JPH10119129A - Method for welding bottom material of tube container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain enough and sure welding between a bottom part opening end of a tube container main body and a bottom material and to obtain high standing stability and complete sealing properties and to keep stably standing posture under installing condition. SOLUTION: A curl part 1b produced by curving inside the bottom part opening end 1a of a tube container main body 1 made of a synthetic resin whose bottom part is opened is molded and after a bottom material 2 placed on this curl part 1b is welded by pressing a hot plate 25, the outside of the welded part is cut by means of a cutter 18 and a recessed part is molded on the bottom material 2 and the welded are between the tube container main body 1 and the bottom material 2 is enlarged to obtain enough and sure welding and by molding the recessed part on the bottom material 2, a stable standing posture under installing condition is kept by itself.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for welding a bottom material of a synthetic resin tube container.

[0002]

2. Description of the Related Art In a tube container made of synthetic resin which can be erected by providing a flat bottom surface, a conventional method of forming the bottom surface is a tube container body 1 having an open bottom surface as shown in FIG. It is set upside down, and a synthetic resin film-like bottom material 2 is placed on the bottom open end 1a, and a hot plate 3 is pressed from above to weld the bottom material 2 to the end face of the bottom open end 1a. After that, a method of cutting and removing an unnecessary portion (outer portion of the cut line 4) of the peripheral edge of the bottom material 2 can be considered.

[0003]

However, in the above-mentioned prior art, the welding peripheral portion 5 is also cut and removed by cutting the peripheral portion of the bottom member 2, so that the welding area is reduced and sufficient welding strength is obtained. There was a problem that it could not be obtained.

Further, the end surface of the bottom open end 1a may be slightly inclined with respect to the horizontal plane due to the bending deformation of the tube container body 1 due to the pressing force of the hot plate 3 during welding or the irregular deformation from the beginning. Bottom open end 1a at low position
In some parts, there was a problem that welding strength was weakened.

Further, in this type of tube container, a flat bottom surface often protrudes outward due to an increase in environmental temperature or an increase in the internal pressure of the container due to external stress (for example, pressure on the body). Therefore, there has been a problem that the standing stability (sitting) of the container is deteriorated.

Therefore, the present invention has been made to solve the above-mentioned problems in the prior art, and provides a sufficient and reliable welding between the bottom open end of the tube container main body and the bottom material, as well as high standing stability. Is to be a technical issue.
Accordingly, it is an object of the present invention to provide a tube container which exhibits perfect sealing performance and stably maintains an upright posture during standing.

[0007]

Means for Solving the Problems In order to solve the above technical problem, a first aspect of the present invention is to provide a synthetic resin tube container body having an open bottom with a bottom open end bent inward. A step of forming a curled portion with a guide hole having a shape corresponding to the peripheral shape of the bottom of the tube container body, and a cutter is provided upright on an upper peripheral edge of the guide hole, and a sleeve guide controlled to move vertically is provided. In the holding device, the tube container body is set upside down, the synthetic resin film-like bottom material is placed on the cutter, and the hot plate is lowered from above the sleeve guide while lowering the sleeve guide. Then, the bottom material is pressed against the bottom open end of the tube container body and welded, and then, after moving the hot plate, the cutter receiving plate is lowered to be pressed against the bottom material,
It comprises a step of cooling the bottom material and cutting the outside of the welded portion with a cutter, and a step of forming a recessed concave portion in the bottom material.

[0008] A second aspect of the present invention is a method for forming a curled portion by bending an open bottom end of a synthetic resin tube container body having an open bottom portion inwardly, and forming the curl portion. The tube container main body is set upside down in a holding device having a guide hole having a shape corresponding to the circumferential shape, a cutter standing upright on the peripheral edge of the guide hole, and a sleeve guide controlled to move up and down. At the same time, a synthetic resin bottom material having a recess formed in advance is placed on the cutter, and while the sleeve guide is lowered, the hot plate is lowered from above the sleeve guide so that the bottom material is opened at the bottom open end of the tube container body. After the hot plate is moved, the cutter receiving plate is lowered and pressed against the bottom material, and the bottom material is cooled and the outside of the welded portion is cut by the cutter. And the process, consisting of.

