DE1629640A1 - Foil made of plastic that can be deformed under heat with a decorated surface and process for its production - Google Patents

Description

"Heat-deformable plastic film with a decorated Area and method of making it The invention relates to a film made of material deformable under heat with at least one decorated Surface. It also relates to its manufacturing process, its further processing by deformation, as well as on the objects made from this film will.

So far, special efforts have been made to article the end to manufacture a plastic whose: mass from the processing point of view or the price shows off practical characteristics, and - skin the best possible characteristics having.

An attempt was made to produce objects whose mass was made up of a in the case of heat deformable material, such as polyvinyl chloride or an acrylonitrile-butadiene-styrene and its skin made of polyester, one special resistant material.

Films made of amorphous polyesters are already known that are hot and by pressure on an area of very little thickness (in the order of magnitude of a few tenths Millimeters) made of thermoplastic material that can be glued to tolerates these films. The composite foils that result from the compound These two materials can be used to manufacture objects by deforming them serve with thin walls that are relatively soft, such as cups for Jelly or jam, etc.

The. Limitation of the thickness of the base to a few tenths of a millimeter in fact allows the hot bonding (i.e. without solvents) of the two materials because it allows it under the effect of the plasticity differences at the deformation temperature avoid the following: - on the one hand, a heterogeneous mechanical connection of the composite material (liquid coating on a pasty surface), - on the other hand, irregularities in the deformation when deforming between the two Component materials.

For example, with only a small number of thicknesses, the backing layer lost the The polyester when it was the backing had been brought to the bonding temperature was approached to be attached to, inevitably any mechanical Stop because of the considerable calorie mass of the pad. In other words it was so far it has not been possible to put the polyester, which was still soft, on the hotter surface discard '1 before this polyester any mechanical hold under the influence lost the calories given off by the pad.

There are also known manufacturing processes for deformed objects, which have thick walls and which are accordingly rigid, these objects have a thin liner of molded polyester.

In this regard, articles are known which consist of a thin layer Polyethylene teraphthalate of an amorphous type are made intimately on a plastic mass is applied, which consists of an injectable thermoplastic material. However, these items are made in two stages, namely: the film is made first introduced into the cavity of an injection mold by deformation under vacuum. Then plastic at at least 300 ° C is sprayed onto the film that is on the The bottom of the cavity of the injection mold remains. This results in a weld of the injected material on the film, which is subjected to low melting if the precaution is taken, the injection mold will be at a temperature from 50 to 70 C by means of a suitable cooling circuit.

This latter method makes it possible to avoid the difficulties that occurs with the heating of the two components of the composite material an equal temperature, but does not permit one through heat to achieve deformable semi-finished product, namely a film.

In addition, it is obvious that there is still between the melting temperature the polyester film that lines the cavity of the mold and the thickness of the one to be injected Materials there is a relationship between the injection conditions and the distribution of the Heat exchange concerns.

Because of these difficulties, all the more it was never suggested to use a pre-decorated polyester film as the material that is intended is to form one of the surfaces of a thermally deformable sheet.

It is a general object of the invention to overcome these difficulties balance.

For this purpose it concerns a procedure which allows the To carry out manufacturing starting from: its amorphous polyester film, which in particular has a previously decorated surface, its subsurface heat-deformable material that is compatible with and with the printing ink of the film Film tolerates and a suitable strength for making rigid objects due to later deformation (in any case larger than a few tenths of a millimeter, which represent the only previously known limits for the documents on which Polyester panels are spread out and welded), one composite film in which the said film is the natural one without any change Maintains the appearance of its decoration.

According to the invention, the method consists in: on the one hand, the film and on the other hand to bring the base layer to sufficiently high temperatures, but which are different in order to ensure a plastic state for each of the parts to achieve (essentially paste-like), which is suitable for a welding of this Materials suitable by simply depositing one on top of the other, but sufficient low, so that each of these materials offers a mechanical resistance that its handling permitted; - the temperature of the film at a lower value than to keep its melting temperature; - the gases, especially those from the Removing the backing layer and the monomers released from the film from the weld zone; Spread soil film on the backing layer; - if necessary, the film to smooth the surface, the composite sheet thus obtained to cool.

