JPS6322313A - Seal header - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a seal header of a sealing device for sealing a sheet film to the edge of a tray.

(Prior Art) When packaging meat, vegetables, mushrooms, etc., it is common practice to load them into a tray-shaped packaging container and seal the edge of the tray with a sheet-shaped film.

One example is what is known as a heat sealing device.

Its features include a tray receiver that receives a tray with an outer periphery of the lip and is moved up and down by an appropriate vertical movement mechanism; A frame-shaped seal header is provided to press the I-shaped film against the tray that is raised together with the tray receiver, and a heater is arranged on the lower surface of the seal header at a portion corresponding to the outer periphery of the tray mouth edge. When the tray comes into contact with the heater l'ii+, the sheet-like film is welded and sealed to the outer periphery of the I and Lero edges.

Furthermore, regarding a sealing device that automatically performs this sealing, there is a technique disclosed in Japanese Patent Application Laid-open No. 33903/1983 (see FIG. 3).

The feature is that the tray 1 is coated with adhesive on the outer edge.
A tray receiver 11.2 is provided which receives the tray receiver 10 and is moved up and down by a suitable vertical movement mechanism.
A sheet-like film 114 disposed above 12 and inserted between the tray holder 112 and the tray holder 112 is pressed against the adhesive surface of the tray 110, which is raised together with the tray holder 112 as the tray holder 112 rises. It is known to have a seal header 116 having an elastic pressing member for sealing.

(Problems to be Solved by the Invention) However, the above-mentioned conventional techniques have the following problems.

When sealing a sheet film to two parts of a PVC tray, etc., it is difficult to perform a good seal with the first sealer because the tray softens and deforms first due to the difference in melting point between the film and the tray. It is necessary to increase the thickness of the tray, or to make the film a two-layer structure and use a film with a low melting point on the side that contacts the tray, resulting in high costs.

On the other hand, if the sealing temperature is kept low to prevent the tray from deforming, the seal strength will be weak (this may cause the seal to peel off during transportation, or if the height of the contents of the tray is higher than the outer rim of the mouth). There is a problem that the film J is easily peeled off because force is applied in the direction without peeling it off.

The method of sealing the outer periphery of the mouth with adhesive is effective because it can overcome the above-mentioned problems, but the problem is that trays coated with adhesive are relatively expensive, resulting in high costs. Has a point.

Therefore, the present invention has been made to further improve the above-mentioned heat sealing device, and its purpose is to perform reliable sealing without peeling of the seal portion,
In particular, it is an object of the present invention to provide a seal header that enables raised packaging.

(Means for solving problems) In order to solve the above problems, the present invention has the following configuration.

That is, by relatively approaching and abutting a tray having an outer peripheral edge placed on a tray receiver, the sheet-like film interposed between the tray and the tray is welded to the outer peripheral edge of the tray. In the seal header of the seal device,
An impulse heater is provided on the bottom of the seal hesoter main body at a portion corresponding to the outer periphery of the mouth edge of the tray, and is capable of rapidly heating the sheet film for welding and sealing, and an impulse heater is provided at an appropriate position at least inside the impulse heater. and a cushioning material, the lower end of which is set to be located an appropriate distance below the lower end of the impulse heater, and which presses the sheet-like film against the outer periphery of the mouth edge.

(effect) Next, the operation will be explained with reference to FIG.

In FIG. 2(b), when the tray 26 is placed on a tray holder (not shown) and moved in the direction of the arrow, the film 28 inserted between the outer periphery of the mouth edge 38 of the tray 26 and the seal header 10 is removed from the tray 26. Approach the bottom surface of seal header 10 while contacting the top surface. Then, the cushioning material 50a150b first comes into contact with the film 28 and presses the film 28 against the outer peripheral portion 38 of the mouth edge of the tray 26. Furthermore, as the tray 26 rises slightly, the impulse heater 46 comes into contact with the film 28.

At this point, the impulse heater 46 is energized, and the film 28 is welded to the outer peripheral portion 3B of the mouth edge of the tray 26 in a short time.

At the same time, the cutting heater 48 is also energized, and the excess portion of the film 28 outside the tray 26 is cut.

(Embodiments) Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

First, the configuration will be explained in detail.

FIG. 1 is a diagram showing the main parts of the sealing device near the seal header 10. As shown in FIG.

Reference numeral 10 denotes a seal header, the details of which will be described later, are shaped like a rectangular bar.

The seal header 10 is suspended from a suitable support 14 fixed to a frame 12 via a port 16 so as to be vertically movable.

A spring 20 is loaded between the lower and upper surfaces of the support 14 and constantly biases the seal header 10 downward.

Reference numeral 18 is a nand for regulating the downward movement of the seal header 10.

