METHOD FOR APPLYING A PATTERN TO A BODY

Description

[0001] Method for transferring a pattern onto a body. The invention relates to a method for transferring at least one pattern onto a body according to the type defined in more detail in the preamble of claim 1. Polymethyl methacrylate (PMMA), also known as acrylic glass and marketed under the brand name Plexiglas® by Röhm GmbH, is a transparent thermoplastic and is used to manufacture a wide variety of objects and items. PMMA is used, for example, in the automotive industry for the production of transparent cover elements, components of lamps and windows, in construction as glazing, in the semiconductor industry as photoresist, in model and prototype construction as a substitute for mineral glass, in shipbuilding as submarine pressure hulls, in household goods, in horticulture, in art, and the like.To manufacture a PMMA component, the appropriate raw materials are mixed in liquid form and then hardened under heat and pressure through a polymerization process. Such a component can be shaped under the influence of heat and pressure to adapt its form to customer requirements and its intended use.

[0002] The intended use of a PMMA object may require that at least part of its surface be patterned. Such a pattern can serve a technical purpose, such as collecting and diffusely scattering incident light to create a uniform light distribution, or it can be purely aesthetic. Other reasons for applying a pattern to an object include adding text, symbols, or instructions, such as a hazard warning symbol with explanatory text on a warning sign.

[0003] To transfer patterns onto these objects, the objects are typically chemically, thermally, and / or mechanically processed after their manufacture. For example, a surface can be etched, laser-engraved, or machined. Paints and varnishes can also be applied to imprint a pattern onto an object. However, a disadvantage of this method is that an additional processing step is required after the object has been manufactured.

[0004] WO 2011 / 000636 A1 discloses a light guide plate with embedded defects and a corresponding method for its manufacture. The light guide plate can comprise or consist entirely of PMMA. At least part of the surface of the light guide plate is provided with optical defects that serve to selectively scatter light. For this purpose, a printed film is bonded to the light guide plate during extrusion or casting, with the printed film positioned between the light guide plate and the film. The printed film remains on the light guide plate. According to the publication, the printed film is also made of PMMA.

[0005] A method for manufacturing a composite component is known from DE 10 2019 213 905 A1. Before the polymer matrix material cures, the composite component is provided with a peel ply. After the polymer matrix material has cured, the peel ply is removed from the composite component to create increased surface roughness. A coating is then applied to the roughened surface area of ​​the composite component using a thermal spraying process. The use of peel ply in the manufacture of composite components is well known and allows for the creation of surface areas that can be coated or painted with exceptional reliability. Furthermore, during intermediate storage of the composite component, the peel ply protects its surface from contamination or damage.Furthermore, EP 2 489 499 A1 discloses a fiber composite component which is bonded to a film to create an optically appealing surface. For this purpose, the fiber composite component is placed in one half of an injection molding tool, and the corresponding, optionally structured, film is placed in the other half of the injection mold in such a way that, when the injection mold is closed, a gap is formed between the film and a wall area of ​​the fiber composite component. This gap is filled with an adhesive to bond the film and the fiber composite component. The film also remains attached to the component in this process.

[0006] CN 114 867 58 A discloses a method comprising the features summarized in the preamble of claim 1. Reference is also made to US 10 118 315 B1.

[0007] The present invention is based on the objective of providing an improved method for transferring patterns onto bodies, which allows the transfer of patterns onto bodies with a comparatively low workload, is cost-effective and easy to use.

[0008] According to the invention, this problem is solved by a method for transferring at least one pattern onto a body having the features of claim 1.

[0009] In a method for transferring at least one pattern onto a body, also referred to here as a structural body, the surface of the body is at least partially structured for transferring the pattern, wherein the following method steps are carried out according to the invention: Providing a contour body or contour material, both of which have a negative contour corresponding to the pattern to be produced; applying a flowable and curable substance to at least a section of the contour body or contour material; curing the substance to produce the structural body; and separating the structural body and the contouring material.

[0010] The substance is either a pure substance or a mixture of substances. To produce the body and transfer the pattern onto its surface, it is sufficient to wet the contour body or contour material with the flowable substance, which is in a liquid, pasty, or slurry-like state, and to separate the two again after the hardening process.

[0011] The process can be repeated iteratively to create a layered structure. In this way, another layer of the substance is applied to the created body.

[0012] The method according to the invention provides for the following additional process steps: Providing a mold; placing the contour body or contour material into the mold; filling the mold with the flowable and curable substance before and / or after the contour body or contour material is / has been placed into the mold; removing at least the structural body from the mold.

