JP2568430B2 - Seal device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sealing device used for a packaging device, and more specifically, to an improvement in the shape of a seal rubber provided in the sealing device.

<< Prior Art >> In general, a sealing device used to form a bag by heating and melting a film or the like to seal the film is as shown in FIG. 6, for example. That is, a heating plate 1 in which a heater is embedded above is disposed so as to be movable up and down, and a receiving member 2 is disposed below the heating plate 1 so as to face the same. A seal rubber 3 having a flat surface is mounted on the upper surface of the receiving member 2, so that the films 4, 5 can be reliably pressed at a predetermined pressure.

Then, an upper film is placed between the hot plate 1 and the seal rubber 3.
4, the lower film 5 is pressed and heated, whereby the two films 4, 5 are fused and heat-sealed.

<< Problems to be Solved by the Invention >> However, since the surface of the seal rubber for sealer described above is flat, when there is a foreign substance 6 such as water, oil, or solid matter between the films 4 and 5, The part could not be heat sealed. That is, the hot plate 1
Since the opposing surfaces of the seal rubber 3 and the seal rubber 3 are both parallel planes,
The entire surfaces of the films 4 and 5 sandwiched between the two also come into contact almost at the same time, so that the foreign substance 6 cannot escape to the outside and stays between the films 4 and 5. And
The foreign substance 6 contributes as a heat insulating material at the time of sealing. As a result, an unsealed portion is generated, and the periphery of the foreign material 6 cannot be completely pressed between the films 4 and 5 due to the presence of the foreign material 6, resulting in an incomplete sealing portion. . And, specifically, 2-4%
Defective products had occurred with the probability.

Therefore, the inventor of the present invention created a projection 7 having a substantially triangular cross section on the surface of the seal rubber 3 'as shown in FIG. 7, and the foreign substance 6 was removed by the projection 7. did.

In this sealing rubber 3 ', since the tip of the projection 7 is certainly relatively sharp, even if there is a foreign substance 6 between the films 4, 5, the tip of the projection 7 pushes the foreign matter 6 out. Films 4 and 5 can be sealed.
However, when the two films 4 and 5 are sandwiched and pressed between the projecting portion 7 and the hot plate 1, the projecting portion 7 does not undergo much elastic deformation, and as a result, the sealing portion is very thin at the tip of the projecting portion 7. There is only a linear portion, and the sealing force is weak, and even if sealing can be performed once, there is a risk of peeling after that. In practice, defective products have been generated with a probability of about 1%. Further, in this example, there is also a problem that a line seal is formed regardless of the presence or absence of the foreign matter 6.

The present invention has been made in view of the above-described various problems, and an object of the present invention is to provide a sealing device capable of reliably sealing even if a foreign substance or the like exists between films to be bonded. Is to provide.

<< Means for Solving the Problems >> In order to achieve the above-described object, in the sealing device according to the present invention, a heating member capable of heating and melting a film, and a predetermined interval between the heating member and the heating member with the film interposed therebetween. The heating member and the sealing rubber have a sealing rubber disposed to face each other, and the heating member and the sealing rubber relatively move forward and backward by linear motion, and sandwich the film at a predetermined pressure from both sides thereof to heat seal the film. On the premise of the sealing device described above, a bulged portion having a small curvature and a substantially arc-shaped cross section was formed at a predetermined position on the surface of the sealing rubber. Further, a protruding portion was formed at the tip of the bulging portion. And the protrusion is
The shape was tapered at the tip with a large curvature, and was formed so as to protrude to the outside at normal times and to be buried in the bulging portion when being sandwiched.

{Operation} A film is inserted and arranged between the sealing rubber and the heating member. In this state, when the film is relatively moved and moved forward, first, the projection formed on the seal rubber comes into contact with the film, and the film is held between the film and the heating member at a predetermined pressure. When the sealing rubber and the heating member further approach each other, the contact pressure of the projection with respect to the film increases. Therefore, even if there is a foreign substance or the like in (between) the members to be adhered with which the projection is in contact. Dislodges the foreign material on both sides. Even if the foreign substance is a solid substance or the like, a strong force is applied to the foreign substance by the tapered projection, so that the foreign substance is reliably separated and pushed away on both sides. Therefore, in a state where the members to be bonded are in direct contact with each other, the members are sandwiched between the sealing rubber and the heating member at a predetermined pressure, and are thermally sealed.

