JPH08258813A - Bottom sealer in packaging machine - Google Patents

Abstract

PURPOSE: To obtain a bottom sealer capable of firmly conducting a bottom sealing without peeling a seal, damaging a material of a film, and breaking an edge of a seal in a packaging machine. CONSTITUTION: In a tubular film surrounding an article fed at a fixed interval along an article feed path, an upper mold 10 and a lower mold 11 for conducting a bottom sealing on a part of a film between articles are disposed so as to move close to each other. On the opposed surfaces of the upper mold 10 and the lower mold 11, corrugated parts 10a, 11a fitted to each other and flat sealing parts 10b, 11b opposed to each other with a small gap of δ at end parts thereof on the bag side are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bottom sealer in a packaging machine, and more particularly to a tubular film surrounding an article fed at a constant interval along a feeding path of the article. The present invention relates to a bottom sealer for a packaging machine.

[0002]

2. Description of the Related Art In the above bottom sealer, FIG.
As shown, the articles 1,
1 ... at regular intervals, and the film 5 in the portion between the articles 1, 1 ... Is pressed from above and below by the upper mold 10 and the lower mold 11 to obtain the results shown in FIGS. It is bonded as shown in. Considering the state of air at the time of FIG. 10B, since the film 5 is crushed flatter than the tubular shape,
A place for the internal air is needed. As a result,
There is air going to the part A behind the article 1 and the part B ahead of the item 1. There is no problem because the A part is open backwards, but B
There is a limit because the air in the part is a bag of limited size,
For example, a method of pushing the portion B of the bag from the outside to reduce the amount of air is adopted.

[0003]

However, since the internal pressure is applied, the seals c and d are about to be peeled off. The seal portion d is in a state where the inner surface poly is also solidifying, but the seal portion c is still in a melted state and is easily peeled off. The present invention improves the shape of the sealer in order to eliminate such drawbacks.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a tubular film that surrounds articles fed at regular intervals along the feed passage of the article 1, and an upper mold 10 and a lower die 10 for bottom-sealing the film between the articles. A mold 11 is provided so as to be close to each other, and corrugated portions 10a and 11a each having a shape to be fitted to each other on the facing surfaces of the upper mold 10 and the lower mold 11 and a minute gap δ at the end portion on the bag side.
Is a bottom sealer in a packaging machine provided with flat seal portions 10b and 11b facing each other.

[0005]

When the film 5 first enters between the upper mold 10 and the lower mold 11, the sealing portion of the film 5 between the corrugated portions 10a and 11a is first melted. Next, the seal portions of the flat seal portions 10b and 11b are melted. Next, since the film 5 between the flat seal portions 10b and 11b has a small heat capacity, it is hardened first. Next, the seal portions of the corrugated portions 10a and 11a are hardened.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 2, articles 1, 1, ... Are sent forward on a supply conveyor 2 by dogs 3, 3 ... at regular intervals, that is, rightward in FIG. The film 5 is rolled into a film 5, and the both ends of the film 5 are sandwiched between the fin sealers 7 and 7 and continuously sealed, and sandwiched by the upper and lower feed conveyors 8 and fed, and then the upper and lower Upper mold for bottom seal 1
0, the seal is cut by the lower mold 11, and the discharge conveyor 1
2 is sent out. Reference numeral 13 is a heater for the upper mold 10 and lower mold 11, and 14 is a comb conveyor for feeding the article 1 at the upper mold 10 and lower mold 11.

The upper mold 10, along the feeding path of the article 1,
A pair of upper links 20, 2 are provided on both front and rear sides of the lower mold 11.
0; 21, 21 and lower links 22, 22; 23, 23 are provided so as to be synchronously rotated by a motor 19, and upper and lower supports 2 are provided at the ends of these links 20, 21, 22, 23.
The front and rear ends of 4, 25 are supported so as to rotate, and the shafts 28, 29 are attached to the central tubes 26, 27 of the upper and lower supports 24, 25.
Are fitted so as to move up and down, and the upper die 10 and the lower die 11 are fixed to the lower and upper ends of these shafts 28 and 29, respectively. Axis 2 above
A stopper nut 30 for adjusting the amount of deflection is screwed onto the parts 8 and 29.

As shown in FIGS. 5 and 6, the pins 32, 32 planted on both sides of the upper mold 10 and the lower mold 11 are loosely fitted in the vertical grooves 33, 33 extending downward from the support 24 and the support 24 is provided. Adjusting screws 34, 34 provided on both sides of the upper mold 10 and the recess 3 of the upper mold 10
Compression springs 36, 36 are inserted between the parts 5, 35.
As shown in FIGS. 5 and 6, the pressure bar 40 fixed to the upper end of the shaft 28 extends to both sides and engages with a horizontal guide cam fixed to the side (not shown).