According to the bottom peripheral shape of the tube container body,
And, a pressing jig provided with a concave portion having a pressing surface inclined downwardly in an expanded manner on the lower surface is disposed above the sleeve guide,
After setting the tube container body upside down on the holding device,
It is preferable to lower the heated pressing jig and press the outer edge of the bottom open end of the tube container body with the pressing surface of the pressing jig to form the curled portion.

After blowing hot air from above onto the film-shaped bottom material welded to the open bottom end of the tube container body, a cooling press jig provided with a convex portion having a desired shape on the lower surface is lowered and pressed. It is preferable to form a concave portion on the bottom member by applying the concave portion.

[0011]

Since the curled portion is formed in advance at the bottom open end of the tube container body, the area for welding to the bottom material is increased, whereby strong and reliable welding can be achieved over the entire circumference.

Further, since the depression is formed in the bottom material, the bottom surface of the tube container does not protrude outwardly, and the standing stability is improved.

According to the third aspect of the present invention, the forming of the curled portion and the welding of the bottom material can be easily and efficiently performed in a series of steps using the same holding device.

According to the fourth aspect of the present invention, the welding of the bottom member and the forming of the concave portion can be easily and efficiently performed in a series of steps using the same holding device. At times, the bottom material is bent and deformed, and the outer edge is displaced inward and pressed against the upper surface of the curl portion.Therefore, the unwelded portion slightly remaining on the lower surface of the outer edge portion of the bottom material also becomes It is completely welded, thereby sufficiently strengthening the tight welding assembly between the tube container body and the bottom member, and improving the appearance of the bottom of the formed tube.

[0015]

FIG. 1 shows an embodiment of a step of curling the bottom open end 1a of a tube container body 1 inward prior to welding of a bottom member 2. FIG.

The holding device 10 is provided on a table 11 with a ventilation hole 13.
And a plurality of cylinders 14 for vertically controlling the movement of a rod 15. The upper end of the rod 15 has a guide at the center corresponding to the shape of the bottom of the tube container body 1. A hole guide 17 is provided, a sleeve guide 16 on which a cutter 18 is erected is fixed on a peripheral upper surface of the guide hole 17, and the rod 1 is fixed by a spring 19.
5 is urged upward, and a water cooling passage 16 a is opened in the sleeve guide 16.

A heated pressing jig 20 is provided above the sleeve guide 16 and has a concave portion 21 on the lower surface having a pressing surface 22 corresponding to the peripheral shape of the bottom of the tube container main body 1 and inclined downwardly and expanding. Are arranged to be vertically movable.

The pressing jig 20 is provided with a ventilation hole 23 functioning as an air vent communicating with the upper end of the concave portion 21, and the lower end around the concave portion 21 is provided with a heat insulating material 2.
4, the angle α of the pressing surface 22 with respect to the vertical is preferably about 60 ° from the results of many trial productions.

Therefore, when the tube container main body 1 is set upside down in the holding device 10 and the heated pressing jig 20 is lowered with the ventilation holes 13 and 23 functioning as air vents being opened, the heat insulating material 24 is formed. Sleeve guide 16
Since the pressing surface 22 presses the outer edge of the bottom opening end 1a of the tube container main body 1 while contacting and pressing down the upper surface, the bottom opening end 1a heated and softened by the pressing jig 20 is bent inward. This is formed on the curled portion 1b (see FIG. 1B).

The formation of the curled portion 1b can increase the welding area to the bottom member 2, but the curling method is not limited to this embodiment.
For example, a method using a pressing jig that presses the bottom open end 1a of the tube container body 1 in the horizontal direction from the outside while heating, or a method in which the upper end of the inner peripheral surface is previously formed into a curl-shaped inwardly curving shape. It may be carried out by a method using a forming jig or the like.

FIG. 2 shows an embodiment of a step of welding the bottom member 2 to the curl portion 1b formed at the bottom open end 1a of the tube container body 1. In this step, the pressing jig 20 Instead, a hot plate 25 (FIG. 2A) and a cutter receiving plate 26 with a water cooling device (FIG. 2B) are used.

