JP6856934B2 - Heat sealer - Google Patents

Description

The present invention relates to a configuration of a crimping portion and a receiving portion of a heat sealer.

Examples of such a heat sealer include a sealing device (impulse type heat sealer) disclosed in Patent Document 1 below. The heat sealer seals by melting the seal portion by crimping and heating the seal portion of the packaging material (object to be sealed).

The configuration of the crimping portion and the receiving portion of the heat sealer is shown in FIG. FIG. 4 is a vertical cross-sectional view of the seal portion in the orthogonal direction. In FIG. 4, the crimping portion 100 is arranged at the upper part, and the receiving portion 200 is arranged at the lower part.

The crimping portion 100 includes a pressing body 101 formed of aluminum and an elastic body 102 formed of silicon rubber attached to a lower portion thereof. Further, the receiving portion 200 includes a receiving portion 201 formed of aluminum, an elastic body 202 formed of a thin silicon rubber arranged on the upper surface of the receiving body 201, and a fluororesin tape 203 covering the elastic body 202. A heater 204 arranged on the heater 204 and a fluororesin tape 205 covering the heater 204 are provided. PTFE is used as the fluororesin tape.

As shown in FIG. 4, the film F to be sealed is placed on the upper surface of the fluororesin tape 205 constituting the receiving portion 200, and the crimping portion 100 is crimped from above to heat the heater 204. As a result, the seal portion of the film F is melted to complete the seal.

Japanese Unexamined Patent Publication No. 2016-203983

The problems in the above heat sealer are as follows. The material of the object to be sealed in the above heat sealer is, for example, a resin film such as polyethylene, and the heating temperature of the heater is set to 250 ° C. or less.

On the other hand, in the medical field, a fluororesin film (for example, PTFE) is used as a bag for enclosing liquid nitrogen, and there is a demand for sealing such a film. In addition, in the case of nuclear power, a bag of fluororesin film is used as a bag for storing waste materials, and in the case of semiconductors, in order to avoid ultraviolet rays. As described above, in recent years, there has been a demand for a seal made of a fluororesin film.

Here, fluororesin has a higher melting point than polyethylene or the like, and includes PTFE (melting point 327 ° C.), PFA (310 ° C.), FEP (260 ° C.), etc., and compared to PTFE, PFA and FEP. Is easy to seal due to its low melting point. Therefore, at present, it is used when a fluororesin having a relatively low melting point such as FEP is used for sealing. However, PTFE accounts for 70 to 80% of the fluororesins currently on the market, and therefore, it is very cheap compared to other fluororesins. Therefore, if PTFE, which is the most difficult to seal among fluororesins, can be sealed, an inexpensive fluororesin can be used.
On the other hand, the melting point of PTFE is 327 ° C., and therefore, it is necessary to raise the heating temperature by the heater to nearly 400 ° C. However, as described above, the same fluororesin tape (PTFE) is used as the material for protecting the heater, and there is a possibility that it will stick to the object to be sealed. Further, although an elastic body made of silicon rubber is used for the surface of the crimping portion, the normal temperature of the silicon rubber is 250 ° C. or lower, and it cannot withstand the temperature of 400 ° C.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a heat sealer capable of sealing even a material having a high melting point such as PTFE among fluororesins.

In order to solve the above problems, the heat sealer according to the present invention is
A crimping portion and a receiving portion that sandwich the sealed portion of the object to be sealed, a heater arranged along the sealing portion on the surface side of the receiving portion, a first heat insulating body arranged on both sides in the width direction of the heater, and a heater. A second heat insulating body arranged on the back surface side, an elastic body arranged on the surface opposite to the heater of the second heat insulating body, and a third heat insulating body arranged on the front surface side of the crimping portion are provided.
The surface of the heater is characterized in that it protrudes toward the crimping portion side with respect to the surface of the first heat insulating body.