24 is a stopper, and the seal header 10 is the tray 2.
The amount of upward movement of the seal ladder 10 is limited when it is pushed upward as the seal ladder 6 moves upward.

28 is a sheet-like film pulled out from a roll (not shown), and two pairs of endless healds 30a, 30b
, 31a, and 31b at both side edges. And the endless belts 30a, 30b, 31a, 31
b is intermittently driven by a power transmission means (not shown) to feed the film 28 by a fixed distance in a direction perpendicular to the plane of the paper in FIG.

32a and 32b are a pair of parallel links, and the tray 26
The part of the film 28 corresponding to the upper part is removed from the film 2
The tray 26 of No. 8 is brought into contact with a portion outside a position corresponding to the outer periphery of the mouth edge of the tray 26 and lifted upward.
The paper is stretched to eliminate wrinkles.

The parallel links 32a and 32b are moved up and down by a suitable cam mechanism, and the film 2 is moved by the endless heald.
When the film 8 is fed by a fixed length, it moves upward to put the film 28 in an elongated state. Although not shown, the film 28 is preheated by a preheating plate and fed to the sealing position by a fixed length.

26 is a tray, and 34 is a tray holder on which the tray 26 is placed and moved up and down by an appropriate mechanism. Although not shown, a cushioning material made of a suitable material such as silicone is disposed on the upper surface of the tray receiver 34 to ensure that the tray 26 is brought into contact with the seal header 10.
can be brought into contact.

Next, the structure of the seal header 10 will be explained in detail with reference to FIG.

FIG. 2(a) is a perspective view of the seal header 10, and the overall shape of the seal header 10 is a rectangular bar.
There is a penetrating space 36 in the center. Seal header 1
The size of 0 is appropriately selected depending on the size of the tray 26 to be sealed and the size of the outer peripheral portion 38 of the mouth edge thereof. The space 36 is provided in the sealing ladder lO because the contents of the tray 26 to be sealed may swell above the outer rim 38 of the tray 26.

The material forming the seal header main body 11 of the seal header 10 is preferably made of aluminum, brass, copper, etc., which are materials with good thermal conductivity.

A female threaded hole 40 is provided on the upper surface of the seal header 10 for screwing the bolt 16 described above.

FIG. 2(b) shows a sectional view taken along the line /lA in FIG. 2(a).

42 is a water channel provided in the seal header body ll,
Cooling water 44 is passed through it. The purpose of cooling is to protect cushioning materials 50a, 50b, etc., which will be described later, by absorbing heat from an impulse heater 46 and a cutting heater 48, which will be described later.

46 is an impulse heater, and seal header 10
It is arranged in a concave groove 47 provided on the bottom surface.

The impulse heater 46 is formed of a coiled heating wire, and its lower end protrudes from the bottom surface of the seal header 10. The inner wall surface of the groove 47 and its surroundings are □Seal header IO
The upper half of the impulse heater 46 is fixed in the groove 47 to prevent the impulse heater 46 from sagging. Ceramic is used because it has excellent insulation and heat resistance.

50a and 50b are cushioning materials made of silicone rubber tubes, and grooves 51a and 5 are provided on the bottom surface of the seal header 10 with the impulse heater 46 therebetween.
1b.

A silicone tube is used because it has excellent heat resistance, and a sponge may also be used as long as it has heat resistance and elasticity.

It is not always necessary to arrange two 4' 50a and 50b on the cushion, and the outer cushion material 50b may be omitted for reasons described later.

The lower ends of the damping members 50a and 5Qb protrude downward by a predetermined length from the lower end of the impulse heater 46. This is because the film 28 is pressed and then welded by the impulse heater 46.

48 is a cutting heater that removes excess film 2 after sealing.
In order to cut B, the outer peripheral part 3 of the mouth edge of the tray 10 to be sealed
It is provided outside the position corresponding to the edge of 8. The installation method is to fix the heating wire by providing four a53 on the bottom surface of the Bakelite fixing part 52 fixed to the bottom surface of the seal header 10.

At this time, in order to reliably cut the excess portion of the film 28, the lower end of the cutting heater 48 is positioned below the lower ends of the cushioning materials 50a, 50b. However, this cutting heater 48 does not need to be fixed to the seal/nodder 10, and may be arranged around the seal header 10 in an appropriate manner.

Next, the operation will be explained in detail.

In FIG. 1, the seal film 28 is pulled out from a roll (not shown) and two pairs of endless healds 30a, 30b are attached.
, 31a, 31b, and the endless healds 30a, 30b, 31a.

When the film 31b is rotated in a predetermined direction, the film 2B□ is fed by a fixed length toward the seal header 10.

At this time, if the spread film 28 is passed over a preheating plate (not shown) and heated, it becomes easy to seal it in the stretched state.

Of course, the temperature of the preheating plate needs to be below the melting point of the film 28.

