JP2000142604A - Sealer for tube container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealer for sealing one of ends of a tube for a tube container with a hot blast for forming an end seal wherein turbulence of the hot blast in a nozzle for ejecting the hot blast is prevented, thereby uniformly heating the tube seal so as to prevent seal strength from being uneven and a resin from bulging when the tube is cut. SOLUTION: One of ends of a pipe 1 forming a nozzle 10 is an inlet port 7 for a hot blast, while the other end is an ejection end 2. Ejection ports 5 of the hot blast surrounding a peripheral face of the injection end 2 are formed laterally symmetrical with respect to a symmetric plane M, while the ejection end 2 is covered by a straightening face 21 including a line connecting between respective symmetric positions of the laterally symmetric ejection ports 5 or a line protruding from the above line toward the inlet port.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tube container sealing device for manufacturing a tube container having an end seal portion having an arbitrary shape such as a round cut type.

[0002]

2. Description of the Related Art A squeeze port with a cap is formed at one end of a flexible tube, the contents are filled from the other end, and this end is flatly press-sealed to seal an end seal portion. Are widely used as containers for paste-like toothpaste, food, cosmetics, pharmaceuticals, adhesives, and the like. In many cases, at least the innermost layer of the tube is formed of a heat-fusible film such as polyethylene, and when forming the end seal portion, a hot air method or a heat seal method is used according to the material of the tube. The sealing part is heated and pressed by a high-frequency sealing method, an ultrasonic sealing method, or the like to be sealed.

[0003] In particular, when a tube to be sealed (hereinafter, simply referred to as a "tube") is made of only a resin layer and has a large thickness, a hot air method is often used. This hot air method is a method in which hot air is blown to the inside of an end seal portion of a tube and heated to a sealable temperature and then pressed, for example, one end of a pipe having an outer diameter slightly smaller than the inner diameter of the tube. A nozzle having a hot-air jet formed of a row of small holes or slits formed on the pipe peripheral surface along the sealed edge is used to seal the opening of the nozzle. Hot air is introduced into the nozzle by inserting the nozzle into the tube so as to face the seal portion. Then the hot air blows out from the injection port,
The seal is heated annularly against the inner surface of the tube.
When the temperature of the seal portion reaches the sealable temperature, the nozzle is pulled out and pressed immediately to form an end seal portion. The end seal portion formed using the nozzle is formed in a straight line shape (flat shape) whose end is perpendicular to the axis of the tube.

[0004] Most of the conventional tube containers are of the flat type described above, but recently, tube containers having a so-called round-cut type end seal portion have been produced due to design requirements and the like. Was. As shown in FIG. 6, the round-cut end seal portion is formed by flat-press-sealing the end seal portion S of the tube T so as to form a semicircular or semi-elliptical shape. In order to form the round seal type end seal portion S, a round seal nozzle as shown in FIG. 7 is used.

The round seal nozzle 100 is a pipe 1 having an outer diameter slightly smaller than the inner diameter D of the tube T.
01, one end of the pipe 101 serves as an inlet 107 for hot air, and the other end of the pipe 101 is cut into a bilaterally symmetrical chevron with the diameter of the pipe as a ridgeline 102. An injection port 105 composed of a number of rows of small holes or slits is formed on the peripheral surface of the pipe along the edge 103, and the chevron opening of the pipe 101 is formed by the ridge line 1
02 is covered with a gable roof-like surface material 104. In some cases, two or more rows of the injection ports 105 are formed in parallel.

A flange 106 is attached to the pipe 101 on the side of the hot air inlet 107, and is connected to a hot air supply source.
When the nozzle 100 is inserted into the upper end of the tube T filled with the contents and hot air is introduced into the nozzle from the inlet 107 at a predetermined pressure, the hot air radiates from the injection port 105 toward the inner wall of the tube T. It is injected. When the sealing portion of the tube T reaches the sealable temperature by the hot air, the nozzle 100 is withdrawn and the sealing portion is immediately pressed to form an end sealing portion. Since the end seal portion formed using the nozzle 100 has a semi-circular or semi-elliptical convex shape, cutting the tube along the outer edge of the end seal portion makes it possible to seal the round-cut tube container. An end is formed.

