DE7505064U - DEVICE FOR CUTTING AND WELDING THERMOPLASTIC RAIL MATERIALS - Google Patents

Description

Patent attorneys Dipl.-Ing. F. Weickmann,

Dipl.-Ing. H.Weickmann, Dipl.-Phys. Dr. K. Fincke Dipl.-Ing. F. A. Weickmann, Dipl.-Chem. B. Huber

8 MUNICH 86, April 2nd Φ

PO Box 860 820

MOHLSTRASSE 22, CALL NUMBER 98 39 21/22

Pc / pc

FMC EUROPE N.V. Denderstraat, 56 B-93OO Aalst / Belgium

; Device for cutting and welding thermoplastic sheet materials

The invention relates to a device for

Cutting and welding of sheets of more thermoplastic, material for the production of bags or the like.

It is known that such a device between a Set of drive rollers can be placed upstream and suction conveyor belts downstream.

The web is generally folded over one another in the longitudinal direction so that it forms a two-ply, laterally open film arrangement forms that intermittently with respect to the cutting and

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and welding device is advanced.

When the web has advanced with respect to the cutting and welding device by a length that of one to be produced Bag, the cutting device is set to the desired temperature by a built-in heating resistor is held, set in motion in the downward direction, so that at the same time the two layers of the web cut off and along the Cutting line are welded together. After this operation, the cutting and welding rod is in its upper starting position returned while the web is advanced another bag length.

In some processing machines, the cutting and welding rod is used formed by a simple, heated sheet that is pressed against a welding roller at the moment of the cutting and welding process creates over which the train runs.

In other machines, the cutting and welding rod is formed by a metal wire running in the transverse direction an electric current runs that keeps the wire at a high temperature. The wire is going up and down between two lateral ones Moves sets of clamping rods that hold the web during the cutting and welding process without any possibility of regulation.

Such devices are not very versatile, and they can can only be used if thin foils with a low melting point and a slow cycle are to be welded. Besides that the cutting lines have numerous defects and they have very different strengths, so that in use as bags can crack.

The invention is therefore directed to a cutting and welding device to create that are effective for films made of thermoplastic material with increased melting point and with decreased Melting temperature tolerances can work.

The cutting and welding rod should be able to be kept at a very high temperature of over 600 ° Celsius, thereby avoiding charring of the webs and the cutting and welding process within a limited zone with relative very should be carried out at a low temperature.

The method according to the invention and the device according to the invention are characterized by the characterizing features of the main claim or the first device claim.

The cutting and welding device according to the invention comprises a Cutting and welding rod with built-in electrical heating resistance that intermittently moves up and down between lateral clamping and cooling rods are moved, which hold the double track during the cutting and welding process.

The device according to the invention is characterized by an upper movable arrangement with a carrier on which on the one hand the cutting and welding rod provided with an electrical heating resistor is attached and, on the other hand, elastic and adjustable two clamping and cooling rods are attached symmetrically with respect to the cutting and welding rod, by a drive system for the intermittent up and down movement of the upper movable assembly, through a cooling circuit for the lower and upper clamping and cooling rods for the internal circulation of a cooling liquid, which keeps the temperature of these rods below half the most favorable threshold value for the criteria of the respective procedure, and by means of lifting and separating devices the web from the clamping and cooling bars after the welding process.

The latter means for lifting and separating the web preferably comprises a compressed air supply system which at least on the contact surfaces of the upper and lower clamping and cooling bars upstream of the cutting and cutting bar one in the direction allows the web directed air flow, which has the double effect of advancing the web by forming a To facilitate air cushioning and to prevent the web from sticking to the Kiemmund cooling rods after the welding process.

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The following are preferred embodiments of the invention explained in more detail with reference to the accompanying drawing.

