JPS624297B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves continuously forming a web of packaging material, including a support layer and at least one outer layer of thermoplastic material, into a tube-like shape, the longitudinal overlapping edges of which forming a packaging container by sealing and forming a transversely sealed portion in the tube of the packaging material;
This invention relates to a packaging machine that continuously manufactures a large number of packaging containers by filling them with contents and sealing them.

Conventionally, in the above-mentioned packaging machines, there has been a problem that when the sealing jaw is pressed against the tube of the packaging material from both sides to form a lateral seal portion, the packaging material adheres to the sealing jaw and is difficult to separate from it. This makes it difficult to mass-produce packaging containers at high speed, hinders complete sealing of packaging containers, and produces packaging containers with poor shapes.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to eliminate the drawbacks of conventional packaging machines as described above and to provide a simple and convenient packaging machine.

The packaging machine according to the invention comprises a forming device for continuously forming a web of packaging material into a tube-like shape, comprising a support layer and at least one outer layer of thermoplastic material and moving downwardly through the packaging machine; a sealing element for sealing two longitudinally overlapping edges of the tube of material; and a sealing element disposed on either side of the tube of packaging material below said forming device to form a transversely sealed portion of the tube of packaging material; a pair of form-seal devices cooperating to form the container and a fill pipe for penetrating the open top end of the web of packaging material to fill the packaging container, each of the form-seal devices comprising: two parallel longitudinal heating zones having a sealing jaw having a length exceeding the width of the tube of flattened packaging material, the sealing jaws each extending over its entire length; and between the two heating zones; The fluid discharge hole is characterized by being provided with an open fluid discharge hole.

The packaging machine according to the invention will now be described in detail with reference to the accompanying drawings, which show only the details necessary for an understanding of the invention. FIG. 1 shows a packaging machine for liquid-filled one-way packages made from heat-sealable materials. A web of laminate material 2 comprising a paper-like support layer and an outer layer of thermoplastic material from a roll of material 1
is unrolled. The web 2 of material passes through a guide pulley 3 at the top of the machine and then passes approximately vertically downward through the machine while being converted into a tube-like shape. During the descent of the material web through the machine, a continuous transformation into a tube-like shape is effected by a forming device 4 which has an approximately circular hole in the center through which the material web passes. By means of a sealing element 5 placed next to the forming device 4, the two longitudinal edges of the web 2 of packaging material which are superimposed on each other with the aid of the forming device are sealed, so that the packaging material with a longitudinal seal is formed. Tube 6 is created.

At a certain distance down from the forming device 4, a pair of cooperating forming sealing devices 7 are installed;
The device 7 compresses the tube 6 of packaging material in an area extending across the tube while being moved downwardly at the speed of the tube 6, the heat supplied there causing the thermoplastic layers of material to seal together. A sealed part of the tube 6 is obtained. By continuously feeding the contents to the lower end of the tube 6 through a filling pipe 8 passing through the open upper end of the tube, the sealed part or packaging container 9 can be completely filled with the contents. The forming and sealing device is shaped such that the lower end of the packaging tube 6 has a substantially rectangular cross-sectional shape, so that the sealed and then cut packaging container 9 has sealing fins projecting from the upper and lower ends of the packaging container. Apart from 10, the shape is almost a parallelepiped. Once the packaging container 9 has been separated from the tube of packaging material, a closing process takes place during which the sealing fins 10 are folded in and sealed against the side walls of the packaging container, so that the packaging container is approximately in the shape of a parallelepiped.

FIG. 2 shows the bottom of the forming seal device 7. The forming seal device is generally elongated in shape and includes a recessed tube-shaped area 11 facing the tube of packaging material and a lip 12 located at the bottom end of the device and projecting towards the tube of packaging material. 3, the lip of which supports the main body of the seal, namely the seal jaw 13, which is shown enlarged in FIG.

The sealing jaw 13 is of long, narrow shape and has a length that exceeds the width of the flattened packaging tube. The seal jaw 13 is attached to the lip 12 of the device 7 in such a way that its active side faces the tube of the packaging material. The working surface 14 is provided with two parallel longitudinal heating zones 15 which are shaped like parallel strips mechanically attached to the working surface 14 of the seal made of non-conductive material along their entire length. made of electrically resistive material. The heating zone 15 or strip is a connecting line (not shown)
can be connected to a power source via a power source and heated to a suitable operating temperature. In the center of the sealing jaw, viewed in its longitudinal direction, two fluid drainage holes 16 are provided on the working surface, which drains are connected to the tubes 17 (FIG. 4) and other tubes and lines located inside the sealing jaw 13. (not shown) to a source of pressure fluid. Seal Jyo 13 is further lip 12
includes elements for mounting this seal jaw (not shown) and two longitudinal internal cooling tubes 18.

