DE3119961A1 - Film-welding device for welding and severing household film bags - Google Patents

Abstract

A film-welding device for welding and severing household film bags of thermoplastic material, in particular for packaging frozen goods, has a support bar provided with an electrical heating apparatus and a pivotable pressing bar interacting with said support bar. Between the heating apparatus and the pressing bar a film web folded in two layers can be unwound from a roll accommodated in the device housing. For the reliable welding and simultaneous severing in only a single operation of the film web which is taken off from a roll and joined to form a bag, the heating apparatus has at least two heating conductors arranged at a distance from and parallel to one another, of which one heating conductor is provided for welding and the other heating conductor for severing the film web. Instead of two heating conductors, the heating apparatus may also have three heating conductors, by means of the two outer heating conductors of which the film web (14) can be welded and severed by the central heating conductor thereof. By this means, in the case of the subsequent film strip taken off from the roll, one lateral seam is already welded.

Description

Foil sealing device for welding and separating household

film bags The invention relates to a film welding device for welding and separating household foil bags made of thermoplastic material, in particular for the packaging of frozen goods, with an electric heating device Support bar and a swiveling pressure bar cooperating with this, between which a two-layer folded sheet of film from one in the device housing Role is unwindable.

Known film welding devices of the aforementioned type have a heating device on, with a single heating conductor both for welding the film web as well as for their separation. To form a bag is first to seal one long side and then the other long side of the To be able to separate the film web with simultaneous welding. Then can fill the bag from the side opposite its fold and after Weld or seal the filling process again on this side. This is done immediately Either align the air in the foil bag before the welding process or by an air suction device of the film sealing device sucked out of the foil bag. However, it can often not be avoided that the film web is wrinkled in the area of its welding or separation zone, causing an these creases of the foil bag after its welding and separating process in some Cases are not tightly sealed with certainty, so that rewelds are required or the contents must be repackaged in another foil bag. Except for those film sealing devices in which the heating conductor is used both for welding and is provided for separating the film web, such film welding devices are known, in which the heating conductor is only used to weld the film web, while the separation of the film bag from the film web by means of a cutting device of the film welding device by means of a knife or the like. he follows. This is the parting line away from the welding or sealing plane, so that by the separation process there is no influence on the weld seam. This is known to have a disadvantage Solution, however, that in addition to the actual welding or sealing process additional work required to separate a bag from the film web is.

The object of the present invention is to provide a film sealing device to create, in which the parting line from the welding or. Sealing level removed is, with both the welding or sealing and the separation of the Film bag from the film web by a single handling process on the part the operator can be triggered.

This object is achieved according to the invention in that the heating device has at least two heating conductors that are spaced parallel to one another, of which the one heating conductor to Welding and the other heating conductor is provided for separating the film web. By pressing down the support ledge on the one hand the welding or sealing and on the other hand the separation the film web is initiated via a switch that can be depressed at the same time. Included is the welding plane away from the parting line, so that the welding process from Separation process and vice versa remains unaffected. Thus, on the surface of the heating conductor intended for separation generate a higher temperature than on the surface of the heating conductor intended for welding.

If now in addition to the use of a Heizleiteas only for the welding Another heating conductor of the foil bag is used solely for separating the foil bag is provided by the film web, so is to form a new bag first in turn to weld the separated long side of the film web. This operation can be saved if, as proposed according to a further feature of the invention, the heating device has three heating conductors running parallel to one another at a distance has, through the two outer heating conductors of which the film web can be welded, and with the middle heating conductor of which the film web can be separated.

Thus, when pre-welding the second longitudinal side of the bag and its simultaneous separation from the film web also at the same time the seal the first longitudinal side of the bag to be subsequently formed from the film web. For safe separation of the bag from the film web, the the heating conductor causing the separation of the film web on its contacting the film web The surface is more heated than the heatsealing band causing a weld.

To generate different temperatures on the surface of the intended for welding heating conductor opposite the surface of the separation making heating conductor is according to a further feature of the invention each heating conductor used for welding is covered with an insulating jacket, while the heating conductor causing a separation of the film web a bare contact surface having. This ensures that the heating conductor causing the separation is on its surface is hotter than the heating conductor intended for welding. Instead of sheathing a heating conductor used for welding, after Another feature of the invention is each one used for welding Heat conductor also be covered by a strip of insulating material during the separation The heating conductor provided for the film web is arranged bare on the insulating strip.