Fig. 1 is a perspective view of one according to the invention Cutting and welding device for thermoplastic sheet materials for manufacture of bags and the like;

Fig. 2 is a perspective, partially broken detail view and shows the cooling water supply system and the compressed air supply system for the clamping and cooling rods;

Fig. 3 is a partial section on a further enlarged scale

and shows the elements of the cutting and welding rod and the clamping and cooling rods of the device of FIG Fig. 1;

Fig. 4

to 9 are schematic explanations of the individual phases a working cycle of the cutting and welding device according to the invention, FIG. 7 showing part of the Fig. 6 shows on an enlarged scale.

The cutting and welding device according to the invention according to FIG. 1 is generally denoted by 1 there. It is conventionally arranged between a set of drive rollers 2A and 2B adjustable gap pressure and any type that is upstream of the Device 1 are arranged, and on the other hand a set of suction conveyor belts, of which only the lower suction conveyor belt 3B and its deflection roller 4B are shown to clarify the drawing. The latter elements are located downstream of the device

The arrangement shown as an example in Fig. 1 is intended to to treat at the same time two webs 5,6 of a film or a sheet made of thermoplastic material. These tracks come from conventional supply rolls, not shown, on which they are wound.

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Optionally, but not necessarily, each path will go through a longitudinally folded egg is formed, so that a double-layer, laterally open film arrangement is formed.

It can be readily seen that when the webs 5 and 6 are advanced intermittently, according to a conventional method the device 1 in the direction transverse to the direction of movement cuts off and welded the layers of belts made of plastic material and formed into bags 7 and 8, which are now taken along by the suction conveyor belt 3B. Each of the bags is made up of one conventional technology in itself consisting of a laterally open film arrangement, which at both ends by welds 7A, 7B and 8A is locked.

It should be noted that between the drive rollers 2A, 23 and the cutting and welding device 1, a number of guide fingers 9,1o, 11 and 12 etc. is provided, the main task of which is to control the run of the webs 5 and 6 between the delivery side of the drive rollers and the inlet of the cutting and welding device 1 and any formation of wrinkles in the riien impede.

The cutting and welding device 1 according to the invention essentially comprises the following elements:

- an upper, movable arrangement with a carrier 13, which is provided with a locking device 14 and on the one hand the cutting and welding rod 15 and, on the other hand, two clamping and cooling rods 16A and 16B mounted symmetrically with respect to the cutting and welding rod;

- A lower, fixed arrangement with two clamping and Cooling rods 17A and 17B, which are adjustable on a cross member 18, which forms part of a frame, not shown, of the machine arrangement.

The two previously mentioned arrangements will now be described in detail will be described with predominant reference to FIGS.

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The two clamping and cooling rods 17A and 17B of the lower, fixed Arrangement are mounted separately on a common support plate 19, which in turn on the cross member 18, for example is fastened with the help of screws 2o. Each of the two clamping and cooling bars 17A and 17B is on both of them Ends on the support plate 15 by means of a lower support rod 17C or 17D a screw 21A or 21B and a nut and Lock nut 22A or 22B attached. In addition, blocks 23 are provided for alignment. In this way it is therefore easy to use Accuracy both the distance i -between the two clamping and cooling rods 17A and 17B and the position of these rods in Relation to the vertical symmetryL> ene X, X1, as well as the height of the two rods one below the other in relation to a lower plane Y, Y1 in which the tracks 5 and 6 move.

Overall, these setting options are very important, and it must be ensured that the best results are obtained in the course of experiments were achieved with a distance 1 of 5 mm between the inner walls of the clamping and cooling rods 17A and 17B.

Each of the two KleT <m and cooling bars 17A and 17B includes an its upper inner corner a longitudinal channel 24 in which cool water or another cooling fluid circulates. To this end are the longitudinal channels 24 each connected to an inlet line 24a and an outlet line 24b, as well as a connecting line 25 at its other end. This creates a coolant circuit in the clamping and cooling rods 17A and 17B, which allows to keep the temperature of these rods below a limit value for various criteria of continuous Production, such as the type of material of the webs 5 and 6, their thickness, the length and width of the bags to be produced, etc. the cheapest is.

