JPH11268713A - Heat sealer for thick matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealer that applies heat-sealing to thick plastics. SOLUTION: Heating is applied doubly on the same position at the overlapping part of plastics from both sides at the outside or from one side and the inside by high-frequency induction, and at least one side is formed, without being flat, in a shape of a Nichrome round wire in an appropriate diameter having a protuberance as seen in the sectional view, and heating is applied further with a large amount of electric current and after that the electric current is cut off and cooling is applied immediately. In the case of a tape 4 used for packing machine, heat sealing is applied in one or more of narrow wideths, being in parallel with the longitudinal direction of the tape 4 in an appropriate length. As a concrete instance for manual operation, a tight-binding and piling-up table or the like and a pressing lever or the like having an electric code obstructive to works of tight-binding and piling up are separated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealer for heat-sealing a thick plastic and a packing machine as an application example thereof.

[0002]

2. Description of the Related Art Conventionally, it has been considered that thick polyethylene of 0.2 mm or more cannot be heat-sealed.
Therefore, when hanging a flat strap such as a PP band with a thickness of 0.5 mm on the luggage, use a metal or plastic tying tool or put a heated metal plate between the stacked flat straps,
The surface in contact with the flat string melted, but it was pulled out to the extent that it did not melt to the back side, and both sides were pressed to cool and bond.

[0003] Further, since soft vinyl chloride having a thickness of 0.2 to 0.5 mm can be heated by high-frequency induction, it has been heat-sealed with a high-frequency welder.

[0004]

The method of using the fastener is time-consuming and requires one fastener per string, which is extra costly. What was welded between the overlapping portions of the flat string had to be heated beforehand, so the switch could not be used immediately after switching on. Also, the plastic that adhered to the hot plate was burned by the welding,
The surroundings tended to smell for a long time. Further, since the movement of the heat thin plate is different from the movement of the pressing plate by 90 degrees, the mechanism has to be complicated accordingly.

[0005] Consumers hated vinyl chloride because dioxin is generated when it is burned, and it has become unacceptable to the market if it is not replaced with a substitute film. Since there were few, processing was difficult. Therefore, in both cases, a method was desired in which a thick plastic could be heat-sealed easily or with conventional equipment.

[0006]

The same position of the overlap of the film or the like is heated from both sides by an external heater or from one side by an internal and external heater by high-frequency induction, and at least one of them is not flat. It has a convex portion in cross-section like a nichrome round wire having an appropriate diameter, so that it can easily bite into the partner and conduct heat. Then, a large current was applied to both heaters for a short time under pressure to heat the heaters, cut off electricity, and immediately cooled.

[0007] In the case of a flat cord of a packing machine, the heat seal is made one or several narrow pieces of an appropriate length parallel to the length direction of the cord. As a hand-operated type, a binding / stacking stand and a pressing lever with a power cord were separated to make it easier to bind.

[0008]

[Function] Even with thick plastics, the heater is heated from both sides and bites into the other party, so that heat can be transmitted quickly and completely sealed, but at the same time it cools quickly, so the calorific value can be saved, and extra heat is required. Did not accumulate and did not adversely affect the surroundings. In the case of vinyl chloride as well, the heat generated by the impulse heat sealer heater was added to the weak heat generated from the high-frequency welder, so that the sealing was sufficient.

[0009]

1 and 2 are perspective views of a packing machine to which a heat sealer according to the present invention is applied. At first, as shown in Fig. 2, it is a half of the packing machine, but it is connected with the power supply and the cord, and removes the pressing lever and upper heater 1 that make it difficult to work, and only the other half, the binding, the stacking table, and the lower heater 2 After the end is sandwiched between the terminal fixing portions 3, the PP band 4
Is turned around the entire luggage 5, the required length of the PP band 4 is doubled beyond the first terminal fixing portion 3, and then wrapped around the tension portion 6 and pulled and fixed.

Next, as shown in FIG. 1, the detached pressing lever / upper heater 1 is fitted to a predetermined position at its fulcrum 7 and combined with the binding / stacking / lower heater 2.
The upper heater 8 is pressed against the overlapping portion of the PP band 4 by the pressing lever 9 with an appropriate pressure. Although the hand is omitted, when the switch button 10 is pressed here, there is a lower heater 11 below the overlapping portion of the PP band 4, and the terminal from the heater is connected to the fulcrum 7 at the same time. Therefore, a current larger than that of the controller built in the pressing lever 9 flows through both heaters for a predetermined period of 1 to 2 seconds. Since the PP band 4 is heated from both sides, it melts along the shape of the heater and welds to each other.

