DE882911C - Method and device for the production of folded film material, in particular for packaging purposes - Google Patents

Description

Process and device for the production of folded film material, especially for packaging purposes The invention relates to sheet material such as for Packaging, as well as foils, which consist of an artificial mass that are exposed to heat becomes soft and is preferably translucent. The foils are with folds, bulges Od. Like. Provided, with nvei or more foils on the heads of these folds or Bulges can be connected to one another in such a way that at least one in one Direction relatively stiff or resistant to bending disc or Wall is preserved.

In order to obtain such folds, the foils can be used in the cold state be corrugated in a machine so that more or less sharp edges are created. However, this method is particularly useful for those composed of translucent sheets Packs are unsuitable because the foils, as a result of their relative properties Brittleness more or less break, so that their strength and appearance in the finished packaging material are impaired. In addition, the wrinkles remain not dimensionally stable in the process mentioned, which reduces the strength properties of the material continues to deteriorate.

Furthermore, one is about designs with sharp, straight folds the surface of the film bound and thus the folds of a z. B. soft, rounded Not give shape. According to the invention, a film of the type mentioned above is used for Passage between engaging teeth or the like provided folds brought to which heat is supplied in such a way that the film is heated to a temperature where she is in which or plastic state passes. In this state it is provided with folds or the like and then on a supporting organ, z. B. a roller, of the same shape as the film transferred and remains in it until it cools down.

Appropriately, the film can before its introduction between the rollers, in which it is provided with folds or the like, are preheated.

Furthermore, the film can be combined with another film by means of a solution or glue while it is still in the pleats, where the temperature of the two foils is measured so that the formation of bulges, Wrinkles or the like causing stresses in the finished product avoided will.

Further features of the invention emerge from the following description of the exemplary embodiments illustrated in the drawings. It shows Fig. I line Machine for the production of foils according to the invention, schematically and partially in section, FIG. 2 shows another embodiment of a machine, partially in section, Fig. 3 is a section along the line III-III of Fig.2.

In Fig. I 25 denotes a rotatably arranged roller on which a Foil roll made of translucent material, e.g. B. acetyl cellulose is attached.

The film 26 is pulled off this roller and, if necessary, over a turning roller 27 passed between two rollers 28, 29, the surface of which is one of the desired shape of the foils has a correspondingly designed profile. In the present Case, the rollers are provided with axially extending tooth-like projections which, as can be seen from the figure, engage in one another. The rollers 28,29 are heated to a suitable temperature, for example by means of in a known manner steam passed through the inside of the roller. It is advisable to warm the foils in front of theirs Entry between the rollers to a temperature before which at least approximately that Corresponds to the temperature of these rollers. This preheating can be done with the help of an or several preheating rollers or by means of hot air, the film web is thermally insulated can be, as indicated in the figure at 50. When passing through each other The foil 26 is folded over with meshing teeth. As a result of the heating, the film is become soft and plastic. The film remains in the teeth of the roller 29 during its continued rotation until the film is fed into another roller 30, which is provided with teeth which are in engagement with the teeth of the roller 29.

Arrangements known per se for releasing the film can expediently be used be used by the roller 28 and to hold it in the teeth of the roller 29. The roller 30 does not need to press against the roller 29, but can to a certain extent There should be play between their teeth.

The roller 30 is expediently by means of a special drive driven so that a contact between the rollers teeth and a jamming the slide does not take place. In this way, the slide can move freely the occurring temperature change move laterally, which is caused by the fact that the roller 30 is relatively cold or cooled and such a temperature has that the film is rigid and dimensionally stable with regard to its folds.

Near the roller 30 is an arrangement for brushing Adhesive or solvent, such as acetone, on the back of the ribs of the folded foils appropriate. This arrangement is shown schematically in the figure by one of these substances Containing container 31 and a rotatable roller od. Like. 32 indicated which the latter with its lower part immersed in the brewing container 3 r and against the the roller 30 lying film is applied. The roller 32 can optionally be automatic can be switched off when the machine comes to a standstill in order to prevent the film is dissolved by the acetone and adheres to the roller 30.

