DE1479111A1 - Process for the production of two-layer or multi-layer molded parts - Google Patents

Description

process for the production of two-layer or multi-layer molded parts Ss is known, multilayer pipes, hoses, foils, Pro-'ile od. The like. Made of various Types or types of plastic using pressure and / or heat by welding or gluing together. For example, it is known to be multilayered Pipes, hoses, foils, etc. made from different types of thermoplastic material by means of a corresponding number of plasticizing devices and accordingly trained multi-layer spray head, the still hot or warm extruded layers are connected to one another by pressing them together.

The main purpose of producing such multi-layer structures is to High-quality and expensive plastics with certain properties only in to the smallest possible extent and only have to use where these specific properties are required, however, wherever these properties are not important or other properties are also required, corresponding to others and in particular also to be able to use less valuable plastics.

To connect such different types of plastic masses to one another in such a way that that the connection safely withstands all and especially high loads, is often very difficult if not impossible. Different for plastic foils In terms of material structure, attempts have already been made to take account of these difficulties to wear that the surface of the foils are treated with oxidizing agents Subjects to gases or liquids, producing the oxidizing ones Fabrics for example with the help of a point discharge in the immediate vicinity of the one to be connected Surfaces is made.

Also for making hoses from several layers of thermoplastic Plastic of different chemical structure is known to interact with one another to connect- ~ n surfaces to increase the adhesion with an oxidizing one to treat acting gas. Thereby the gas in the room, the two from each other concentric ring nozzles squeezed out adjacent tubular sleeves from the exit at the ring nozzles to their union by pressing together enclose, introduced or in this space by spark discharge in a high voltage field be generated.

The present invention is concerned with the two-dimensional connection of two or several layers of different types or types of plastic and the purpose of to eliminate the shortcomings of the well-known processors. According to the invention it is proposed to from adjacent surfaces of successive layers, of which at least every second is made of thermoplastic material, one with in the longitudinal direction extending dovetail or otherwise with an undercut provided projections and the other to form with corresponding grooves, wherein after known plasticization of the plastic compound, all layers are made of thermoplastic Plastic is molded in an extrusion head and then in thermoelastic or thermoplastic Condition under possible further shaping when applying pressure as well as possibly Heat by means of the projections and grooves fit together with the or merged with the adjacent layers and optionally with this or these can also be connected by welding or gluing.

In contrast to the known methods, this is based on the invention procedure mainly in the creation of a mechanical connection between the ribs, whereby also in such a case where the mutually different Plastic compounds of the individual layers no or only a poor adhesive bond make it possible to produce a good and lasting and especially a very A connection between the layers that can withstand high loads is achieved. so far the nature of the plastic compounds used can do this, but also without Difficulties also a correspondingly more or less firm adhesive connection can be achieved by welding or gluing. The fact that the manufacture of the mechanical connection between the layers simultaneously with the manufacture the plastic structure itself results in comparison to what is conceivable per se Establish a mechanical connection by sliding their Adjacent surfaces with dovetail-shaped or similar projections or grooves provided prefabricated plastic layers considerable manufacturing technology Advantages and especially the possibility of very thin and flexible layers connect with each other in such a way, The term layer is by no means intended only here understood in the sense of layers that are relatively thin in relation to their two-dimensional extent earth, it should rather also be relatively thick, massive or hollow profiles include. Accordingly, it is of course also possible to use a plastic profile round, oval, rectangular, etc. or more complex shaped cross-sections by way of mechanical anchoring, a deck sciato made of a different plastic to raise.

Another essential advantage of the method according to the invention consists mainly in the fact that plastics also come along with it -; iit very considerably Reliably combine differing physical properties because the interlocking projections and grooves form a buffer zone, which is capable of the different behavior of different plastics to compensate as much as possible. Plastic combinations can be realized accordingly, the very different and especially very high requirements fully do justice to the situation with conventional means, however, under certain circumstances not or can only be achieved unsatisfactorily. This also applies to such Plastic combinations in which high-quality plastics are used to make them cheaper cheap carrier raw materials can be combined, whereby products are still obtained that meet the requirements both physically and chemically perfectly meet.

Depending on the type of plastic combination or the intended use of the finished product, it may be desirable or necessary, a hike in the hills to prevent or to ensure complete gas impermeability. This can be done in a simple manner that between each other adjacent surfaces of two or two consecutive layers an intermediate layer from a metal or plastic polie, from an optionally pretreated, For example, glued or resinated paper or the like. Is embedded. Included it is conceivable that this intermediate layer as one of the profiling of each other facing surfaces of adjacent plastic layers correspondingly shaped thin Intermediate layer is formed or as a correspondingly thicker intermediate layer with appropriately profiled surfaces, in which case the plastic layers as it were are held together via this intermediate layer.