As shown in FIG. 5, a cylinder 52 is fixed downward to the pressure bar 40 via a pair of legs 50, 50 and a plate 51, and a piston 53 of the cylinder 52 extends downward in a frame 54, a pair. It is fixed to both ends of a knife 56 provided to move up and down in the groove 58 of the upper die 10 via knife guide pins 55, 55. As shown in FIG. 6, the lower mold 11 has a knife 5
6. A groove 57 for receiving 6 is provided.

As shown in FIGS. 3 and 4, the lower mold 11 has an upper mold 10
Is approximately vertically symmetrical, and the corresponding parts are indicated by adding '. FIG.
As shown, the cam follower 61 is symmetrical to the cam follower 41.
Is engaged with a horizontal guiding cam 62 which is symmetrical with the cam 42, and is supported by a fixed pressure receiving cam 63 which is symmetrical with the pressure cam 43. The receiving cam 63 is fixed, and the pressure cam 43 is shown in FIG.
As shown in the figure, it is supported so as to be slidable up and down by the adjusting screw 47 via the suspension frame 45, and the height can be adjusted. Therefore, the distance between the pressure cam 43 and the pressure receiving cam 63 is set to the cam follower 41 of the pressure bar 40,
Since the dimensions of the shafts 28 and 29, the upper mold 10 and the lower mold 11 of the sealer are determined, the sealing pressure of the pressure spring 44 can be adjusted by adjusting the height of the pressure cam 43. Reference numeral 46 is an adjusting screw of the pressure spring 44.

As shown in FIG. 1, corrugated portions 10a and 11a are shaped so that the opposing surfaces of the upper mold 10 and the lower mold 11 are fitted to each other at the center.
And has flat seal portions 10b, 11b approaching each other with a minute gap δ at the sealed bag-side end. For example, the height difference between the 15 peaks and valleys of the corrugated portions 10a and 11a is 0.377 mm.
Then, the minute gap δ at which the flat seal portions 10b and 11b approach each other is 0.1 mm. The small gap (0.1 mm in this case) provided in the flat seal portions 10b and 11b is about 0.06 mm × 4 of four PE (sealant material) 5a having the thickness of the film 5 shown in the example of the figure. Cut it in half. In addition, 5b is an aluminum layer, 5c is a kop, and each thickness is 0.01 mm, 0.0
It is 37 mm.

Next, the operation of this device will be described. The pair of upper links 20 and 21 are rotated counterclockwise in FIG. 2 by the drive motor 19, and the pair of lower links 22 and 23 are rotated clockwise in synchronization with each other. 24 and 25, shafts 28 and 29 supported by the central tubes 26 and 27, and upper and lower molds 10 and 11 also rotate in the same direction as the upper and lower links 20, 21, 22, and 23, respectively. Upper mold 1
Before contacting 0 with the lower die 11, the upper die 10 projects downward by the elastic force of the springs 36, 36, and the lower die 11 projects upward by the corresponding springs 36 ', 36' (see FIG. 9) to provide a stopper. The nuts 30 and 31 are in contact with the cylinders 26 and 27, respectively, and the upper mold 10 and the lower mold 11 are always in a vertical state and move in parallel along a circular locus.

Thus, as shown in FIG. 2, the upper mold 10 and the lower mold 1
When 1 is contacted at a position between the articles 1 and 1 of the film 5 which is rolled into a tubular shape from between the blind conveyor 14, the upper die 10 is connected to the spring 3 through the pressure bar 40 and the shaft 28 in FIG.
6 is actuated relatively upward against the resilience of the spring 6, and similarly, the lower die 11 is actuated relatively downward in contact with the resilience of the spring, and the upper die 10 and the lower die 11 sandwich the film 5 from each other. It will be sent horizontally in a straight line.

As shown in FIGS. 3 and 4, when the cam followers 41 on both sides of the pressure bar 40 hit the surface of the cam 42, the spring 36 causes the upper die 10 to project linearly along the cam surface. Move to. That is, link 2
A part of the circular movement of 0, 21, 22, 23 is cam 42, 62
Move the sealer in a straight line by bending it.
Also, the length of linear movement can be changed by changing the amount of this deflection. At this time, the drive motor 19 moves unequally so that the upper die 10 and the lower die 11 are fed at the same speed as the film 5. At this time, since two pairs of rotary links are used to drive the sealer such as the upper mold 10 and the lower mold 11, high-speed sealing can be performed, and since the sealer is vertically inserted between the articles, it is easy to fold the film. The air can be easily removed, and the length of the package to be packaged can be shortened.