A rotatably mounted roller 33 carries another roll of film, preferably , made of the same translucent material as the foil 26. From this roller becomes the film strip 34 is guided over a roller 35 provided with a cylindrical surface, the z. B. by means of springs. The like. Is held pressed against the roller 30. the folded film 26 and the flat film 34 are when passing between the rollers 30 and 35 connected to each other.

The two foils glued together can now that they are cold and are dimensionally stable, easily removed from the rollers. In which The embodiment shown is the one-sided corrugated foil formed by these foils 36 passed between a pair of rollers 37, 38, which with suitable pressure against they concern.

A roll of film is attached to a roller 39, one of which is a film 40, suitably made of the same translucent material as the foils 26, 34, is guided over the roller 38. With the aid of an arrangement 31, 32 of the type described above The free fold backs of the corrugated foil 36 are kind of covered with solvent or adhesive, such as acetone, moistened, and between the rollers 37, 38, the film 40 is on these Back strengthened. An endless fire can occur between the roller 37 and a roller 41 42 be arranged. In the same way, a band 43 extends between the Roller 38 and a roller 44. The mutually facing parts of the belts 42, 43 can be arranged so - that they cooperate with support rollers 45, which for this ensure that the ligaments are kept at a distance from one another by holding them against press the foils. During the. Passage of these foils between the belts 42, 43 they are attached together. The foils are between the tapes optionally - dried with the help of a fan, which creates a stream of air between the foils generated. For the same purpose, the foils; during the -D passage between the bands 42, 43 z. B. be heated by means of warm air.

The parts of the film web to which the solvent is to be applied comes, can be surrounded by housings 51 and 46, which prevent this substance can freely escape to the surrounding atmosphere. A suction pump 47 can by a Line 48 are in communication with the housing 46. The pump 47 sucks the solvent receiving air into a container 49 containing an absorbent, e.g. B. silica gel, contains.

The preheating of the film 26 before it enters between the rollers 28, 29 is important for achieving a uniform and smooth film surface. It has been shown that the film material according to the invention in contrast for example paper has a very high coefficient of thermal expansion, and this has the consequence that the films pucker or bulge when heated while they are clamped between the rollers for folding. While The film should therefore - be able to expand freely after the heating itself. To also during the connection of the foils, tensions in them due to the high coefficient of expansion To avoid the film material, it is of great importance that dile both films 26, 34 hoods essentially the same temperature. If, on the other hand, the foils are different Temperatures, the warm foil contracts when it cools down9 something would cause the cold film to pucker or bulge. Through this, that the rollers 30 and 35 and the films are relatively cold, different Advantages gained. So can solvents, like Aeeton, with a boiling point that is lower than the temperature required to deform the film, with Advantageously, they can be used without the fabric drying off. Since the rollers 30, 35 and the foils against them are cold or at room temperature, you can do without Difficulty even with foils made of material with different expansion coefficients associate. If the solvent causes temporary expansion of one of the foils, the temperature of the other film can be chosen so higher that after evaporation of the solvent and cooling the two films to room temperature stresses in the foils, which could give rise to wrinkles or the like, are eliminated. A Another important feature of the invention is, as can be seen from the above, that the Temperature is such that an occurrence of unfavorable stresses in the finished Foil product is avoided as far as possible.

With regard to the appearance of the foils, it is important that the acetone or solvent or adhesive attached to the head of the folded sheets will.

In the device described, the assembly of the translucent Films with each other continuously. After that composed of three foils Foil material has passed between the belts 42 and 43, it can for example be cut into slices or the like.

The invention also includes an embodiment in which the finished sheet material consists only of a flat and a corrugated film, as indicated at 36. A foil material assembled in this way can be used without difficulty Rolls are wound.

Furthermore, it is also conceivable to combine more than three foils put together, for example, so that alternately every second film is flat or is wavy. So-called secondary is particularly suitable as the material for the foils Acetyl cellulose, which is malleable at 90 to 1300 C. Instead of acetone or methyl ketone, that boils at 56 to 58 ° C, methyl ethyl ketone can be used. As another Example of solvents can be methyl glycol acetate with a boiling point of 138 to 1520 C, which is particularly applicable to hot bonding. Also foils made of hydrate cellulose can be used in certain cases.

In certain cases it is useful, for example a lateral To allow rotation of the film, the rollers 28 and 29 in the same way relative to be arranged to one another, as the rollers 29, 30 according to de! m above.