In an expedient further training d-he invention can also are provided for the purpose of an external coating of the plastic layer combination with hardening materials such as cement mortar, phenolic resin, casting resin or the like outer tarpaulin of at least one of the two outer plastic layers with a dovetail-shaped or otherwise provided with an undercut To train profiling.

In the same way that the plastic layers are connected to each other can also be an external coating on the plastic layer combination the specific wishes or requirements of chemical, physical, color, price or similar nature invoice wearing.

Depending on the type of body or structure to be produced, d. H. whether these are sheets, plates, foils, pipes, hoses, profiles or the like, what kind of cross-sectional shapes and dimensions should be, how many layers are to be implemented, which combinations of plastics are provided, etc., different paths can be taken in the production will. For example, it is so in the production of a two-layer plate when combining a layer of thermoset plastic with a layer of thermoplastic plastic, as well as if thermoplastic for both layers Plastic is used, possible on one flat side with a Dovetail-shaped or similar grooved prefabricated thermoset or the one thermoplastic layer by means of the thermoplastic second layer Apply extruder and slot die. When using thermoplastic Plastic for both layers is also possible using two Extruder and nozzles the two layers directly at or shortly after their formation to unite with each other. Provided this is the thermoplastic state of the melt Unfortunately, the wet is in approximately the same temperature range, the two can Masses * at approximately the same temperature and in approximately the same state immediately be brought together, for example in the production of pipes in a single Multi-layer spray head.

In the same way, however, multi-layer bodies, such as, for example, can also be used Pipes, made of thermoplastics with different, especially strong from each other different processing temperature, produce in a single multi-layer spray head, In this case, however, it turns out to be expedient to ce the substance with the higher Processing temperature immediately after entering the forming tool to bring the desired shape and by cooling to the temperature range (ps other Plastic as well as these others Plastic with the merge cooled mass strand at a point where it already has a has covered a certain distance, for example about 100 mm. To achieve the required Cooling of one plastic can expediently in the multi-layer extrusion head a channel system can be provided which allows cooling as required or also to heat, which then also meets the requirements for processing further different combinations of materials can be met.

Of course, the applicability of the above is limited mentioned measures and possibilities not on the production of only two-shift and roughly tubular structures, rather it also extends to multilayered structures and above all on structures of other shapes. Likewise, of course, also exist with regard to the formation and arrangement of the interlocking and interlocking Toothings of the facing layer surfaces a large number of the most varied Options. For example, these gears can be identical or different Shapes, dimensions, distances, etc. are carried out. Likewise with a connection of three or more layers between each two of these layers different Toothings are applied. there is also the option of proportional thick layers and coarse toothing to form these as hollow bodies, which are then at a later point in time, if necessary with any filler material have it filled out.

The different swelling capacities of the various thermoplastic Plastics in the thermoelastic state can be used when using the above called working principle despite the interlocking in the individual layers regulate mostly large differences in wall thickness well and properly. Likewise @ ods but also the different viscosity of the various thermoplastic Melting when two or more mass strands are united by corresponding ones Temperature control, choice of a suitable compression ratio and setting take into account the screw speed of the extruder in a satisfactory manner, in particular so that in the area caused by the interlocking of the layers on these Thickening an excessive advance of the melt is reliably prevented the intention is to place an intermediate layer approximately in between two plastic layers Form of a metal or plastic film, a metal or textile fabric, a if necessary, incorporate using glue, resins or similar pretreated paper, etc., this also results in a number of the most varied of possibilities.

For example, a pre-formed film can be inserted into one on the forming tool formed film shaft and introduced by a pull-off device or transported directly through the two mass strands and at the same time be embedded between the layers. However, the shaping of the film can also be used can also only be made in the deformation tool by. the foil shaft accordingly trained or equipped with appropriate facilities and tools.