First, as shown in FIG. 2A, the sleeve guide 16 is raised to the original position, the sheet film 30 as the bottom material 2 is placed on the cutter 18, and the tube 13 is opened with the vent hole 13 opened. The sleeve guide 16 is lowered with respect to the container body 1 to a predetermined position,
The hot plate 25 heated to 0 ° C. is lowered, and about 2
The sheet film 30 is pressed on the upper surface of the curled portion 1b for seconds.

Next, after the hot plate 25 is retracted, FIG.
As shown in (b), the cutter receiving plate 26 is lowered and pressed against the sheet film 30 to cool the sheet film 30, and the outside of the welded portion is cut by the cutter 18;
The sealing operation is completed.

The material of the tube container body 1 may be any thermoplastic synthetic resin that can be welded with a hot plate, or this thermoplastic synthetic resin may be used as a sealing layer. It is preferable to use a laminate (EVOH) or a laminate of aluminum laminate films.

Examples of the bottom member 2 include a single-layer sheet film of the above-mentioned thermoplastic synthetic resin, a laminated film in which a reinforcing material (such as polypropylene, polycarbonate, polystyrene, and polyethylene terephthalate) that resists a change in pressure inside and outside the container is laminated. The sheet film 30 or a sheet of the thermoplastic synthetic resin or a laminated sheet provided with an EVOH layer on the sheet, and a thermoformed molded article which is formed in advance so as to have the concave portion 2a is preferable.

FIG. 4 shows an example of the bottom sheet film 30. The outer layer 31 has a heat-resistant lacquer coating.
The intermediate layer 32 as a deformation prevention reinforcing layer is made of polypropylene,
The middle layer 33 is made of EVOH, the inner layer 3
4 is made of low-density or ultra-low-density polyethylene.

FIG. 3 shows an embodiment of a process of forming a concave portion 2a which is hardly deformed by inverting and protruding outward in a bottom material sheet film 30 welded to the tube container body 1.
That is, first, as shown in FIG.
Hot air is sprayed from the upper nozzle 27 to the central portion of 0 to soften it by heating.

Next, as shown in FIG. 3 (b), the cooling press jig 28 having the convex portion 29 of a desired shape formed on the lower surface is lowered, and the convex portion 29 is pressed against the sheet film 30 to form the concave portion 2a. Mold and cool and cure.

When the concave portion 2a is formed, since the sheet film 30 is bent and deformed, and its outer edge is pressed inward while being displaced inward, the sheet film 30 slightly adheres to the lower surface of the outer edge of the sheet film 30. The remaining unwelded portion 30a (see FIG. 4) is also completely welded to the curled portion 1b.

FIGS. 5 to 7 show variations in the shape of the concave portion 2a. A reinforcing portion 35 made of the reinforcing material is formed in the bottom member 2 shown in FIG.

FIGS. 8A to 8F show variations of the bottom peripheral shape of the tube container formed by the guide holes 17 of the sleeve guide 16. FIG.

[0032]

According to the present invention, since the curled portion is formed in advance on the open end of the bottom of the tube container body, the welding area with the bottom material is widened, and thereby the welding is strong and reliable over the entire circumference. Can be achieved, and complete sealing properties can be obtained.

Further, since the recessed portion is formed in the bottom member, the bottom surface of the tube container does not protrude outwardly, so that the standing stability of the tube container and the stability in transporting the filling line are improved.

According to the third aspect of the present invention, the forming of the curled portion and the welding of the bottom material can be easily and efficiently performed in a series of steps using the same holding device.

According to the fourth aspect of the present invention, the welding of the bottom member and the forming of the concave portion can be easily and efficiently performed in a series of steps using the same holding device. At times, the bottom material is bent and deformed, and the outer edge is displaced inward and pressed against the upper surface of the curl portion.Therefore, the unwelded portion slightly remaining on the lower surface of the outer edge portion of the bottom material also becomes It is completely welded, and the welding strength can be further increased.

[Brief description of the drawings]

FIG. 1 is a state explanatory view showing one embodiment of a curl forming step in the present invention.

FIG. 2 is a state explanatory view showing one embodiment of a bottom material welding step in the present invention.

FIG. 3 is a state explanatory view showing one embodiment of a step of forming a concave portion on a bottom material in the present invention.

