DE3439822A1 - Process for the production of a plastics film with a grain structure, in particular a natural leather grain structure - Google Patents

Abstract

In a process for producing a plastics film with a grain structure, in particular a natural leather grain structure, a layer of liquid plastic is poured or spread onto a film web having the grain structure in negative form, vulcanised and then peeled off. The film web used which has the negative form of the grain structure is made of silicone rubber. This has the advantage that the film web can be produced very simply by pouring onto complicated surface contours and reproduces these contours in a precise negative form, so that the precision is repeated during the subsequent pouring or spreading procedure and, because of the elasticity of the silicone rubber, the complicated embossing structure of the silicone rubber film web is not impaired during peeling off of the vulcanised layer.

Description

Process for the production of a plastic film

with a grain, in particular a natural leather grain Die The invention relates to a method for producing a plastic film with a Grain according to the preamble of claim 1.

In a known method of the type in question, the material is the sheet of paper with the grain, in the surface of which the negative form the grain has been introduced by embossing by means of an embossing roller and the is treated with a substance that causes the poured-on liquid plastic to stick prevented. Embossing the grain into the surface of the paper requires a hard surface of the embossing roller, i.e. one made of metal, so that the grain can only be produced artificially. The use of paper for the negative form having film web thus has the monotony and simplicity of the grain to Follow what is not wanted.

The invention is based on the object of a method of the relevant Specify the type in which the grain is not monotonous and simple, but rather as possible corresponds to a natural leather grain, the surface of a fabric or the like.

The object on which the invention is based is achieved by the characteristics of claim 1 specified teaching solved.

The invention is based on the basic idea that the use of No silicone rubber as a casting base for the liquid plastic to be drawn on is absolutely necessary, however, in the manufacture of the casting underlay procedure enables even the most complicated surface contours such as that of a natural leather grain, a fabric, fleece, a wooden surface or the like and removed as a negative shape in the surface of the silicone rubber can be represented.

According to a further development of the method, the the grain in negative form having film web of silicone rubber on a thermoplastic Foil web, the surface of which has the grain in positive form, poured on or painted on, vulcanized and peeled off. The use of a thermoplastic Foil web as an intermediate stage in the transfer of the scar enables a great deal exact transfer of a grain to this thermoplastic film web, as this can be brought into a liquid state by appropriate heating can, so that the material can penetrate into the finest depressions of an embossing template and can still be withdrawn immediately afterwards.

It is particularly advantageous that the positive form of the grain an embossing roller is used to emboss the thermoplastic film under heat and pressure can be, whose embossing surface consists of silicone rubber and the grain in negative form having. This negative mold can be created in a simple manner by pouring the silicone rubber on it to form a natural grain surface.

The process can also be made endless in that the ends of the thermoplastic film web forming the intermediate stage before application of silicone rubber are bonded together and so form an endless thermoplastic Film web is formed, wherein the embossed surface of the thermoplastic Foil web in the area of the butting edges under heat and pressure an embossed nut and thus an endless positive form is generated, w <> at the r Siliçnku tEichuk covers the entire circumference the endless thermoplastic Film web applied and so an endless web of silicone rubber is produced, which enables the continuous casting process. The endless path only needs to be so long that the poured liquid plastic has time to vulcanize has to be peeled off before the film web representing the casting base from silicone rubber reached the Aufgießort again.

A particularly expedient development of the invention is claimed 6 specified. In particular, this method solves the difficult problem associated with the use of a natural leather surface as the initial shape is created, that this leather surface is not in a continuous form.

Thus, in principle, only one can be used as a coining nut throughout Produce the designated embossing layer, e.g. in the form of an elongated rectangle. If this is bent into a tube, it occurs at the edges that abut against one another a discontinuity so obvious that a continuous imprint of a Thermoplastic film alone with such a tubular curved embossed nut not possible.