In the case of pipes and hoses, for example, this can also be the case proceed that a plastic-laminated one provided with crimped longitudinal ribs Metal foil is inserted into the multi-layer spray head or its foil shaft, the front end of which is behind the first mass feed pipe of the spray head is shaped into a toothed tube, which is now attached to the start of operation Before setting up, apply the two ground strands from the inside and outside. During transport of the film, which in turn by a special take-off device or a-c: directly can be accomplished by the two mass strands themselves, then forms the part of the film that has not yet been formed into a tube continues according to the film is drawn into the deformation tool independently to form the toothed tube. Unless the Foil on one or both sides with a dem Corresponding layer material Plastic application is provided, a good weld can be achieved at the same time will.

A two-layer or multi-layer manufactured in the manner according to the invention Hose can, in particular by using its own heat, easily can also be processed using the blow molding process. True, the distribution the plastics in the blown hollow body are then usually not uniform especially in any angled areas, by appropriately selecting one with dyes pigmented outer layer this can easily be made invisible.

For the bodies produced by the method according to the invention and structure gives a large number of uses, for example for roof and exterior wall cladding in the form of panels with an exterior Layer made of particularly weather-resistant thermoplastic material as well as with an inner layer made of another thermoplastic material with good heat insulating properties. This could also be done between layers very close hollow teeth are used. By subsequent foaming with phenolic resin foam or the like then had measure in hand, between the two Plastic layers to realize a sound and heat insulating intermediate layer.

Also in panel form, it could also be used as a floor covering with an intermediate layer made of metal foil, which with the appropriate connection Avoid electrostatic charges from plate to plate and simultaneous grounding would.

There are also numerous possible combinations for pipes and hoses of the most diverse thermoplastics with oaer without an intermediate layer diverse Possible applications, for example for gas pipes or also for pipes for forwarding of fuels, for the latter Pall, for example, a chemically resistant one inner trouble with good mechanical strength properties exhibiting outer layer made of soft PVC of high Shore hardness in oil and petrol resistant Setting could be considered.

Profiles with large wall thicknesses naturally require proportionally large amounts of material. With such profiles, the pricing could be be influenced advantageously that according to the method according to the invention a core from cheap raw material with a coating of a high quality material and, if necessary is also provided in a visually particularly advantageous color scheme. Depending on The purpose of these profiles could of course also be used here again Intermediate layers made of film, fabric, paper or the like are introduced, for example Metal inserts for handrail profiles to prevent electrostatic charging.

Thin tubes with an inner layer made of acetal resin and a Outer layer made of high-pressure polyethylenes can be used advantageously to make aerosol bottles, processed into petrol cans or other containers.

Multi-layer films can be used with a suitable number of raw materials easily stretch up to thicknesses of 0.5 and more millimeters. Accordingly offers the possibility of using foils for wound capacitors according to the method according to the invention produce, for example, by embedding an intermediate layer of copper foil between two layers of polycarbonate. but there is also the possibility by embedding a wide variety of metal foils between foils made of suitable @@ Plastic radiation protection films with a low square meter weight or the like.

Z @ @rich we; other possible uses are conceivable.

Z @ Explanations of the method according to the invention are in the Z @@ chnung some embodiments shown.

1 to 8 show different possibilities for training of the layers as well as their connection to one another, FIG. 9 shows a two-layered cross-section Tube, Fig. 10 the connection of two plastic layers with embedded between them Foil, FIG. 11 in a schematic representation a double spray head for implementation of the method according to the invention, FIGS. 12a and 12b, cross sections according to the lines A-A and 3-E of FIGS. 11 and 13 show, in two views, a different device for Implementation of the method according to the invention.

The layer 1 shown in FIG. 1 in a section is at its a flat side with one another at equal intervals. deanranged and the same Dimensions having dovetail-shaped grooves 2 or projections 3 formed. This layer can be made of either through or thermoplastic Plastic prefabricated element act that by means of the dovetail-shaped Grooves or projections with a thermoplastic or thermoelastic state to be applied second layer of thermoplastic material through toothed Mechanical intervention and possibly also by welding or gluing should be connected. The form shown is also applicable if it is a question of this layer at the same time rit with a corresponding further one To form the layer in a multiple tool and immediately or shortly afterwards to connect with this according to FIG. 2, so that the dovetail-shaped Ledges 5 of layer 4 fill in the bottom 2 of the layer.

According to Figures 3 to 8, three layers 1, 4 and 6, all of which can be made of thermoplastic material, as well as those but any one of them can be made of thermosetting plastic, interlocked with each other. As the figures show, both the thickness ratios the layers as well as the arrangement and design of the grooves and projections are different to get voted. For example, it is also possible to make corresponding arrangements to be provided for thick foils.