Such a method allows the polyester film to be placed on the backing material, which is at a higher temperature, under conditions "to be depositedZ ', which allow the dimensional characteristics of this polyester film to be preserved and accordingly any decoration that could be printed on this film.

The essence of the process is to put the polyester film on to keep its optimal softness temperature as long as possible, for example by a cylinder with thermal control and this polyester film by a sudden Temperature change to "seize" in the moment in which it is on the carrier material is applied.

For this purpose it is imperative that the application process only lasts a fraction of a second and is not affected by disturbances such as the appearance of gas bubbles between the polyester film and its bearer. Therefore it is necessary to largely ventilate the area or even to clear, in which the connection of the two foils takes place.

From the time these conditions are met, connects the polyester film in place with its wearer and will immediately insoluble from it.

As a result, the heterogeneous plasticities are no longer necessary of the two components must be taken into account to avoid further deformation of the composite Slide to be considered because of the relative distribution of the strengths of the two materials it is practically permitted to leave the polyester film out of consideration.

Starting from such a complex material, it is then possible to by simply deforming articles to produce that have the same characteristics as those represent that so far by deforming the polyester film and then spraying of the plastic, Further features and advantages of the invention emerge from the following description of one of the attached schematic Drawings illustrated embodiment.

FIG. 1 shows in perspective a film after the winding, FIG. 2 shows a schematic side view of a machine for the production the film of Fig. 1, Fig. 2a is a schematic representation of a modification of the manufacturing process according to Fig. 2, Fig. 3, 4 and 5 are schemes which allow to explain the production of such a film.

In Fig. 1- a film 1 is shown, which gradually, as in detail will be explained below, is applied to a base 2 to a film 3 to form.

First, it is explained that the thickness "c" of the film 1 is very small is, on the order of twenty-five to fifty microns, comparable to the thickness "E" of the base 2, which vary from five tenths to five millimeters can; or film 1 is produced starting from polyesters, in particular diol pententerephthalate; on its surface la opposite the base 2 is a decor that has the grain: of a precious wood limited, imprinted by processes, -the only techniques based on photography and gravure. The films of this type are made by different Manufactured by companies, in particular THE GOODYEAR TIRE AND RUBBER COMPANY -and some of them are in the French patent No. 1,353,477; - The base 2 consists of a plastic that is compatible with these polyesters. These materials can be made of polyvinyl chloride or consist of an acrylonitrile-butadiene-styrene and are abbreviated as P.V.C. and A. B. S. designated.

It is also possible to use a mixture of P.V.C. for such a film. and by A.B.S. or treated polystyrene.

One of the manufacturing processes for the film 3 is, for example, the following: The from A.B.S. existing pad (Fig. 2) is at a temperature of approximately 1800 ejected from a wide and narrow extrusion die 4 and between the Cylinder 5a, 5b out of a surface treatment system.

It is very difficult, in fact, to have a constant, even distribution of the extrusion pressure in the opening of such a nozzle. From it there are slight irregularities in the thickness of the extruded document which can be corrected all the more easily by a pair of cylinders than in this one Stage at a temperature of around 1200 this pad is still in the soft State.

In addition, in order to maintain this plastic state, the Cylinder 5 heated by a hot water circulation of about 800.

The base 2 is then inserted between cylinders 6a, 6b, in which a heat exchange medium such as water circulates.

This so-called "connection" unit is as close as possible the preceding unit and in any case at a distance from the latter that in consideration of the cooling factors of the base 2 (thickness, temperature, flow rate in the direction of arrow f2) this pad still when entering the connecting cylinder is in a plastic state and in this case, for example a temperature of 120 °.

