DE1546867C3 - Process for the production of plastic layer material and device for its implementation - Google Patents

Description

The invention relates to a method for the production of at least two-layer, smooth or cellular formed plastic layer material using at least one on a plastic film web applied plastic layer impermeable to air after it has solidified, further developments of this process and devices for performing the method.

It is already known (GB-PS 8 83 174), a film made of regenerated cellulose with a plastic application to be provided by, for example, when using aqueous solutions of a polyvinylidene chloride copolymer the water is quickly absorbed by the hydrophilic web which dehydrates the coating and such accelerates its hardening. This known method is not suitable for use when applying to Plastic film webs, since in the known manner there is insufficient adhesion of the coating on the Plastic film can be achieved and thus adversely affects the strength and durability of the layer material will.

The wrapping of textile materials is also known

and the like with foams based on polyisocyanate by means of a dipping or spraying process (DE-PS 10 10 050). Since the foamable mixture to be applied can be found immediately after mixing begins, it is not possible to apply foils and tapes on one side using a squeegee or anilox rollers with a foam pad to provide.

There are different ways of applying plastic to paper and other absorbent surfaces Process known (US-PS 23 12 927, US-PS 23 20 513, Allgemeine Papierrundschau 1953, pp. 1014 and 1016), the all of the capacity of the paper or the absorbent surfaces to absorb the material to be applied Make use of substance that is generally not present in plastic films The method according to US-PS 23 12 927 a gravure roll is used for the coating, in which The method according to US Pat. No. 2,320,513 is the porous material to be coated from both the coating side and heated from the rear

The invention is based on the object in the production of at least two-layer, smooth or cellular plastic layer material using at least one on a very thin and sensitive, completely gas and liquid-permeable, smooth plastic film strip applied after her Drying airtight plastic layer to ensure that this because of its thinness with large Layer to be applied uniformly without the formation of skins and the application remaining liquid underneath and without any thermal or mechanical hazard, in particular without stretching or distorting the wafer-thin film on which the application is located is dried.

According to the invention, this object is achieved in a process for the production of at least two-layer, smooth or cellular plastic layer material by applying at least one plastic layer that is impermeable to air after it has dried a plastic film web solved in that min- ^ o at least one plastic solution or dispersion using an engraved roller (gravure forme cylinder) is applied evenly to the film web, this is guided around a heated drum, the Temperature of at least part of the thickness of the film web at a temperature below its melting temperature. door is held value and the film web during its circulation around the drum on its coated side dried with hot air and then over at least one cooling roller and to one Supply roll is performed.

Further, advantageous possible embodiments of this method are given in claims 2 and 3 above specified.

Further developments of the method according to the invention contain the above claims 4 to 12.

Devices suitable for carrying out the method according to the invention are given in the above Claims 13 to 15 specified.

When using plastics for packaging or similar purposes, three factors have proven to be the most important, namely cost, impermeability to gases, moisture vapor and the like, and mechanical strength. In a cellular material in which a plastic ^h> is embossed layer and a second plastic layer to the embossed layer sealingly connected so that fused is that numerous air pockets arise, is the use of substantially impermeable plastics material of considerable importance for preventing the Loss of the cushioning effect of the material under constant and sustained pressure.

The invention enables the production of a relatively inexpensive plastic material, which in Strip shape can be used or processed to create a cellular material and a with the previously known techniques yields benefits that were previously unattainable with the aid of the invention it is possible, for example, to create plastic layer material in which the carrier or base material is a Have thickness on the order of 0.013 to about 0.075 mm and can be even thicker, while the relatively impermeable layers have a thickness on the order of 0.0025 mm can, but is not critical. In this way, the weight of the resulting layer material is on a kept very low value. Because the impermeable material, compared to plastics like for example, polyethylene and polyvinyl chloride, which are expensive products, are used in very small quantities the resulting increase in costs is small. Furthermore, the duplication of plastics can be used when using the method and the device according to the invention at web speeds of the order of magnitude of 300 m / min perform with the result that the processing costs are also kept to a minimum be reduced.

