JPS641300B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shaping device for forming suitable synthetic resin welding pieces on both sides of a synthetic resin film, and more specifically, for protecting the side edges of the film. Another object of the present invention is to automatically form and attach welding pieces that act to weld both ends of the film accurately and at high speed when the film is formed into a tube body.

Synthetic resin films, particularly those molded into tube containers, have a structure in which several types of synthetic resin sheets are laminated, or a synthetic resin sheet is laminated on aluminum foil.

In order to roll such a film into a tube, the film is rolled, and both ends of the film are overlapped and heated and pressurized.
A method is used to weld the synthetic resin forming the films on both sides of the overlapped film.

By the way, as mentioned above, the film is constructed by laminating several types of synthetic resin sheets or by using aluminum foil, so the side edges of the film are covered with this film. Each layer will be exposed.

For this reason, a problem may arise in that a layer with poor water resistance or content resistance is exposed on the tube surface.

In addition, the welding of the overlapped ends on both sides is achieved and maintained simply by welding by heating and pressurizing, and is achieved by welding between extremely thin sheets that are in direct contact with each other. Therefore, sufficient bonding strength is not necessarily achieved. Not that you can get it.

Therefore, as a film for forming tube bodies,
At both ends of the film, welding pieces made of a synthetic resin material that is the same as the synthetic resin material forming both surfaces of the film or that welds extremely strongly to this synthetic resin material are placed on both sides of the film, covering at least the side end surfaces of the film. A film with a shape that covers it has been invented.

The film having this welding piece can keep the side edges of the film body completely covered with the welding piece, and the welding piece can strongly weld the overlapping edges on both sides. ,
It is extremely effective when molded into a tube body.

Since this welded piece is to be newly shaped to the film body which has already been formed into a long and narrow belt shape with predetermined dimensions, various means have been considered for attaching the welded piece to the film body. There is.

However, when shaping this welded piece to the film body, it is important to note that the shape of the welded piece to be shaped is almost constant, and that the film body is extremely long in the form of an elongated strip, so it is necessary to continuously form the welded piece to the film body. Since there are requirements such as being able to form a welded piece and being able to automatically form it, conventional methods have never been able to satisfy these requirements, and the shaping operation of this welded piece has become extremely inefficient.

The present invention has been devised to eliminate the drawbacks of the conventional examples described above and to satisfy all the requirements regarding the shape of the welded piece.One embodiment of the present invention will be described below with reference to the drawings.

The shaping device according to the present invention includes a die 2 connected to an extruder 1, and two nozzle heads 5, 5 facing each other at an interval slightly narrower than the width of the film 15.
are provided, and nozzle grooves 7, 7 are formed on the opposing surfaces of the nozzle heads 5, 5, which are cut and formed along the running direction of the film 15 with a width that allows the side edges of the film 15 to enter the position with a little margin. A nozzle opening 6 through which the molten resin 17 supplied from the extruder 1 to the die 2 is extruded is opened on the surface facing the end of the film 15 into which the nozzle grooves 7 have entered.

That is, the molten resin 17 supplied from the extruder 1 to the die 2 is guided from a sprue 3 in the die 2 to an injection path 4 that is divided into two, and a nozzle opening opened at the tip of the injection path 4. 6 into the nozzle groove 7.

As shown in FIG. 5, the nozzle opening 6, which is opened on the surface opposite to the side end of the film 15 into which the nozzle groove 7 has entered, is located at the center in the width direction of the surface opposite to the side end of the film 15 into which the nozzle groove 7 has entered. It is better to let
It is advantageous to position it slightly above the nozzle groove 7 along the traveling position of the film 15.