These cylinders 6a and 6b are heated or depending on the situation chilled, depending on the calories received or given off by pad 2, which, if necessary, from an infrared heater ?? Rl? heated can be.

In addition, the cylinder 6a ensures the synchronous entrainment with the displacement the base 2 and the heating by touching a film la. This movie will heated to a temperature below 6o - 700 C since it will start at this temperature would to-stretch.

Depending on the temperatures and the sticking of the film to prevent on his cylinder, the latter can prevent the latter from sticking Be provided with a coating layer.

Ultimately, this film gradually settles in the soft state and without sliding onto its base 2, in order to be very intimate by welding to connect with this latter. The resulting film is then cooled.

It has now been found that near the cylinder and the support the hot air and in the gaseous state of these materials in plastic state released monomers accumulate and - on the one hand between between the base and the film, and on the other hand between the film and the cylinder 6a can be included.

BAD OR @ The film is then in the plastic state separated from the base, deformed and warped by the expanded gases and rolling between the cylinders can, among other things, form unaesthetic wrinkles that Show the start of breaks or cracks.

In order to avoid this gas inclusion, the surroundings of this unit 6 kept free as it allows the maintenance of the plastic state. In addition, a small spacer cylinder 7 holds the film from the cylinder 6a in one Clearance to allow the gases to escape.

In addition, the distance between the cylinder 6 is controlled so that it is in essentially corresponds to the thickness of the film 3, so that that of the latter The pressure to be withstood between the cylinders is very low, the connection will accordingly caused by the temperature and not by the pressure.

In this way, the polyester film 1 becomes in accordance with the temperature the base 2, which is well above 70 ° "gripped". This results in the following, that the decor is not deteriorated by excessive stretching of the heated film will.

It is understandable that, thanks to the cylinder 6a, the film simple deposited on the substrate and, if necessary, simply "smoothed" by this cylinder, under the same conditions as those in which a slide with a side Movement of the back of the hand is struck down.

Finally, the decorative dess-ins against abrasion during use The surface of the film provided with this decoration is used to protect the film3 arranged opposite the base and the printing color of the designs is on the welding level incorporated into the bulk of this composite film and appears on the page of the film by showing through.

It is therefore necessary to choose a printing color that is in the On the one hand, the welding temperature applied to the film is capable of being used and on the other hand the usual heat distortion temperatures Foil can be exposed without the risk of decomposition caused by Gas release would cause bunkers or swelling. In particular, be Printing inks, which may be based on acetate chlorides, before printing stabilized by adding classic suitable supplements.

A printing ink is preferably chosen whose type is favorable for the mutual adhesion of the film and the document is and will be avoided all products that could play the role of copper, the opposes their connection.

It should be pointed out -that the plastic-state of the foil 3 at the exit from the connection unit 6, a treatment of the decorated surface allowed on the surface. So this can be "grained" - by applying a Roller that has stripes or sinuous ornaments that are suitable for the desired Effect.

In the above procedure, the document? from an extruder made on the basis of this, but it could just as easily be a similar base are manufactured starting from a calender, as is the case in particular, if the document from P.V.C. should be produced.

In fact, the calenders make it possible to produce thinner bases and it would be sufficient to insert the base 2 into the connecting unit at the exit from the calender to ring in.

It should also be noted that the derivation the gases from the welding zone is only necessary if the pad 2 is lying flat shape is delivered. This is mainly the case when the roller 6a is responsible for this serves to carry the film 1 on the base 2, with the plane of the latter forms a very closed dihedral angle, which is responsible for the accumulation of the Gases would be cheap.

It is accordingly evident that the gases are easily "discharged." can be made by this dihedral angle of the meeting of the film 1 and base 2 is opened further. In this case, the accumulation of gases is switched off and there is a natural discharge of the gases as soon as they arise.