The tray 26 to be sealed is conveyed onto the tray tray 34 by a suitable means such as a belt conveyor, and the tray tray 34 is moved upward by a suitable vertical movement mechanism.

At this time, the parallel links 32B, 32b rotate to push up both ends of the film 28, thereby stretching the film 28 to prevent wrinkles during sealing.

The rotation of the parallel links 32a and 32b does not necessarily have to coincide with the upward movement of the tray receiver 34, and the film 28 may be pushed upwards whenever the sealing device is in operation.

The tray 26 that has moved upward is pressed against the lower surface of the seal header 10 by the tray receiver 34 together with the stretched film 28.

At this time, the seal header 10 is pushed upward, but the impact force is absorbed by the spring 20, and the stopper 24
The amount of movement is limited by

Next, it will be explained with reference to FIG. 2(b).

When the film 28 and the outer edge 38 of the tray 26 come into contact with the seal header 10, an appropriate switch circuit (not shown) is activated, and the impulse heater 46 is powered from a power source (not shown).
Power is supplied to the Note that before the impulse heater 46 comes into contact with the film 28, the cushioning materials 50a, 5
The lower end of 0b is located below the impulse heater 46, and the film 2 is placed on the outer periphery 3B of the tray 26.
g, the contents of the tray 26 will be transferred to the tray 26.
Even if the sealing portion of the film 28 is raised to a higher position than the outer peripheral portion 38 of the mouth edge, the portion of the film 28 to be sealed can be brought into close contact with the outer peripheral portion 38 of the mouth edge.

Further, due to the effect of the inner cushioning material 50a, even if the film 28 is melted by the impulse heater 46, the tension of the film 28 does not act on the melted part, so the film 28
will not be torn.

The impulse heater 46 supplied with electric power is instantaneously heated to the welding temperature of the film 28, so that the impulse heater 46 melts the film 28 while pressing both sides against the cushioning materials 50a and 5-Ob, and melts the film 28 at the opening of the tray 26. It can be welded to the edge outer peripheral portion 38 in a short time.

The film 28 on the outside of the outer circumferential portion 38 of the mouth is connected to the cutting heater 4
Since the film 28 can be cut along the shape of the seal header 10 by the cutter 8, the film 28 can be finished with an attractive appearance without leaving any excess film.The cut film 28 is wound onto a winding roll (not shown).

The sealed tray 26 is lowered by the vertical movement mechanism and transported to a predetermined position by an appropriate transport mechanism, and the above-described operation is repeated to seal the next tray.

A linear heater may be used as the impulse heater 46, but a coiled heater has a larger welding area and can provide a stronger seal.

Furthermore, even if a coiled heater expands thermally, the coil can absorb the expansion, so that displacement of the heater position due to thermal expansion can be prevented.

In addition, the film 28 is
Since it is lifted and sealed while maintaining its stretched state, it is possible to seal without wrinkles. Furthermore, since the film 28 is maintained in a stretched state, the film 28 can be cut smoothly.

By arranging a thermocouple at an appropriate position on the seal header, which was not provided in this embodiment, it is possible to control the temperature of the heater and also to protect the heater.

Although the present invention has been variously explained above with reference to preferred embodiments, the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. It is.

(Effects of the Invention) According to the present invention, when welding a film to a tray, the film can be welded by rapid heating with a heater, so deformation of the tray due to heat can be prevented, and thick walls can be welded. Cost-intensive requirements such as the use of trays, duplication of films, and application of adhesives can be eliminated.

In addition, since the cushioning material can be welded without pressing the inside of the heater, a seal with sufficient strength can be achieved, and it is particularly effective in that a sufficient seal can be achieved even when the inside of the tray is swollen.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a part of the vicinity of the seal header of a seal device using the seal header according to the present invention, and Fig. 2 (a
) is a perspective view of the seal header according to the present invention, (b) is A
3 is a diagram illustrating the operation based on a sectional view of the section -A, and FIG. 3 is a diagram showing a part of the conventional sealing device near the seal header. 10... Seal header, 46... Impulse heater, 'soa, 50b... Cushion material,
48... Cutting heater.

Claims (1)

[Claims] 1. By relatively approaching and abutting a tray having an outer periphery of the opening placed on the tray holder, the sheet film inserted between the tray and the tray is In the seal header of the sealing device that welds to the outer periphery of the edge, an impulse heater is provided at a portion of the bottom of the seal header main body corresponding to the outer periphery of the mouth edge of the tray and is capable of rapid heating in order to weld and seal the sheet-like film; a cushioning material disposed at an appropriate position at least inside the impulse heater, the lower end thereof being positioned an appropriate distance below the lower end of the impulse heater, and pressing the sheet-like film against the outer periphery of the mouth edge; A seal header characterized by comprising: