JP2000168736A - Heater wire, and impulse sealer using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely form a non-welded part which becomes a ventilation path for deaeration process, on a sealed section by sealing the opening of a weldable packaging bag using a heater wire wherein a high resistance section and a low resistance section alternately continue in the longitudinal direction. SOLUTION: A ribbon-like heater wire 1 is constituted in such a manner that a high resistance section 2 wherein a heat-weldable material can be heat- welded by applying power, and a low resistance section 3 wherein the heat- weldable material cannot be heat-welded by applying power, are alternately continue. Such a heater wire 1 can be easily formed by coating Cu, a Cu alloy or the like of which the electric resistance is low, with a specified interval on the surface of a core material of which the electric resistance is high comprising a ribbon-like Fe-Cr based alloy, a Ni-Cr based alloy or the like. The coating of the low resistance material may be performed by simply winding the low resistance material which is formed into a sheet-form on the surface of the high resistance material, or the low resistance material may be directly laminated on the core surface of the high resistance material using plating, sputtering or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for sealing an opening of a heat-sealable packaging bag, and more particularly to a heater wire used in the sealing process.

[0002]

2. Description of the Related Art A packaging bag made of a heat-sealable material, for example, a packaging bag made of a synthetic resin such as polyethylene, is cut into a flat film tube at a predetermined length, and the opening is heated and welded. Some are made by bag.
As one of the heat welding methods, a method using an impulse sealer is known. This uses an impulse sealer that includes a heater base having a heat welding surface on which a heater wire is disposed, and a pressing body that presses the heat weldable packaging bag against the heat welding surface. A pressure is applied to the welding surface, a large current is instantaneously applied to the heater wire, and the heat is generated to heat and weld the opening of the packaging bag. A linear heating welding portion corresponding to the heater wire, that is, a linear sealing portion is formed on the packaging bag produced by the impulse sealer.

[0003] By the way, in the case of a packaging bag filled with powdery and granular materials, for example, a rice bag, if the opening is sealed after filling the contents into the bag, air is trapped in the packaging bag. Since inconvenience occurs in subsequent handling, for example, loading and delivery of a plurality of packaging bags, it is necessary to perform deaeration processing. Therefore, measures have been taken to perforate the packaging bag or to form a ventilation passage so that the air can be removed.

As a technique relating to the ventilation passage, there is a technique in which an unwelded portion is forcibly formed in a seal portion of a packaging bag, and the unwelded portion is used as air vent. As forcibly forming the unwelded portion, a portion where the packaging bag comes into contact with the heater wire in a non-pressurized state is created by providing irregularities on the heat welding surface of the heater base, and the portion is unwelded. To insert the Teflon plate into the opening of the packaging bag, for example, so that the heat transfer of the heater wire can be cut off,
A method is adopted in which a portion where a Teflon plate or the like is inserted is not welded.

[0005]

However, in the method in which the unwelded portion is formed by providing irregularities on the heat-welded surface of the heater base, even in the non-pressurized state, the heat of the heater wire is slightly conducted from the surroundings. Although not completely welded, a so-called temporary welded state is likely to occur. That is, the unwelded portion provided in the seal portion has not been able to sufficiently function as a ventilation passage. In the method of forming a non-welded portion by inserting a Teflon plate or the like into the opening of the packaging bag, the unwelded portion can be formed to a certain extent, but the structure of the impulse sealer itself becomes complicated,
This is not preferable in terms of device design.

Accordingly, the present invention provides a sealing technique in which, when sealing the opening of a heat-sealable packaging bag, an unwelded portion serving as a ventilation passage can be reliably formed simply by improving the heater wire. With the goal.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a high-resistance portion capable of heat-welding a heat-weldable material by energization, and a low-resistance portion capable of heat-welding a heat-weldable material by energization. The heater wire was formed such that the resistance portion and the resistance portion were alternately continuous in the longitudinal direction. According to the heater wire of the present invention,
Heat is generated only in the high-resistance portion, and the low-resistance portion only contributes to electricity supply. For this reason, even when a heat-weldable material is brought into contact with the heater wire of the present invention, only the portion in contact with the high-resistance portion is welded, and the portion in contact with the low-resistance portion is in an unwelded state. That is,
When a heat-weldable material is brought into contact with a heater wire having such a high resistance portion and a low resistance portion alternately continuous in the longitudinal direction, a welding portion corresponding to the high resistance portion and the low resistance portion is formed. And the unwelded portion can be reliably and continuously formed alternately and continuously.