The essence of this training is to solve this problem to overcome the discontinuity, thereby creating a continuous imprint of a allow thermoplastic film in large quantities. The invention provides for this before, from the discontinuous embossing nut initially by embossing a thermoplastic Foil to create a positive intermediate form, although this is also true in its surface structure is discontinuous, but which has the advantageous property of being thermoplastic Embossing to be deformed.

According to the invention, the area of the positive form in which the discontinuity becomes clear, overprinted by the negative shape of the embossing nut, so that thereby the Discontinuity is lost. Because when embossing the thermoplastic film in the area of the edges abutting one another is also the one required for welding When the temperature is reached during the embossing, the abutment edges are joined together at the same time welded.

Since the embossing is limited in the circumferential direction, a Transition area in which the embossed structure in the originally with the embossing nut embossed structure passes over.

However, this transition is so continuous that it is practical in practice is no longer visible.

The embossing of the thermoplastic film with the embossing nut can be done in easily done in a flat press, although in principle also embossing in a roller press is not excluded. Also the embossing of the thermoplastic Foil with the embossing nut can be made in a flat press, but this is narrow is such that the embossing takes place only in the joint area. The press gap widened expediently in the circumferential direction of the hose to the edges of the Press plates towards the longest possible continuous transition from the overprinting to achieve the original coinage.

To produce the embossing daughter, it is useful that the hose Applied to a roller with the positive form facing outwards, the roller constantly rotated and at the same time, using a doctor blade, spread the layer of silicone rubber on and is then vulcanized to the embossing daughter. The thickness of the coining daughter is this makes it particularly even, and the application with the squeegee ensures a good finish Penetration of the silicone rubber into the pores of the positive mold.

Instead of a natural leather surface, any one can of course another type of surface structure serves as the basis, for example a fabric, Fleece, a wooden surface or the like.

Example: A template made of natural leather, textile or the like is stretched on a flat surface and attached to the edges. Around the edges a frame-shaped boundary is created and a mold is formed in which a silicone rubber with a adhesive effect is poured. This complies with the Surface fine contour the template in every smallest detail, so it penetrates pores and encloses even hair.

The silicone rubber is then vulcanized, gelled or solidified and deducted from the original. This process is repeated several times, the more so several times Generate embossing mothers.

They each have a thickness from 3 - 4 mm and become Connected to each other on the back with adhesive strips.

The structure made in this way from several embossing mothers is combined with a thermoplastic film with a thickness of about 0.8 mm in a platen press brought, the thermoplastic film is below and the stamping film with the Embossed side down over it.

The thermoplastic film is now from below directly and additionally also warmed from above through the embossing mother to approx. 1900 cm and thereby plasticized. The pressure applied at the same time results in the after a certain time exact imprint of the structure of the embossing nut on the thermoplastic film that e.g. made of polyvinyl chloride.

It is then cooled and the embossed thermoplastic film is removed.

The thermoplastic film is made according to the length and the girth an embossing roller cut to size and bent into a tube, the embossed or the grain side is outside. The joint is carefully adjusted and on the back connected with tape. Then the hose is only with the joint in one narrow flat press gebr ## eight, in which the embossing nut is placed over the joint will. This is followed by heating and pressurization, so that the The desired overprinting is carried out in the area of the joint.

At the same time, the mutually abutting ones are welded together Margins.

The one created in this way has a positive form of the embossed structure on its outside having hose is pulled onto a roller and this in a frame with bearings placed and constantly rotating. Then silicone rubber is applied in applied uniform layer thickness, which is then brought to vulcanization will. During these processes, the rotation of the roller is maintained, so there are irregularities in the ## ht "h <t <i i <~ kp j ve 'inolden After the VuikanisaLion d ('1 so erzeule ## IiSllico hose is pulled off and turned inside out, so that now the design, leather, textile or the like taken from the template as a negative form is present on the outer surface. The hose is pulled over a roller after the surface of which is coated beforehand with an adhesion promoter and a silicone adhesive has been. The adhesive layer is then brought to harden.

