JP2009262961A - Sealing method for bag mouth and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently remove condensation on the internal faces of a bag mouth. <P>SOLUTION: In a sealing method, the mouth 32 of a packaging bag 30 is placed along a lower seal bar 13. To weld the bag mouth 32 under pressure from above by means of another seal bar, not shown, compression-preventing bodies 42 provided at both ends of the separate seal bar are pressed against both ends of the seal bar 13, thereby preventing the compression of the bag mouth 32. Consequently, an air-passage gap is defined in the bag mouth 32, thereby enabling evaporation of condensation on the bag mouth due to heat of a heater 14. After a fixed time has elapsed, the compression-preventing bodies 42 are removed, the bag mouth 32 is held and sealed between the seal bar, not shown, and the lower seal bar 13. Thus, condensation remaining on the sealing faces of the bag mouth can be removed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for removing a water film adhering to an inner surface of a sachet containing an article to be packaged and sealing the sachet and an apparatus for carrying out the method.

  Many companies that package products use high-efficiency automatic packaging equipment to increase productivity. However, small businesses or household companies, for example, manually work on local foods or homemade foods. There are still many merchants in the country that sell bags. In such manual bagging operations, the rate of adhesion of moisture contained in food to the bag mouth is higher than that of packaging performed by an automatic packaging device. If a pair of seal bars are used for pressure welding without any means, sealing is performed with water remaining in a film state on the inner surface of the bag mouth, and the aesthetics and storage stability of the product are impaired. In Patent Document 1 below, in order to solve such a problem, the bag mouth is pinched and heated by a pair of upper and lower seal bars, and the water in the bag mouth is thermally expanded and removed by the pinching and heating. In the next process, it is described that sealing is performed by a seal bar. However, some of the water is strongly thermally expanded and leaks to the outside, but the remaining water that loses its expansion energy and is trapped between the seal bars is dispersed and sealed in the form of a mist on the inner surface of the bag mouth by the sealing action. There is a problem that.

  Therefore, in the following Patent Document 2, in consideration of the above-mentioned problem, the bag mouth is previously clamped with a pair of narrow seal bars and line sealing is performed. A technique of sealing a bag mouth with a wide sealing bar is disclosed. However, even in the case of a line seal, a V-shaped groove is formed between the wrapping materials along the line seal, so that water concentrates and accumulates along the groove. There was a problem that water accumulated in the V-shaped groove remained as bubbles in the seal portion.

JP 59-12522 A JP 2001-301717 A

  In order to solve the above-mentioned problem, the present invention provides a bag mouth inner surface when the opening edge of a packaging bag containing an article to be packaged is manually guided between a pair of upper and lower seal bars and welded. In this method, water drops adhering to the bag are removed and sealed in advance, and the bag mouth is narrowed to such an extent that a narrow air gap is left between the bag mouths for a set time with a heated seal bar. Then, a sealing method is used in which the bag mouth is heated and then the bag mouth is pinched and welded using the same seal bar.

The process of narrowing and heating the bag mouth close enough to leave a vent gap between the bag mouths from both sides of the bag mouth and leaving the air gap between the bag mouths without sealing the bag mouth Form. For this reason, air flows freely without resistance in the ventilation gap. Therefore, even if water adheres to the wall surface of the ventilation gap, the water can freely evaporate through the ventilation gap by receiving heat from the heat bars on both sides. If a person who works works pushes the bag from outside during heating and moves the air in the bag, this moving air positively discharges the saturated air to evaporate in the ventilation gap. Thus, evaporation is further promoted.
On the other hand, when this method is applied to a vacuum packaging device, when air is drawn out of the bag with the pressure difference inside and outside the bag, the drawn air is saturated air that evaporates in the ventilation gap. Are actively discharged to the outside.
These effects of promoting evaporation can be caused by preventing the bag mouth from being pinched by the seal bar and leaving a ventilation gap between the bag mouths.

  In addition, moisture that receives heat at the bag mouth due to the approach of the seal bar to the bag mouth expands and vaporizes by heating and evaporates toward the upper part of the ventilation gap. When it reverses due to the resistance of heavier air inside the bag and rises through the ventilation gap, it will promote the vaporization of saturated gas on the wall of the ventilation gap. This can be caused by leaving an air gap in the air.

