JPH0738087Y2 - Sealing device for packaging machine - Google Patents

Description

[Detailed Description of the Invention] (b) Industrial field of application The present invention relates to a sealing device for a packaging machine, and more specifically, to a vacuum packaging machine or a gas displacement packaging machine in which the required exhaust volume in the sealing device is minimized. The present invention relates to a sealing device for vacuum sealing.

(B) Prior Art As a conventional sealing device of the type in which a container film and a cover film to be closely sealed to each other are placed in a vacuum chamber to degas the inside of the vacuum chamber and then both films are pressure-bonded and sealed. , For example, JP-A-51-112687
There is something shown in the issue. As shown in FIG. 2, this sealing device grips the container film f ₁ and the cover film f ₂ by the lower sealing mold c and the housing d that define the vacuum chambers a and b, and then the vacuum chambers a and b are closed. Deaeration is performed by a vacuum pump (not shown), and then the sealing plate g heated by the heating device e provided in the housing b is lowered to contact the cover film f ₂ , thereby adhesively sealing both films. However, in such a device, since the heating device, the seal plate, and the cylinder for moving the seal plate up and down must be housed in the housing, the degassing amount at the time of the seal operation increases, There is a problem that it is necessary to use a vacuum pump with a large displacement and deaeration takes a long time.

Further, if the vacuum is repeatedly applied to the heating device and the vertical drive unit for the sealing plate at each sealing operation, the following adverse effects occur.

(I) When an electric heater is used as the heating device, if vacuum or low pressure acts around the electric heater, air may be exhausted from the inside of the heater, and the insulating seal portion of the heater itself may be damaged. Further, when the surroundings of the electric heater are in a vacuum state, the inside of the heater is also in a vacuum or a low pressure. Therefore, when returning to the atmospheric pressure state again, water vapor and liquid particles generated in the chamber from the packaged object by the vacuum are It will be sucked into the heater, causing insulation failure and damage to the heater.

(Ii) If the vertical drive of the seal plate is inside the chamber,
Water vapor or liquid particles generated from the object to be packaged adhere to the drive unit and cause malfunction.

(C) Problems to be solved by the present invention The problems to be solved by the present invention are to reduce the amount of degassing required at the time of sealing operation by partitioning the inside of the housing with a diaphragm in the sealing device for the packaging machine, and to improve heating It is to prevent vacuum pressure from acting.

(D) Means for Solving the Problem The present invention is directed to a lower seal die that supports the periphery of a container of a container film from below, and a lower seal die that is disposed above the lower seal die and cooperates with the lower seal die. A housing for holding the container film, and a seal for movably arranged in the housing so as to face the lower seal mold and for pressingly sealing the container film and the cover film in cooperation with the lower seal mold. A mold, an electric heater type heating device arranged in the housing for heating the upper seal mold, and a driving device arranged in the housing for moving the upper seal mold up and down with respect to the housing. In a sealing device for a packaging machine, the inside of the housing is divided by a diaphragm whose outer peripheral edge is fixed to the housing and whose inner peripheral edge is fixed to the upper die side of the seal, and the heating device is divided into the divided housings. Located adjacent to the upper seal mold in one part of the housing and the drive device located in the one part, and applying a vacuum only in the other partitioned part and in the lower mold part of the seal. Is configured to let.

(E) Action In the above configuration, when they are sent between the lower seal mold and the housing with the cover film covering the container film, they approach each other and grip the peripheral portion of the container film. After that, the inside of the lower seal mold and the inside of the other part of the housing partitioned by the diaphragm are evacuated to a vacuum state (a state of a pressure lower than atmospheric pressure). Under this condition, the upper seal die descends and cooperates with the lower seal die to pressure-bond the container film and the cover film.