In the manufacture of cushioning material according to the invention it is possible to use a plastic material to cover or coat an impermeable layer and the resulting layer material to Production of a cellular material to be processed immediately. In this way it becomes an interim Handling the multilayer strips or foils is unnecessary, which increases the cost of the finished product again lowers. Furthermore, with the aid of the invention, using double and triple layer material with any desired combination of plastics, plastic-coated Papers, fabrics and the like represent a wide range of diverse cellular material produce. Furthermore, the invention leads to improved types of cellular material in the manufacture of sealing connection of the multilayered sheet material parts to one another.

The invention is explained in more detail below with reference to two embodiments shown in the drawing described. In the drawing shows

F i g. 1 shows a schematic representation of an embodiment of the coating device for production of the layer material according to the invention and

F i g. 2 shows a schematic representation of a second embodiment of the device according to the invention.

In Fig. 1 is an embodiment of the invention for Coating of plastic flat material illustrated in the production of the layer material according to the Invention is a carrier or base material, such as polyethylene, in strip form steadily through the doubling device passed through. The polyethylene plastic is denoted by 10 and, as shown, runs into the device from the right-hand side into it. He is represented by a series of roles 11,12 and 13 fed to a pair of rollers 14 and 15, which has a coating of another plastic on one side of the polyethylene plastic applied The coating applied to the film can be an emulsion, a

Dispersion or solution 17 contained in a suitable container or trough 16. the Roller 15, which is in the form of a rotogravure forme cylinder, is at least partially immersed in the liquid 17 immersed and is coated or coated with the liquid as it circulates. A doctor blade or a doctor blade 18 rests against the surface of the roller 15 and removes any adhering to it excess fluid. When the roller 15 comes into contact with the film 10, the latex liquid or solution becomes 17 printed or layered on the film it is denoted by 19. The roller 14 serves the roller 15 as Back-up roller in order to bring about a uniform deposition of the layer 19 on the film. The printed one Foil is then fed around a series of rollers 20-28 which are attached in an arcuate arrangement are and the coated film on a relatively large cylinder or drum 29 lead on which the applied plastic layer is dried and cured. This known per se The coating process enables extremely thin, even layers to be applied at very high levels Speeds.

The device according to FIG. 1 is particularly suitable for use in applying a coating from Polyvinylidene chloride on the carrier film 10, the thickness of the coating applied in this way being the depth of the depressions present in the pressure roller 15 is controlled. By the in the pressure roller 15 existing depressions are formed relatively flat, it is possible, the carrier film 10 with a To cover a layer of polyvinylidene chloride with a thickness of the order of 0.0025 mm. the Coating liquid can, of course, take many different forms, although one is particular A good coating liquid is an emulsion (latex) which is a copolymer of about 90% by weight polyvinylidene chloride and is 10 wt% acrylonitrile. This creates an elastic coating that is easily embossed leaves. The particle size of the material should preferably not exceed 0.25 μπι, whereupon the mixture with an emulsifying agent and water is combined so that a latex is combined with one for application to the Carrier film arises with the help of a pressure roller suitable as described above. While it is possible to use a liquid latex instead of the water and the emulsifying agent To use a suitable solvent, it is important that the solvent does not attack the carrier material or penetrates into it since, under such circumstances, the carrier material would have the tendency to absorb the solvent to absorb, so that it would then be difficult and time consuming to remove it from the carrier material remove. In cases where the carrier material does not absorb the solvent, the latex can be used instead a solution of the plastic can be used.

With the advance of the film 10 with the latex coating 19 present on its surface over the The individual rollers 20 to 28, which are preferably driven at a uniform speed, spread out by the pressure roller 15 applied latex material islands on the surface of the carrier material from and thus create a uniform coating. The film is initially heated with the aid of Heat radiators 30, 31 and 32, which the carrier film and the applied layer up to a temperature heat, which is substantially below the melting point temperature of the carrier layer.

