DE1978803U - DEVICE FOR WELDING THERMOPLASTIC PLASTIC FILMS. - Google Patents

Description

description
'to register the

KALLE AKTIENGESELLSCHAFT Wiesbaden-Biebrich

for a

Utility model
concerning

Device for welding thermoplastic plastic foils

For welding thermoplastic plastic foils Numerous devices have been developed that both operate discontinuously as well as continuously, many discontinuous devices with pulse bands are equipped. The impulse bands are used to prevent the foils from sticking to the pressed welding jaws provided with covers, which, however, are subject to high wear and tear and are replaced relatively often Need to become. Welding jaws that are permanently heated by electricity and equipped with non-stick coatings are also used are.

KALLE AKTIENGESELLSCHAFT

Gbm 337

Our sign day sheet

PP-Dr.Kn-eg September 6, 1967 2

However, these coatings reduce wastefulness in a considerable amount Measure the heat transfer to the film and also very soon show signs of wear.

Furthermore, a continuous device is known in which heated rollers are used, which are also provided with non-adhesive coatings _{( 3} are the same defects mentioned occur, which are additionally increased by the lack of work safety due to the brief contact of the rollers with the foils.

Another device uses heat from a continuously heated metal block is delivered to a steel belt that is passed by it, which is pressed against the one that is running at the same speed Foil parts is pressed, whereby the welding takes place. However, since the welding points are cooled down the tape is then transferred to a cooled Metal block passed by the cooling on the metal belt and this in turn transfers to the film, the belt then runs back to the heating block via pulleys, the renewed heating takes place. The heating and The cooling process is considerable in this device Delay time, which results in a slow machine

KALLE AKTIENGESELLSCHAFT

Gbm 337

Our sign day sheet

FP-Dr.Kn-eg September 6, 1967 3

speed j that means a low welding performance, makes noticeable. At the same time, both the movable steel belts show in such a device as well as the heating and cooling blocks in a short time significant signs of wear. That the frequent replacement of the Make parts necessary.

In another continuously operating device the foils are welded by means of heated air, whereby the air to be welded from a slot nozzle Foil parts is directed. The advantage is that there is a direct heat transfer to the foils, which means an optimal heat utilization is given. The substantial one Deficiency, however, lies in the fact that even with little The distance between the slot nozzle and the film does not prevent the heated air from scattering when it hits the film can be so that the edges of the welds do not be straightforward. Since the film parts only lie on top of one another and are not pressed together, result There are significant defects in the welding, which often lead to subsequent separation into the individual film parts to lead.

KALLE AKTIENGESELLSCHAFT

Gbm 337

Our sign day sheet

FP-Dr.Kn-eg September 6, 1967

The present innovation is based on the idea, while avoiding the disadvantages mentioned, a discontinuous, however, it is preferable to specify a continuously operating device with which weld points that adhere quickly and easily are adhered to by direct heat transfer to the film by means of a heated gas stream with simultaneous intensive Compression of the film parts can be achieved.

The above-mentioned object is achieved with the aid of a device for welding thermoplastic plastic films using a heated gas stream, which is characterized by film holders 7 and 8 which can be pressed against one another by known means, of which at least one ₅ preferably both, overlying and / or adjacent openings 9, and at least one hot gas nozzle 5 or 6, which has such an arrangement and size for the holder carrying the openings that a gas flow exiting from it, preheated in a known manner, essentially hits the area of the openings of the holders.

According to the innovation takes place in such a device direct heat transfer to the foil parts at the points

KALLE AKTIENGESELLSCHAFT

Gbm 337

Our sign day sheet

PP-Dr, Kn-eg "Sept. 1967 5

where the brackets have through openings, whereby the simultaneous pressing together by means of the brackets results in a firm connection of the foils, at least for the duration of the welding, including until the welded parts adhere. Since the preheated j gas stream emerging from the hot gas nozzle is preferred Air - only hits the perforated brackets. Occurs in the area of the openings Exactly delimited welding parts, while film parts protruding downwards and / or upwards via the brackets not hit and therefore not welded.

The hot gas is inflated on one side if one of the brackets has an opening (Fig. 3). Such a bracket can also be sufficient by a be formed rigid packaging object itself (Fig. 4). If both holders in the preferred embodiment have openings, the hot gas flow is preferably from inflated on both sides (Fig. 1, 2 and 5). For heating the gases up to welding the foils required temperature and for blowing out of the nozzles are known devices on the device according to the innovation arranged.

KALLE AKTIENGESELLSCHAFT

Gbm 337

Our Zeldien. Day sheet

PP-Dr.Kn-eg September 6, 1967 6

The brackets have several, spaced apart openings to achieve _{a weld along a certain distance s} as is the case, for example, when making a weld seam on a package (Fig. 5 and 7) Holders of adjacent weld seams are in use, which additionally have openings one above the other (FIGS. 1 and 6). The last-mentioned holders can also be used for the production of film tubes lying next to one another from two wider sheets of film.

