FILM PRODUCTION METHOD, FILM PRODUCTION ASSEMBLY, AND PLASTIC FILM

Abstract

The invention relates to a film production method for producing a thermally deformable plastic film having an at least two-color design, comprising the following steps: extruding a first plastic to form a molten plastic melt and dispensing the plastic melt of the first plastic in a planar manner in a first thickness by means of an extruder nozzle/slit nozzle; applying a second, scatterable and/or free-flowing plastic in a defined, planar manner in a defined pattern design with a pattern template onto the plastic melt consisting of the first plastic, and calendaring/sizing the thickness of the plastic melt and simultaneously at least partially pressing the second plastic applied in a planar manner in the pattern design into the first plastic by means of a calendar assembly, cooling the melt to form a solid plastic film.

Claims

1. A sheet production process for producing a thermally deformable plastic sheet having an at least two-color design, comprising the steps: extruding a first plastic material into a flowable plastic melt, and two-dimensionally dispensing the plastic melt of the first plastic material in a first thickness using an extruder die or slot die; applying a second scatterable and/or free-flowing plastic material in a defined two-dimensional way and in a defined pattern design using a pattern template to the plastic melt consisting of the first plastic material; and calendaring or calibrating the thickness of the plastic melt and simultaneously at least partially impressing the second plastic material applied two-dimensionally and in a pattern design into the first plastic material by means of a calendar assembly; cooling the melt into a solid plastic sheet.

2. The sheet production process according to claim 1, characterized in that a differently colored first plastic material is used as said second plastic material.

3. The sheet production process according to claim 1, characterized in that said application of the second plastic material to the plastic melt consists of the first plastic material is performed by scattering.

4. The sheet production process according to claim 1, characterized in that for applying the second plastic material, said second plastic material is in the form of granules, a powder, grit or mixture of particles, wherein the particle size of the second plastic material on average corresponds to the final thickness of the plastic sheet, or is thicker by a maximum of 50% and/or thinner, for a minimum of 70%, than the final thickness of the plastic sheet.

5. A sheet production assembly for producing a thermally deformable plastic sheet having an at least two-color design comprising: an extruder with a slot die for producing and dispensing a flat flowable plastic melt of a first plastic material; an application and/or scattering device for applying or scattering a second plastic material onto the plastic melt consisting of the first plastic material; a calendar assembly for calibrating the thickness of the sheet and simultaneously at least partially impressing the second plastic material to the plastic melt consisting of the first plastic material; wherein said application and/or scattering device provided in the zone of the calendar assembly; and the orientation of the plastic melt (1) in the zone of said application and/or scattering device (4) is horizontal.

6. The sheet production assembly according to claim 5, characterized in that said application and/or scattering device includes a round template; and/or a single or double doctor knife assembly.

7. The sheet production assembly according to claim 5, characterized in that said calendar assembly and said application and/or scattering device are combined, wherein the application and/or scattering device is arranged above a first calendar roll, and second roll and third calendar roll are provided in order to perform thickness calibration, wherein the second calendar roll and third calendar roll[s] are arranged above one another.

8. The sheet production assembly according to claim 5, characterized in that a transport belt assembly is provided behind said extruder die, wherein the extrusion is performed onto said transport belt assembly.

9. A thermally deformable plastic sheet having an at least two-color design comprising: a first plastic material with a first color and at least one second plastic material with a second color different from the first color, wherein said plastic materials are molten together, the second plastic material is incorporated in the sheet at least partially, and by more than 30% of the sheet thickness in the thickness dimension, and at least one surface of the sheet has a defined design/pattern formed by said two-color design.

10. The sheet according to claim 9, characterized in that said first and second plastic materials are made of the same material and have different colors, wherein said first and second plastic materials are selected from the materials: olefin-based thermoplastic elastomers, TPU, TPE-O, urethane-based thermoplastic elastomers, TPU, TPE-U, PVC, a flexible thermoplastic material, polyethylene, polypropylene, polyvinyl chloride, polyurethane as such or as a component of copolymers, or in mixtures, unfilled as well as provided with an inorganic filler.

11. The sheet according to claim 9, characterized in that a material compatible with the first plastic material and having similar properties in the cold and heated states may also be employed as the second plastic material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In the following, Examples of the invention are described in some detail using the enclosed drawings in the Description of the Figures, the latter being intended to illustrate the invention, and are not to be considered limiting:

[0052] FIG. 1 shows a schematic Example of the disclosed plastic sheet production assembly;

[0053] FIG. 2 shows a detailed side view of the scattering device within the disclosed plastic sheet production assembly according to FIG. 1;

[0054] FIG. 3 shows a schematic second Example of the disclosed plastic sheet production assembly; and

[0055] FIG. 4 shows a polished transverse section of a plastic sheet with a design produced by the disclosed process.

DETAILED DESCRIPTION OF THE INVENTION

[0056] The plastic sheet production assembly includes an extruder 2 at the exit of which an extruder die 3 is provided, by means of which it is possible to extrude a first plastic material 12 into a flat flowable plastic melt 1.

[0057] Further, the plastic sheet production assembly includes a calendar assembly 5, 6, 7 that serves to calibrate the thickness of the plastic melt 1 or plastic sheet 1. In this preferred Example, the calendar assembly has three calendar rolls, i.e., a first one 5, a second one 6, and a third calendar roll 7. The second 5 and third 7 calendar rolls are arranged above one another, together forming a second calibrating stage. The first 5 and second 6 calendar rolls are arranged with a horizontal set-off, together forming a first calibrating stage.

[0058] A further particular feature in this Example is the fact that the first calendar roll 5 has a significantly larger diameter as compared to the subsequently arranged further calendar rolls 6 and 7, so that an application and/or scattering device 4 can be provided on the upper side of the first calendar roll 5 to create sufficient space for an additional process step, namely scattering.

