Method for manufacturing a decorative part

Abstract

The invention relates to a method for producing a decorative element in which a decorative layer is arranged on a visible side of a substrate and the decorative layer is provided with a visible-side coating. In the method according to the invention, lumpy decorative material is provided for producing the decorative layer, which is applied to a flat substrate.

Description

[0001] The invention relates to a method for producing a decorative part, in which a decorative layer is arranged on a visible side of a carrier and the decorative layer is provided with a visible-side coating.

[0002] Decorative parts, such as those used particularly in the interiors of motor vehicles, are molded parts that typically comprise a carrier and a decorative layer applied to the carrier. The decorative layer is arranged on the side of the decorative part, and thus of the carrier, facing the user, thus forming the so-called visible side of the decorative part. The opposite side of the decorative part is formed by the carrier and can be referred to as the mounting side. The carrier provides the decorative part with the necessary dimensional stability and is generally intended for fastening the decorative part.

[0003] Decorative parts must meet high standards regarding their visual and tactile quality, as well as dimensional accuracy and resistance to environmental influences. For this purpose, the decorative layer is typically coated with a protective transparent top layer.

[0004] A method for producing a decorative part with a transparent cover layer is disclosed, for example, in EP 2 298 528 A1. Here, a decorative layer is laminated with a transparent film on its visible side and with a barrier layer on its mounting side. The laminated decorative layer is formed into a preform, which is subsequently overmolded with a transparent plastic to form the cover layer and back-injected with a supporting plastic to form the carrier. The result is a decorative part in which a transparent film is arranged between the cover layer and the decorative layer, and in which a barrier layer is arranged between the carrier and the decorative layer.

[0005] The present invention aims to provide a method for producing a decorative part that enables a new design and statement for the decorative part. The method is intended to be particularly suitable for the production of interior trim parts for motor vehicles and thus suitable for mass production with essentially consistent quality of the decorative part.

[0006] In view of this, the present invention proposes a method for producing a decorative part in which, in addition to the generally usual steps, a piece-like decorative material is provided and the piece-like decorative material is applied to a flat substrate.

[0007] The flat substrate can be single- or multi-colored, transparent, or translucent. The flat substrate can contribute to the design effect on its own, or it can simply serve as a support for the piece in the decorative material for attachment to the substrate, or it can partially form the substrate itself.

[0008] The carrier of the decorative part is preferably made of plastic in a conventional manner and serves for handling and, usually, also for mounting the decorative part in the vehicle. The carrier typically has fastening elements on its mounting side for locking, gluing, or otherwise connecting the decorative part to the vehicle's chassis.

[0009] The substrate can be adhesive or have an adhesive coating, so that the decorative material adheres to the substrate. The substrate can be a nonwoven, a hot melt adhesive, a plastic film, or even a finished part, particularly made of plastic. The substrate can be formed integrally with the carrier.

[0010] The substrate can be made of a synthetic or natural material. A plastic is a synthetic material in this sense. A mineral component can be a natural material that forms the substrate or is comprised by it.

[0011] The pieced decorative material can be colored, and if necessary, it can be colored or brightly colored.

[0012] The decorative lump material can be metallic or synthetic. The decorative lump material can be produced as a powder by machining, atomizing, crushing, or grinding, or in some other way. The decorative lump material can include chips or glitter.

[0013] The lumpy decorative material is particularly preferably a natural material. This results in an aesthetic appearance on the visible side of the decorative part that is determined by the natural properties of the lumpy decorative material. A natural material offers the advantage of a not completely uniform surface design and / or coloring. These differences in the individual pieces or fractions of the lumpy decorative material are preferably used to create an individual aesthetic appearance on the side of the decorative part. The use of natural materials leads to the appearance of a rather arbitrary design. The natural lumpy material can be selected from the group comprising mineral lumpy decorative material or organic lumpy decorative material. These materials can also be used in combination to produce the decorative part. Slate or mica are particularly suitable as mineral lumpy materials.Eggshell, mother-of-pearl, or tortoiseshell are preferred organic lumpy materials. Natural materials can also be color-modified through pigmentation, for example, by spraying or dipping, or through a chemical process. Typically, the surface of the lumpy decorative material is modified only to the extent that the natural inhomogeneity of the lumpy decorative material remains recognizable.

[0014] According to the present invention, a lumpy decorative material is understood to mean in particular a decorative material with a particle size of between 0.1 and 50 mm, preferably between 2 and 25 mm, particularly preferably between 0.25 and 10 mm.

[0015] According to a preferred embodiment of the present invention, the provision of particulate decorative material comprises cleaning and / or fractionating the particulate decorative material. The cleaning can be carried out with the aim of removing unstable organic residual components of the starting material. The cleaning can involve chemical cleaning or modification. If the cleaning is carried out in liquid form, the cleaning process step usually also includes a drying step. The drying or cleaning can take place before or after fractionating. Fractionating can be carried out by sieving or sifting. The desired particle size or particle size distribution can also be adjusted by comminuting the particulate material.