The drum 29 around which the coated material 10 passes is preferably at one temperature kept high enough to prevent excessive heat loss from the sheet material, however, it is not yet sufficient to melt the carrier layer Drum 29 hardened and dried around by means of a plurality of air nozzles 33 and 34. the Air nozzles 33 are in the form of numerous in one

ίο arranged in the transverse direction tube 35 in a small amount Openings arranged at a distance from one another, while the air nozzles 34 have a plurality of openings in form a laterally adjacent pipe 36. The pipes 35 and 36 are connected to a central manifold 37, each pair of pipes 35, 36 together with the common manifold 37 in a shield 38 is housed of the plurality of distribution lines 37 is indicated by a dash-dotted line Main distribution line shown 39 hot air supplied In this arrangement meet when walking around of the material around the drum 29 jets hot air onto the layer 19.

When using a polyvinylidene chloride emulsion, the temperature should be of 33 and 34, air exiting from the nozzles preferably is of the order 150 to 205 ⁰ C. This increases the temperature of the polyvinylidene coating, the drum 29 at the same time keeping the carrier material below its melting point. It has been found that when using polyethylene as the carrier material in a drum with a diameter of about 135 cm and at a forward speed of the carrier material of about 300 m / min, the infrared radiators 30 to 32 emit enough heat to keep the temperature of the latex coating up to to a value not exceeding 80 ° C. Air temperatures of 250 to 205 ° C then bring about complete drying and hardening of the coating. In the case of carrier material with a higher melting point, higher preheating temperatures can be used.

After the material exits below the last of the air nozzles, it is fed with the help of a series of Driven rollers 40 to 44 are removed from the drum 29, the rollers 40 and 42 being cooled to bring the composite film or sheet material 10 'to room temperature.

The according to the method according to the invention and with the aid of the in F i g. 1 shown device produced film 10 'can be used to produce a three-layer film in which the middle Layer is impermeable to gas and moisture vapor, while the outer layers are relatively can be fused at low temperatures by means of heat. For this purpose, the film 10 'from a There are relatively thin, for example 0.025 mm thick, carrier layer 10, the latex layer 19 can be about 0.0001 of the thickness of the carrier layer. The finished material 10 'can with the impermeable Layer inside out on a spool

^h0 wound or fed directly to a device for the production of cellular material.

To form a three-layer material, two strips of the film 10 'are joined together The structure of the device then consists of individual

"" 'two drums, preferably on one substantially below the melting point of the means Heat-fusible carrier layer of the multilayer strips to be joined together

Temperature are maintained. In the case of polyethylene, the temperature should preferably not exceed 83 ° C. Below one drum there is a row of three driven rollers over which a film is placed is fed. A corresponding set of rollers is attached below the other drum

From a first supply roll, foil is fed upwards around the first drum and around the associated rollers via a guide roller the carrier film and the impermeable layer, for example, polyvinylidene chloride, to heat up to a 80 ⁰ C temperature not exceeding. It has been found that infrared wavelengths in the approximate range of 3.2 to 3.5 μm radiating radiators lead to good results.

From a second supply roll, coated film is wrapped around a guide roll and from there upward the second drum and fed around the associated rollers. At the film's trajectory the second supply roll and around the second drum is a corresponding set of heat emitters arranged to the carrier film and the polyvinylidene layer in the same way as in connection with the Foil from the first supply roll described to be heated. Rolls over which the train runs will become preferably cooled to the temperature of the polyvinylidene layer, after it has been heated by the infrared heater, to bring it up to about 15 ° C. this causes the polyvinylidene to become amorphous and this condition lasts for hours.

The treated foils are then passed over rollers and brought together between pressure rollers that the polyvinylidene coatings come into contact with one another. This makes the two of them stick Layers together firmly and permanently, so that the polyvinylidene coatings bond together so that they form a single middle class. The film then becomes a supply roll via appropriate rolls guided onto which the finished film is wound. When using carrier films with a thickness in the On the order of 0.0125 mm, the total thickness of the multilayer material is only slightly more than 0.025mm.

The layer material produced by means of the device described above can be used at extremely high Speeds of the order of 300 m / min can be produced, it being understood is that this device with the device according to F i g. 1 can be combined to the continuous Production of the three-layer plastic layer material without the coated carrier material in between Having to transport the processing materials unnecessarily.

