JPH0542918A - Shrink furnace - Google Patents

Abstract

PURPOSE:To freely adjust the thermal distribution in the longitudinal direction in a furnace and always obtain a stable constricted appearance of the thermally constricted film regardless of the conditions of articles to be packed, by arranging heaters within the furnace in a plurality of groups in the longitudinal direction thereof and providing temp. controllers of the heaters every group. CONSTITUTION:An upper support plate 8 and many far infrared ray heaters 10 via support plates 9 of both sides A are arranged inside a shrink furnace 5 in which articles 4 to be paced are transferred by a conveyer 7. These heaters 10 are arranged in plural rows in both lateral and longitudinal directions of the furnaces respectively every support plates 8, 9 and divided into total nine groups composed of A-group and B-group about the upper support plate 8 and on the other hand, the heaters are diveded into C-group composed of three groups. And the temp. of the heaters 10 of respective groups is controlled by a thermal controller respectively to enable to be optimum for the thermal distribution within the furnace in accordance with the condition of the articles packed and also to finish the thermal constriction film to always show a stable constricted appearance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shrinking furnace applied to half shrinking packaging in a packaging machine.

[0002]

2. Description of the Related Art As shown in FIG. 5 (a), a can 2 is filled in a corrugated paper tray 1 whose upper side is opened.
As shown in FIG. 6B, the shrinking furnace for half-shrink-wrapping the wrapped product 4 formed by covering the heat-shrinkable film 3 such as polyethylene film is the inner wall upper surface and inner wall side surface of the furnace 5 as shown in FIG. 6A. A plurality of rod-shaped infrared heaters 6 are arranged on the and to heat the encapsulated product 4 carried on the conveyor 7, and the infrared heaters 6 arranged in the longitudinal direction of the furnace are shown in FIG. As shown in FIG.

[0003]

When the shrinking furnace 5 is shrunk in such a shrinking furnace 5, there is a drawback as shown in FIG. As shown in FIG. 7 (a), the wrapped product covers the can 2 with the film 3 and adheres it to the tray 1. The flaps HL of the film 3 are formed at both ends of the tray 1. This flap part H
It is necessary to cleanly shrink L to shrink it to a completely sealed state with no space, as shown in FIG. 7 (d).

In the case of the conventional shrink link furnace shown in FIG.
7 (b) and FIG. 7 depending on conditions such as a change in film material, a change in shape of the tray 1 and the can 2, a change in outside temperature.
As shown in FIG. 7C, when viewed from the direction A in FIG.
The film 3 does not adhere to the tray 1 and a space 8 is created,
It tends to be in a contracted state with uneven appearance and poor appearance. Since such an external finish does not work as a product, it becomes a defective product.

The present invention solves these drawbacks and provides a shrink furnace capable of always providing a stable appearance finish as shown in FIG. 7 (d).

[0006]

The structure of the present invention for achieving the above object will be described with reference to FIGS. 1 to 3 corresponding to the embodiments. Heat shrinkage occurs in a corrugated paper tray 1 filled with a can 2. In a shrink furnace in which the heat-shrinkable film 3 is shrunk by heating the encapsulated product 4 formed by covering the film 3 with the heater 10 in the furnace, a plurality of groups A and B in the length direction of the furnace are used. , C, and heaters 1 for each group
0 is provided with a temperature control device 11.

Further, the heater for each group is provided with a distance control device 24 for adjusting the distance to the encapsulated product.

[0008]

Since the present invention is configured as described above, the heaters of each group are adjusted in temperature and distance from the encapsulated product according to the conditions of the encapsulated product. Therefore, the heat-shrinkable film covered with the encapsulated product can always have a stable shrinkage appearance.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 1. An upper support plate 8 and both side support plates 9 are provided in a shrink furnace 5 in which a conveyor 7 for conveying an encapsulated product 4 runs. A far-infrared ceramic heater 10 is disposed through the far-infrared ceramic heater 10, and the far-infrared ceramic heater 10 has a plurality of rows in the lateral direction of the furnace, that is, seven rows in the figure and a plurality of rows in the length direction of the furnace, that is, in the figure In this example, it was arranged in 9 rows, and this was formed by group A formed by 2 rows on both sides in the lateral direction and 3 rows in the longitudinal direction, 3 rows in the center in the lateral direction and 3 rows in the longitudinal direction. It is divided into a total of 9 groups consisting of group B and side supporting plates 9 are arranged in a plurality of rows in the vertical direction of the furnace, that is, two in the figure.
The cells were arranged in rows and a plurality of rows in the length direction of the furnace, that is, 9 rows in the figure, and this was divided into a group C formed by two rows in the vertical direction and three rows in the length direction.