An embodiment of this type is shown in Fig. 2a, where a calender group of two rolls 21 and 22 is shown, between which a P.V.C. mass 23 is rolled out. This latter is smoothed on its surface and by a Cylinder 24 and then taken over by a cylinder 25.

In this type of production, the film is fed through a roller 26a and deposited on the convex surface of the pad 2'-. It is clear to see that the dihedral angle "D" is wide open here and it is therefore not necessary to provide a spacer cylinder similar to cylinder 7 of FIG.

Then the production method that is suitable for the circumstances is chosen, depending in particular on the thickness of the film to be produced or even the type of the processed plastic.

It should also be noted that the plastics that make up the film 3 form, can exhibit softness and impact resistance at ordinary temperature, which can fluctuate within a very wide range. They can be significant in particular Endure deformations as well as their temperature is brought to about 1200, whereby these deformations can become permanent after cooling.

Accordingly, it is easy to understand that such films 3, if their Plasticity is chosen in a suitable manner, rolled up in the form of rollers and also - quickly and without difficulty thanks to cutting tools of the kind used in the leather or wood industry in which they are cut into sheets of dimensions as required for the Manufacture or cladding of the desired items are needed.

Such a composite film is actually industrial Product. In particular, can this slide in contrast to the known glued polyester films are produced in large formats.

It is not necessary to heat the foils in vacuum ovens in order to achieve the Remove solvent. Finally, there is no risk of "splitting" of the different plastic layers.

In Fig. 3, a film element or a drawing plate 3a is identical Kind of like the slide), which is previously heated to a temperature of about 1200 became.

This board is between the two molds 8a, 8b of a punching die arranged to produce a small plate 9 thin wall and substantially of uniform thickness-is formed (Fig. 5), It must be said that this Plate has a circular, flat bottom, by a semicircular Bead 10 is limited, which in turn is extended by a cylindrical edge 11 whose cut surface represents the support base of the small plate.

It is easy to imagine that a KFaft "F" pointing to the mold 8a is brought into action to close the mold that has the effect Deform the blank until "its surfaces are true to the surfaces of the molds customized have (Fig. 4).

Of course, particularly strong deformations occur in the zone of the bead 10. The semicircular part has the tendency to elongate and has accordingly, the tendency to become thinner, while the side extension 11 the inclination has to wrap around the connecting fillet 12.

It is clear that in these zones, even with a sufficiently elastic Foil internal tensions of opposite directions would occur when opening the foil would not be in a plastic state that would allow all sewing parts for the film and its decor to be avoided.

It goes without saying that a result similar to the above would be achieved by placing the drawing blank on a mold, for example the permanent mold 8a would be placed and the drawing blank would be pressed onto the edge of the mold, after which a vacuum would then be created in the mold. Slight differences in strength occur in the zone of the edge 10, while the initial surface of a considerable Was subjected to expansion.

In addition, such a result would be achieved in the punching tools would be used with punches and dies that similar to deep drawing tools for sheet metal.

But in any case, the deformed drawing blank 9 is cooled down immediately list, before opening the mold or before releasing the board from the die or the tools achieved a rigid plate (Fig, 5) that does not need any support and is strong enough to withstand the shocks of its handling, storage and endure use.

It should be noted that the cut surfaces 3t of the film (Fig. 3 and 5) at the end of the operation outside the field of vision, even the side, of the rigid decorated article.

It is accordingly clear that the foils 3 make possible the manufacture of rigid articles, their decorated surface can be seen in relief or in hollow relief, depending on the type of deformation used.

For this it is enough: to heat such a film until its soft state is reached} - to put the foil on a model and to deform it, until it has faithfully adapted to the surface, - the so deformed film closed cool.