[0013] The method according to the invention thus provides for the creation of the pattern to be produced on the body in a single step during the curing process using the contour body or contour material. By transferring the pattern onto the body during its production, additional surface finishing steps after the body's manufacture are eliminated, thereby reducing the labor and costs associated with producing the patterned body. The contour bodies or contour material transfer a kind of "structure" onto the surface of the body created by the curing process.

[0014] By using a mold, the structural body can be produced in a desired shape.

[0015] Films of varying thicknesses and hardnesses are used as contour-defining bodies or materials, and these contour-defining bodies or materials can be, for example, films made of different materials or consist of films with additional silicone-like substances.

[0016] The properties of these contour materials must compensate for any shrinkage parameters of the casting material, as otherwise stresses can be introduced into the casting material and ultimately lead to fracture of the structural element. They should also be relatively inert, resistant to bases, alcohols, and nonpolar solvents, and exhibit a low coefficient of friction. Such low coefficients of friction reliably prevent the material curing in the mold from adhering to the contour elements or materials, as well as to the mold itself.

[0017] Various methods can be used to contour the shapes or materials. These may have undergone suitable chemical, thermal, and / or mechanical treatment. For example, these shapes or materials may be etched, engraved, stamped, pressed, embossed, deep-drawn, crumpled, or similar processes.

[0018] According to a further advantageous embodiment of the process, the substance hardens through: an increase in temperature; a decrease in temperature; a chemical reaction; and / or drying.

[0019] Thus, various mechanisms are possible for converting the still-flowable substance into a solid state. This allows the use of a wide variety of pure substances or mixtures of substances for the production of the structural body.

[0020] The method according to the invention provides that the contour bodies or materials are fixed in the mold before the substance is poured in. This prevents slippage in the mold during the pouring process. This allows the desired pattern to be transferred particularly reliably to the body produced by curing, so that after demolding, the corresponding pattern is present in the intended surface area of ​​the body. Various methods can be used for fixing in the mold, for example, attaching the contour bodies or materials using form-fit, force-fit, and / or material-fit fasteners such as hooks, screws, eyelets and cords, adhesives, hook and loop fasteners, and the like.

[0021] According to a further advantageous embodiment of the process, the substance hardens through a polymerization process, forming a thermoplastic polymer, in particular polymethyl methacrylate (PMMA). Plastics and resins allow the production of materials with a wide variety of physical properties. The thermoplastic polymer preferably used is... PMMA used. The substance, that is, the one used to manufacture PMMA Various additives such as inorganic and / or organic color pigments, activators or the like can be added to the starting materials used in order to specifically adjust the physical properties of the structural body to be produced to meet customer requirements.

[0022] A further advantageous embodiment of the method according to the invention provides that the substance is heated during curing. The substance can be actively heated externally, for example by heating elements placed in the mold. However, the substance can also be heated internally during curing, for example due to an exothermic polymerization process. Additionally or alternatively, during the curing process, increased pressure relative to the surroundings can be exerted on the substance in the mold, or the casting process can be carried out under a (partial) vacuum.

[0023] According to a further advantageous embodiment of the method, a mold sealed from the environment is used, which is opened for inserting the contoured bodies or materials and for removing at least the structural body. Using a mold sealed from the environment reliably prevents the introduction of dirt particles and foreign matter during the curing process. Consequently, the body has few to no defects, thereby increasing its physical properties, particularly its mechanical strength. Furthermore, the use of a sealed mold allows the body to be formed into virtually any desired three-dimensional shape.

[0024] Preferably, during curing, the contour bodies or materials transfer a pattern onto the structural body such that the differences between the protrusions extending away from the body and the valleys extending into the structural body of the structured surface area are less than 100 mm, preferably less than 10 mm, particularly preferably less than 1 mm, and especially less than 0.1 mm. Using the method according to the invention, it is thus possible to transfer a wide variety of patterns onto a corresponding body. The pattern can have any extent on the surface of the structural body to be produced during the casting process. The entire surface of the body can be provided with the pattern, or only parts thereof. The difference between the protrusions and valleys of the pattern can preferably be in the range of 100 mm to 0.1 mm.The surface of the object can therefore be textured with waves, dents, cracks, grooves, and the like. The patterned surface areas can also be roughened by creating a particularly small difference between the raised and lowered areas. Thus, there are virtually no limits to the design possibilities for transferring patterns onto the object.

[0025] In a casting setup, the mold can be a single piece or multi-part, and can be open to the environment or closed. The mold forms the mold cavity.

[0026] Further advantageous embodiments of the inventive method for transferring patterns onto bodies will become apparent from the examples which are described in more detail below with reference to the figures.