Since the device is designed according to the innovation, The fact that the hot gas stream impinges essentially in the area of the openings in the brackets has to be seen in the usual way To be able to use nozzles with certain dimensions, in some cases proven to be useful, to arrange several nozzles side by side.

In the case of brackets that have openings one above the other, for the reasons just mentioned, the Nozzles arranged one above the other. The nozzles can be mounted on one or both sides of the brackets.

E KALLE AKTIENGESELLSCHAFT

Our Zeldien day sheet

Gbm 337 FP-Dr.Kn-eg September 6, 1967

The former arrangement is adopted, if only one bracket is provided with openings (Fig. 3) _s while for supports carrying in the preferred embodiment both apertures, the reversible attachment is preferable, as this, in particular with extremely thin films, is avoided, that the impinging gas flow deforms the foils to one side, as could be the case with one-sided impingement. The one-sided arrangement should also be selected if one holder is represented by a sufficiently rigid packaging item.

In principle, all commercially available nozzles are used as hot gas nozzles Constructions can be used as long as their outlet openings and their arrangements on the mounts of the claim correspond to the fact that the gas flow should essentially only hit the brackets themselves directly. Have in action however, slot nozzles have proven to be particularly favorable, with preference also being given to those with a gap width can be varied by means of a diaphragm. Through this a correction of the gas flow is possible with a variable exit velocity.

As a rule, the nozzles are in a specific, however usually attached a short distance from the brackets,

: 56/006 10 T 7; 66 A

KALLE AKTIENGESELLSCHAFT

3 37

Our sign day sheet

FP-Dr.Kn-eg September 6, 1967 8

however, it may be useful in some cases when the nozzles are resiliently in contact with the brackets. at Such a construction can make the facilities that usually used to press the brackets together, such as. Feathers, partly or entirely in elimination

come.

In another embodiment, the nozzles are with distribution boxes connected that an equally strong outflow of gas from several adjacent and / or superimposed Nozzles made possible.

If the device with its various embodiments is used in a discontinuous mode of operation, the cooling of the welding points is achieved in the simplest way by pressing them together Holders are opened, whereby the cooling takes place through the air circulation. Leave with such a device however, only low welding speeds can be achieved. In order to accelerate the cooling and thus to be able to use the device for re-welding, is A cooling gas flow is blown into the hot gas nozzles after the hot gas flow has been switched off. This allows the Welding speed may be increased.

KALLE AKTIENGESELLSCHAFT

Gbm 337

Our signs

PP-Dr.Kn-e

Day sheet

September 6, 1967 9

In modification of the devices mentioned so far are also those in use where, in addition to the hot gas nozzles Cooling gas nozzles, preferably slot nozzles 2o and 21, are arranged are. These can also rest resiliently on the brackets and also connected to junction boxes 18 and 19 be (Fig. 8). Such a device is suitable for continuous operation, in which after the Welding process the brackets pressed together opened, the sealed foils around a certain Route further transported by means of known facilities and the brackets are closed again by pressing, with the aid of an emerging through the cooling gas nozzles With a cool gas flow, the visual spots are completely cooled, while another is already in the welding zone Welding takes place.

A preferred embodiment of the device has by means of known devices such as push rods, chains, rollers, etc., movably arranged brackets that with the inserted foils at the hot and possibly existing cooling gas nozzles with a certain feed speed to be led by. Such a device enables continuous operation with

<Ättl

KALLE AKTIENGESELLSCHAFT

Gbm 337

Our Zeldien day sheet

FP-Dr.Kn-eg September 6, 1967 Io

improved welding speeds. Here, however, a coordination of the transport speed is required the respective film material, as well as the temperatures of the hot and possibly cooling gas, from which certain j dimensions of the device that are not to be undercut result. The cooling of the film by means of cooling gas is mainly necessary when it is used the optimal machine speed the Schxveissstellen not solidify fast enough.

In a particularly useful modification of the aforementioned device, the movable brackets are as flexible belts guided endlessly over rollers 22, at least one of which has openings (FIG. 8). In such an arrangement the foils become continuous passed through the hot and possibly cooling gas zone, whereby they are pressed against one another. After passing through the cooling zone the brackets open automatically as a result of the deflection, whereby the welded foil parts e.g. to the Be released for the purpose of separating or winding. Depending on the distance between the roles results a certain distance at which the brackets are pressed together. The length of this on the device

KALLE AKTIENGESELLSCHAFT

Gbm 337

Our sign day sheet

FP-Dr.Kn-eg September 6, 1967 11

The distance to be determined depends on the speed the transport., the film material, the length of the hot gas zone, any gas cooling and the Welding temperature. However, in order to avoid changes to a given construction, the length of the Distance, i.e. the distance between the pulleys, in the case of the device sufficiently dimensioned that all common types of film, the different welding temperatures require that can be processed on the device. With such a device can be considerable Achieve continuous working speeds.