[0007]

However, when end sealing is performed using the above-described conventional round sealing nozzle 100, unevenness occurs in the joining state of the seals, and in some cases, the sealing strength of the end sealing portion is partially reduced. When the tube is pressed during the pressure test process, the tube may rupture from this weak part.In other cases, the heating temperature of the end seal part is too high, and the resin in the seal part is still insufficient after crimping. Before the resin is solidified, it is sent to the pressure test process and ruptures.Before the resin is solidified, the outer seal of the end seal is cut off. occured.

The inventor of the present invention has investigated the cause of these problems and found that the cause is that turbulent hot air is generated in the nozzle and that the hot air is not uniformly jetted from the jet port 105. That is, as shown in FIG. 8, when hot air is pressed into the nozzle 100 from the inlet 107, the hot air travels straight through the pipe 101 and collides with the ridgeline 102 and the gable roof-like surface material 104 at the deepest point. The turbulence is generated, particularly in the space between the two gable roof-like panels 104. For this reason, a large pressure loss occurs in the nozzle, and the injection efficiency of the hot air is reduced. In addition, depending on the position of the injection port 105, for example, the injection pressure is largely different between the portion 105a near the ridgeline 102 and the portion 105b far from the ridgeline 102, and the injection direction is also straight. It was also found that heating unevenness occurred as a result. Further, when an end seal having a different shape is required from design requirements, the above-mentioned round seal nozzle 100 cannot cope with it. Therefore, the object of the present invention is
End seals of various shapes that draw curves can be formed, preventing turbulence of hot air in the nozzle, thereby uniformly heating the tube seals, resulting in uneven sealing strength and cutting resin. An object of the present invention is to provide a tube container sealing device capable of preventing the protrusion.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a sealing device for sealing one end of a tube for a tube container to form an end seal portion, wherein an inner surface of the tube is provided. A nozzle having a diameter that can be inserted into the tube by injecting hot air into the tube and injecting the hot air to the sealable temperature, and an opening at one end of the pipe is an inlet for hot air. The other end is an injection end, and on the peripheral surface of the injection end, an injection port of hot air consisting of a row of small holes or slits bent in the axial direction of the pipe surrounds the peripheral surface of the injection end. The injection port is formed bilaterally symmetric with respect to a plane including the axis and the two base points with a base point at a point where a straight line passing through the axis of the pipe intersects the peripheral surface of the pipe. Part along the outer edge of the injection port Te, to provide a seal device for a tube container characterized by having a rectifying surface including a straight or convex and is a line from the inlet port side of the straight line connecting the respective symmetrical positions with respect to the symmetry plane.

[0010] With the above-mentioned structure of the tube container sealing device, the introduced hot air flows smoothly along the straightening surface and is distributed to each part of the injection port.
Turbulence and pressure loss in the nozzle are reduced, and uniform hot air is jetted from each part of the injection port, thereby uniformly heating the seal portion of the tube. Also, by forming the two base points inclined with respect to the axis, or by forming the row of injection ports in a different shape,
End seals of various shapes can also be formed.

Further, according to the present invention, a rectifying member having a rectifying surface including a straight line connecting the symmetrical positions of the left-right symmetrical small hole rows or the slits or a line protruding toward the inlet from the straight line is formed in the pipe. A sealing device for a tube container provided in an end portion. Thus, there is an advantage that the shape of the nozzle and the shape of the flow straightening surface can be shaped without any restriction.

It is preferable that the rectifying surface is configured so as to be convex toward the inlet port beyond a straight line connecting two symmetrical points of the injection port closest to the inlet port. As a result, the pressure loss is further reduced because the bending angle when the hot air comes into contact with the rectifying surface is further reduced, and the hot air in the pipe is more uniformly distributed to all portions of the injection port formed on the peripheral surface of the pipe. In addition, the sealing portion of the tube can be more uniformly and efficiently heated.