According to another important feature of the invention, at least the clamping and cooling rod 17B, which is on the side of the Drive rollers 2A and 2B is provided with a controllable supply system for pressure, which allows it, as later in to be explained individually, on the one hand to facilitate the feeding of the foils into the interior of the cutting and welding device, in that this supply takes place according to the air cushion principle, and other

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on the other hand, the foils are glued to the clamping and cooling rods to prevent after the welding process.

The clamping and cooling rod 17B is provided with a row for this purpose provided by inlet ducts which are evenly distributed over the side facing the drive rollers 2A and 2B. This Inlet conduits supply small internal bores 27 which open freely on the upper surface of the clamp and cooling rod 17B and form a number of evenly distributed openings 28.

Thus the properties of the air jet, i.e. its pressure, its volume, its duration, continuous or intermittent Output, which can be varied, is the arrangement of the inlet ducts 26 connected via special lines 29 to two junction boxes 3o and 31, which are assigned to track 5 and 6, respectively are. These two junction boxes are supplied with compressed air in parallel by a general source of compressed air connected to the Main line 32, at least one two-way control valve 33 and two branch lines 34 and 35 is connected.

Each of the junction boxes 3o and 31 has an inlet, the is connected to the corresponding branch pipe 34 or 35, and outlets corresponding to half the number of inlet pipes 26th

Each of the junction boxes 3o and 31 is conventionally with Valves or flaps are provided for regulation, which allow the pressure or the distribution of the pressure at the outlet of the openings 28 to be regulated very precisely.

In addition, it is simple to supply all or only half of the openings 28 continuously or intermittently.

It is obvious that the clamping and cooling rod 17A also can be provided with a compressed air supply system, although this is less required as the bags made by the cut and sponge process are made by the Suction conveyor belt 3B, with which the respective bag is in contact, can be withdrawn from the device 1.

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The upper, movable arrangement will now be described in detail mentioned earlier.

The cutting and welding rod 15 comprises an edge 15A, which simultaneously effects cutting and welding, and an electrical one Heating resistor 15B. It is on the carrier 13 with the help of thin, metallic connecting members 36 with a V-shape Cross-section suspended and fastened.

The carrier 13 comprises at both ends pegs 37 which are articulated are attached to fixed side walls of a conventional control system, which is not shown for the sake of simplicity of the drawing is and that it allows the carrier 13 intermittently in conventional Ways not belonging to the present invention to move up and down.

In addition, the carrier 13 comprises a locking device at one of its ends K, which is attached to a cantilever arm 38. This locking device can be connected to one of the openings 39 and 4o cooperate, which are offset by approximately 90 ° in a circular arc-shaped part 41, which is shown in phantom in FIG shown is urri is connected in any way with the movable arrangement.

This locking device 14 allows the cutting and welding rod 15 to be blocked as follows:

- Either in the working position when the bolt interacts with the opening 39; in this position the Rod performs a welding operation every time the beam 13 moves up and down;

- or in the switched-off position, if the bolt with the opening 4o cooperates; in this position the cutting and welding rod does not work with the tracks 5 and 6 together, although the carrier 13 continues to move up and down.

To achieve a better distribution of the clamping effect on the webs to be cut and welded 5 and 6 are the Clamping and cooling rods 16A and 16B, as shown in FIGS

and 2, arranged in groups of two: 16A and 16B on the one hand and another symmetrical set, of which the upstream rod 16C can be seen in the figures is.

The arrangement of viar rods is on the support 13 with the aid of Brackets 42 attached, which are adjustable and distributed on the two side surfaces of the support in a number of for example two pieces per clamping and cooling rod are attached. Each of the mounting brackets comes with a vertical guide rod 43 provided, along which the corresponding clamping and cooling rod 16A and 16B, 16C in the vertical direction opposite to Effect of an adjustable control spring 44 can be shifted, as will be explained in detail later. The initial length of the guide rods is also adjustable in such a way that the clamping and cooling rods in relation to a vertical plane of symmetry X, X1 and a horizontal plane Y, Y1 of the tracks 5 and 6 can be set with great accuracy.