On the other hand, at this time, the pressurizing cams 43, 43 are pressed by the springs 44, 44 by the elastic force of the springs 44, 44.
Is pressed downward, and this force presses the upper die 10 downwards via the pressure bar 40 and the shaft 28 to give a welding pressure to the film 5, while this welding pressure is applied to the lower die 11, the shaft 29, and the cam follower. It is supported by the pressure receiving cam 63 via 61, 61.
First, when the film 5 is inserted between the upper mold 10 and the lower mold 11, first, the sealing portion of the film 5 between the corrugated portions 10a and 11a is melted. Next, the seal portions of the flat seal portions 10b and 11b are melted. Next, since the film 5 between the flat seal portions 10b and 11b has a small heat capacity, it is hardened first. Next, the corrugated portion 10
The sealed portions of a and 11a are solidified.

When the film 5 is thus welded, the piston 53 of the cylinder 52 shown in FIG.
4. The knife 56 is operated downward via the knife guide pins 55, 55 to cut the welded film 5 and separate the individual articles 1, 1 ... .. are separated and sent to the discharge conveyor 12. After that, the upper mold 10 and the lower mold 11 are separated into upper and lower parts, respectively, protruded by the springs 36 and 36 ', and move in a circular locus. Thus, in the above apparatus, since the sealer is rotated by two pairs of links, high-speed sealing can be performed, and strong pressing can be performed by the pressure cam and the pressure spring, so that a strong seal can be achieved. .

[0017]

As described above, according to the present invention, when the film 5 is inserted between the upper mold 10 and the lower mold 11, the corrugated portion 10a,
The total pressure is applied to the portion 11a and P of the corrugated portions 10a and 11a
Since pressure is applied to the flat seal portions 10b and 11b after the E5a is melted, the air pressure acting on the weld portions is reduced by the flat seal portions 10b and 11b and weakened, so that the welding pressure of the seal also weakens and the breakage occurs. To prevent. That is, when the flat seal portions 10b and 11b are not provided, the air pressure in the bag is received at the seal creases, and the force of peeling the seals works, and the strong seal pressure easily causes the seal creases to break, and the material is also saved. However, as in the present invention, the flat seal portion 10 is provided between the corrugated portions 10a and 11a and the bag.
By providing b and 11b, the flat seal portions 10b and 11
b receives air pressure in the bag and flat seal portions 10b and 11b
However, since the corrugated seal solidifies and maintains a strong seal, there is no peeling of the seal, there is no damage to the material of the film 5, and there are no edge cuts in the seal, and a firm bottom seal is possible. It is a thing.

[Brief description of drawings]

1A is an enlarged cross-sectional view of an upper die and a lower die of an embodiment of the present invention, FIG. 1B is an enlarged cross-sectional view of a film thereof, and FIG. 1C is a cross-sectional view of the folded state. .

FIG. 2 is an explanatory diagram showing an outline of an apparatus to which the present invention is applied.

FIG. 3 is an enlarged view of a main part thereof.

FIG. 4 is an end view thereof.

FIG. 5 (a) is an enlarged cross-sectional view of the upper mold part and the lower mold part,
(B) is a perspective view of a part thereof.

FIG. 6 is a side view thereof.

FIG. 7 is an enlarged side view of the upper horizontal guide cam.

FIG. 8 is a longitudinal sectional view thereof.

FIG. 9 is an enlarged vertical sectional end view of a part of the upper die and the lower die.

FIG. 10A, FIG. 10B, and FIG. 10C are explanatory views sequentially showing a conventional sealing operation.

FIG. 11 is a vertical cross-sectional view at the time of sealing.

[Explanation of symbols]

 1 Article 10 Upper mold 11 Lower mold 10a, 11a Corrugated part 10b, 11b Flat seal part δ Minute gap

Claims (1)

[Claims] 1. In a tubular film surrounding an article fed at a constant interval along an article feed passage, an upper die and a lower die for bottom-sealing a film in a portion between the articles are provided close to each other. A bottom sealer in a packaging machine, in which a corrugated part having a shape to be fitted to each other and a flat seal part facing each other with a minute gap are provided on the bag-side end of the corrugated part and the lower mold.