  In addition, the above operation and effect are when the packaged product and the liquid contained in the packaged product are at a relatively low temperature. If the packaged product is at a high temperature, steam is actively generated from the contained liquid. When doing so, the following effects occur. That is, for example, when filling food bags with little time elapsed after cooking, the steam generated from the relatively hot juice cooked with food products causes the packaging bag to expand due to the flow resistance caused by the air gap in the bag mouth. , It flows out of the bag through the ventilation gap. The outflow pressure in this case has the momentum to counteract the air flow effect in the ventilation gap, and the generated steam is actively discharged out of the bag to promote the elimination of saturated gas in the ventilation gap where vaporization proceeds by heating the seal bar. Demonstrate the effect. Since the bag mouth receives heat from the heat bar, the vapor passing through the ventilation gap is not condensed on the surface of the passage gap.

  In the apparatus shown in the side view in FIG. 2, a horizontally long lower seal bar 13 in which a heater 14 is embedded is fixed to an upper part of a front surface of a base 19 fixed in an inclined manner with respect to a machine base frame 11, and stands on the machine base frame. A bell crank 17 pivotally supported on the tower frame 15 provided via a pin 16 fixes an upper seal bar 12 in which a heater 18 is embedded. A lever 21 supported on a bracket 20 behind the machine frame via a shaft 23 is connected to the bell crank 17 via a rod 22, and a gear 25 fixed to the shaft 23 is a first reversible first type. It connects with the pinion 27 which the motor 26 supports. The first motor 26 swings the bell crank 17 around the pin 16 with the rotational power of the pinion 27 via the gear 25 and the rod 22, so that the upper seal bar 12 approaches and separates from the lower seal bar 13. To do.

  FIG. 1 is an observation view from the front surface of the lower seal bar 13 already described, and the opening edge 32 of the packaging bag 30 containing the article to be packaged 31 is manually introduced onto the seal bar 13. In this case, the opening edge 32 is positioned by touching the stoppers 28 at two positions on the upper surface of the seal bar. The seal bar is provided with a heat insulating material 35 on the lower side from the boundary line 34 to prevent danger caused by the fire power of the operator.

  FIG. 3 is a partial view showing the right half of the upper and lower seal bars. A linear motion type second motor 41 formed by a fluid cylinder is disposed on each side of the upper seal bar 12. Accordingly, a blocking body is formed that prevents the upper and lower seal bars 12 and 13 from pinching the opening edge of the bag. That is, by pressing the compressed air acting on the piston 43 and pushing out the pinching prevention body 42 formed by the piston rod toward both end surfaces 44 of the lower seal bar 13 as shown by the arrows 45, Desirably, a gap of 0.1 mm to 3.0 mm is formed to prevent pinching of the bag mouth.

  The cylinder 46 installed on the upper seal bar 12 in FIG. 2 includes a holding pin 48 through a tension spring 47 inside, and the upper seal bar 12 approaches the lower seal bar 13 with the power of the first motor 26. In the process, the pressing pin 48 presses the wrapping bag 30 against the upper surface of the heat insulating material 35 at the portion of the phantom line 48 in FIG. 1 to limit the play movement of the wrapping bag.

  In FIG. 1, the operator operates the foot-operated operation switch 50 in FIG. 5 in synchronism with manually attaching the bag 30 to the lower seal bar 13. At the same time, the timer 51 starts and integration starts, and at the same time, the first motor 26 and the second motor 41 start rotating. For this reason, the upper seal bar 12 that is normally separated in FIG. 2 tries to approach the lower seal bar 13, but immediately before that, the pinching prevention body 42 in FIG. 12 and 13 are prevented from contacting at intervals of 0.1 mm to 3.0 mm. As a result, as shown in FIG. 5, the seal bars 12 and 13 approach each other until the air gap 52 for air removal is formed between the bag mouths of the wrapping bag 30, and the heaters 14 and 18 are sealed for a preset time. The bag mouth is heated through the bars 12 and 13, and heat is added to the water remaining in the ventilation gap 52 to continue evaporation.

  In some cases, the operator applies a force as indicated by an arrow 53 to the wrapping bag 30 from the outside, and pushes the air in the wrapping bag inner head space 54 through the ventilation gap 52 to eliminate saturated air in the ventilation gap. Can promote evaporation.

