JPH0323405B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention involves sealing the sides of a long heat-sealable sheet material while folding it vertically, and then sealing it horizontally to form a pocket. The present invention relates to a method of manufacturing a packaging bag, in which a bag is filled with liquid or powder, and after filling, the upper end of the pocket is sealed to continuously package a certain amount of the contents.

[Conventional technology]

In conventional manufacturing methods of this type, predetermined portions of the sheet material are laterally sealed by passing the heat-welded sheet material between a pair of rotary sealing rollers. Furthermore, in the device described in Japanese Patent Publication No. 53-44872, a pair of holder shafts are rotatably attached to a sealer frame that reciprocates along the film transport direction, a sealer is provided on each of these shafts, and the holder shaft is Gears provided at each end mesh with each other, one holder shaft is provided with a sprocket, and a chain is installed between this sprocket and a drive sprocket that rotates at an inconstant speed and is provided at a lower position in a direction perpendicular to the film transport direction. It was passed over.

[Problem to be solved]

With conventional sealing means, if the heat-welded sheet material is transferred at a speed higher than a certain speed, the sealing time will be shortened and the seal will be defective, so the transfer speed of the flexible sheet material must be kept below a certain speed. Nakatsuta. Especially when the contents are liquid,
When filling the pocket with liquid, the liquid splashes and drops enter the next sealing area (i.e. the top edge of the pocket and the bottom edge of the next pocket), and the area where the droplets entered is heated to high temperature (200℃ to 250℃) for a short period of time. When sealed (heat welded), the droplets expand and cause seal failure. When the contents are liquid, it is necessary to take a long sealing time at a relatively low temperature (around 150°C) in order to prevent seal failure. However, in order to lengthen the sealing time, the speed at which the sheet material is fed must be slowed down, which unavoidably reduces production efficiency.

In addition, what is described in Japanese Patent Publication No. 53-44872 is
Although it is possible to prevent the speed of feeding the sheet material from slowing down, the position of the drive sprocket remains stationary, and the sprocket provided on the holder shaft reciprocates in an arc along the direction of film movement together with the holder shaft. Therefore, the location where the film is sealed is located downward from the axis in the film transport direction. Therefore, if the holder shaft is moved too far to the right from the position shown in reference FIG. 1, the sealing position will also fall too far from the film transport axis, which may cause wrinkles in the film and a seal failure. Therefore, in the cited example, the holder shaft can only be moved by a short distance to the right, meaning that the sealer follows the film transfer over a short distance while being crimped, so the sealing time cannot be increased. It is difficult. In addition, an eccentric crank mechanism or the like was required to provide non-uniform rotation to the drive sprocket. Therefore, this invention enables the transfer of heat-welded sheet material at a higher speed while ensuring reliable sealing, thereby improving production efficiency. It is an object of the present invention to provide a method for manufacturing a packaging bag which is improved and whose structure is not complicated and whose operation is highly reliable.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention seals the sides of a long heat-sealable sheet material while folding it vertically, and then vertically moves a pair of horizontal sealing rotary rollers having protrusions on the circumferential surface. This bracket lowers to follow the sheet material that is transferred downward during sealing by pressing the sheet material with the protrusions of both rollers, filling the pocket formed at this time with the contents and filling. A method for manufacturing a packaging bag in which a rotary sealing roller is repeatedly raised and lowered while sealing the upper end of the pocket and the lower end of the next pocket. The chain is passed between a gear that is driven by the other roller and has the same diameter as the other roller, and a chain sprocket that is connected to a drive source and is located below in the same direction as the sheet material transport direction. , a plurality of gears are meshed with this chain, and one of these gears is always given a biasing force in the direction of tensioning the chain, and the gear used for the sealing rotary roller is lowered parallel to the direction in which the sheet material is transported. When the sealing roller goes down, the chain loosens and slows down the rotation of the gear so that the protrusion continues to press the sheet material without changing the pressing force even when the sealing roller goes down, and when the sealing roller goes up, one of the gears The chain is tensioned again by the biasing force applied to the sealing roller, and the sealing rotary roller is rotated quickly.

〔Example〕

Preferred embodiments of the present invention will be described below with reference to the drawings.

A folding means 3 for vertically folding a long heat-welded sheet material 2 on a frame 1; and a sheet material 2.
A transfer means 4 is provided with a means for transferring the vertically folded material downward and sealing the side surfaces, and a sealing material 2 whose side surfaces are sealed by the transfer means 4 and is transferred downward is sealed in the horizontal direction. Seal means 5 are provided for application. After the pocket whose bottom is sealed at the sealing means 5 is filled with the contents from the supply pipe 6 for supplying the contents, the upper end of the pocket is sealed. Since the filled packaging bag 10 is formed continuously, the upper end of one pocket becomes the lower end of the next pocket. Although the sealing means for the side surface of the long sheet material 2 is provided on the transfer means 4, it may be provided at any location before reaching the sealing means 5.