In addition, each clamping and cooling rod has an L-shape, wherein a channel 45 is provided in the horizontal flange, in which a coolant can circulate.

The four clamping and cooling rods are provided for this purpose Longitudinal channels are connected as follows: on the one hand, the clamping and cooling rods 16B and 16C are connected by connecting lines 46 connected in series, and in the same way the connecting line 47 connects the clamping and cooling rod 16C and their respective ones Pole. On the other hand, an inlet line 48 and an outlet line 49 for cooling liquid are provided.

Otherwise, the upstream clamping and cooling rods are 16B and 16C are provided with a compressed air supply system corresponding to that of the lower rod 17B. In this case too, as already described above, inlet lines 26A are provided in connection with the bores 27A, those on the lower surface of rods 16B and 16C are distributed. These inlet lines branch off from junction boxes 3oA and 3IA. The junction boxes are via branch lines 34A and 35A connected to a three-way control valve 33A, which is

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on the other hand is supplied by a main line 32 A.

As in the case described above, the pressure and the distribution of the pressure at the outlet of the openings 28A can also be very precise here be managed.

It should be noted that it is for a visual check of the position and the control operations of the cutting and welding rod 15 and the upper clamping and cooling rods 16A, 16B and the lower Clamping and cooling rods 17A, 17B is advantageous if the various, previously mentioned elements do not have the same length. For example, the lower clamping and cooling rods 17A, 17B has a length which exceeds that of the cutting and welding rod 15 by 1 o mm, while the upper clamping and cooling rods 16A and 16B shorter by 10 mm than the mentioned welding and Cutting bar are.

Referring now to FIGS. 4-8, the various Phases of a work cycle of the cutting and welding device according to the invention are explained.

When the double-ply web 5 is fed through the drive sirils 2A, 2B and is withdrawn by the suction conveyor belts 3B etc. in the direction of the arrow F1, the upper movable assembly is located in the upper position shown in FIG.

It should be noted that during this phase a schematic through The air outlet shown by the arrow F2 takes place between the upper and lower surfaces of the two-ply web 5 on the one hand and the upper and lower clamping and cooling bars 16B and 17B, on the other hand, occur and facilitate the advancement of the web and prevents the web from sticking to the bars.

At the right moment according to the length of the cut and the bag to be welded is the movable, upper assembly with the cutting and welding rod 15 and the clamping and Cooling rods 16A, 16B lowered in the direction of arrow F3 by acting on the carrier 13, while the lower clamping and Cooling rods 17A, 17B remain stationary.

Due to the mutual displacement of the lower levels of the cutting and welding rod 15 and the clamping and cooling rods 16A and 16B and the dimensioning of the rage springs 44 block the clamping and cooling rods 16A and 16B the web 5 against the inner Clamping and cooling rods 17A and 17B and hold the web in place, while the cutting and welding rod 15 is not yet in contact with the web and the air outlet is interrupted.

That area of the membrane that is to be cut and welded is not supported, but between the mouth of the gill Cooling rods held. The various elements of the device now assume the position shown in FIG.

From this stage on, the clamping and cooling bars 16A and 16B rest against the web 5 and the carrier 13 continues to move downwards in the direction of arrow F3. The cutting and welding rod 15 also moves further downwards against the effect of control springs 44, and it moves past the lower level of clamp and cooling bars 16A and 16B and cuts and welds the membrane 5.

It should be noted that the penetration depth of the cutting and welding rod can be regulated with accuracy depending on the web thickness. For example, with e; * ner path thickness of 15 μπι the depth of penetration of the cutting and welding rod about 0.5 mm. The temperature of the cutting and welding rod also depends on the thickness of the web. For example, the temperature of the welding rod for a sheet thickness of 15 μΐπ is about 600 ° C. Finally, the temperature of the clamping and cooling bars should be kept at around 15 ° C. At the end of the cutting and welding phase the individual elements are in the mutual position shown in FIG.

