JP3433304B2 - Stretch film welding equipment for automatic packaging line - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic wrapping apparatus for wrapping a container containing an object to be packaged such as food with a stretch film and welding the overlapping portion of the film on the bottom surface. The present invention relates to a stretch film welding device in a packaging line. 2. Description of the Related Art An example of a conventional automatic packaging line is shown in FIG. 5 (showing the plane of the line) and FIG. 6 (showing the side of the line). This packaging line is a belt line A, B, C
, And the containers 31 are transferred by the belt conveyor 30 in each line. The direction of the arrow in the figure is the transfer direction for moving the container forward. [0003] In the belt line A, the container 31 accommodating the articles to be packaged is transported in the forward direction indicated by the arrow, and at the end thereof, the roll of the stretch film 32 wound by the roll 32a is moved in parallel above the belt surface. The film 32 is set by the forward transfer of the container 31.
Surrounds the container 31 in the vertical direction from the front, and surrounds the rear end of the film 32 cut by the cutting means so as to be wound around the bottom surface of the container 31. [0004] In the belt line B, a stretch film 33 wound by a roll 32b is provided upright on the belt in the middle of the line, and the container 31 from the preceding process is transported in the forward direction, so that the stretch film 33 is stretched. The film 32 is wrapped around the container 31 in the lateral direction from the front and is surrounded. At this time, the film 32 laterally surrounded from the front
After cutting, both ends are wrapped around the bottom surface of the container 31. As a result, when the packaging of the film 32 from the vertical direction and the horizontal direction is completed, the ends of the film 32 are multilayered at the front and rear positions of the bottom surface of the container 31. Film overlap part 32
a, 32b (see FIG. 7). [0005] At the end of the belt line B, a heater 34 is installed. The heater 34 has a structure in which a filament 35 is provided on the lower surface of a flat heater plate 36.
Passes while contacting the upper surface of the heater plate 36. As a result, the film overlapping portions 32a and 32b on the bottom surface of the container 31 come into contact with the heater plate 36 and are welded by the heating of the heater plate 36. Next, in the belt line C, the container 31 after the film packaging and welding is transferred and taken out, and thereafter, boxes are stacked. [0007] In order to solve the above-mentioned problems, a stretch film packaging apparatus for an automatic packaging line according to the first aspect of the present invention is a conveyor for performing stretch film packaging of containers transferred in the automatic packaging line. Between the end of the container and the beginning of the conveyor in the next step, and in contact with the film overlapping portion formed before and after the bottom surface of the container .
In response, a recess is formed before and after the holding case, and
A plurality of protruding surfaces that are parallel with the upper surface in the recess
The front and rear heaters are configured by housing the heat radiator,
Further along the upper surface of the heater before and after the holding case,
Contact the end of the conveyor and the start of the next process conveyor
The plate is elongated . As described above, on the bottom surface of the container 31, the end portions of the film 32 surrounded from the vertical direction and the horizontal direction are stacked in multiple layers in front and behind the bottom surface of the container 31 in the forward direction. The overlap portions 32a and 32b are formed, and the overlap of the film 32 is rare at the center portion of the bottom surface, and a gap 37 is formed at this portion. The film 32 on the bottom of such a container 31
When the upper surface of the above-described conventional heater plate 36 is brought into contact with the above-mentioned heat-welding for the overlapping condition, the film overlapping portion 32
The a and 32b contacted the heater plate 36, and the center gap 37 at the bottom face could not contact the heater plate 36, and could not be welded at this location, resulting in wasteful thermal efficiency of the heater 34. In addition, the heater plate 36 has a flat surface, and the heating of the heater plate 36 performs uniform heat welding on the plate surface, so that the film overlap portions 32a, 32b before and after contacting the heater plate 36 are formed. However, only uniform welding is performed. As a result, only the surface layers of the film overlapping portions 32a and 32b are thermally welded, and the sealing performance is very weak, and the film is easily peeled off after thermal welding. It had disadvantages. SUMMARY OF THE INVENTION The present invention has been made to solve such a drawback. In an automatic packaging line, it is possible to efficiently wrap a container with a stretch film and weld the overlapping portion of the bottom film. It is an object of the present invention to provide a stretch film welding apparatus in an automatic packaging line in which welding is performed to achieve firm sealing. [0013] In order to achieve the above object, a stretch film packaging apparatus in an automatic packaging line according to the present invention is provided with an end of a conveyor for performing stretch film packaging of containers transferred in the automatic packaging line. A heater having an upper surface forming a plurality of protruding surfaces was installed at a position between the film and the starting end of the conveyor in the next step and in contact with a film overlapping portion formed before and after the bottom surface of the container. Further, the plurality of protruding surfaces of the heater may be configured to form parallel linear protruding surfaces. In the stretch film wrapping apparatus for the automatic wrapping line constructed as described above, a plurality of protruding surfaces are formed on the upper surface of the heater. The container placed at a distance from the heater and transferred onto the heater is subjected to partial concentrated heating due to the protrusion of the heater on the film overlapping part on the bottom surface. A much stronger seal can be achieved. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view of a stretch film welding apparatus according to the present invention. FIG. 2 is a top view of FIG. FIG. 3 is a side view showing the state of contact between the heater surface and the film overlapping portion of the container in the present invention. FIG. 4 is a bottom view showing the positional relationship between the film overlapping portion of the container and the heater. The heater 1 shown in FIG. 1 is installed between the belt lines B and C shown in FIGS. 5 and 6, and the structure of the belt lines A, B and C is as shown in FIGS. The rubber belt 11 is provided between the driving wheels 10 which are driven to rotate.