When the packaging material coated with thermoplastic material is transformed into a tube and filled with the desired contents, clamping of the tubes 6 of the material with respect to each other takes place in certain lateral areas by means of the forming sealing device 7. At the same time that the forming sealing device is moved downwards synchronously with the tube 6, it is pivoted in a direction towards the tube from its rest position at a distance from the tube and passes through the position shown in FIG. A position is reached in which the two devices are parallel to each other and a partially flattened tube is placed between them. In this position, the sealing jaw 13 attached to the lower end of one forming device 7 rests against the opposite jaw attached to the lower end of the cooperating forming device 7 via a flattened sealing area. The cooperating molding devices may be of the same type or may be unheated and have a working surface of a flexible material such as rubber. In this position the heating area 15 of the sealing jaw is energized and the heat is transferred to the area 15.
The thermoplastic material on the inside of the tubes facing each other melts and welds together as the material is transmitted through the highly compressed material. The sealed packaging container is then separated from the remaining material tube by cutting through the sealing area, which cutting can be accomplished by a knife housed in the recess of the unheated opposing jaw. The knife is activated after the sealing action and the two heating zones 1
The tube of material is cut in the sealed areas between 5 and the working surface 14 of the sealing jaw 13 placed between these areas serves as a supporting tool for the knife. Alternatively, the cutting between the two sealed areas can of course take place in a later separation step.

Once the sealing operation and possible cutting of the sealed area has been carried out, the forming sealing device 7 also reaches its bottom limit position, after which these two devices are retracted from the tube and compress the tube again to seal it. moved upward to form a zone. When the sealing jaw is retracted from its position compressing the packaging material, the material tends to follow the return movement of the sealing jaw, which causes the sealing area to return quickly enough to create a vacuum as described above. This is due to the fact that air cannot flow in between. In order to prevent the packaging material from being affected by the return movement of the jaw, a fluid is allowed to flow into the area between the sealing jaw and the area of the sealed material so that the fluid prevents the creation of a vacuum and thereby protects the material. This eliminates the danger of the seal following the seal during its return movement. Fluid transport takes place via two holes 16 terminating in the working surface of the sealing jaw, these holes being located in the center of the sealing jaw and ensuring a uniform and rapid fluid flow.

Since the area between the two strip-shaped heating areas 15 is more concave than the heating areas, it is particularly advantageous to allow fluid to flow into that area. This means that the inflowing fluid enters the space between the working surface of the sealing jaw and the surface of the wrapping material facing it, which is essentially closed during compression of the material layer. A certain pressure is therefore created since fluid is prevented from directly escaping from the space between the working surface of the sealing jaw and the surface of the packaging material.

The preferred working fluid is air, although water may be used in some cases, such as when additional cooling is desired. The fluid delivery may be continuous, but may also be stopped or activated, for example by a valve controlled by the position of the seal jaw.
If the working fluid consists of air, the conveyance of the fluid is preferably continuous, but this does not necessarily mean that the evacuation of the fluid through the holes 16 in the seal jaw is continuous. The reason is that the fluid outlet hole is covered to some extent by the packaging material depending on the design of the sealing jaw and the location of the exit hole, so when the sealing jaw is pressed against the packaging material during the sealing process, fluid transport is prevented. This is because they may be cut off to some extent.

Each sealing jaw may be provided with one or more fluid outlet holes terminating in the working surface of the sealing jaw and directed toward the packaging material. The fluid discharge holes lead to a common pipe 17 in the sealing jaw, which pipe is connected via a closable connection line to a source of pressure fluid, such as a compressor or a pump. In a conventional type of seal jaw that includes two parallel heated zones spaced apart from each other, if the fluid outlet ends between those zones, and if the part where the fluid outlet ends is It is advantageous if the effect in this respect is achieved if it is recessed, in which case the fluid may be pressure is created. This effect can be further enhanced by suitably designed channels provided on the working surface of the seal jaw.
In many cases, a discharge hole is simply provided in the longitudinal center of the sealing jaw, which is suitable for uniform drainage towards both ends of the sealing jaw, thereby providing a satisfactory distribution of the pressure fluid.

Finally, in sealing jackets with an internal tube (FIG. 4) for a cooling medium, such as air, the operation of the jacket can be achieved by simply connecting tube 18 to tube 17 or via a tube not shown. By connecting directly to the surface, this cooling fluid can also be used as a working fluid.

[Brief explanation of the drawing]

FIG. 1 schematically shows a packaging machine according to the invention. Second
The figure shows a part of the molding device included in the packaging machine shown in FIG. 1 in an enlarged manner. FIG. 3 shows an enlarged view of the mold sealing jaw supported by the molding device according to FIG. FIG. 4 shows a cross section of the seal jaw shown in FIG. In the figure, 2...Packaging material, 13...Seal jacket,
14... Working surface, 16... Inflow pipe (exhaust hole), 1
5... Heating area.

Claims (1)

[Claims] 1 a forming device for continuously forming into a tube-like shape a web of packaging material comprising a support layer and at least one outer layer of thermoplastic material and moving downwards in a packaging machine; sealing elements for sealing longitudinally overlapping edges and disposed on either side of the tube of packaging material below said forming device to form a lateral sealing portion in the tube of packaging material for forming a packaging container; a pair of cooperating mold-seal devices and a fill pipe for passing through the open top end of the packaging tube to fill the packaging container, each of the mold-seal devices being flattened; two parallel longitudinal heating zones each having a sealing jaw having a length exceeding the width of the tube of packaging material, the sealing jaw extending over its entire length;
A packaging machine comprising: a fluid discharge hole opening between the two heating zones.