In Fig. 2 and 3, 1 10 denotes the machine frame, which is a roller 111 carries, the outer profile 112 of which corresponds to the desired film shape.

In the present case the roller 111 is with axially extending teeth Mistake. The roller 11 is rotatable in bearings 113 fixedly connected to the frame stored. In an inner bore of the roller is a stationary one with little play Slider 114 fitted, which is fixedly connected to the frame. The cylindrical The outer surface of the slide 114 is on a part of the surface circumference m an axial Length which corresponds approximately to the length of the teeth 1 to 12, cut away, as at 115 is indicated. The recess 115 stands over a channel 116 and a pipe 117 with a vacuum pump in connection (not shown).

A recess 118 is nearby but separate from said one Recess 115 arranged and Lanln either with the outside air in connection, You can use compressed air from a pressure source through an axial channel 1 19 in the slide 1 14 or a line 120 are supplied. Dler slider or the Shaft 114 also has a leash inner recess 121, which is made of a heating medium, such as steam, oil or the like. Can be flowed through, through a channel I22 and lein Tube 123 is inserted which extends over most of the length of the recess 121 extend. The steam escapes through a channel 124 which is at the same end of the The slide is located like the passage 122. The roller III is with continuous radial Channels 125 are provided which open out at the base of the teeth 112. These channels can, like can be seen from the figures, alternately offset relative to one another. Farther can the cross-sections of the channels in the direction from the center of the roll to the outside, after increase the sides.

Another roller 126 cooperates with roller II 1, which is in the Frame 110 is rotatably mounted and in the one with little play stationary slide shaft 127 is attached. The slide 127 is with an inner Recess 128 is provided, a heating medium through a tube 123 similar Tube 120 is fed. The slide 127 is also useful with an outer one Recess 130 formed, which is in communication with the outside air or the compressed air can be fed. The outer periphery of the roller 126 has teeth that fit into the Teeth 112 of the roller 111 engage. Radial channels 125 extend from one Side of the roller following the feet of its teeth.

A third roller 131 is provided with teeth that coincide with the teeth the roller 111 are engaged. The roller 131 is provided with an inner bore, into which a stationary slide 132 is fitted. The slide 132 is with a recess 133 extending from the surface, which via a channel 134 is in communication with a vacuum source. The roller 131 is still with a inner recess 135 provided, through which a cooling medium, such as water, flows fed through a pipe 136 of the same shape as the pipe 123 can be. Immediately on the recess 133, but separate from it in the surface of the slide shaft 132 a track or groove 137 is provided which with the external atmosphere or a Druckltqnelie is in connection. The roller Like the other rollers, 131 is provided with radially extending channels 125.

A roller 138 with a smooth cylindrical outer surface lies on the roller 131 at. If necessary, special arrangements can be made to achieve or regulate a Contact pressure between the rollers 131 and 138 may be provided. Referred to in Fig. 2 139 a container for a solvent such as acetone. A roller plunges into this 140 or the like, while another roller 141 both on said roller as rests against the ribs of the film web which is in engagement with the roller 131. the Rollers 140 and 141 are rotatable, so that the solvent with their help on the Rips or folds on the back of the foils.

The rollers 140 and 141 can optionally be housed in a housing 142 be included.

The recess 115 in the slide 114 extends in the circumferential direction between or substantially between the points of engagement of the roller 111 with the Rollers 126 and 131. The wall separating the recesses 115 and 118 is in the middle or located slightly in front of the meshing between rollers 111 and 131. The recess 133 in the slide 132 extends between the engagement or contact points between roller 131 and rollers 111 and 138.

A foil tape 143, e.g. B. from acetyl cellulose, passed through a gap bounded by walls 148 which add heat to the belt and thus preheat it. The foil tape can grind against one of the gap walls, to increase heat transfer. The film can be put on by two heating devices provided rollers 144 run, which also ensure that the film web is completely flat and is kept smooth.

The film is then inserted between the teeth of rollers 111 and 126, that they fold. The film then remains in the teeth of the roller 111, as shown in FIG of the invention is achieved in that the surface of the film facing against the roller on these teeth by means of the negative pressure acting from the inside via the channels 125 is sucked tight.