Further, when the distance between the sealing rubber and the heating member is further reduced, the protrusion is crushed by the reaction force from the heating member and buried in the bulging portion, and the surface shape of the bulging portion having a small curvature is obtained. The surface becomes a gentle curved surface,
The film contacts the sealing rubber over a relatively large area. Therefore, the portion where the protrusion contacts is relatively strongly heat-sealed to ensure reliable sealing, and the portion where the bulging portion contacts ensures a relatively wide sealing area.

<< Embodiment >> A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an example of a vacuum packaging apparatus in which the present invention is used, and its schematic structure will be described. As shown in FIG.
The lower film 14 continuously drawn from the first raw film 13 is forwardly transferred through the claw members 12 disposed at predetermined intervals of the endless chain 11 provided therebetween. ing. A molding box 15 is provided in the vicinity of the carry-in side of the lower film 14, and recesses 14 a having a predetermined shape are formed in the lower film 14 at predetermined intervals in the molding box 15.

Although not shown, a package supply unit is provided in front of the forming box 15 in the traveling direction, and supplies the package 16 sequentially into the recess 14a. Further, a second material film 17 is disposed substantially above the center of the conveyance path of the lower film 14, and an upper film 18 is continuously supplied from the second material film 17, and a lower film 14 is provided. The upper part is covered.

Further, a vacuum chamber 19, in which the sealing device of the present invention is disposed, is disposed forward of the coating point X of the upper film 18 in the traveling direction, and sucks and removes the air in the concave portion 14a. The contact between the lower film 14 and the upper film 18 is heat-sealed. Further, a horizontal cutter means 20 and a vertical cutter means 21 are disposed further forward in the traveling direction of the vacuum chamber 19, and cut predetermined positions of the lower film 14 and the upper film 18 in the horizontal and vertical directions. Is manufactured and carried out.

Here, the vacuum chamber 19 will be described in detail. As shown in FIG. 2, the vacuum chamber 19 has an upper vacuum box 23 and a lower vacuum box 24. A plate 25 is provided and the lower vacuum box 24
Is formed with a recess 24a having an upper opening. This recess 24a is formed in the recess 14a formed in the lower film 14.
And the recess 14a is inserted into the recess 24a during vacuum processing.

Further, a seal rubber 26 is provided on the upper surface of the lower vacuum box 24 located on the peripheral edge of the recess 24a. Then, when the upper vacuum box 23 is closed with respect to the lower vacuum box 24, the lower film 14 and the upper film 18 are hermetically pressed at the peripheral portions of both, and the two films 14, 18
The air between them is evacuated and subjected to vacuum treatment. At the same time, the hot plate 25 is lowered, and a predetermined position is sealed by heating and pressing the films 14 and 18 between the hot plate 25 and the seal rubber 26.

Here, in the present invention, as shown in FIG. 3, a relatively large radius (small curvature) is applied to a part of the surface of the seal rubber 26 described above.
A bulged portion 27 having a substantially arc-shaped cross section is integrally formed so as to protrude. And the projection height is set very small. In addition, the bulging portion 27 is provided in the recess of the lower vacuum box 24.
It is arranged annularly near the periphery of 24a and is closed (see FIG. 4).

Further, in the present invention, a small protrusion 29 protruding upward is formed at the foremost portion of the bulging portion 27 (this small protrusion 29).
Is also set small). The cross section of the small projection 29 is formed in a substantially right-angled isosceles triangle shape, and the upper end thereof is rounded by dropping the corner (arc with a minimal radius: large curvature).

Next, the operation of the above embodiment will be described.In accordance with the same process as the conventional vacuum packaging, the packaged object 16 is inserted and arranged in the recess 14a of the lower film 14 and the upper part thereof is covered with the upper film 18. Vacuum chamber
Transferred to 19.

Here, a vacuum sealing process is performed. At this time, the lower and upper films 1 located around the recess 14a are formed.
When the foreign substance 30 exists between the points 4 and 18, heat sealing is performed according to the following steps. That is, the lower vacuum box 24 rises, and the small protrusion 29 of the seal rubber 26 comes into contact with the lower film 14. Next, as shown in FIG. 5 (A), when the hot plate 25 moves downward and the distance between the hot plate 25 and the seal rubber 26 is reduced, the contact pressure of the small projections 29 on the lower film 14 increases. Then, the small protrusion 29 pushes the foreign substance 30 on both sides. At this time, since the cross section of the small protrusion 29 is substantially triangular, even if the foreign substance 30 is a solid substance or the like, it is reliably separated. be able to.