The action and effect of the heat sealer according to this configuration will be described. When sealing the seal portion of the object to be sealed, the seal portion is sandwiched between the crimping portion and the receiving portion, and the heater is heated to melt the sealed portion and seal the seal. The heater is in a state of being surrounded by the first to third heat insulating bodies, and for these heat insulating bodies, a material having a heat resistance of 400 ° C. or higher can be selected. Therefore, there is no problem even if a material such as fluororesin is heated by a heater. Further, the heater protrudes from the surface of the first heat insulating body, and the heater surely contacts the seal portion when crimping. Further, the heater is arranged in the order of the second heat insulating body and the elastic body on the back surface side, and even if the heater is heated to 400 ° C., the elastic body does not rise to this temperature, for example, the heat resistant temperature. However, silicon rubber having a temperature of about 250 ° C. can be used. The elastic body allows a crimping force to be applied to the seal portion. As described above, it is possible to provide a heat sealer capable of sealing even a material having a high melting point such as fluororesin (PTFE).

The second heat insulating body according to the present invention preferably uses a material softer than that of the first heat insulating body.

By using such a material, the second heat insulating body is deformed according to the state of the surface of the object to be sealed when a crimping force is applied, so that heating can be uniformly performed over the entire sealed portion.

The second heat insulating body according to the present invention preferably has a laminated structure in which thin plate-shaped materials are layered.

By using a thin material, it is possible to construct a second heat insulating body that is more easily deformed than the first heat insulating body.

In the present invention, it is preferable that the second heater is embedded inside the third heat insulating body.

By providing such a second heater and, for example, auxiliary heating after sealing, it is possible to suppress the formation of wrinkles in the sealing portion, and it is possible to form a sealing portion having good quality.

Side view showing a configuration example of an impulse heat sealer Cross-sectional view showing the configuration of the crimping portion and the receiving portion (before crimping) Cross-sectional view showing the configuration of the crimping portion and the receiving portion (after crimping) Cross-sectional view showing the configuration of the crimping portion and the receiving portion according to the prior art

A preferred embodiment of the heat sealer according to the present invention will be described with reference to the drawings. As an example of the heat sealer, an impulse type heat sealer will be described. FIG. 1 is a side sectional view of the heat sealer. The heat sealer according to the present invention can seal a fluororesin sheet (particularly PTFE) having a high melting point.

<Overall configuration of heat sealer>
The main body 1 of the heat sealer is composed of an upper frame body 2 and a lower frame body 3 that are integrally connected. The upper frame body 2 is provided with a transformer for driving the heater, a control box, and a crimping lever 4. The crimping lever 4 is attached so that a pair of left and right arms can rotate with respect to the shaft 5. Further, the crimping lever 4 is provided with a coil spring 6 for applying a crimping force, and the crimping force can be adjusted by the adjusting portion 7. The lower frame body 3 is provided with a plate 8 on which an object to be sealed is placed.

A crimping portion 10 is provided on the tip end side of the crimping lever 4, and a receiving portion 20 is provided so as to face the crimping portion 10. The object to be sealed (packaging material) is sandwiched between the receiving portion 20 and the crimping portion 10 of the crimping lever 4. Further, the crimping portion 10 and the receiving portion 20 may be pressurized by an air cylinder or other actuator.

<Structure of main parts>
Next, the configuration of the crimping portion 10 and the receiving portion 20 which are the main portions will be described with reference to the vertical cross-sectional view of FIG. As shown in FIG. 2, a heater 21 is arranged on the upper surface of the receiving portion 20. The heater 21 is formed in an elongated shape along the seal portion, that is, along the vertical direction of the seal surface. The width is about 5 mm. The first heat insulating bodies 22 are arranged on the left and right sides of the heater 21. The material of the first heat insulating body 22 is not particularly limited, and for example, a laminated body of glass fiber sheets (trade name: Myorex) and a high-strength cement-based heat insulating plate (trade name: Hemisal) can be used. .. These materials have a heat resistance of 400 ° C. to 500 ° C., and have sufficient heat resistance even when sealing a fluororesin sheet.

A second heat insulating body 23 is provided on the back surface side of the heater 21, and the second heat insulating body 23 is configured as a laminated body in which a plurality of heat insulating sheets 23a are laminated. The second heat insulating body 23 is made of a material softer than that of the first heat insulating body 22. For example, mica is preferable. Some mica has a heat resistance temperature of more than 600 ° C., and has sufficient heat resistance even when sealing a fluororesin sheet.