Although the individual heating conductors to form the heating device as Individual pieces can be arranged side by side in parallel, so it may be advantageous be if, as proposed according to a further design feature of the invention, the heating conductors are formed from a wire laid in one piece through end loops are. The heating conductors provided for welding can in turn be sheathed or cover, while the middle part of the one-piece heating conductor loop is advantageous has a bare contact surface.

Instead of sheathing the heating conductor intended for welding these could all also be laid bare, if, as in accordance with a further design feature of the invention proposed the heating conductor intended for separating the film web has a higher electrical resistance than that provided for welding Heating conductor.

Simplified assembly or, if necessary, easier repairs the heating device can be achieved if, as in accordance with a further design feature proposed the invention, the heating device together with the heating conductors and the insulating strips or the sheaths are combined to form a structural unit, which can be used in its entirety in the device housing.

To protect the transformer supplying the heating device with electricity as well as the switching elements and in terms of avoiding overloads proposed according to a further feature of the invention, the heating conductor to heat one after the other by means of a sequence circuit known per se by first the heat conductor performing a weld and then a separation of the film web carrying out heating conductors are connected to the circuit.

The invention is shown in one embodiment in the drawing and is explained in more detail below. They show: FIG. 1 the film welding device according to the invention seen in a perspective view on the top, but when pivoted freely Pressure strip, Fig. 2 the front heating device comprising the three heating conductors having area of the film sealing device in a cross section according to the line II-II of Fig. 1, Fig. 3 the front area of the film sealing device with the pressure bar opened in a top view.

First of all, it should be said that the one shown in the drawing Embodiment shows only a film sealing device schematically. For example the electrical leads and switches are not shown for the sake of simplicity, all missing or only partially shown components are known per se May have structure.

The film welding device shown in FIG. 1 has a device housing 10, in the interior of which a not shown, a transformer, Switching and connecting devices having electrical circuit is arranged, the may possibly also include a suction fan known per se, the suction nozzle of which is made the device housing 10 is led out and in the area of the top of the Front side of the device housing 10 arranged heating device 12 protrudes. In the rear area of the device housing, which has an approximately rectangular base area 10, a trough-like receiving space 13 is sunk into which one becomes a roll wound film web 14 shown in dash-dotted lines are inserted can. The front sides of the receiving space 13 are pulled up to bearing tabs 15, on which a cover part 16 is pivotably articulated, which in turn with a pressure strip 17 is connected, which can be pivoted together with the cover part 16. on On one side, next to the pressure strip 17, there is a switching pin 18 on the cover part 16 arranged, the when pressing down the cover part 16 with a in a housing sleeve 19 guided switching rod 20 for switching on the heating device 12 and possibly

can also come into contact with the suction fan, not shown.

In the embodiment shown in FIGS the heating device 12 is three arranged in parallel and spaced apart next to one another Heating conductors 21 to 23, which can be formed, for example, from a round wire. Instead of a round wire, however, it is also possible, for example, for each heating conductor a tape, a flat wire or the like. to use. Anyone can use the heating conductors 21 to 23 designed as parallel and spaced apart conductor piece be that via, for example, two-sided end rollers in the interior of the device housing 1Q is out and tensioned there and with an introducing the electric current Contact terminal is in communication. It can be seen from the drawing that the heating conductors 21 and 23 are insulated, while the heating conductor 22 has a bare surface having. There is, as can be seen in particular from FIG the illustrated embodiment, the insulation from two strips of insulating material 24 and 25, between which the heating conductors 21 and 23 are embedded, during the for Separation of the film web 14 provided heating conductors 22 between the heating conductors 21 and 23 at the same distance and running parallel to them freely on the insulating strip 24 is arranged horizontally. If the heating conductors 21 to 23 are the same the surface temperature of the heating conductor 22 is higher than that through the insulating strip 24 effective temperature of the heating conductors 21 and 23. Contrary to that shown in FIG Embodiment could achieve the same effect if the heating conductor 21 and 23 would be sheathed with an insulating material, while the heating conductor 22 to The top of the device housing 10 remains free.

As can be seen in particular from FIG. 3, the heating conductors 21 to 23 can also be formed by a single wire by the heating conductor 21 with the heating conductor 22 by an end loop 26 integrally connected to this is, while the heating conductors 22 and 23 via a further end loop 27 with one another are in one-piece connection. These end loops 26 and 27 may, for example Be placed over deflection rollers 28 rotatably mounted on the device housing 10.