As shown in FIG. 2, the sealing means 5 includes a pair of rotary sealing rollers 51 and 52, which are rotatably attached to the bracket 7. A pair of rotary sealing rollers 51 and 52 each have protrusions 51A, 51B, 52A, and 52B for sealing, and when these protrusions 51A and 52A or 51B and 52B come into contact, they are crimped and clamped between them. The sheet material 2 is laterally sealed.
The seal width is approximately 15mm. The bracket 7 is provided with an adjustment member 71 for adjusting the distance between the pair of sealing rotary rollers 51 and 52. This bracket 7 is attached to the back plate 11 of the frame 1 so as to be movable up and down. A slide rail 12 is provided on the back side of the back plate 11, and a slider 13 fixed to an arm 15 projecting from a long hole 14 formed in the back plate 11 slides on the slide rail 12. The upper end of a connecting rod 16 is pivotally connected to this slider 13, and the lower end of this connecting rod 16 is pivotally connected to an operating rod 17. One end of the operating rod 17 is attached to the frame 1 with a pin 17A to serve as a pivot point. The tip of the operating rod 17 is in contact with the cam 18. When a rotating shaft 19 provided at an eccentric position of the cam 18 rotates, the tip of the operating rod 17 moves up and down due to the action of the cam 18. When the tip of the operating rod 17 moves up and down, the connecting rod 16 moves up and down, and along with this, the slider 1
3 also moves up and down. When the slider 13 moves up and down, the arm 15 fixed to this slider 13
And the bracket 7 will move up and down.

One rotary sealing roller 52 constituting the sealing mechanism 5 is provided with a gear 20 having the same diameter as the roller 52, and a chain 21 is stretched around the gear 20. The chain 21 is stretched over a chain sprocket 22 that is connected to a drive source via a reduction mechanism or the like, and the chain sprocket 22 and the gear 2
A plurality of gears 20A and 20B are meshed with each other. The gear 20A is rotatably attached to a rocking plate 23, and the tip of the rocking plate 23 is constantly pulled in a direction to pull the chain 21 by a spring 24. When bracket 7 descends, gear 2
The chain 21 that is stretched over the roller 52 is loosened, and the rotational speed of the roller 52 is therefore slowed down. When it is too late, the protrusions 51A and 52A (or 51B)
and 52B) are facing each other, so the sealing time can be extended. loose chain 2
1 is pulled by the spring 24 and returns to the gear 20
The tension of the spring 24 is preferably designed so that the bracket 7 has finished descending and is beginning to rise. Chain 21 due to the presence of spring 24
does not come off from the gear 20, but when the bracket 7 descends, the force of the chain 21 that rotates the gear 20 loosens, making it necessary to momentarily stop the rotation of the roller 52 or slow down its speed.
The roller 52 (same as the roller 51, which is a driven roller) rotates once per second, for example.
Projections 51A, 51B, 52 during rotation
The design is such that the speed is reduced only when A and 52B face each other, that is, the frequencies are different. That is, the rotational speed of the roller 52 when the protrusions 51A and 52A and 51B and 52B are facing each other and can be sealed may be made slower than that of the roller 52 in other conditions.

In order to reduce the load associated with the vertical movement of the bracket 7, it is desirable that the bracket 7 be made of a material that can be made as lightweight as possible, such as aluminum. Furthermore, it is also possible to design the position of the pin 17A, which is the fulcrum of the operating rod 17 shown in FIG. 4, to be freely changed. By changing the position of the pin 17A, which serves as the fulcrum, the vertical stroke of the bracket 7 can be changed very easily. If the distance required for lowering the bracket 7 is increased, the sealing time can be further increased. The relationship between the sealing time and the length of the bag in the feeding direction (pitch, length of the finished bag) is 60 seconds/bag making speed (manufactured per minute) when the rollers 51 and 52 rotate at a constant peripheral speed. (number of bags) x seal width (mm)/pitch (mm) From the above formula, protrusions 51A and 5 of rollers 51 and 52
The time during which the sealing material 2 is held between 2A, 51B and 52B can be calculated. For example, pitch is 100mm
In this case, 60/60 x 15/100 = 0.15 (seconds), and if the pitch is 50 mm, 60/60 x 15/50 = 0.3 (seconds). Depending on the contents to be filled, if the sealing time is 0.15 seconds, there is a risk of producing defective products. If the method of the present invention is applied, the sealing time can be increased without changing the bag making speed.