A modified device for producing three-layer material from two coated layers Foil uses two drums in an adjacent position and at a distance from each other, the bo is slightly less than the total thickness of the two sheets of film to be joined. In this way the two foils are placed under pressure to effect the joining. The individual tracks are then guided upwards around the drums via rollers, whereupon the joined film is turned over the cooling rollers is passed around.

The two webs are preferably coating polyvinylidene passed around and around the drums with them befindendem on the outer sides of the coating and the backing sheets are heated by infrared heaters so that the temperature of the coating up to at least about 120 ⁰ C to 135 ° C increases when the polyvinylidene -Coatings on the foils are brought together in this heated state, they adhere together, the rollers 78 to 80 being cooled in order to lower the temperature of the foil, preferably immediately below 37 ° C. The finished film then runs over rollers 88, 89, 90 and 91 and is wound onto a supply roller 92

In certain cases it is desirable to have a primer layer such as an epoxy or a butadiene-based resin such as the combination of polyvinyl chloride with butadiene, to be used to sandwich the impermeable coating and the substrate to produce better adhesion. In most cases an aqueous dispersion of the resin will be used desirable, although the use of a solution is possible provided, however, that the Solvent as described above, does not attack the carrier material.

The duplication of plastics using a primer layer is shown in FIG. 2 illustrates in which the web of carrier material is designated by 93. It is fed from a supply roll 94 around rolls 95 and 96 around a gravure forme cylinder 97 is supplied. Part of the outer circumference of the forme cylinder 97 is in a the primer material-containing bath 98 is immersed with the amount of the on the forme cylinder adhering primer material through the doctor blade 99 and the depth of the in the forme cylinder existing wells is controlled.

A support or press roller 100 interacts with the forme cylinder 97 in such a way that some pressure is exerted on the film in order to ensure that the primer material is evenly applied to the web 93 of the carrier material. After it has been coated, it runs up past the heat radiators 101 and 102 and from there around the drum 103 . The drum 103 is preferably to be kept below the melting point of the carrier material of the web 93. The component 104 surrounding part of the circumference of the drum 103 has a plurality of air nozzles for directing heated air onto the coating.

Although any suitable primer material can be used, an example of a satisfactory primer material is a polyvinylidene dispersion containing a partially polymerized resin and about 40% solids, such as colloidal silica -Latex coating has been heated and cooled, the film web runs to a coating with polyvinylidene latex according to FIG. 1 via roles 106 to 109.

The application of the polyvinylidene coating and its hardening is carried out in a manner similar to that described in Connection with F i g. 1 illustrated and described corresponds so that for Designation of the elements which correspond to one another according to FIG. 1 and 2 the same, with a dash provided reference numerals have been used. For example, the polyvinylidene by the Form cylinder 15 'in cooperation with the support

909 633/6

roller 14 'applied, whereupon it over the roller 20' and then up to the heat radiators 3 Γ and 32 ' is guided past and over the drum 29 ', in the course of this period of time from the nozzles 33' and 34 ' Hot air strikes the layer to cause it to harden. The heated material is then removed from the Drum 29 'is removed and runs around cooling drum 42' and from there around rollers 43 'and 44' onto the supply roll 110.

The resulting material web 111, which consists of a suitable carrier web with successive Coatings made of a primer resin and an impermeable resin such as polyvinylidene, exists, can then be used in this form for packaging or other uses, or it two such multilayer webs 111 can be used for Create a multi-layer component can be joined together.

From the foregoing it can be seen that this improved material works at extremely high speeds can be produced and that only a relatively small amount to produce a more effective flat material Quantities of the impermeable resin are required that have considerable strength as well has the property of fusing by means of heat. The use of relatively small Amounts of an impermeable resin such as polyvinylidene do very little to increase the resulting costs for the flat material, with practice has shown that the achieved large Benefits more than outweigh the minor additional costs.

The improved layer material as described above has a relatively small one Weight and is essentially impermeable to gases and moisture vapor. This layer material is particularly suitable for the production of material described in DE-PS 12 37 294, in which at least one of the foils to be doubled is provided with a large number of separate embossings is, and the imprints in turn by a

ι ο the counter foil are sealed off.