As shown in FIG. 2, in the most effective embodiment of the shaping device according to the present invention having such a configuration, the film 15 is moved from the raw material roll 8 wrapped with the film 15 to the guide roller 9, Brake roller 10, both tension rollers 11, 12, drive roller 1
3, the guide roller 14 sends it out as it is to the next processing step, and both tension rollers 1
The film 15 is held in a constant tension state between the tension rollers 11 and 12, and the film 15 is tensioned between the tension rollers 11 and 12 by the braking force of the braking roller 10 against the winding force of the drive roller 13. The installation position is made straighter, and both tension rollers 1
1, 12 is made as small as possible to prevent the film 15, which is traveling at a constant speed, from being undulated or displaced between the two tension rollers 11, 12.
The die 2 is placed between the two tension rollers 11,
Both ends of the film 15 located between the third
As shown in the figure, it is preferable to arrange it so that it enters into the nozzle groove 7.

The shape of the welded piece 16 is such that the film 15 travels at a constant speed and the molten resin 17 flows from the nozzle opening 6.
By being continuously extruded at an extrusion amount per unit time that is set in accordance with the traveling speed of the film 15, the side edge of the film 15 that has entered the nozzle groove 7 is extruded into the nozzle groove 7. The molten resin 17 is attached.

Molten resin 17 attached to the side edge of this film 15
The film 15 is attached with a cross-sectional shape regulated by the shape of the nozzle groove 7, but as soon as the film 15 leaves the nozzle groove 7, it deforms into a slightly rounded cross-sectional shape and its volume is extremely small, so that it does not escape from the nozzle groove 7. After only a short time, it is almost cooled and solidified and formed into a welded piece 16.

By the way, as is clear from the shaping operation of the welding piece 16 described above, in the case of the illustrated embodiment of the shaping of the welding piece 16, the film 15 is moved at high speed while the side end is shallowly inserted into the nozzle groove 7. , it is necessary to achieve extremely stable and wave-free running movement between the tension rollers 11 and 12. For this purpose, the running posture of the film 15 running on the running path of the film 15 facing the die 2 must be kept constant. Stability can be increased by providing a guide plate or the like to maintain the temperature.

As is clear from the above description, the present invention allows the welded pieces 16 to be continuously and automatically formed at both ends of the film 15 to have a substantially constant cross-sectional shape. When forming a tube body using the film 15, a good tube body can be formed, and the die 2, which is the main part, has a simple structure and is easy to manufacture. As long as the running speed of the film 15 is constant, the extrusion amount only needs to be set and maintained at a constant value that is compatible with the traveling speed of the film 15. Therefore, operation control is extremely easy and can be achieved accurately, and has many excellent effects. .

[Brief explanation of drawings]

FIG. 1 is a perspective view of essential parts showing an embodiment of the apparatus of the present invention. FIG. 2 is a diagram showing the overall arrangement of a shaping device using the device of the present invention. FIG. 3 is a partially cutaway front view of the device of the present invention. FIG. 4 is an enlarged vertical sectional view of the main part of the device of the present invention. FIG. 5 is an enlarged side view of the nozzle head portion. FIG. 6 is a longitudinal sectional front view of a film body shaped by the apparatus of the present invention. Explanation of symbols, 1: Extruder, 2: Die, 3: Channel, 4: Injection channel, 5: Nozzle head, 6: Nozzle opening, 7: Nozzle groove, 8: Raw material bobbin, 9, 14: Guide roller , 10: Brake roller, 11, 12: Tension roller, 13: Drive roller, 15: Film, 16: Welded piece, 17: Molten resin.

Claims (1)

[Claims] 1. At both ends of the synthetic resin film 15, which is in the form of a long and narrow belt with a constant width, is moved.
This is a device for continuously shaping a welding piece 16 that protects the side edges of the film 15 and acts for welding.
Nozzle heads 5, 5 are provided facing each other at an interval slightly smaller than the width of the film 15, and the height and width are such that the side edges of the film 15 can be inserted into the opposing surfaces of the nozzle heads 5, 5 with a little margin. A nozzle groove 7 is formed in the shape of a groove along the running direction of the film 15, and the film 1 inserted into the nozzle groove 7 is
This apparatus for shaping a synthetic resin film has a nozzle opening 6 for extruding the molten resin 17 supplied from the extruder 1 on the surface facing the 5-side edge.