  The timer 51 in FIG. 4 transmits the signal of step S1 and step S2 after the preset time from the start of integration, and sends an operation signal to the first motor 26 and the second motor 41. As a result, the air pressure with respect to the piston 43 of the linear motion motor in FIG. 3 is removed, and the power of the first motor 26 in FIG. 2 pushes the upper seal bar 12 against the lower seal bar 13 to open the bag mouth of the bag 30. It will be pinched. As a result, the bag mouth is welded as the seal bars 12 and 13 approach in FIG.

  At the initial temperature received by the inner surface of the bag mouth by the seal bars 12 and 13 in FIG. 5, the surface of the air gap 52 does not reach melting, but the melting proceeds as time elapses in the evaporation of water vapor in the air gap 52, and the bag When both seal bars 12 and 13 exert a pinching pressure against the mouth, it is desirable that the melting progresses sufficiently and the bag mouth is welded.

  FIG. 6 shows a different embodiment of the element for preventing the pinching of the bag mouth by both the seal bars 12 and 13, and a shaft 65 having a partly cut surface 66 can be rotated in the lower seal bar 13. Deploy. Normally, when both seal bars 12 and 13 approach each other, a gap 67 is formed between the seal bars due to the resistance of the shaft 65, forming a ventilation gap in the bag mouth. Is rotated so that the cut-off surface 66 faces the upper seal bar 12, so that the gap 67 disappears and the bag mouth is pinched and sealed by the seal bar.

  In the description shown in FIG. 4, the first motor 26 that approaches and separates the seal bar and the second motor 41 that prevents the bag mouth from being pinched by both seal bars are provided. This is an embodiment in which one servo motor 60 fulfills the above-described function. In the following configuration, commonly called a servo cylinder or a robot cylinder, a ball screw is rotated in a cylinder 61 by a servo motor 60, and an upper seal bar 12 at the tip of a rod 62 engaged with the ball screw moves. By adjusting the rotation angle of the ball screw with the servo motor 60, the amount of movement of the rod 62 in the axial direction can be controlled, and the approach amount of the upper seal bar 12 to the lower seal bar 13 can be controlled, and both seal bars can be controlled. It is possible to control the narrowing of the bag mouth that forms a gap between 12 and 13, and the force that presses both seal bars to pinch the bag mouth. Note that the reference numerals used for the constituent elements in the figure are the same as or similar to the constituent elements shown in the other figures if they match the reference numerals used in the other figures.

  The present invention can also be applied to a batch-type vacuum packaging apparatus or a vacuum packaging apparatus having a function of conveying a packaging bag, both of which are manually fed to a seal bar. FIG. 8 shows a vacuum packaging device that seals the bag 30 while transporting the bag 30 by the belt conveyor 70 while eliminating moisture adhering to the bag mouth of each bag. Boiled foods such as oil raising, oden, and kelp with soybeans need to be vacuum-packed, and the drawing shows an example.

  When the seal bar 71 provided in the belt conveyor 70 at equal intervals is used as a pillow, and the bag is mounted on the belt conveyor 70 so that the bag mouth is manually applied to the seal bar 71, the power of the belt conveyor 70 makes the bag 1 It moves intermittently by pitch and is fed into the lower area of the chamber 72. The chamber 72 includes a seal bar 74 connected to the pressurizing device 73, and a timer operates in synchronization with the timing when the chamber 72 descends and covers the wrapping bag 30, and thereafter, the operation proceeds by this timer. The air in the chamber 72 is exhausted through the hose 75, and the seal bar 74 is lowered onto the seal bar 71 by the pressurizing device 73 with a delay, and the bag mouth of the bag 30 is sealed and sealed.

  However, as shown in FIG. 9, the upper seal bar 74 is provided with a linear motion type motor 41 as shown in FIG. 3 at both ends thereof, and the pinching prevention body 42 that contacts the piston rod of the motor is the lower seal bar 71. It faces to the upper surface of. When the accumulated time by the timer is reached, compressed air is sent into the motor 41 from the tube 76 on one side connected to the motor 41, and the pinching prevention body 42 protrudes. Even if the seal bar 74 is lowered by the air pressure sent to the upper chamber of the diaphragm 80 of the pressurizing device 73, a gap is generated between the lower seal bar 71 and the upper seal bar 74, and the bag is wrapped as shown in FIG. A ventilation gap 52 is formed in the bag mouth. In this case, of course, the descending force of the clamping block 42 by the compressed air is larger than the descending force of the seal bar 74 due to the pressure received by the diaphragm 80. Can be substituted. Therefore, in the present application, the expression “motor” that operates the pinching prevention body in claim 3 includes a direct acting type such as a fluid cylinder, the following electric rotary type, and an electromagnetic solenoid. The electric rotary motor refers to the power source of the pinching prevention body 65 shown in FIG.