To form a household foil bag like - as indicated in Figure 1 - Find a film web 14 use, which consists of a simply folded film strip is formed. In Fig. 1 this fold is on the left side of the film sealing device, However, this is irrelevant for the formation of foil bags, since the fold could also be on the right-hand side, if the film roll is accordingly in the receiving space 13 is inserted. For the production of a bag is now first the cover part 16 is pivoted with the pressure strip 17 into a closed position, so that the pressure strip 17 presses the film web 14 onto the heating conductors 21 to 23. The two film parts of the film web 14 are first welded in the edge area, however, only the weld seam produced by the heating conductor 21 is used because the protruding piece of film web is severed by the heating conductor 22. After the pressure strip 17 has been pivoted up, a piece of the film web 14 Peel off the roll in the appropriate length of the bag, by doing again Depression of the pressure bar 17 on the one hand that via the heating device 12 a piece of film web pulled out from the outside is welded by means of the heating conductor 23, while the heating conductor 21 welds the piece of film web remaining in the film sealing device and between the two weld seams of the heating conductors 22, the two pieces of film separates from each other.

This forms a bag that is initially still open on the right-hand side. After filling this bag, this piece of bag can be seen from the front with its still open side between the pressure strip 17 and the heating device 12 are placed, the suction nozzle 11 in such film welding devices that Have an air suction pump that may be inserted into the interior of the bag. By Depression of the pressure bar 17 is activated via the switching pin 18 at the same time Switching pulse triggered, which first puts the suction pump into operation, so that the Air is largely sucked out of the bag in order to then switch on the heating device, so that the bag webs are welded together.

As mentioned above, the contact trigger may be used as an initiation of the electrical current in the heating conductor via a not shown, per se known sequential circuit take place, advantageously first the one weld Through heating conductors 21 and 23 are heated to be delayed afterwards too heat up the heating conductor that is performing the separation.

As already mentioned, the embodiments shown are only examples Realizations of the invention, which is in no way limited solely to it on the contrary, many other arrangements and applications are possible.

Password: ~ sealing bar "List of reference symbols 10 device housing 11 suction nozzle 12 heating device 13 receiving space 14 film web 15 bearing bracket 16 cover part 17 Pressure bar 18 switch pin 19 housing sleeve 20 switch rod 21 heating conductor 22 Heating conductor 23 Heating conductor 24 strips of insulating material 25 strips of insulating material 26 end loop 27 end loop 28 deflection roller Blank page

Claims (9)

Claims: 1. Foil sealing device for welding and separating Household film bags made of thermoplastic material, in particular for packaging of frozen goods with a display bar having an electrical heating device and one with this cooperating, pivotable pressure bar, between which a two-layer folded sheet of film from one housed in the device housing Role can be developed, that is, the heating device (12) at least two spaced-apart heating conductors (22, 23) arranged parallel to one another has, of which one heating conductor (23) for welding and the other heating conductor (22) is provided for separating the film web (14). 2. Foil welding device according to claim 1, characterized in that the heating device (12) has three heating conductors running parallel to one another at a distance (21 22,23), through whose two outer heating conductors (21,23) the film web (14) can be welded and the film web can be separated with its central heating conductor (22) is. 3. Foil sealing device according to claim 1 or 2, characterized in that that the heating conductor (22) causing the separation of the film web on its the film web the contacting surface is more heated than the heating conductor causing a weld (21.23). 4. Foil sealing device according to one or more of the preceding Claims, characterized in that each heating conductor used for welding (21,23) is encased with an insulating jacket, during which a separation of the Film web causing heating conductor (22) has a bare contact surface. 5. Foil sealing device according to one or more of claims 1 to 3, characterized in that each heating conductor (21, 23) used for welding is covered by an insulating strip (24, 25), during the separation the heating conductor (22) provided for the film web (14) bare on the insulating strip (24) is arranged. 6. Foil welding device according to one or more of the preceding Claims, characterized in that the heating conductors (21,22,23) from a through End loops (26,27) integrally connected wire are formed. 7. Foil sealing device according to one or more of claims 1 to 3, characterized in that the heating conductor intended for separating the film web (14) (22) has a higher electrical resistance than that provided for welding Heating conductor (21,23). 8. Foil sealing device according to one or more of the preceding Claims, characterized in that the heating device (12) together with the Heating conductors (21,22,23) and the insulating strips (24, 25) or the sheaths a structural unit are summarized in their entirety in the device housing 410B can be used. 9. Foil sealing device according to one or more of the preceding Claims, characterized in that the heating conductors (21,22,23) by means of an known sequential circuit can be heated one after the other by first one The heat conductor (21, 23) carrying out the welding and then a separation of the film web (In) through heating conductors (22) are connected in the circuit.