Thereafter, when the distance between the two becomes narrower, FIG.
As shown in the figure, the small protrusion 29 is crushed by the reaction force from the hot plate 25 and buried in the bulging portion 27, and the surface of the seal rubber 26 becomes a gentle curved surface (the small protrusion 29 is not exposed). ), The lower film 14 comes into contact with the sealing rubber 26 with a relatively large area. At this time, since the projecting height of the small projection 29 is low, the small projection 29 is smoothly embedded in the bulging portion 27, and the small projection 29 caused by the embedding is formed.
The lower and upper films 14 and 18 are relatively strongly heat-sealed at locations corresponding to the small projections 29 by the clamping force (restoring force of the raw projections 29) generated between the lower and upper heating plates 25.

When the hot plate 25 continues to move downward and the space between the hot plate 25 and the seal rubber 26 is reduced, the bulging portion 27 is crushed by the reaction force of the hot plate 25 as shown in FIG. Bulge
The lower and upper films 14, 18 are heat-sealed at a position corresponding to the bulging portion 27 by the pinching force (restoring force of the bulging portion 27) generated between the heat plate 27 and the hot plate 25 (however, it is performed in the previous process). Small projection 27
Is slightly weaker than the seal strength of the portion corresponding to

By doing so, even if the lower and upper films
Even if the foreign substance 30 exists between the layers 14 and 18, a relatively wide sealing area can be secured. Also, both films 1
Even in the case where the foreign matter 30 does not exist between 4 and 18, the small projection 29 and the bulging portion 27 are crushed according to the same process as above, and a relatively wide sealing area can be secured. In the sealing process performed in accordance with the above-described steps, the incidence of defective products having incomplete sealing portions could be suppressed to 0.1% or less. Thereafter, a vacuum sealing process or the like is performed according to a normal method, and the vacuum package 22 is manufactured.

In the above-described embodiment, the case where the seal rubber 26 is provided in the vacuum chamber 19 of the vacuum packaging device has been described. However, the present invention is not limited to this, and the sealing device in a normal packaging device (without performing vacuum processing) is described. And other various packaging devices.

<< Effects of the Invention >> As described above, in the sealing device according to the invention, a bulging portion having a small curvature and a substantially arc-shaped cross section is provided at a predetermined location on the surface, and a tapered tip having a large curvature is further provided at the tip thereof. Because of the arrangement, even if a foreign substance such as a solid substance exists between the films to be heat-sealed, the projections can separate the foreign substance and push away on both sides thereof, and the solid portion surely becomes strong at the portion corresponding to the projection. Heat sealing can be performed.

In addition, since the protrusion is easily embedded in the bulging portion, the film to be heat-sealed also contacts the bulging portion, and the bulging portion has a small curvature so that the film is in contact with the film in a relatively large area. Therefore, a relatively wide sealing area can be secured.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of a vacuum packaging apparatus in which a sealing device according to the present invention is used, FIG. 2 is an enlarged sectional view of a main part thereof, FIG. FIG. 5 is a view showing an arrangement state of the sealer seal rubber, FIG. 5 is a view for explaining the operation, FIG. 6 is a sectional view showing a conventional seal rubber, and FIG.
The figure is a cross-sectional view showing a seal rubber previously created by the present inventors. 25: hot plate (heating member), 26: seal rubber, 27: bulging part 29: small projection (projection)

Claims (1)

(57) [Claims] 1. A heating member capable of heating and melting a film, and a seal rubber opposed to the heating member at a predetermined distance with the film interposed therebetween, wherein at least one of the heating member and the seal rubber is provided. By moving relatively forward and backward by linear motion and sandwiching the film at a predetermined pressure from both sides thereof, in a sealing device for a packaging device that heat seals the film, at a predetermined position on the surface of the sealing rubber A bulged portion having a small curvature and a substantially arc-shaped cross section is formed, and a tapered tip having a large curvature that protrudes to the outside at a tip of the bulged portion in normal times and is buried in the bulged portion when sandwiched. A sealing device characterized by forming a projection in a shape of a circle.