In addition, such a self-supporting film is aligned with To prefer molecules to a classic soft film; the result of a duplication of consists of two foils and which must be applied to the skeleton. The advantages of Hot deformation of this film is all the more pronounced than the surface of the film to be produced and the skeleton to be covered would have to have more pronounced contours or bulges are pronounced.-The hot-formed film 3 takes a slight in the zones 10 and 12 Appearance deviating from the initial decor, but with uniform effects (For example, broadening the grain of a wood decor to give it its appearance of olive wood) while a foil of classic type in the same Zones would have irregular distortions and even cracks in their decor. The connection between the elements of the glued film is in fact not enough enough to keep her to avoid mutual sliding in the zones of significant deformations0 Also Internal tensions, which can only disappear in a plastic state, act constantly against the adhesive forces that can be attributed to sticking to a skeleton.

It should be pointed out that procedures are known which allow to apply a thin film of thermoplastic resin on a base of the same type and to connect with her. In particular, a process for glazing polystyrene films, that consists in a "shock" polystyrene film - i.e. one copolymerized with Budadiene - Apply to a base of "crystal" polystyrene.

However, there are two materials that are the same Belong to the family and tolerate the monomers present in their bulk each other flawlessly.

In addition, the pad and the film are both of the same type Temperatures brought and there are only heat conditions to ensure the film to "grab" it by a sudden change in temperature. If the polyester is too much heated, it would stick to the cylinders while this problem was absolute is absent from polystyrene, which is brought to around 80 without any drawbacks can be.

Accordingly, and even if certain system elements are this classic Process for the manufacture of the composite industrial product according to the invention can be used, the The fact that this is a completely different manufacturing process acts, and that the products obtained are fundamentally different from one another are.

Of course, the present invention is not limited to the above The description is limited, but on the contrary includes all modifications that the specialist can carry out.

In particular, the decor of the film 1 is of course of the type and adapted to the determination of the article to be produced. This decor can for example Imitate ceramic tiles, upholstery fabric, etc.

In addition, films could be played simultaneously or one after the other on each of the Surfaces of the base 2 are applied.

In addition, the intimate connection of the mutually contracting Materials of the film and the base are lightened by binders that chosen depending on the nature of these materials and, for example, in the Printing ink of the decor of the film are introduced.

Claims (5)

Claims: 1. Process for the production of an amorphous Polyester film, which in particular has a previously decorated surface and of a Web made of a thermally deformable material that blends with the printing ink of the Filmes and this film tolerates and a sufficient strength for the making of suitable for rigid objects due to subsequent deformation, (whereby this strength in any case larger than the few tenths of a millimeter, which are the only ones up to now known limits represent for the bases on which polyester cladding spread out and firmly attached) a composite film ~, in which the said film shows the natural course of its decor without any changes, d u r c h e k e k e n n n z e i n e t, that the film on the one hand and the base on the other hand to sufficiently high temperatures, which, however, differ from one another are to be brought to a plastic (essentially pasty) state that is suitable for welding these materials by simply laying one on top of the other, taking the temperatures however, are sufficiently low for each of these materials to have a mechanical Offers resistance that allows it to be manipulated and that the temperature of the film is held at a value below that of his Melting temperature lies that the gases in particular those released by the pad and the film Monomers removed from the welding zone and the film finally on the base is spread and smoothed on it, after which the so obtained, composite Foil is cooled. 2. Foil made of thermally deformable plastic material, which by Execution of the method according to claim 1 can be produced, characterized in that that the polyester film is decorated in particular under the shape of an imitation wood will. 3. Thermally deformable film according to claim 2, characterized in that that the decoration consists of printing ink introduced between the film and the substrate consists. 4. Heat deformable film according to one of claims 2 or 3, characterized in that the thermally deformable material consists of a) polyvinyl chloride (P.V.C.) or b) an acrylonitrile-butadiene-styrene (A.B.S,) or c) a mixture by A. B. S. and by P.V.C. consists' 5. Method of deformation a film according to any one of claims 2 to 4, around an object with thin walls manufacture, characterized in that the film is heated until it is their reached plastic state that the film is applied to a mold and deformed until it has adapted itself intimately to the surface of the model, after which the so deformed film is cooled.