As can easily be seen from FIGS. 1 to 5, w @@@ elne equally good connection between the layers also because @@ ensured when the Grooves approximately with a circular cross-section and one sufficiently smaller than the diameter of the circular cross-section formed outer opening and also the projections would be trained accordingly. Wide shapes of the grooves and projections are conceivable.

A corresponding embodiment for a two-layer pipe shows the Fig. 9. The inner tube 7 engages here with its projections 8 in a suitable manner the grooves 10 of the outer tube 9.

However, the reverse arrangement would also be possible, as would the the two tubes 7 and g do not necessarily have the same thickness here have to. The arrangement, which is basically the same, can of course also be used with thin-walled ones Meet pipes and hoses.

, The arrangement of FIG. 10 differs from their own ge @. Fig. 2 ir essentially only in that between the two layers 1 and 4 a their grooves and projections 2 or

7 un. 5 adapted film 11 of constant thickness is embedded.

For example, it could be a metal foil that on one or both sides with the layers 1 and optionally used for the production 4 thermoplastic plastic used is laminated, which is then in addition A weld can also be achieved for mechanical anchoring.

De: as seen from above for the production of two-layer pipes or hoses Multi-layer spray head of the Pig. 11, 1 2a and 12b points for connecting the two Mass spaces 13 and 14 separated from one another by the tubular part 12 on two Extruder not shown, the connecting pieces 15 and 16 on. The one for the inner layer certain, at the connection piece 15 axially entering mass flow is initially between the inner surface of the Eii 12 and the outer surface of the mandrel 17 into a tubular Strand is formed and the one intended for the outer layer is also formed on the side Mass flow entering nozzle 16 initially between the outer surface of part 12 and the inner surface of the spray head housing 18 formed into a tubular strand (Figure 12a). These two strands are then in the further by means of the in particular Way formed end region of the part 12 on their adjacent surfaces formed with grooves and projections corresponding to those of FIGS. 1 to 10, until finally the two mass flows formed in this way, with the grooves and Interlocking projections, unite at the end of part 12 and form a two-layer Forming intertwined internally and externally smooth tubing ($? ig.

12b).

The spray head shown in FIGS. 11, 12a and 12b is of course only one embodiment. Other shapes are conceivable, especially for the Formation of the end region of the part 12, so that the shape and the merging of the two mass strands can be done in another way. Lach Fig. 13 slides on its upper side with the dovetail-shaped projections 7 provided, made of thermoplastic or thermosetting plastic prefabricated plate 1 with their underside resting in the direction of the arrow through the rectangular slot 19 of the slot nozzle housing 20. For connection to an extruder, not shown, is on the top of the Housing the connecting flange 21 is provided through which the nozzle channel @@ vertical is passed, which is then in the housing 20 in the Feed direction is deflected, so that the mass flow through it is inclined to the plane of the plaSte 1 uf this meets and with it, the between the projections 3 formed grooves 2 filling and the contiguous Ge plate-shaped layer Forming 4 united. At the front end of the housing 20 is, for example, not shown vertilaien elongated holes provided, od by means of the adjusting screws.

@G@. 23 adjustable in height and lockable by means of the screws 25 Bar 24 arranged, by means of which the thickness of the layer 4 in the desired Way can influence or regulate.

Claims (3)

Claims 1. A method for producing two or more layers Molded parts made of thermoplastic and optionally thermosetting plastic, characterized in that that mutually contiguous surfaces of successive layers (1,4; 1,6,4; 7,9), at least every second of which is made of thermoplastic material, the one with dovetail-shaped or otherwise extending in the longitudinal direction rit an undercut provided projections (5) and the other with corresponding Grooves (2) formed wi: d, wherein after known plasticization of the plastic compound the layers of thermoplastic material are molded in a die head and then in the thermoelastic or also thermoplastic state under any case Shaping when applied before ruck such as possibly heat by means of the projections and Butene merged with the adjacent layer (s) in a matching interlocking manner and possibly with this or these by welding or gluing can also be connected. 2. The method according to claim 1, characterized in that between the adjacent flat layers of two or; e of two successive layers a thin intermediate layer (11) made of a metal or plastic film, on one if necessary, pretreated, e.g. gelled or resinated paper, of metal or textile fabric or the like. Is embedded. 3. The method according to claim 1 or 2, characterized in that for External coating with hardening materials such as cement mortar, phenolic resin foam, Cast resin or the like external surface of at least one of the two @ external Schict @. with a dovetail or something else is formed with an undercut profiling.