[0059] In the extruder 2, the first plastic 12 is molten and extruded from the extruder die 3, and fed to the subsequently arranged calendar assembly 5, 6, 7. The calendar assembly 5, 6, 7 has such a design that the plastic melt 1 can be laid down horizontally on the first calendar roll 5 of the calendar.

[0060] A scattering device 4 with a round template 10 is provided as a part of the application and/or scattering device 4, wherein a rotary template scatterer 4 is used in this Example. Using this scattering device 4 with the round template 10, a second plastic material 8 is applied to said flowable plastic melt 1 having a defined design. The second plastic material 8 is preferably the same as the first plastic material 12, but with a different color, so that a two-color design is obtained.

[0061] The second plastic material 8 can be in the form of granules, a powder, grit or mixture of particles, so that it is scatterable or free flowing. Thus, a pattern can be applied to the first plastic material 12, whereby an at least two-color design is ultimately formed. The second plastic material 8 in the form of a scattering material preferably has particle sizes within the range of the later sheet thickness. Particular designs in which the coloring is larger than the particle size must be prepared from several particles, which is realized by a corresponding template. With smaller particles, a superficial penetration into the flowable plastic melt 1 is only possible, which results in only partial rather than complete coloring of the produced plastic sheet with the design 1, however. In contrast, particles of the second plastic material 8 that are too large are deformed during a calibrating step to be performed subsequently, and could change the design adversely.

[0062] It may be noted here that it is also possible to achieve three- or four-color as well as multi-color designs by applying an additional third or further plastic materials, in which the scattering processes can be performed by means of one application and/or scattering device 4, but also by means of several ones arranged one behind another.

[0063] Further, a closed feeding tube 9 with an integrated conveying screw can be provided for embodying the application and/or scattering device 4, wherein the second plastic material 8 is transported axially into the round template 10. On the lower side of the feeding tube 9, there are adjustable outlet openings for the second plastic material 8, so that a defined uniform and continuous flow of material to a double doctor knife assembly 11 mounted on the bottom side can be ensured thereby. Said double doctor knife assembly 11 coats the second plastic material 8 from inside through the openings of the template 10, being precisely applied to the plastic melt 1 passing by below in accordance with the template pattern.

[0064] After the second plastic material 8 has been applied to the plastic melt 1 consisting of the first plastic material 12, a thickness calibration is performed through the calendar assembly 5, 6, 7 with the two further rolls 6 and 7, so that a defined plastic sheet 1 is formed. In these rolls 5, 6, 7, the second plastic material 8 scattered on in a powder form is virtually pressed into the plastic melt 1, melting together with this 1 to form a strong bonding between the first 12 and second 8 plastic materials. The plastic melt 1 provided with a differently colored powdered scattering material 8 is calendared to the desired thickness, wherein particles of the powdered scattering material 8 having dimensions larger than the sheet thickness are pressed to the sheet thickness and are not elongated, or only slightly so, depending on their size. Finally, the plastic melt 1 with the design is cooled down and drawn off as a plastic sheet 1 with a design.

[0065] FIG. 2 shows a detailed side view of the scattering device within the disclosed plastic sheet production assembly according to FIG. 1.

[0066] FIG. 3 shows a schematic second Example of the disclosed plastic sheet production assembly.

[0067] In this variant embodiment, a transport belt assembly 13 is arranged between the extruder die 3 designed as a slot die, on which the sheet is laid down at first after extruding and subsequently supplied to the scattering device 4.

[0068] FIG. 4 shows a polished transverse section of a plastic sheet with a design 1 as produced by the disclosed process. The produced plastic sheet 1 consists of a first plastic material 12 and a second plastic material 8 applied through a defined pattern design, which are molten together and thus form the plastic sheet 1 having a two-color design.

[0069] It is clearly seen that a sheet with a design having coloring until a certain depth was produced as the final product, so that this produced sheet is very resistant against abrasion, because the design was applied not only superficially.

[0070] The following is a description of the invention in a supplementary, but not limiting way by means of a concrete Example including the two Figures explained above:

[0071] An LLDPE-based TPO is used as the base material. The material has a light gray coloring and forms the first plastic material 12. The same material, but with a black coloring, is ground into a powder and thus forms the second plastic material 8. A sieve fraction with an average diameter of 0.8 mm is used.

[0072] Twenty-five percent of the total mass of the finished plastic sheet 1 is scattered thereon as a powder in the form of the second plastic material 8. Ovals having dimensions of 3 mm6 mm in the main directions were selected as the design. The calendar gap is adjusted to a value of 0.45 mm. The draw-off speed of the sheet is 4 m/min.

[0073] The powder, i.e., the second plastic material 8, is not completely pressed into the base material, i.e., the first plastic material 12, so that some roughness is formed in contrast to the non-scattered surface, which results in a significant reduction of the slipping properties, ultimately bringing about considerable and obvious advantages when used, for example, as a floor covering for a vehicle.

[0074] The material was further processed into a floor covering for a vehicle, and in examination relating to abrasion, it could be found that the surface looks exactly as it did at the start after 1000 revolutions in a Taber test, while the printed patterns have lost their colors already after 500 revolutions.

LIST OF REFERENCE SYMBOLS

[0075] 1 plastic sheet/plastic melt

[0076] 1 plastic sheet with design

[0077] 2 extruder

[0078] 3 extruder die

[0079] 4 scattering means

[0080] 5 first calendar roll

[0081] 6 second calendar roll

[0082] 7 third calendar roll

[0083] 8 second plastic material

[0084] 9 feeding tube/supply

[0085] 10 round template

[0086] 11 doctor knife/double doctor knife

[0087] 12 first plastic material

[0088] 13 transport belt assembly