This roller is used as an embossing roller in a device for continuous Embossing of a thermoplastic film used. The embossing roller creates a thermoplastic Foil is continuously embossed, and a longer section of it is endlessly connected, wherein the connection point is embossed by means of the embossing roller, so that there a continuous transition of the positive embossing pattern is generated.

Then it is on the side of the endless thermoplastic film that the positive embossing pattern has silicone rubber poured on or painted on and at the same time a woven or knitted web is applied for reinforcement. The silicone rubber is vulcanized, gelled or solidified and peeled off from the template so that an endless band of silicone rubber is formed, which has a desired surface structure, in particular a natural leather grain.

This endless band of silicone rubber is placed in a device in which it rotates slowly and continuously.

The surface with the grain in the negative form becomes more fluid Plastic applied, brought to solidification and then peeled off and wound up.

Claims (10)

Claims: 1. A method for producing a plastic film with a grain, especially a natural leather grain, by adding a layer of liquid plastic onto a film web having the grain in negative form poured or painted on, vulcanized and then peeled off, d a -d u r e k e k e nn n n e i n e t that as the negative form of the grain exhibiting Foil web such made of silicone rubber is used. 2. The method according to claim 1, d a d u r c h g e k e n n -z e i c h n e t that for the production of the film web silicone rubber on a thermoplastic Foil web, the surface of which has the grain in positive form, poured on or is painted on, vulcanized and peeled off. 3. The method according to claim 2, d a d u r c h g e k e n n -z e i c h n e t that the positive form of the graining of the surface of the thermoplastic film is formed by embossing under heat and pressure by means of an embossing roller, whose The embossing surface consists of silicone rubber. 4. The method according to claim 2, d a d u r c h g e k e n n -z e i c h n e t that the ends of the thermoplastic film web before the application of the silicone rubber are connected to each other and so an endless thermoplastic film web educated is, wherein the embossed surface of the thermoplastic film web in the area of the abutting edges under heat and pressure with an embossing nut embossed and so an endless positive form is produced, and that the silicone rubber Applied over the entire circumference of the endless thermoplastic film web and thus creating an endless web of silicone rubber. 5. The method according to claim 2, d a d u r c h g e k e n n -z e i c h n e t that there is a web on the poured or painted on silicone rubber is applied from a knitted fabric or woven fabric for reinforcement. 6. The method according to claim 3, d a d u r c h g e k e n n -z e i c h n e t that the embossing surface is produced in that on the surface of a Grain pattern, especially a natural leather, silicone rubber as uniform A thick layer is poured or painted on and then vulcanized to form an embossed nut is that the embossing nut is peeled off the leather and that with her a negative form the surface representing the grain of the natural leather under heat and pressure the surface of a thermoplastic film is embossed that the thermoplastic Foil with its opposite edges butting against each other to form a tube is shaped that the embossed surface of the thermoplastic film in the area of the abutting edges under heat and pressure with the embossing nut over embossed and so an endless positive form is produced, on which a layer of Silicone rubber is poured or painted on, which becomes an embossing subsidiary is vulcanized, which is peeled off the positive form and with the negative embossing surface is glued to the outside on the circumferential surface of the embossing roller. 7. The method according to claim 6, d a d u r c h g e k e n n -z e i c h n e t that the embossing of the thermoplastic film with an embossing nut in one Flat press takes place. 8. The method according to claim 6, d a d u r c h g e k e n n -z e i c h n e t that the embossing of the thermoplastic film with the embossing nut in one narrow, essentially flat flat press takes place. 9. The method according to claim 8, d a d u r c h g e k e n n -z e i c h n e t that the embossing gap extends in the circumferential direction of the hose to the edges the press plates expanded continuously. 10. The method according to claim 6, d a d u r c h g e k e n n -z e i c h n e t that the hose is applied with the positive form facing outwards on a roller, that the roller is constantly rotated while applying the layer of silicone rubber by means of a doctor blade is painted on and then vulcanized to form the embossing daughter.