[0016] It is understood that the lumpy material can initially be provided in fractions of different particle size and / or color, material or other properties of the decorative material and that the different fractions can be mixed or combined individually in surface areas that can lie next to each other on the decorative part.

[0017] Preferably, the decorative material is applied to the substrate in a predetermined pattern. This pattern can consist of and be formed by a single decorative material. Different particle fractions can also be mixed in a pattern. The pattern can also consist of different decorative materials.

[0018] Application can be done by hand or with a squeegee. The pieced material can be bonded to the substrate on its own or can be contained in a suspension containing the pieced decorative material and a carrier liquid. The liquid can simply be a carrier for the application of the pieced decorative material and can evaporate or dry. The liquid in the suspension can also contribute to the design on its own and can, in particular, be colored, translucent or transparent, or crystal clear, so that, for example, the visible side of the carrier can be seen through or next to the individual particles of the pieced material on the visible side, and the aesthetic appearance of the decorative part is determined by the material and / or surface quality of the carrier.

[0019] The lumpy material can be applied to the substrate by singulation using a frequency, for example, a vibrating table. The substrate can also be a medium-permeable substrate, such as a nonwoven or a perforated substrate made of a material that is inherently impermeable to medium. Suction pressure can act through the substrate, drawing the lumpy decorative material toward the substrate and holding it there or at least temporarily bonding it to it, for example, by adhering to an adhesive or adhesive-coated substrate.

[0020] It goes without saying that, for example, a predetermined suction pattern can be created on the side opposite the decorative material, either by appropriate temporal and / or spatial distribution of negative pressure areas on the surface of the substrate or by a perforated diaphragm or the like. In the latter case, the application of suction pressure does not result in the substrate being coated with the pieced decorative material over the entire surface of the substrate. Rather, the substrate is only provided with the pieced decorative material where the suction pressure is acting. This allows a pattern to be created from the pieced decorative material. It goes without saying that the suction pattern on the side opposite the pieced material can be created differently at different stations in a continuous substrate treatment line. At each of the stations, a different decorative material can be bonded to the substrate.This can also result in a corresponding pattern.

[0021] For similar reasons, a template can be provided during the application of the decorative material, for example, by sprinkling or the like, through which a pattern of the lumpy decorative material is applied in a predetermined manner. The template can have recesses in the desired design through which the lumpy material is applied to the substrate.

[0022] According to a preferred embodiment of the present invention, the particulate decorative material is applied to the substrate such that the decorative layer is formed on the visible side by the particulate material and the substrate, and / or the aesthetic design is also determined by a visible surface of the carrier. As previously mentioned, the substrate or carrier can be transparent or translucent. The substrate can also be implemented unevenly together with the decorative material, so that parts of the carrier are exposed on the visible side, while others are completely covered and / or masked by the particulate decorative material and / or the substrate.

[0023] This can be done in various ways. For example, nonwoven fabric or paper can be coated with a varnish, glue, or powder coating. The decorative material in the form of particles or flakes is sprinkled or sprayed onto this flat carrier while the glue, varnish, or adhesive powder coating is not yet cured. As the material hardens, the particles or flakes are bonded to the carrier, or at least fixed to it. During the hardening process, the various layers can be laminated in a press under heat and pressure to arrange the particles in a plane. The decorative layer with the desired dimensions for the decorative part can be created from a corresponding flat layer by punching. This decorative layer can then be back-injected on the back and given a coat of varnish on the visible side, which can also be applied by injection molding.To make the injection-molded substrate visible, the particles of the decorative material can be applied to a transparent or translucent film coated with an adhesive, such as a resin, to fix the particles in a continuum. This film can be back-injected with the substrate or glued to a substrate. The visible side can then be coated with an opaque varnish.

[0024] The particles of the particulate decorative material can be applied to a carrier, particularly one of the type mentioned above, and fixed in the injection mold via this carrier in such a way that the particles of the decorative material are arranged between the carrier and the mold cavity. After back-injection molding to embed the particles, the carrier can be removed. A cover layer can then be applied to the visible side. The carrier can be three-dimensionally structured in order to arrange the particles in the carrier with a profile transverse to the planar extent of the decorative part. After the visible side is coated with a transparent or translucent layer, this results in an enhanced optical depth effect.

[0025] Alternatively, the particles of the decorative material can be embedded in or mixed with a liquid matrix of a curing, possibly translucent or transparent material. This suspension is formed or drawn out into a flat layer using a squeegee, for example, and possibly applied to a film for handling purposes, which can be removed again during subsequent production steps. After the matrix has cured and, if necessary, cut to the appropriate size, the decorative layer is back-injected or over-injected.