Further, since the second heat insulating body 23 is softer than the first heat insulating body 22, the crimping portion 10 can exert a uniform crimping force over the entire area of the sealing portion at the time of crimping. In particular, by forming a laminated body, its function can be more exerted.

An elastic body 24 is provided on the back surface side of the second heat insulating body 23. The elastic body 24 is formed of, for example, silicone rubber. The heat-resistant temperature of silicon rubber is about 250 ° C even if it is high, but even if the heater 21 is heated to 400 ° C, the second heat insulating body 23 is interposed between them, and the temperature of 400 ° C is not transmitted as it is. , Does not deteriorate. By arranging the elastic body 24 under the heater 21, the elastic body 24 is compressed at the time of crimping, and the elastic force can be applied to the seal portion.

The surface of the heater 21 protrudes slightly from the surface of the first heat insulating body 22, so that the heater 21 can surely come into contact with the sealed portion of the object to be sealed. As a result, the heat of the heater 21 can be reliably transferred to the seal portion. Further, the receiving portion 20 is provided with a water channel 9, and the sealing portion can be cooled.

A third heat insulating body 11 is arranged on the surface of the crimping portion 10. As the third heat insulating body 11, the same material as that of the first heat insulating body 21 can be used. Further, a second heater 12 is provided inside the third heat insulating body 11. The second heater 12 is used as an auxiliary, and has a width of about 10 mm. By heating with the heater 21 (about 400 ° C.) and then heating with the second heater 12 to about 200 ° C., it is possible to suppress the formation of wrinkles in the seal portion. The second heater 12 may not be provided.

<Seal operation>
Next, the operation when sealing is performed will be described. As shown in FIG. 2, the object to be sealed F is positioned between the receiving portion 20 and the crimping portion 10. The work can be easily performed by using the plate 8 shown in FIG. Set so that the seal portion is located just above the heater 21. Next, the crimping lever 4 is lowered, and the sealing portion is sandwiched between the receiving portion 20 and the crimping portion 10. The state at this time is shown in FIG.

The surface of the heater 21 is pushed down until it is flush with the surface of the first heat insulating body 22. As a result, a predetermined crimping force acts on the seal portion. At the same time, the object to be sealed is sandwiched between the third heat insulating body 11 and the second heat insulating body 23, pressure is applied, and the object to be sealed is firmly fixed. This suppresses the formation of wrinkles.

Next, by heating the heater 21, the object to be sealed in the sealed portion is melted and sealed. In the case of fluororesin, the melting point is as high as 330 ° C., but it can be sufficiently sealed by heating the heater 21 to 400 ° C. Further, the heat resistant temperature of the heat insulating body around the heater 21 is 400 ° C. or higher, which can sufficiently withstand.

Further, by heating to 200 ° C. by the second heater 11 after heating by the heater 21, it is possible to further suppress the formation of wrinkles in the seal portion and form a high quality seal portion.

<Another Embodiment>
In the present embodiment, the impulse type heat sealer has been described as an example, but the present invention can be applied to other types of heat sealers.

1 Heat sealer body 10 Crimping part 11 Crimping part 11 Third heat insulating body 12 Second heater 20 Crimping part 21 Heater 22 First heat insulating body 23 Second heat insulating body 23a Insulating sheet 24 Elastic body

Claims (4)

A crimping part and a receiving part that sandwich the seal part of the object to be sealed,
A heater placed along the seal on the surface side of the receiving part,
The first heat insulating body arranged on both sides in the width direction of the heater,
The second heat insulator placed on the back side of the heater,
An elastic body placed on the surface opposite to the heater of the second heat insulating body,
A third heat insulating body arranged on the surface side of the crimping portion is provided.
A heat sealer characterized in that the surface of the heater projects toward the crimping portion side with respect to the surface of the first heat insulating body. The heat sealer according to claim 1, wherein the second heat insulating body uses a material softer than that of the first heat insulating body. The heat sealer according to claim 1 or 2, wherein the second heat insulating body has a laminated body structure in which thin plate-shaped materials are laminated in layers. The heat sealer according to any one of claims 1 to 3, wherein a second heater is embedded in the third heat insulating body.

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