  A descending line 90 in FIG. 10 shows a state in which the air pressure in the chamber drops from the atmospheric pressure of 0 Mpa to the vacuum pressure of −0.1 Mpa. In order to prevent jumping out from the bag, for example, when vacuum suction is cut in the region X, the upper seal bar 74 is lowered toward the lower seal bar 71 at the point 91 in the figure, and Y The water adhering to the bag mouth of the bag 30 is evaporated by the heat of the heater 78 in the seal bar 74 in FIG. After that, when the set time by the timer is reached, air pressure acts from the tube 77 into the direct acting motor 41, and the blocking force of the pinching blocker 42 is eliminated. As a result, the air pressure acting on the upper surface of the diaphragm 80 is welded by pressing the seal bar 74 against the lower seal bar 71 and pinching the bag mouth of the bag 30.

It has been described that the heat for evaporating the water and the heat for sealing the bag mouth are performed by the heater 78 installed on the upper seal bar 74. When the heater 79 is installed on the lower seal bar 71 that moves integrally with the belt conveyor 70, energization is possible through a rotary terminal that rotates integrally with the belt. However, such a device is comparatively large and uneconomical, and in this type of vacuum packaging device including a batch type, the vacuum suction time for one time is around 10 seconds, sometimes more than that, When the chin bar 72 is covered around the seal base 71 as shown in FIG. 9, the electricity to the upper seal barter 78 is further transmitted to the lower seal bar 79 to be heated, thereby evaporating water and saving the power. Mouth welding can also be performed.

State diagram of manual feeding of bag mouth to seal bar Side view of the entire device Partial illustration of the seal bar Device block diagram Explanatory drawing of bag mouth stenosis by seal bar Explanatory drawing of the Example from which a pinching prevention body differs Example of different examples of blocking and blocking pressure at the bag mouth Different embodiment diagram of the entire packaging device Enlarged view of section IX-IX in the previous figure Illustration of vacuum action

Explanation of symbols

12... Upper seal bar 13... Lower seal bar 26... 1st motor 30... Wrapping 41... 2nd motor 42 and 65. Ventilation gap 71 Upper seal bar 72 Chamber 73 Lower seal bar

Claims (3)

This is a method in which when a bag mouth of a packaging bag containing an article to be packaged is manually introduced between a pair of upper and lower seal bars and welded, water drops adhering to the inner surface of the bag mouth are removed in advance and sealed. And
During the preset time, the bag mouth is heated with a heated seal bar so that a narrow ventilation gap remains between the bag mouths, and this heating action causes the water in the bag mouth to flow. A sealing method of evaporating through an air gap and then welding by pressing the bag mouth with the seal bar. A pair of heating-type seal bars, an operation switch for operating a timer, and a motor driven by the operation switch;
Almost in synchronization with the manual introduction of the opening edge of the packaging bag containing the article to be packaged between a pair of upper and lower seal bars, and by starting operation of the timer by operating the operating switch, A ventilation gap is formed at the opening edge of the wrapping bag with a motor, and both seal bars are brought close to the area, and the water adhering to the ventilation gap is evaporated by heating of the approaching seal bar. A sealing device that releases the blocking of the bag mouth and clamps the bag mouth with a seal bar for welding. A chamber having a pair of heating type seal bars therein, a timer for starting integration in synchronization with closing of the chambers, and a pinching blocker disposed at both ends of the pair of seal bars,
The timer is used to integrate the working time of the vacuum acting in the chamber by a timer, and the pinching blockers at both ends of the seal bar on one side are almost synchronized with the sealing of the bag containing the packaged items in the chamber. The power of the motor pushes it toward the seal bar on the other side to prevent pinching of the bag mouth, and the water adhering to the air gap formed in the bag mouth by such pinching prevention is evaporated by the heat of the seal bar. The sealing device which releases the blocking of the bag mouth and then presses the bag mouth with the seal bar and welds with the integrated signal of the timer.