[0026] With a view to increasing design possibilities and also for better support, particularly of a relatively brittle decorative material through embedding and with a view to the conventional injection-molded coating of the visible side with the coating, a preferred embodiment of the present invention proposes to at least partially incorporate the decorative material into the substrate or to introduce a paste between the pieced decorative material. In this case, surface portions of the substrate or the paste can be located at the level of the visible surface of the pieced decorative material. The pieced decorative material then protrudes less from the substrate than if the pieced decorative material were merely applied to the substrate.The decorative material can also be introduced into the substrate during injection molding, for example, if the decorative material is regularly mixed with a small cone size of no more than 1 mm with the plastic granules fed into the injection molding machine, either beforehand or during introduction into the injection molding machine. This melt, containing the decorative material, is injection molded to produce the carrier, which can then form the decorative part itself. This part can be placed into another injection mold if necessary and overmolded with plastic material on the back or visible side to create a carrier or a visible coating.

[0027] Alternatively, in two-component injection molding, a plastic carrier can first be formed, which, after being transferred to another mold cavity, is overmolded with the melt containing the lumpy decorative material. This part can also be placed in another injection mold, if necessary, and overmolded with plastic material on the visible side to create the carrier or the transparent or translucent visible coating.

[0028] The high pressure exerted during injection molding enhances the appearance of a flat surface formed by a multitude of individual particles of the lumpy decorative material. The visible coating, which is usually a plastic applied by injection molding, protects the resulting decorative surface from environmental influences and achieves a smooth, technical-looking surface finish.

[0029] To increase the impression of a continuum, a preferred development of the present invention proposes comminuting the pieced decorative material during application to the substrate, in particular breaking the pieced decorative material when pressed against the substrate. For example, the flat substrate and the pieced decorative material can be bonded to one another in a continuous process in which both are moved in a uniform direction of movement, while the decorative material is moved on a carrier such as a conveyor belt and the substrate is brought increasingly closer to the decorative material and finally pressed against it. In this process, a fragile decorative material can break, whereby the particles that initially form a larger piece remain in close proximity due to the bonding with the substrate and thus cover a fairly large area of ​​the substrate.

[0030] It goes without saying that after application to the substrate, the lumpy material can be painted and / or sanded with the substrate, if desired. After sanding, the sanded surface is typically cleaned. Sanding particles or sanding dust can be removed by blowing or washing.

[0031] The following describes, by way of example, the production of a decorative part whose decorative layer comprises eggshells.

[0032] The eggshells are cleaned either as particles or in eggshell halves with a chlorine-water mixture for a specific period of time. This dissolves surface dirt and the inner egg membrane. The eggshells are then dried.

[0033] In the next step, the dried eggshells are crushed. The various particle size fractions are then sieved into specific particle size classes.

[0034] The eggshells are placed on the matrix or embedded within a matrix. The eggshells are evenly applied to the matrix by scattering. The eggshells are applied to the matrix either by hand, with a doctor blade, or by singulation using a frequency. The matrix is ​​bonded to the eggshells under pressure and temperature.

[0035] The resulting matrix, coated with eggshells, is placed in a mold and back-injected with a plastic material to form the carrier. The resulting semi-finished product is transferred to another injection mold and overmolded with a lacquer to create a visible coating. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 2 298 528 A1

[0004]

Claims

[1] Method for producing a decorative part in which a decorative layer is arranged on a visible side of a carrier and the decorative layer is provided with a visible-side coating, characterized by that the production of the decorative layer comprises the steps of: providing pieced decorative material and applying the pieced decorative material to a flat substrate. [2] Method according to claim 1, characterized by that the lumpy decorative material is a natural material selected from the group comprising mineral lumpy decorative material, in particular slate or mica, and organic lumpy decorative material, in particular eggshell, mother-of-pearl or tortoiseshell. [3] Method according to claim 1 or 2, characterized by that the lumpy decorative material has a particle size of between 0.1 and 50 mm. [4] Method according to one of the preceding claims, characterized bythat the provision of lumpy decorative material comprises cleaning and / or fractionating and / or crushing the lumpy decorative material. [5] Method according to one of the preceding claims, characterized by that the pieced decorative material is applied to the substrate in a predetermined pattern of a single pieced decorative material or a pattern of different pieced decorative materials. [6] Method according to one of the preceding claims, characterized by that the piece-like decorative material is applied to the substrate by a suction pressure acting through the substrate on the side opposite the decorative material. [7] Method according to one of the preceding claims, characterized by that the piece-shaped decorative material is applied to the substrate in such a way that the decorative layer is formed on the visible side by the piece-shaped decorative material and the substrate and / or the carrier. [8] Method according to one of the preceding claims, characterized by that the piece-like decorative material is at least partially introduced into the substrate and / or a paste is introduced between the piece-like decorative material. [9] Method according to one of the preceding claims, characterized by that the lumpy decorative material is crushed when applied to the substrate, in particular when pressed against the substrate. [10] Method according to one of the preceding claims, characterized by that the pieced decorative material is painted and / or sanded after application to the substrate.