In the present invention, the high-resistance portion capable of heat-welding a heat-weldable material by energization is a so-called electrothermal resistance material which is made of a high-resistance material having a high electric resistance. And alloys composed of Ni-Cr alloys. Further, the low-resistance portion in the present invention, which cannot be heat-welded by energizing a heat-weldable material, is a so-called conductive material, which is made of a low-resistance material having a low electric resistance, such as Cu,
One made of a Cu alloy or the like can be used. In the above and the following, the term “wire” of a heater wire is not limited to a so-called linear shape, but includes any shape that can be formed of a material forming the heater wire, such as a ribbon shape or a plate shape. It is used as a thing.

In order to make the high resistance portion and the low resistance portion alternately continuous in the longitudinal direction like the heater wire of the present invention, a low resistance material is coated on the surface of the core material made of the high resistance material. It is preferable to coat at predetermined intervals. This is because the heater wire according to the present invention can be easily formed using a core material made of a high-resistance material, that is, a commercially available heater wire. The coating of the low resistance material is, for example,
It is only necessary to make the low-resistance material into a thin plate shape and wind the thin plate around the surface of the core material made of a high-resistance material. You may.

Further, since the heater wire according to the present invention can be applied to an impulse sealer, it is possible to easily and reliably form a ventilation path for degassing in a heat-sealable packaging bag. If the impulse sealer provided with the heater wire in the present invention, by performing a sealing process on the opening of the packaging bag, it is possible to reliably form a linear seal portion in which the welded portion and the unwelded portion are alternately and continuously provided. Since the unwelded portion does not have a temporarily welded state as in the prior art, the unwelded portion sufficiently functions as a ventilation passage.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. First, an embodiment of a heater wire according to the present invention will be described with reference to FIG. As shown in FIG. 1, the heater wire 1 in the present embodiment has a ribbon-like shape,
High resistance portions 2 made of a -Cr alloy and low resistance portions 3 made of Cu are alternately and continuously formed. The heater wire 1 in this embodiment has a width of 3.2 mm and a thickness of 0.5 mm.
5mm width and 0.1mm thickness on a ribbon-shaped Fe-Cr alloy
mm in the form of a thin plate, and the distance between the low-resistance portions 3 is 5 mm.
It is formed by winding at a distance so as to be 0 mm.

Next, an impulse sealer provided with a heater wire according to the present invention will be described with reference to FIG. The impulse sealer 4 shown in FIG. 2 is for sealing a rice bag P as a packaging bag, and FIG. 2 schematically shows the mechanism. Impulse sealer 4
Has a heater base 7 in which a ribbon-shaped heater wire 5 similar to that shown in FIG. 1 is arranged on a heat welding surface 6, and a pressing body 8 that presses the rice bag P against the heat welding surface 6. It is. The rice bag P is held by clip means (not shown) so that the seal corresponding portion 11 of the opening 10 for filling the rice grains 9 is located between the heater base 7 and the pressing body 8. In addition, a Teflon sheet 12 for preventing image sticking is combined with the front surface of the heater base 7 on which the heater wires 5 are arranged.

FIG. 3 is a schematic plan view of a rice bag sealed by the impulse sealer 4 of the present embodiment. In the seal portion 13 sealed by the impulse sealer, the welded portions 14 and the unwelded portions 15 were alternately and continuously formed in a straight line. When all the unwelded portions 15 were confirmed, none was in a temporarily welded state, and the function as a ventilation passage could be sufficiently performed.

[0014]

According to the present invention, heat-weldable materials are
The welded portion and the unwelded portion can be reliably formed, and when the ventilation passage is secured by a packaging bag such as a rice bag, the unwelded portion as the ventilation passage can be reliably formed in the seal portion.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a heater line according to an embodiment.

FIG. 2 is a schematic sectional view of an impulse sealer according to the embodiment.

FIG. 3 is a schematic plan view of a sealed rice bag.

[Explanation of symbols]

 1, 5 Heater wire 2 High resistance part 3 Low resistance part 4 Impulse sealer 6 Heat welding surface 7 Heater base 8 Pressing body 13 Seal part 14 Welding part 15 Unweld part P Rice bag

Claims (3)

[Claims] 1. A heater wire in which a high-resistance portion that can heat-weld a heat-weldable material by energization and a low-resistance portion that cannot heat-weld a heat-weldable material by energization are alternately continuous in the longitudinal direction. 2. The heater wire according to claim 1, wherein a high resistance portion and a low resistance portion are formed by coating a low resistance material at predetermined intervals on a surface of a core material made of a high resistance material. 3. A heater base having a heat welding surface having a heater wire disposed on a surface thereof, and a pressing body for pressing a heat weldable packaging bag against the heat welding surface, wherein an opening of the packaging bag is in a pressurized state. The impulse sealer according to claim 1, wherein the heater wire is a heater wire according to claim 1.