To avoid minor signs of wear and tear the brackets and rollers in case of very fast transport in continuous operation are useful in a further Execution the pile holders are not guided directly over the rollers, but with over rollers or gears running chains connected upwards and / or downwards protruding (Fig. 9) - · In addition to the extensive freedom from wear the slip resistance is also guaranteed. The film holders can again have openings It has to be bands, however, especially with brackets made of metal, proven to be useful, these as single plates lying close to one another or overlapping

E KALLE AKTIENGESELLSCHAFT

Gbm 337

Our sign day sheet

PP-Dr.Kn-eg September 6, 1967 12

to be attached (Pig. 9). This has the advantage that the deflection reduces the bending stress, as is the case with bands is given, is largely turned off. The individual plates are lying close to one another or overlapping arranged j because with larger gaps there is a risk j that the welds at the open ends the gaps are not exactly limited.

The brackets are in the devices where both Have openings, normally arranged in such a way that, when pressed against one another, the openings are completely or at least partially superimposed. For welding An arrangement of very thin foils, which must be particularly supported during welding, is advantageous when which the openings do not lie on top of one another or a holder does not have an opening. This gives the Foils have a special hold and are against burning in of holes largely secured by the stream of hot gas.

The openings in the brackets can be arbitrary, e.g. be slot-shaped or square, but in particular round openings, e.g. in the Production of weld seams on shrink film packaging has proven itself in practice.

KALLE AKTIENGESELLSCHAFT

Gbm 337

Our sign day sheet

FP-Dr.Kn-eg. 6th Sept., 1967 13

Depending on the purpose of the film use and the requirements, which must be placed at the welding point, are the openings at more or less large intervals arranged to each other, so that individual point-shaped Result in welding points. Should, however, be proportionate, for example If tight weld seams are made, the openings are located at a small distance from each other, so that depending on their width or their diameter, the brackets are chain-like. are designed. In particular, a distance of less than 1 mm in the production of tight weld seams has proven to be proved particularly favorable.

The vertical or horizontal brackets can basically have any size, but will these preferably to the welding widths required in each case Voted. For the production of weld seams see especially narrow, band-shaped brackets.

The brackets can be made of any material as long as they remain dimensionally stable at the welding temperatures. In addition to metal, for example Textiles or the temperature-resistant plastic polytetrafluorethylene can also be used.

KALLE AKTIENGESELLSCHAFT

Our sign day sheet

Gbm 337 FP-Dr.Kn-eg September 6, 1967

The following figures are examples of the new ones Devices shown, but without being limited to these embodiments.

1 shows a schematic cross section through a vertically arranged device, such as is suitable, for example, for welding a packaging made from a sheet of film F for an object G. In the distribution boxes 1 and 3, heated gas enters at 2 and 4, which flows out through the nozzles 5 and 6 and the nozzles 5a and 6a arranged above them onto the clamps 7 and 8 which are pressed together. The hot gas stream hits the foil ends Io that are pressed against one another at the level of the through openings 9 and 9a. The boxes 1 and 4 are pressed against the brackets 7 and 8 together with the nozzles on the inside by means of spring devices 11. Boxes 1 and 3 can, however, be omitted for some purposes. _s in which case the nozzles 5 _S 5a, 6 and 6a directly fed by a common or separate hot gas blower.

Fig. 2 shows a schematic cross section of a vertical arranged device in which the boxes 1 and 3 with the .Gaseintrittsöffnungen 2 and 4 at a small distance

56/006 10 T 7. 66 A

KALLE AKTIENGESELLSCHAFT

Gbm 337

Our sign day sheet

FP-Dr.Kn-eg September 6, 1967 15

of the brackets 7 and 8 are arranged. The gas flow, which emerges from the slot nozzles 5 and 6, meets the brackets at the level of the openings 9

Fig. 3 shows a schematic cross section of a vertical arranged device j in which the holder 7 no Has openings, while the holder has 8 openings at 9. The counterpressure against the holder 7 is achieved by the spring device 12 on the holder 8. The hot gas stream is fed directly into the nozzle 6 by a fan V.

FIG. K shows a schematic cross section of a horizontally arranged, opened device, in which the object G to be packaged in the film F represents the counter mount for the mount 7, which is provided with openings 9 ₃ . The superimposed film ends 13 and 13a are pressed together after the holder 7 has been pressed (by means of a spring device, not shown) against the object G and in this state they are welded by means of the hot gas stream directed from the box 1 via the nozzle 5 to the opening 9.