Note that the member indicated by the reference numeral 25 in FIG. 4 is a guide member. Furthermore, in FIG. 1, two sheet materials are sealed at the same time, but it is also possible to seal one sheet material or three or more sheet materials at the same time.

〔effect〕

As explained above, according to the present invention, in order to perform lateral sealing, a pair of rotary sealing rollers having protrusions on the circumferential surface are attached to a vertically movable bracket. It descends following the flexible sheet material that is transferred downward during sealing, and when it descends, the rotation speed of the roller is slowed down to prolong the sealing time, and it rises again to form the top edge of the pocket and the next bottom edge. Since it descends while sealing the desired area, the sheet material itself can be transported at the same or faster speed than before even if sufficient time is taken for sealing, eliminating the risk of sealing defects and reducing the overall It became possible to increase production volume. Further, in the sealing means of the present invention, one of the pair of rotary sealing rollers is driven by the other, and the other roller is connected to a gear having the same diameter as the roller and a drive source, and is driven in the same direction as the conveying direction of the sheet material. A chain is spanned between a chain sprocket located below, and a plurality of gears are meshed with this chain, and one of these gears is always given a biasing force in the direction of tensioning the chain. The chain is configured so that when the rotary sealing roller descends, that is, when the gear provided on the roller also descends, the chain loosens, and when it is ascending, the chain becomes tense due to the biasing force applied to one of the plurality of gears. Because of this, the sealing rotary roller rises,
The lowering is done in a straight line, increasing the reliability of the seal. In addition, when the sealing rotary roller descends with the sheet material crimped by the protrusion, the chain that is wrapped around the gear with the same diameter as the roller loosens, which slows down the rotational speed of the roller and reduces the transport speed of the sheet material. The sealing time can be increased regardless of the In particular, the sealing time can be easily set because the gear has the same diameter as the sealing rotary roller. Furthermore, since the gear and chain sprocket are parallel to the direction in which the sheet material is transported, even if the chain sprocket remains stationary, the lowering of the gear as the sealing rotary roll is lowered is in the direction in which the sealing material is transported. Since the sheet material is linear along the transport axis, the sheet material is not deviated from the transport axis, so there is no risk of wrinkles in the sheet material and poor sealing. Furthermore, the vertical movement of the gear provided on the other roll is parallel to the transport direction of the sheet material, and when the roll descends, the chain loosens, slowing down the rotation of the roll, and the chain sprocket is equipped with an eccentric crank mechanism, etc. There is no need to set it up and rotate it at non-uniform speeds, the mechanism is simple, and maintenance is easy.
Operation reliability also increases.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view showing a preferred embodiment of the present invention, FIG. 2 is a sectional view of the sealing mechanism, FIG. 3 is a plan view of the sealing mechanism, and FIG. 4 is a schematic view from the direction of the arrow in FIG. 3. FIG. 5 is a schematic explanatory diagram showing an example of a driving means for a rotary sealing roller. DESCRIPTION OF SYMBOLS 1... Frame, 2... Long heat-welded sheet material, 5... Seal mechanism, 7... Bracket, 20
... Gear, 21 ... Chain, 22 ... Chain sprocket, 20A, 20B ... Multiple gears,
51, 52...Rotating roller for sealing, 51A, 5
1B, 52A, 52B...Protrusions for sealing.

Claims (1)

[Claims] 1. A long heat-welded sheet material is folded vertically to seal the sides, and then a pair of horizontal sealing rotary rollers having protrusions on the circumferential surface is attached to a vertically movable bracket; This bracket descends following the sheet material that is transferred downward during sealing by pressing the sheet material with the protrusions of both rollers, filling the pockets formed at this time with the contents, and after filling, the rotary roller for sealing A method for manufacturing a packaging bag in which the bag is repeatedly raised and lowered while sealing the upper end of the pocket and the lower end of the pocket, wherein one of a pair of rotary sealing rollers is driven by the other, and the other roller is driven by the other roller. A chain is strung between a gear of the same diameter as the roller provided at The gears are meshed, and one of these multiple gears is always given a biasing force in the direction of tensioning the chain, and when the gear provided on the sealing rotary roller descends parallel to the direction in which the sheet material is transported, the chain loosens. By slowing down the rotation of the gear, the protrusion continues to press the sheet material without changing the pressing force even when the rotary sealing roller descends, and when the rotary sealing roller ascends, one of the multiple gears
A method for manufacturing a packaging bag, characterized in that the chain is tensioned again by the biasing force applied to the chain to quickly rotate the sealing rotary roller.