Still further, according to the present invention, the jet end of the pipe is cut along an outer edge of the jet port, and the cut portion is covered with a gable roof-like face material. And a rectifying member including the rectifying surface is mounted on the inner surface of the tube container. The insertion end of the nozzle into the tube container is cut into a spire shape, and the cut surface is covered with a gable roof-like surface material, so that the nozzle can be smoothly inserted into the tube end. In the case of forming a round cut type end seal portion, it is only necessary to attach the above-mentioned rectifying member to a conventionally used round cut nozzle, so that costs can be reduced as compared with a case where a new nozzle is formed. .

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments of the present invention will be described with reference to the drawings. The embodiment shown in FIG. 1 is a nozzle for forming a round-cut type end seal on a tube, and this nozzle 10 has a rectifying member 20 mounted in a nozzle body 11. Nozzle body 1
Reference numeral 1 denotes a pipe 1 having an outer diameter that can be inserted into a tube to be sealed. One end of the pipe 1 is an inlet 7 for hot air, and the other end is an injection end 2.

On the peripheral surface of the injection end 2, an injection port 5 composed of a row of small holes bent in the direction of the axis XX of the pipe 1 is formed so as to surround the peripheral surface of the injection end 2. . The injection port 5 has two axes P1 and P2 at which a straight line L passing through the axis XX of the pipe 1 intersects the peripheral surface of the pipe 1 as a base point.
It is formed symmetrically with respect to a plane (symmetric plane) M containing -X and the two base points P1 and P2. The injection end portion 2 includes a straight line N connecting the respective symmetric positions n and n of the injection port 5 with respect to the symmetry plane M or a straightening surface 21 including a line R protruding from the straight line toward the inlet 7. have.

Further, the injection end 2 is cut along the outer edge of the injection port 5, and this cut portion is cut into a gable roof-like face material 4,
4 is covered. A rectifying member 20 including the rectifying surface 21 is mounted on the inner surfaces of the gable roof-like surface members 4 and 4. Since the flange 6 is attached to the inlet 7 side of the pipe 1 and connected to a hot air supply source, when hot air is introduced into the nozzle body 11 from the inlet 7 at a predetermined pressure, the hot air flows through the pipe 1. The gas is radially injected from the injection port 5 toward the inner wall of the tube to be sealed.

The straightening member 20 is shown in FIGS. 1 and 2 (a).
(B) and as shown in FIG. 3, in the state where the nozzles are mounted on the nozzle body 11, the gable roof-like surface members 4, 4 have inscribed surfaces 24, 24, and the outer edge of the row of the injection ports 5. Along the plane of symmetry M, there is a rectifying surface 21 including a line R protruding toward the inlet 7 from a straight line N connecting the respective symmetric positions n, n of the injection ports symmetrical to the left and right with respect to the symmetry plane M. The rectifying surface 21 is provided with two injection ports q1, q2 closest to the inlet 7.
Is formed on the inlet 7 side beyond the line Q connecting the two, and the rectifying surface 21 has a cone shape whose diameter gradually decreases toward the inlet 7 as a whole. This rectifying member 20
When the inscribed surfaces 24, 24 are inscribed and bonded to the gable roof-like surface materials 4, 4, the cone-shaped rectifying surface 21 comes to be located at the outer edge immediately along the row of the injection ports 5, The flow of the hot air passing through the injection port 5 is not hindered by the rectifying surface 21.

The nozzle 10 is inserted into the sealing end of the tube filled with the contents and sent to the end sealing step, and when hot air is introduced at a predetermined pressure from the inlet 7, the hot air is rectified to project in a cone shape. It comes into contact with the surface 21 at a gentle angle and is evenly distributed along the rectifying surface 21 toward the injection port 5, and the hot air injected uniformly heats the sealing portion of the tube. At this time, since there is no space in the nozzle 10 where the hot air is disturbed, no turbulence occurs, and the flow of the hot air toward the injection port 5 is smoothly adjusted, so that the pressure loss is reduced.

When the sealing portion of the tube reaches the sealable temperature by the injection of the hot air, the nozzle 10 is withdrawn and the sealing portion is immediately pressed to form a round end seal portion. Since the end seal portion is heated to a uniform temperature throughout, the seal strength after crimping becomes uniform for each portion, and in the next pressure test step, rupture due to partial sealing failure or overheating occurs. Absent. Further, the resin does not protrude from the cut portion in the shape of a whisker when the seal end is cut.