KALLEAKTIENGESELLSCHAFT

. "'- ■" Our sign day sheet

Gbm 337 FP-Dr.Kn-eg September 6, 1967

Fig. 5 shows a side view of a part of a narrow, band-shaped holder 7 or 8 with circular openings 9 arranged next to one another.

Fig. 6 shows a side view of a wider, band-shaped Bracket 7 or 8 with side by side and one above the other, slot-shaped openings 9 j for producing a foil tube welded on both sides or a double weld seam can serve.

FIG. 7 shows a side view of a point-shaped weld seam produced on a part of a packaging _{by means of the holders 7 and S 3, which are provided with circular holes according to FIG. 3.}

Fig. 8 schematically shows a device in plan view for continuous welding with the - depending on Width and design of the brackets - welded film webs or one or more adjacent to each other Weld seams can be produced. The two film parts 14 and 14a are held by the holders 7 and 8 guided by the pairs of rollers 15 and 15a elastic are pressed together. The rollers 15 are rigid in this device, the rollers 15a by means of spring devices

56/006 10 T 7. 66: A

KALLE AKTIENGESELLSCHAFT

Gbm 337

Our sign day sheet

FP-Dr.Kn-eg Sept 6, 196? 17th

lines 12 arranged elastically.

The distribution boxes 1 and 3 enter at 2 and 4 hot gas flow through the wide slot nozzles 5 and 6 to the openings 9 of the brackets and the compressed foil parts Io meets. In the subsequent cooling zone, a cooler Gas flow at 16 and 17 into boxes 18 and 19 enters and leaves it again through nozzles 2o and 21, the welded film is cooled down. The endless holders are guided over the pulleys 22. (The end Reasons for better representation are the brackets with the openings in relation to the other parts of the device drawn greatly enlarged and cut at the same time at the level of the openings).

Fig. 9 shows a side view of a part of an endless Bracket, which consists of overlapping individual plates 23 which in turn are provided with circular openings 9 are. The holder is on an endless chain 24 attached protruding upwards. Such a holder can be attached to a device of FIG. 8, wherein the chains are guided over the rollers or, if necessary, gears 22 while the pairs of rollers 15 and 15a hold the film press the lugs together.

Claims (6)

KALLE AKTIENGESELLSCHAFT Our Zeidien Tag Blatt Gbm 337 FP-Dr.Kn-eg 6.Sept. 1967 1. Device for welding thermoplastic plastic films under. Use of a heated gas stream, characterized by by known means to each other pressable film holders (7) and (8), of which - At least one, preferably both., over and / or have adjacent openings (9) and at least one hot gas nozzle (5) or (6), which to the The holder carrying the opening has such an arrangement and size that an emerging from it, in known manner, preheated gas flow essentially impinges on the area of the openings of the holder. 2. Device according to claim 1, characterized by and / or superimposed hot gas nozzles. 3. Device according to one of claims 1 or 2, characterized by means of hot gas nozzles arranged on both sides of the brackets. 56/006 10 T 7. 6 «A KALLE AKTIENGESELLSCHAFT Our sign day sheet Gbm 337 FP-Dr.Kn-eg September 6, 1967 4. Device according to one of claims 1 to 3, characterized by the arrangement of slot nozzles. 5. Device according to one of claims 1 to 4, characterized by nozzles pressed against the brackets. 6. Device according to one of claims 1 to 5, characterized by nozzles connected to distribution boxes. 7. Device according to one of claims 1 to 6, characterized by cooling gas nozzles (2o and / or 21) arranged next to the hot gas nozzles, 8. Device according to one of claims 1 to 7, characterized by movably arranged holders, ο Device according to one of Claims 1 to 8 ₅ characterized by flexible and endless over rollers (22) guided mounts. 56/006 10 T 7. 66 A KALLE AKTiENGESELLSCHAFT Our signs Day Gb m 337 PP-Dr.Kn-eg 6.Sept. 19ö7 2o vlO. Device according to one of Claims 1 to 9, characterized by with endless, over in particular Cogwheels guided chains upwards and / or downwards connected brackets. 11. The device according to claim Io, characterized by Brackets j consisting of closely spaced or overlapping individual plates connected to the chains. 12. Device according to one of claims 1 to 11, characterized by brackets which have both openings, but whose openings are arranged in such a way that that they do not or only partially lie on top of one another when the brackets are pressed together. 13. Device according to one of claims 1 to 12, characterized by holders with round ones Openings. --- ^. KALLE AKTIENGESELLSCHAFT Gbm 337 Our sign day sheet FPHDr ..Kh-eg September 6, 1967 21 14. Device according to one of claims 1 to 13, characterized by holders whose openings only at an extremely short distance, especially less than 1 mm, are arranged from each other. 15. Device according to one of claims 1 to 14, characterized by band-shaped holders. KALLE AKTIENGESELLSCHAFT