a heating element composed of a strip plate-shaped member having a plate height lower than the groove depth and curving repeatedly along the longitudinal direction in a wave shape in the plate width direction is inserted. In the space around the heating element in, the inorganic filler is divided into a plurality of times with respect to the entire groove depth, and the inorganic filler previously filled is sequentially filled until a semi-dried state is obtained. Finally, a method of manufacturing a heater unit, characterized in that the inorganic filler is filled to a state where it is slightly raised from the upper end of the groove, and then the inorganic filler in the groove is dried until the conductivity disappears. 7. The method for manufacturing a heater unit according to claim 6, wherein after the drying is completed, a portion raised from the upper end of the groove is cut off so as to be flush with the surface around the groove. 8. A seal holder, which is attached to a packaging device, has a heater unit, and serves as a base material of a sealing device for sealing by melting a resin film by heat on a welding surface formed on one surface. The seal holder is characterized in that a concave groove for mounting the heater unit, which is open in the passing direction, is formed on at least one surface orthogonal to the passing direction of the member to be sealed. . 9. The seal holder has attachment parts attached to the frame on the packaging device side at both ends, and radiates heat evenly to intermediate positions of the both ends at each position in the longitudinal direction. 9. The seal holder according to claim 8, wherein a heat radiating portion having the same size as the attaching portion is formed as described above.