The rectifying surface 21 is preferably mirror-finished. Thereby, the pressure loss of the hot air is further reduced, the heat reflection is improved, and the thermal efficiency is improved. The rectifying member 20 is preferably made of the same material as the material of the nozzle body 11, for example, stainless steel or formed of ceramics. This reduces the risk that the rectifying member 20 may be damaged due to a difference in the coefficient of thermal expansion or the like and may be separated from the inner wall of the gable roof-like surface member 4.

The rectifying member 20 may be a solid molded body with a solid interior, or may be a hollow body having only the skin. In addition, since the nozzle in the present invention only needs to have the above-described rectifying surface at the injection end portion, the rectifying member including only the rectifying surface 21 without attaching the gable roof-like surface members 4 and 4 is preferable. May be attached. In this case, the pipe may not be cut diagonally along the outer edge of the injection port, but may be left as a cylinder. The nozzle 10 may be designed to have a shape that facilitates insertion in the step of inserting the nozzle into the tube, and there is an advantage that there is no restriction between the shape of the tip of the nozzle and the shape of the straightening surface in this design.

In FIG. 1, the injection port 5 is shown as one row of small holes, but a slit may be used instead of the small hole row. In the case of a slit, the face materials 4 and 4 need to be intermittently connected to the pipe 1 by a connecting member so that the pipe is not divided by the slit surrounding the pipe peripheral surface. In any case of the row of small holes and the slit, not only one row but also two rows or more may be formed in parallel.
From the viewpoint of the strength of the seal portion, it is preferable to form about three rows. In the case of a row of small holes, the diameter of the small hole, the interval between adjacent small holes, the width of the slit, etc. are not particularly limited, and the required seal strength and seal width, or the injection port is a seal. It can be appropriately selected according to the state of the part to be performed.

In the above embodiment, the axis X of the pipe 1
Although the straight line L passing through −X is perpendicular to the axis XX, that is, the diameter is shown, the straight line L may be inclined with respect to the axis XX. In this case, for example, as shown in FIG.
1 can be formed. The row of the injection ports 5 is symmetrical with respect to the plane of symmetry M and the axis X- of the pipe.
Since it is only necessary to bend in the X direction, the side view may be a straight line or may be convex or concave toward the inlet 7. The row of the injection ports 5 may have an irregular shape in side view, for example, a waveform. In this case, a corrugated end seal portion S2 can be formed in the tube T as shown in FIG. 5, for example.

(Test Example) A nozzle of the embodiment shown in FIG. 1 was prepared. Specifications are shown below. Nozzle body 11 outer diameter: 29 mm, inner diameter: 24 mm, length 36 mm, axial height of face material 4: 18 mm Small hole diameter of injection port 5: 0.8 mm, number of small holes: 76 in the first row,
Second row 70 pieces Straightening member 20 Axial height: 22 mm Further, as Comparative Example 1, a conventional nozzle (Comparative Example 1) having the same shape as the nozzle body 11 of the above-described embodiment and without inserting the straightening member 20, and a conventional example as Comparative Example 2 The number of small holes of the injection nozzle of the mold nozzle was increased from Comparative Example 1 to 76 in the first row, 70 in the second row,
One having 36 pieces in the third row was prepared. Plastic blow tube (outer diameter 33mm, length 130mm, thickness 0.5
mm), ten tube container samples filled with the contents were prepared for each of the nozzles, and the nozzles were inserted into the seal ends of the respective tube container samples.
The inner wall was heated for 60 seconds at a hot air temperature (° C.) and an injection flow rate (NL / H) shown in Table 3 below, immediately pressed under a pressure of 4 kg / cm ² G, and cut to form a round cut end seal portion. With respect to the nozzle of Comparative Example 1, as Comparative Example 3, an experiment in which the hot air temperature (° C.) and the injection flow rate (NL / H) were made higher than in the example was also performed.

After pressing the adhesive strength seal portion, each tube sample after 1 minute is laid on a health meter, a 50 mm square plate is placed on the tube, and the plate is pressed to break the end seal portion. The health meter reading (kg) was recorded. Table 1 shows the measurement results. Judgment was 100 (kg) or more. The appearance inspection was performed on each sample of which the seal portion was cut by compression, and the peeling of the seal portion was visually inspected. Judgment was indicated by ○ when peeling was not found in the seal portion, and by x when peeling was found. Table 2 shows the results.