Certain embodiments of the apparatus can be used in a single continuous process Production of plastic layer material and for the immediately subsequent formation of the layer material used to cellular material. For example, the method and the device according to FIG. 1 use for continuous production of cellular material. This makes it possible to eliminate some of the heating and cooling operations, making the process more effective create.

From the foregoing it is clear that, of course, depending on the desired structure of the End product combinations of the device

can be det. For example, it would be possible to use a continuous process to produce plastic films to coat and to form a three-layer material from them and then to form the cellular material according to the invention, the three-layer layer material with a two-layer material connect to.

1 sheet of drawings

Claims (15)

Patent claims: 1. Process for the production of at least two-layer, smooth or cellular Plastic layer material by applying at least one air-impermeable after it has dried Plastic layer on a plastic film web, characterized in that at least one plastic solution or dispersion using a gravure roller (gravure forme cylinder) is applied evenly to the film web, it is guided around a heated drum, wherein the temperature of at least a portion of the thickness of the film web is at one below it Melting temperature lying value is maintained and the film web during its circulation around the Drum dried on its coated side with hot air and then over at least one cooling roller and is fed to a supply roll. 2. The method according to claim 1, characterized in that a latex consists of a mixed polymer Polyvinylidene chloride and acrylonitrile is used as the layer material. 3. The method according to claim 1 and 2, characterized in that at least two plastic solutions or dispersions on the film web to form a base coat of an adhesive Material and - after it has been dried by heating - the mixed polymer coating be applied. 4. Further development of the method according to claim 1 for the production of three-layer material, characterized in that two coated film webs on the layer sides with one another be sealingly connected. 5. The method according to claim 4, characterized in that the coated film webs below Are welded together under the influence of heat. 6. Further development of the method according to claims 1 and 2 for the production of three-layer Material, characterized in that two coated film webs are carried out quickly after their Cooling on the sides of the layer are pressed together. 7. Further development of the method according to claim 1 or 3 for the production of cellular layer material, characterized in that a coated film web in the heated state for production a plurality of spaced apart, separated cells embossed and in heated state with a second heated coated film web on the layer side in press contact is brought and then cooled. 8. The method according to claim 7, characterized in that a copolymer is used as the layer material made of polyvinylidene chloride and acrylonitrile is used. 9. A further development of the method according to claim 1 ^{b ()} or 2 for the production of cellular layer material, characterized in that a coated film web is embossed in the heated state to produce a plurality of separated cells arranged at a small distance from one another and is rapidly cooled for> and with a second, rapidly cooled, coated film web is brought into pressure contact on the layer side. 10. The method according to claim 9, characterized in that polyvinylidene chloride as the layer material is used. 11. The method according to claims 7, 8 and 9, characterized in that polyethylene is used as the sheet material. 12. The method according to claims 7, 8 and 9, characterized in that polyvinyl chloride as Foil web material is used. 13. Device for performing the method according to claims 1 to 3 with a roller coating device and heating and cooling devices, characterized by at least one engraved roller (gravure forme cylinder) (15, 15 ', 97), which cooperates with a pressure roller (14, 100) and in a one containing the layer material (17) Container (16, 16 ', 98) circulates through a plurality of heating elements (30-32, 31', 32 ', 101, 102), the are arranged along the film web (19,111,193) coated by the gravure roller, by a provided with a cooling device drum (29, 29 ', 108), the film web on its periphery receives, and on the circumference of a plurality of on the outer, coated side of the Hot air nozzles (33, 34, 33 ', 34') directed towards the film web are arranged, as well as by subsequently to the Drum (29, 29 ', 108) arranged, the film web discharging, at least partially with cooling devices provided guide rollers (40-44, 43 ', 44', 96, 95). 14. Apparatus for performing the method according to claim 3, characterized by the series connection two devices according to claim 13, of which the first the base coat on the film web and the second on the Plastic layer applies 15. Apparatus for performing the method according to claim 4, characterized by the association of two devices according to claim 13 and a subsequent pair of press rollers through which the coated and cooled film webs are passed and combined on the layer side.