The temperature control of each of these heater groups is performed by a temperature control device 11, which as shown in FIG. 2a has a controller 12 connected to the group A, a controller 13 connected to the group B, and a controller C. A controller 14 connected to the group, and a control panel 15 connected to each of the controllers 12, 13, 14
Composed of and. And each controller is shown in Fig. 2 (b).
As shown in FIG. 5, each heater group, that is, the heater of the group C is provided with the power supply line 16 and the thermocouple wire 17 for temperature detection, the temperature of the heater of the group C is detected and displayed by the detector 18, and the signal thereof is the controller. 19 is sent to the control controller 19 by the input power source 20 from the control panel 15 and normally, for example, a heating voltage of 100 V is sent to the holding controller 22 via the circuit 21, and the holding controller 22 heats the heaters of the group C. To be done.

When the heater of the group C reaches a predetermined temperature, the signal is sent to the controller 19 via the detector 18. Here, the voltage supply of 100V is stopped or the holding voltage (for example, 20V) is supplied from the holding controller 22 to the heater via the holding circuit 23 by 20V. As a result, a complete heating voltage of 100 V is not turned on and off, and 10
Since the control is performed between 0 V and 20 V, temperature control of the heater group is easy and accuracy is improved.

By providing such a temperature controller to each heater group, temperature distribution in the furnace becomes possible as shown in FIG. 4, and when shrinked, a shrink-packed product having an appropriate appearance can be obtained. Furthermore, each of the heater groups described above is an encapsulated product 4
Has a distance control device 24 capable of arbitrarily adjusting the distance to
The distance control device 24 is arranged in the upper heater groups A and B as shown in FIG.
A guide bar 25 fixed to the upper support plate 8 as shown in FIG.
A rotary shaft 28 having a handle 27 provided on a main body cover 26 that supports the guide bar 25, a worm gear 29 provided on the rotary shaft 28, and the guide bar 25 provided so as to mesh with the worm gear 29. Worm gear 30
The upper support plate 8 is moved up and down by the rotation of the handle 27, and in the side heater group C, both side support plates 9 are provided as shown in FIG. It is composed of a bar 33 with a screw attached to the upper support plate 8 via a joint 31 and screwed into a female screw guide 32 provided on the main body cover, and a rotation handle 34 of the bar 33. The guide bar 3 fixed to the upper support plate 8 and provided on the body cover as shown in FIG.
5, the side support plate 9 is moved left and right by the rotation of the rotary handle 34.

[0013]

As described above, according to the present invention, the heaters in the furnace are arranged in a plurality of groups in the lengthwise direction of the furnace, and the temperature control device for the heater is provided for each group. The temperature distribution in the length direction can be adjusted freely so that the heat-shrinkable film can always have a stable shrinkage appearance according to the conditions of the encapsulated product, and the heater of each group can be separated from the encapsulated product by a distance. When a distance control device for adjusting the temperature is provided, the temperature distribution in the furnace can be further finely adjusted.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, in which a is a front view and b is
Is a view taken along the line AA.

FIG. 2a is a temperature control circuit diagram in FIG. 1a, and b is a partial circuit diagram thereof.

FIG. 3A is a side view of a distance control device for an upper heater group, b
Is a side view of the distance control device for the side heater group, c is B- of b
FIG.

FIG. 4 is an explanatory diagram showing an example of temperature control of the present invention.

FIG. 5 is an explanatory view of half shrink packaging, where a is before packaging,
b shows after packaging.

FIG. 6 shows a conventional example, in which a is a front view and b is a side view.

FIG. 7 is an explanatory diagram of a packaging form.

[Explanation of symbols]

 1 Tray 2 Can 3 Heat Shrink Film 4 Encapsulated Product 5 Shrinking Furnace 10 Heater 11 Temperature Control Device 24 Distance Control Device

Claims (2)

[Claims] 1. A shrinking furnace in which a heat-shrinkable film formed by covering a corrugated paper tray filled with cans with a heat-shrinkable film is heated in the furnace to shrink the heat-shrinkable film. The shrink-link furnace is characterized in that the heaters are arranged in a plurality of groups in the lengthwise direction of the furnace, and a temperature control device is provided in the heater for each group. 2. The heaters in the furnace are arranged in a plurality of groups in the length direction of the furnace, and a heater for each group is provided with a distance control device for adjusting a distance from the encapsulated product. The shrink furnace according to claim 1.