[0026]

[Table 1]

[Table 2]

From the above results, it can be seen that when the nozzle of the embodiment is used, a round cut type end seal portion having good adhesive strength and good appearance can be obtained with little variation.
On the other hand, in the conventional nozzle (Comparative Example 1) without the rectifying member, the pass rate of the adhesive strength was low, and half of the appearance was poor. A conventional nozzle in which the number of small holes is increased in order to improve the adhesive strength and appearance (Comparative Example 2), and the hot air temperature (° C.) and the injection flow rate (NL / H) without changing the number of small holes
(Comparative Example 3) did not improve the adhesive strength and hardly improved the appearance. In Comparative Example 3, the sealing portion was overheated, and resin whiskers were generated at the cut portion.

[0028]

The sealing device for a tube container according to the present invention comprises:
The injection end of the nozzle has a straightening surface including a straight line connecting the respective symmetric positions of the injection port with respect to the symmetry plane along the outer edge of the injection port or a straight line protruding toward the inlet from the straight line. Therefore, turbulence of hot air is not generated in the nozzle, and hot air is smoothly and uniformly injected from the injection port, thereby uniformly heating the seal portion of the tube, causing unevenness in seal strength and protrusion of resin at the time of cutting. Thus, a tube container having an end seal portion having excellent appearance and strength can be efficiently manufactured.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention.

FIGS. 2A and 2B are cross-sectional views taken along planes passing through the axis of the embodiment and orthogonal to each other.

FIG. 3 is a perspective view showing a rectifying member mounted on the embodiment.

FIG. 4 is a side view showing a tube container having a modified end seal portion.

FIG. 5 is a side view showing a tube container having another modified end seal portion.

FIG. 6 is a side view showing a tube container having a round-cut type end seal portion.

FIG. 7 is a perspective view showing a conventional round cut type end seal nozzle.

FIG. 8 is a sectional view of the nozzle of FIG. 7;

[Explanation of symbols]

 1: pipe 2: jet end 4: face material (gable roof) 5: jet 6: flange 7: (hot air) inlet 10: nozzle 11: nozzle body 20: rectifying member 21: rectifying surface 24: Inscribed surfaces P1, P2: base point L: straight line M: symmetry surface N: straight line n: symmetry position q1, q2: injection port (closest to inlet) Q: line connecting injection ports q1, q2 R: line T: Tube S1, S2: End seal part XX: Pipe axis

Claims (4)

[Claims] 1. A sealing device for sealing one end of a tube for a tube container to form an end seal portion, comprising a nozzle for jetting hot air to an inner surface of the tube to heat the tube to a sealable temperature. A nozzle having an outer diameter capable of being inserted into the tube, and an opening at one end of the pipe serving as an inlet for hot air;
The other end is an injection end, and on the peripheral surface of the injection end, a hot-air injection port consisting of a row of small holes or slits that bends in the axial direction of the pipe is formed so as to surround the peripheral surface of the injection end. The injection port is formed symmetrically with respect to a plane including the axis and the two base points with a base point defined by two points where a straight line passing through the axis of the pipe intersects the peripheral surface of the pipe; Has a straightening surface including a straight line connecting the respective symmetric positions with respect to the symmetry plane along the outer edge of the injection port or a straight line protruding toward the inlet from the straight line. apparatus. 2. A rectifying member having a rectifying surface including a straight line connecting the symmetric positions of the left-right symmetric row of holes or slits or a line protruding toward the inlet from the straight line is provided in the injection end of the pipe. The sealing device for a tube container according to claim 1, wherein the device is mounted. 3. The rectifying surface is configured to protrude to the inlet side beyond a straight line connecting two symmetrical points of the outlet closest to the inlet. Or the sealing device for tube containers of Claim 2. 4. A jet end portion of the pipe is cut along an outer edge of the jet port, and the cut portion is covered with a gable roof-like surface material. The sealing device for a tube container according to any one of claims 1 to 3, wherein a rectifying member including the rectifying surface is mounted.