In Fig. 7, which is a greatly enlarged view of the central area 6, it is shown in this connection that the web 5 at the moment of its initial contact with the End of the area 15A of the cutting bar is separated, as shown in dot-dash lines, during the welding by progressive fusing of the two areas of the web down to the cooling surfaces of the two sets of clamping and

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Cooling rods 16A, 16B and 17A, 17B takes place. The dwell time of area 15A of the cutting and welding rod in this position is determined by the opening angle of the area of the cam that controls the up and down movement of the cutting and welding rod controls.

immediately thereafter the carrier 13 is raised in the direction of the arrow in the direction F4. The cutting and sealing rod 15 is released from the web 5 while it is still held between the lower and upper clamping and cooling rods 17A and 1 Tb , as well as 16A and 16B. The latter are still under the action of the control spring 44. The various elements are now in the position shown in FIG.

Finally, the assembly of cutting and welding rod 15 and clamping and cooling rods 16A and 16B sets the ascending motion continues in the direction of the arrow F4, releasing the path 5, which its movement in the direction of the arrow F1 with simultaneous Action of the suction conveyor belt 3D on the finished bag 7 and the drive rollers 2A, 2B on the web 5 continues. The path is released all the better when again compressed air, which is indicated schematically by the arrow F2, emerges and the path from the clamping and cooling bars 16A, 163 and 17A, 17B solves.

The various elements are in that shown in FIG Slope, and a new work cycle can begin.

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Claims (6)

17th Ma! 1982 G 75 o5 O64.5
FMC Europe NV Protection claims - Device for cutting and welding sheets of thermoplastic material with a cutting and welding rod, the intermittent up and down between lateral clamping and cooling bars to hold the web in place is movable during cutting and welding, characterized by an upper movable up and down Carrier (13), en the one hand with an electrical Heating resistor (15B) provided cutting and welding rod (15) is rigidly attached and on the other hand elastic and adjustable two clamping and cooling rods (16A, 16B) symmetrical in relation to the cutting and welding rod (15) attached sinr and through cooling channels (24, 24A; 45, 48) for the lower and upper clamping and cooling rods (17A, B; 16A, B) and by separating members (26, 27, 28; 26A ...) for Lifting and separating the web from the clamping and cooling bars. 2. Apparatus according to claim 1, characterized in that the separating members (26, 27, 28; 26A ...) compressed air nozzles have, at least on the contact surfaces of the upper and lower, upstream of the cutting and Welding rod (15) located clamping and cooling rods (16B, 17B) are directed towards the web. 3. Device according to claim 1 or 2, characterized in that that the lower clamping and cooling rods (17A, 17B) are arranged adjustable with respect to a cross member (18). 4. Apparatus according to claim 1 or 2, characterized in that that the upper movable assembly comprises as many sets of clamping and cooling rods as at the same time webs to be treated are present, each of the clamping and cooling bars (16A, 16B) being attached to the carrier (13) with the help of at least two side brackets (42, 43) is held, 'which at the upstream or downstream faces of the carrier (13) are fixed and include guide rods (43) along which the corresponding The clamping and cooling rod can be moved vertically against the action of an adjustable control spring (44) is, furthermore, the useful length of the guide rods and the setting of the control spring are chosen such that when the movable assembly is lowered into the Working position the clamping and cooling rods come into contact with the web and this against the lower Kiemmund Hold the cooling rods under the action of the control springs (44) before the rigidly connected to the carrier (18) Cutting and welding rod (15) goes down over the lower height of the clamping and cooling rods and the cutting and carries out the welding process - 5. Device according to one of claims 2 to 4, characterized in that that the compressed air flow on the contact surface is at least that upstream of the cutting and welding rod (15) arranged upper and lower Clamping and cooling rods (16A, 16B) from a compressed air source via at least two provided with control flaps Distribution boxes over the clamping and cooling rods distributed inlet lines (26) and from these inner longitudinal channels (24) is fed into the clamping and cooling rods which open freely on the upper surface of the stanae. 6. Device according to one of claims 1 or 2, characterized characterized in that the carrier (13) is provided with a locking device (14).