And the container 2 is placed thereon and transported in the direction of the arrow. In the heater 1, two holding cases 4, 4 are provided on the upper surface of the heater case 3 at front and rear positions along the transport direction of the belt 11 at intervals, and concave portions formed in the holding case 4 are provided. As shown in FIG. 2, three cylindrical heat radiators 5 accommodating a nichrome wire therein are accommodated in the place, and by such a structure, the upper surface forms a linear projecting surface having a parallel arrangement. The front and rear heaters 1a and 1b are configured. In order to make the upper surfaces of the front and rear heaters 1a and 1b parallel to each other in a linear protruding surface, the above-described cylindrical heat radiator is juxtaposed, and the upper surfaces of the front and rear heaters 1a and 1b are corrugated. Alternatively, the corrugated plate may be heated by providing a nichrome wire on the lower surface thereof. The upper surfaces of the front and rear heaters 1a and 1b are formed as linear projecting surfaces arranged in parallel.
The upper surface of 1b may have a shape protruding in a plurality of mountain shapes. The front and rear heaters 1a and 1b are positioned such that when the container 2 is mounted on the upper surface in the vertical direction along the forward direction of the line, the front and rear of the bottom surface of the container 2 are the front and rear heaters 1a and 1b. Should be placed on the upper surface of each. The front and rear heaters 1a, 1a, 1
Along the top surface of the belt line B, there are provided communication plates 6, 6 extending above the end of the belt line B and the start end of the belt line C in the next step , and pass from the belt line B to the front and rear heaters 1a, 1b. Thus, the transfer of the container 2 to the belt line C is performed smoothly. A nichrome wire (not shown) housed inside each heat radiator 5 is connected to a controller 8 installed at the bottom of the heater case 3, and the controller 8 controls the temperature of the front and rear heaters 1a and 1b. To do. If means for pressing the container 2 passing therethrough from above is provided above the heater 1, the stretch films 7 can be reliably adhered to each other at the bottom of the container 2. In the stretch film wrapping apparatus in the automatic wrapping line configured as described above, the container 2 transferred to the end of the belt line B has already been moved from the vertical and horizontal directions by the film wrapping process of the previous process. The stretch film 7 is transported in a state of being surrounded. At this time, as shown in FIGS. 3 and 4, the bottom surface of the container 2 has a multilayer overlap portion 7a, 7b of the stretch film 7 before and after along the advance direction. The situation has been formed. When the container 2 is placed on the heater 1 by the transfer of the belt line B, the front and rear heaters 1a, 1a
b are film overlapping portions 7a, 7b on the bottom surface of the container 2.
In this way, intensive partial heating is performed, and a firm seal can be performed. Next, in FIG. 1, the succeeding container 2a pushes the container 2 after heating by the belt line B to the front belt line C, and then the subsequent container 2a is placed on the heater 1. In the same manner as described above, the film of the container 2a is welded. As described above, according to the stretch film welding apparatus in the automatic packaging line of the present invention,
Intensive partial heating is performed only on the front and back film overlaps generated at the bottom of the container by the film packaging process, so that the heater can be used efficiently, and this heat-welded part is a multilayer film. Are welded to each other over the entire layer of the overlapped portion, and a much more solid seal can be achieved as compared with the conventional welding of only the surface layer by the full-surface heater.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side sectional view of a stretch film welding apparatus according to the present invention. FIG. 2 is a top view of FIG. 1; FIG. 3 is a side view showing a contact state between a heater surface and a film overlapping portion of a container in the present invention. FIG. 4 is a bottom view showing a positional relationship between a film overlapping portion of a container and a heater. FIG. 5 is a top view of a conventional film packaging line. FIG. 6 is a side view of FIG. 5; FIG. 7 is a side view showing a contact state of a film overlapping portion with a heater in a conventional film packaging line. [Description of References] 1 ... heater, 1a, 1b ... front and rear heaters, 2 ... container, 3 ...
Heater case, 4 holding case, 5 radiator, 6 communication plate, 7 stretch film, 7a, 7b ... film overlapping portion before and after, 10 ... drive wheel, 11 ... rubber belt, A,
B, C: Belt line.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B65B 11/06-11/52 B65B 51/10

Claims (1)

(57) [Claim 1] Between an end of a conveyor for performing stretch film packaging of a container transferred in an automatic packaging line and a start of a conveyor in a next process, and a bottom surface of the container. Corresponding to the position where it touches the film overlap generated before and after
Form recesses before and after the holding case and
Heat radiation with multiple protruding surfaces that are parallel filaments
The front and rear heaters are configured by housing the body,
Along the upper surface of the heater before and after the holding case,
A contact plate extends over the end of the bear and the start of the next process conveyor.
Stretch film packaging equipment in an automatic packaging line characterized by being long .