[0027] This shows: Figure 1 is a schematic sectional view through a casting arrangement according to the invention for producing a patterned body according to the invention; Figure 2 is a schematic sectional view through the patterned surface area of ​​the body in an enlarged view; Figure 3 is a first embodiment of a body according to the invention; and Figure 4 is a second embodiment of a body according to the invention. Figure 5 is a countertop display showing a model of a third embodiment, namely a contoured body according to the invention that represents a climbing wall with holds and serves as counter lighting.

[0028] Figure 1Figure 1 shows a sectional view through a casting arrangement 9 according to the invention, comprising a mold 4 divided into an upper mold cavity 4.1 and a lower mold cavity 4.2, and a contour body or material 5 inserted into the mold 4. The mold 4 has an opening 10 for filling with a flowable and curable substance 6. The mold 4 can be open to the environment or, as shown in Figure 1, enclosed within a mold cavity 4.2. Figure 1 The depicted components are designed to be sealed off from the environment. Substance 6 is preferably a mixture of the starting materials for the production of PMMA. However, other casting resins can also be used.

[0029] The substance 6 hardens in the mold 4, resulting in a solid body 2 as shown in the following figures.

[0030] During the curing process in the mold 4, a pattern 1, also shown in the following figures, is transferred to the substance 6 by means of the contour body or the materials 5. This pattern 1 can also be referred to as a "structure" or compared to one.

[0031] The contour body or contour material 5 consists of film of varying thicknesses and hardnesses. The contour body or contour material 5 can be made of film of different materials or of films with added silicone-like substances.

[0032] The contour body or contour material has a contour that corresponds as a negative to the pattern 1 to be generated. This transfers the corresponding "structure" to body 2.

[0033] Figure 2Figure 1 shows an enlarged cross-sectional view through pattern 1. A maximum difference ΔX can be seen between the elevations 7 extending away from body 2 and the valleys 8 extending into body 2. This maximum difference ΔX is preferably in the order of 100 mm to 0.1 mm.

[0034] The pattern 1 can extend over the entire surface 3 of the body 2 or cover only a surface area of ​​the body 2. In particular, different patterns 1 are applied to different sides of the body 2.

[0035] Figure 3Figure 1 shows a first embodiment of body 2 as an emergency exit sign. The pattern 1 consists of a left-pointing arrow and the words "Emergency Exit". Light can be coupled into body 2 via a mounting plate 11. The light can be diffused by pattern 1 for improved legibility and visibility.

[0036] Figure 4 Figure 2 shows a second embodiment of the body 2 according to the invention as a room divider. The figure shown in Figure 4 The body 2 shown has differently designed patterns 1 on different sides. For example, individual surface areas of the room divider may have a wave pattern, a sawtooth pattern, or be roughened. Reference symbol list

[0037] 1 Pattern 2 Structural body 3 Surface 4 Mold 4.1 Upper mold cavity 4.2 Lower mold cavity 5 Contour body or structural material 6 Substance 7 Elevation 8 Valley 9 Pouring arrangement 10 Opening 11 Mounting plate ΔX Maximum difference

Claims

1. Method for transferring at least one pattern (1) onto a structured body (2), wherein the surface (3) of the structured body (2) is at least partially structured to transfer the pattern (1), comprising the following method steps: - providing a contour body or contour material (5), which has a contour or structure corresponding to the pattern (1) to be generated; - applying a free-flowing and curable substance (6) to at least one section of the contour body or contour material (5); - curing the substance (6) to create the structured body (2); and - separating structured body (2) and contour body or contour material (5); - producing a casting mold (4); - introducing the contour body or contour material (5) into the casting mold (4); - filling the casting mold (4) with the free-flowing incurable substance (6), before and / or after the contour body for the contour material (5) is / was introduced into the casting mold (4); - removing at least the structured body (2) from the casting mold (4); characterized in that the contour body or the contour material (5) is fixed in the casting mold (4) before the filling of the substance (6), and films of different thicknesses and hardnesses are used as the contour body or contour material (5).

2. Method as claimed in claim 1, characterized in that the substance (6) cures due to: - a temperature increase; - a temperature decrease; - a chemical reaction; and / or - drying.

3. Method as claimed in either one of claims 1 or 2, characterized in that the substance (6) cures due to a polymerization procedure and forms a thermoplastic, such as PMMA.

4. Method as claimed in any one of claims 1 to 3, characterized in that a casting mold (4) enclosed off from the surroundings is used, which is opened to insert the contour body or contour material (5) and to remove at least the structured body (2).

5. Method as claimed in any one of claims 1 to 4, characterized in that a pattern is transferred to the structured body (2) during the curing by the contour body or the contour material (5) such that the differences between protrusions (7) extending away from the structured body (2) and valleys (8) of the structured surface area extending into the structured body (2) are less than 100 mm, preferably less than 10 mm, particularly preferably less than 1 mm, and in particular less than 0.1 mm.