When the seal portion cools 2 to 3 seconds after the end of the power supply, the pressing lever / upper heater 1 is raised and removed, and an excess portion of the PP band 4 at the end of the seal is cut with a cutter or the like, and the terminal fixing portion is removed. 3 may be loosened, and the binding / stacking / lower heater 2 may be removed. Then, as shown in FIG. 2, a linear heat seal 12 parallel to the length direction of the PP band 4 is formed, and the PP band 4 is firmly sealed, that is, welded and joined.

FIG. 3 is an enlarged cross-sectional view of the PP band 4, the upper heater 8, and the lower heater 11 in the seal portion. The lower heater 11 is a normal ribbon having a width of 2 mm, and the upper heater 8 is a nichrome wire having a diameter of 0.8 mm. The lower heater 11 is insulated and fixed to a metal base 13 on which each heater is mounted with a Teflon tape 14. When heating by a so-called impulse heat sealing method, in which a predetermined large current is passed for a short time to heat, and then cut and cooled, the upper heater 8 is sufficiently melted into the PP band 4 to form a strong seal 12. .

[0013] The strength of the seal is whether the overlapping plastic melts sufficiently. In the case of a thin polyethylene band having a thickness of about 0.2 mm or less, heating may be performed only from one side. However, in the case of a thick band such as a PP band, it is completely useless from one side, and heating must be performed from both sides. However, depending on the shape of the heater, considerable time is required, and the influence of a large amount of heat is a problem. Become.

FIG. 4 is a simplified cross-sectional view in which heaters having different cross-sectional shapes are arranged on the upper side of the stacked plastics 16 and heaters in the form of ribbons are all arranged on the lower side, and the table and Teflon tape are omitted. The fact that the heaters face each other above and below the stacked plastics 16 means that they have the same shape in plan. A is a flat ribbon, and there is no problem if the ribbon is thin. However, the thicker the partner, the longer it takes to melt and cool, and if the longer the time, the more heat is accumulated and the part that is unnecessary is deformed.

B and C are a semicircular line and a ball seal line, respectively.
Both bite into the plastic 14 of the other party, and quickly heat and cool only the portion sandwiched between the upper and lower heaters. As a matter of course, the lower side, that is, both sides may have a convex shape. However, if a combination of a 1 mm round wire and a 2 mm width ribbon is used as shown in D, that is, as in FIG. 3, when a heater of a deformed product is made, the heating portions overlap even if the top and bottom are slightly shifted. Sometimes it is easy to make.

E is a high-frequency welder blade made of brass for the upper heater 8, and a ribbon wire of a nichrome alloy or another metal for the lower heater. That is, a plastic film that replaces vinyl chloride, which is highly criticized, is not easily put into practical use due to weak heat generation due to high-frequency induction. However, if a heater with another power supply is added according to the concept of the present invention, it can be solved at this stage. Originally, the electrode of the high-frequency welder had a sharp protrusion to burn off, so if the other heater was a ribbon, it would be just right, but vice versa. If the material of the heater to be added can be copper or brass if the impulse heat sealing method is used, heat can be generated, and the influence of high frequency induction can be considered. Therefore, it is preferable to determine the material in consideration of the welder.

B to E are the shapes proposed by the present invention,
It is not limited to these. Also, the height and size of the protrusions are sharp such as acute and obtuse, but it depends on the thickness of the plastic used. For example, if the diameter of the round wire in D is 1.2 mm or more, the completed seal is heat cut. It also depends on the purpose, for example, if it is about 0.6 mm, only the seal can be used, and cutting cannot be performed.

The tensile strength in the longitudinal direction of the seal portion, that is, the tensile strength in the transverse direction of the seal is as follows:
It depends on how much the tension from the material, thickness, etc. of the PP of the band is distributed to the seal beside, but in this case it is proportional to the length of the seal to a considerable extent, and if it is long enough, up to the strength of the band itself Get closer. The width of the seal is not critical, and its number replaces the strength and thus the length of the seal. In the case of this PP band, by performing two 7 cm lengths or three 5 cm lengths in the combination of FIG. 3, sufficient bonding was always achieved even if the seal finish was somewhat good or bad.