On the other hand, to easily disengage the foils from the teeth of the To bring roller 126, compressed air can through the recess 130 of the toothed roller 126 are introduced, which exerts a blowout pressure on the film through the channels 125. When the film has reached the point of contact between rollers 111 and 131, becomes the connection between the corresponding channels 125 and the negative pressure space 115 interrupted, so that the vacuum holding the film on the roller 111 stops. The foil is instead subjected to suction through the recess 133 exposed in the slide 132 communicating channels 125 in the roller 131, so that the film leaves the engagement with the teeth of the roller 111 and lies tightly. is transferred onto the teeth of the roller 131.

In the embodiment according to FIGS. 2 and 3, this facilitates the ducts 125 flowing out in the middle in front of the recess 118 das Loosen the foil from the teeth of the roller 111 and at the same time press the foil against it the teeth of the roller 131. In order to increase this pressure effect, a Screen 145 placed between and over the sides of roller 111 and 131, so that the compressed air flowing out of the recesses 118 on the roller 131 lying film is directed.

Optionally, the screen 145 can be connected to a compressed air source be provided for blowing in compressed air.

The film is cooled by the roller 131 and remains in its folded position Shape retains its shape. The rollers 140, 141 dampen the back of the folds of the films with them Solvent. Therefore, if a second foil tape 146 between the smooth roller 138 and the roller 131 is inserted, there is a sticking together between the two foil strips, so that a composite foil material is obtained, as indicated at 147 in FIG. The different ones present in the machine Rollers can be driven individually. Furthermore, the feet of the Roller teeth are formed with longitudinally running axial grooves, which are formed by channels 125 or slots with the recesses in the stationary installed in the roller Connect slider. The rollers 111 and 126 and the preheating assembly, respectively 148 can be warmed up by means of low-voltage alternating current, whereby on care must be taken that they are isolated from neighboring elements. The invention includes also those embodiments in which the rollers are made of to solve There are bands that are stretched around two spaced rollers.

Claims (10)

PATENT CLAIMS: t. Process for the production of bulges, Wrinkles or the like. Provided foils, which are made from softening in heat, preferably translucent synthetic material exist, especially for packaging purposes, thereby generally that a film for passage between with interlocking Teeth or the like. Provided rotatable rollers is brought to which heat is supplied in this way is that the film is heated to a temperature at which it is in soft resp. plastic state passes, as well as that it od with folds. Like. Is provided, and that the film is then on a support member, z. B. a roller, of the same shape as the film is transferred, the film remains in the roller until it has cooled down. 2. The method according to claim, characterized in that the film before their introduction between the rollers in which they ad with folds. Like. Provided is preheated. 3. The method according to claim 1, characterized in that the film with another film using a solvent or adhesive while they are still lies in the folds of the rollers, being the temperature of the two Foil is dimensioned so that the formation of bulges -od. like. causative Tensions in the finished material are avoided. 4. The method according to claim 3, characterized in that the temperature of two foils when glued together essentially the same or approximately the same with the temperature of the roller on which the folded film lies during cooling is located. 5. The method according to the preceding claims, characterized in that that the film is caused by a pressure difference created between both sides of the film is held on the roller and / or released from it. 6. The method according to claim 5, characterized in that the film running of the profiled surface of the roller or rollers with the help of a negative pressure, which acts on the side of the film lying against the roller, held in place or with her is engaged. 7. The method according to claim 5 or 6, characterized in that the film is released from engagement with a roller by an overpressure applied to the side of the film lying against the roller acts. 8. The method according to claim 5, 6 or 7, characterized by that the film against a leash roller with the help of an overpressure applied to that of the roller opposite side of the film acts, or by one against said side of the Film directed air flow is kept pressed. 9. Arrangement for carrying out this method according to one of the preceding Claims, characterized by three rotatably mounted rollers (28, 29, 30) which with interlocking teeth, corrugations, elevations or the like and of which two adjacent rolls are sanded with heating devices while the third roller is relatively cold. 10. Apparatus according to claim 9, characterized by devices for joining two foils, while one of them is on the relative cold roller lies. Attached publications: German patent specifications No. 160920, 478 504; French Patent Nos. 726 871, 799 847, 844 583; U.S. Patent No. 2 I39 922.