FIG. 4 is an enlarged sectional view showing an example of a configuration of a bottom member used in the present invention.

5A and 5B show an example of a concave portion formed in a bottom material according to the present invention, wherein FIG. 5A is a cross-sectional view and FIG. 5B is a bottom view.

6A and 6B show an example of a concave portion formed in a bottom material according to the present invention, wherein FIG. 6A is a cross-sectional view and FIG. 6B is a bottom view.

7A and 7B show an example of a concave portion formed in a bottom member according to the present invention, wherein FIG. 7A is a cross-sectional view and FIG.

FIG. 8 is a bottom view showing an example of a bottom peripheral shape of the tube container of the present invention.

FIG. 9 is a sectional view showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1; Tube container main body 1a; Bottom open end 1b; Curl part 2; Bottom member 2a; Depression 3; Hot plate 4; Cut line 5; Welding peripheral part 10; Holding device 11; Table 12; Tube holder 13; Cylinder 15; Rod 16; Sleeve guide 16a; Water cooling channel 17; Guide hole 18; Cutter 19; Spring 20; Pressing jig 21; Depression 22; Pressing surface 23; Vent hole 24; Heat insulating material 25; Cutter receiving plate 27; Nozzle 28; Cooling jig 29; Convex portion 30; Sheet film 30a; Unwelded portion 31; Outer layer 32; Intermediate layer 33; Intermediate layer 34; Inner layer 35;

Claims (4)

[Claims] 1. A curl section wherein a bottom open end (1a) of a synthetic resin tube container body (1) having a bottom opened is bent inward.
(1b), and a guide hole (17) having a shape corresponding to the bottom peripheral shape of the tube container body (1), and a cutter (18) is set up on a peripheral upper surface of the guide hole (17). The tube container body (1) is set upside down on a holding device (10) provided with a sleeve guide (16) that is installed and controlled to move up and down, and a synthetic resin material is placed on the cutter (18). Place the film-like bottom material (2) and place the sleeve guide (1
While lowering 6), lower the hot plate (25) from above the sleeve guide (16) to move the bottom material (2) to the tube container body.
(1) is pressed against and welded to the bottom open end (1a), then the hot plate (25) is moved, and then the cutter receiving plate (26) is lowered and pressed against the bottom material (2). Cooling the bottom member (2) and cutting the outside of the welded portion with the cutter (18); and forming a depressed concave portion (2a) in the bottom member (2). Method of welding bottom material for tube containers. 2. A curled portion in which a bottom open end (1a) of a synthetic resin tube container body (1) having an open bottom is bent inward.
(1b), and a guide hole (17) having a shape corresponding to the bottom peripheral shape of the tube container body (1), and a cutter (18) is set up on a peripheral upper surface of the guide hole (17). The tube container body (1) is set upside down on a holding device (10) provided with a sleeve guide (16) that is installed and controlled to move up and down, and a concave portion ( Two
a) The synthetic resin bottom material (2) molded is placed, and the sleeve guide (16) is lowered while the sleeve guide (16) is lowered.
The hot plate (25) is lowered from above, and the bottom material (2) is pressed and welded to the bottom open end (1a) of the tube container body (1),
Next, after moving the hot plate (25), the cutter receiving plate (26)
Lowering the bottom member (2) to press it against the bottom member (2), cooling the bottom member (2), and cutting the outside of the welded portion by the cutter (18). . 3. A pressing jig (20) having a depression (21) on the lower surface corresponding to the bottom peripheral shape of the tube container body (1) and having a pressing surface (22) inclined downward and widened downward. Is placed above the sleeve guide (16), the tube container body (1) is set upside down in the holding device (10), and then the heated pressing jig (20)
Is lowered, and the outer surface of the bottom open end (1a) of the tube container body (1) is pressed by the pressing surface (22) so that the curl portion (1) is pressed.
The method for welding a bottom material for a tube container according to claim 1 or 2, wherein b) is formed. 4. The bottom open end (1a) of the tube container body (1).
After blowing hot air from above onto the film-like bottom material (2) welded to, a cooling press jig (28) provided with a convex portion (29) of a desired shape on the lower surface is lowered and pressed down, Recess in bottom material (2)
2. The method according to claim 1, wherein (2a) is formed.