The unsealed portion 15 has a heating time of 1 to
Since the cooling takes place in two seconds and immediately, the strength is maintained with little influence from heat. Normal bands should have three times the required intensity, so that part is one third
I just need. In this example, since the heater ribbon width is 15 mm in width, that is, the molten portion is a total of 6 mm, the remaining 9 m
There is no problem because there is m. Since the heater must not cross that part, it is necessary to make the heater wire thicker at the part that crosses to suppress heat generation, or to keep it away from the sealing surface.

Note that the binding / stacking / lower heater 2 shown in FIG.
The functions of the terminal fixing portion 3 and the tension portion 6 are the same as those of a buckle, a stopper, and the like which are usually used as a binding device for a PP band.
They are repositioned so that they are ahead of each other, and they are cantilevered to make it easier to pull out. Not only this shape but also a ratchet gear or other methods may be used.
Further, the lower heater 11 can be provided on the side of the pressing lever / upper heater 1 so as to be, for example, a pliers type.

Although the present invention has been described as an application example of a manual type packing machine, the present invention can be applied to an automatic packing machine which can start up instantly without odor in combination with a binding / stacking device using a motor.

The sealer of the present invention can make the planar shape of the heater not only a straight line but any curve,
It can be said that thick deformed materials, such as the assembly of 0.2 to 0.5 mm air toys and transparent PVC cases, which were conventionally only produced by a PVC processing machine, can be processed with a simple heat sealer.

[0023]

According to the present invention, a thick plastic such as 0.2 to 1 mm, which cannot be processed by a conventional heat sealer, can be easily sealed by the present invention.

According to the present invention, a PVC-substitute plastic which is difficult to process with a high-frequency welder can be processed with only a slight modification to conventional equipment. In addition, since the sharp heater can be easily cut, it is easy to process a thick deformed product of PP or PE resin.

The packing machine to which the present invention is applied is sanitary without the burning smell of the PP band, so that it can be used in places such as stores and offices where the appearance is concerned. If you go, there is no waiting time,
You can use it immediately when you want to use it.

Further, since no preheating is required, no tying tool is required, and the short or once used PP band can be connected and used in a good format, it is very resource saving.

[Brief description of the drawings]

FIG. 1 is a perspective view of a packing machine according to an application example of the present invention.

FIG. 2 is a perspective view of the sealed state.

FIG. 3 is a sectional view of a seal portion.

FIG. 4 is a sectional view showing various heater shapes.

[Explanation of symbols]

1 Press lever / upper heater 2 Binding / stacking / lower heater 3 Terminal fixing part 4 PP band 6 Tension part 7 fulcrum 8 Upper heater 9 Press lever 11 Lower heater 12 Heat seal part 15 Heat seal part 16 Non-heat-sealed plastic

Claims (5)

[Claims] A heater having the same shape in a plane is disposed at the same position on both sides of a plastic overlap, and at least one of the heaters has a nichrome circle having a diameter suitable for the thickness of the plastic. Like a wire, it has a convex section in cross section that is easy to bite into the other party and conduct heat, and it is necessary to apply a large current to both heaters in a short time under pressure and heat it, cut off electricity, and immediately cool as it is A heat sealer that seals thick plastic films and molded products. 2. One of the heaters is a ribbon or a wire made of metal or the like.
The heater has the desired planar shape and is heated by passing a normal current, but the other heater has the same shape with a metal plate and constitutes one of the electrodes of the high-frequency welder, and the other heater or other metal plate is connected to the other heater. 2. The heat sealer according to claim 1, wherein a high-frequency current to be used as the electrode is supplied for heating. 3. A flat string such as a PP band is hung on a luggage by a strapping / stacking device or the like, and then tied up. A packing machine characterized by applying a book or a plurality of linear heat seals from the outside of the overlap and joining them. 4. A heater is arranged at the same position on both sides of the overlap of the flat string, and at least one of the heaters is provided with a mating wire such as a nichrome round wire having a diameter appropriate for the thickness of the overlap. 4. A heater having a convex section in a cross section so as to easily penetrate into the heater and conduct heat, and apply a large current to both heaters in a short time under pressure to heat the heater, cut off electricity, and immediately cool as it is. Packing machine. 5. A binding / stacking unit in which at least the binding / stacking unit is integrated, a pressing lever containing a control part with a power cord and an upper heater are integrated with each other, and the lower heater is disposed on either side. 5. The packing machine according to claim 4, wherein after the flat string is wound around the luggage to form an overlap, when the two bodies are joined, the overlapped portion is sandwiched between the upper heater and the lower heater.