(F) Embodiment An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a sealing device 1 according to this embodiment is shown. In the figure, 2 is a lower seal mold that defines a chamber 3 adapted to accommodate a container r formed in the container film f ₁ , and 4 is a peripheral portion of the container film f _{1 in} cooperation with the lower seal mold. Is a housing adapted to grip. Of the lower seal die and the housing, at least the lower seal die is moved up and down by a cylinder or the like, and grips the peripheral portion of the container film f ₁ when they approach each other. The housing defines a chamber 5.

The housing 4 is divided into upper and lower parts 4a and 4b, and an outer peripheral edge of a diaphragm 6 made of an elastic material such as metal or rubber is sandwiched and fixed between them. The inner peripheral edge of the diaphragm 6 is sandwiched and fixed between the heating device 7 arranged in the chamber 5 and the upper seal die 8 attached below the heating device 7. Therefore, the diaphragm 6 partitions the chamber 5 into an upper portion 5a and a lower portion 5b. The heating device 7 is arranged in the upper portion 5a by the arrangement of the diaphragm so that the vacuum in the lower portion 5b does not act. The heating device 7 has a known structure in which a plurality of electric heaters are provided. A cylinder provided in the chamber 5 is attached to the heating device 7 so that the heating device 7 can be moved up and down together with the upper seal die.

In the above structure, the lower seal die 2 is lowered by a well-known lifting device (not shown) such as a cylinder and stands by in a state of being separated from the housing 4.

When the container film f ₁ is sent between the lower seal mold 2 and the housing 4 with the cover film f ₂ covered thereon, the lower seal mold rises and cooperates with the housing 4 to form the container film f _1. The peripheral part of the container r formed in f ₁ is clamped. After that, when the air in the lower portion 5b of the chamber 3 and the chamber 5 is removed to make a vacuum state, the inside of the container r also becomes a vacuum state.
(Note that when gas replacement is performed, the chamber 5 is exhausted after evacuation.
Fill the lower part 5b with gas. ) After that, the cylinder 9 operates and the upper seal die 8 descends to cooperate with the lower seal die 2 to press the container film f ₁ and the cover film f ₂ around the container r to perform a heat-bonding seal. When the sealing is completed, the lower parts of the chamber 3 and the chamber 5 are exposed to the atmosphere, and then the lower mold for sealing is lowered.

(G) Effect According to the present invention, the vacuum chamber of the sealing device is partitioned to reduce the required exhaust amount during vacuum packaging or gas displacement packaging, so the volume of the vacuum pump can be small and the packaging time is shortened. It is possible to speed up. Further, since the heating device is arranged outside the chamber to be evacuated so that the vacuum does not act, the heating device such as an electric heater is completely free from the vacuum or low pressure, and water vapor etc. It can be completely prevented that the heater is not sucked in and the insulation failure and damage of the heater are caused. Furthermore, since water vapor and the like do not adhere to the drive device, malfunction does not occur.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a sealing device for a packaging machine according to the present invention, and FIG. 2 is a sectional view of a conventional vacuum sealing device. 1: Sealing device, 2: Seal lower mold 3: Chamber, 4: Housing 5: Chamber, 5a: Upper part 5b: Lower part, 6: Diaphragm 7: Heating device, 8: Seal upper mold

Claims (1)

[Scope of utility model registration request] 1. A seal lower die for supporting the periphery of the container of the container film from below, and a housing arranged above the seal lower die for holding the container film in cooperation with the seal lower die. A seal upper die, which is movably disposed in the housing so as to be opposed to the seal lower die and cooperates with the seal lower die to press and seal the container film and the cover film, and is disposed in the housing. A sealing device for a packaging machine, comprising: an electric heater type heating device for heating the upper seal die, and a drive device arranged in the housing for moving the upper seal die up and down with respect to the housing. The inside is divided by a diaphragm whose outer peripheral edge is fixed to the housing and whose inner peripheral edge is fixed to the upper mold side of the seal, and the heating device is divided into one part within the divided housing by the diaphragm. Is located adjacent to the upper mold and the driving device is arranged in the one part, and the vacuum is applied only in the other part separated and the seal lower mold. Sealing device for packaging machines.