EP0850785A1 - Process for decorating a composite article such as a ski, surfboard, skateboard or cycle component - Google Patents

Abstract

This is a new method decorating composites. A decorated complex is assembled with a reinforcing structure. This is based on a resin flowing under heat in a later cycle of hot pressing. There are at least two stages to the process. During the first, the decoration is transferred using the ink sublimation printing onto the first face (100) of a layer of transparent or translucent plastic material (1). In the second, novel stage a collage film (3) is adhered under heat and pressure to the assembly, onto the first face (100). This comprises a contrasting metal or metal alloy sheet (5). A mesh (4) may be placed between the contrast sheet (5) and the first face (100). Preferred materials of construction include aluminium and ionomeric polyolefin. Glass fibre reinforcement is included.

Description

The invention relates to a new method of decorating a composite article. It relates more particularly to articles in the form of laminates grouping together different plastic and composite materials such as skis in general, surfboards, skateboards, some components for cycle and other similar objects.

Sublimation is a technique well suited for decoration of skis. It allows to use many different plastic supports and print patterns any without the need to submit the support to a preliminary specific preparation operation. The transfer principle consists in evaporating inks contained on a backing paper in the form of dry extracts by application of heat and pressure against the support to decorate. The process is clean, fast and without emanation from harmful vapors or solvents.

The decorated support obtained can be secured to a contrast sheet with a bonding film to form a complex intended to be assembled with a reinforcing structure of an article based on hot-melt resin during a cycle hot pressing.

A method using this technique is described in the unpublished French application n ° 95 13758. It consists of transfer a decoration using the printing method sublimable ink (s) on a first face of a layer of transparent or translucent plastic, then stick to hot and pressurized on the first side thus decorated a contrast sheet.

This process is effective and makes it possible to obtain a complex whose decoration is regular and well defined.

To obtain the article in the finished state, the complex is hot pressed on the reinforcement structure at a temperature and at higher pressure than the temperature and the pressure necessary for the realization of the complex. In the case where the contrast sheet is a layer of dry fiber natural or synthetic, the creep of the bonding film is avoided because the dry fiber absorbs part of the material thermoplastic in fusion due to its porosity. The decoration of the complex remains well defined.

However, in cases where the contrast sheet is made of non-absorbent material, such as metal or alloy metallic, absorption of thermoplastic material is not don't. It follows that the collage film flows. Creep results in displacements of particles of matter constituting the collage film, in any direction substantially parallel to the contrast sheet of the complex. Thus the collage film deforms randomly, and the inks, which migrated into the film due to the elevations of temperature and pressure required for bonding, move with the creep of the film. It follows that the quality decoration is reduced because its definition is altered.

The object of the invention is to remedy the above drawbacks clarified.

To do this, the invention proposes a method of decoration of a composite article including preparation of a complex decorated to be assembled with a structure of reinforcement of the article based on hot-melt resin during of a subsequent hot pressing cycle, the process comprising at least two cycles, a first cycle during from which the decoration is transferred by the method printing sublimable ink (s) on the first side a transparent or translucent plastic layer, and a second cycle.

The method according to the invention is characterized in that proceeds in the second cycle by means of a bonding film to hot assembly and pressure on the first side thus decorated, with a contrast sheet of selected material among the group consisting of metals or alloys metallic, and in that, in a step prior to assembling the contrast sheet on the first side, there is a lattice between the contrast sheet and the first side. It follows that the creep of the bonding film is avoided during the hot pressing cycle, and that the inks remain in their place because the material of the film collage is trapped in the mesh of the trellis. The advantage is that the quality of the decoration is good because its definition is stable.

The method according to the invention is also characterized in what the contrast sheet is an aluminum sheet not anodized covered on each side with a film of ionomer type olefin copolymer.

The film acts as a bonding interface and makes aluminum compatible with bonding with most substrates with which it is intended to adhere. She serves also protective against oxidation of the leaf aluminum during storage.

The method according to the invention is further characterized in that that we have a textile tablecloth based on non-woven fibers in contact with the contrast sheet on the side of the contrast opposite to the side in contact with which the trellis. The textile tablecloth based on non-woven fibers attenuates the deformations of the contrast sheet linked to the presence of the trellis.

The method according to the invention is also characterized in a bonding film is placed between the sheet of contrast and the textile tablecloth based on non-woven fibers. The film allows better adhesion between the sheet of contrast and the textile tablecloth.

The process according to the invention is further characterized by the makes the trellis an arrangement of cords in glass fibers forming a grid with square openings. A such a trellis structure is easy to manufacture.

The method according to the invention is finally characterized in that that the transparent plastic layer or translucent, the first collage film, the trellis, the contrast sheet, second collage film, and tablecloth textile based on non-woven fibers, are joined together in one operation. The manufacturing is therefore fast and costs are minimized.

The invention also relates to a complex of decoration intended to be assembled with a structure of reinforcement based on a hot-melt remainder of an article composite, said complex comprising a layer of material transparent plastic with a first side decorated obtained by the printing method of sublimable ink (s), characterized by the fact that a contrast sheet which covers the first side with the transparent plastic layer is assembled on the face of the plastic layer by means of a collage film, in that the contrast sheet is chosen among the group consisting of metals or alloys metal, and in that a trellis is arranged between the contrast sheet and the first side in one step prior to assembling the contrast sheet on the internal face.

The complex according to the invention is also characterized by the fact that a textile sheet based on non-woven fibers is arranged in contact with the contrast sheet on the side of the contrast sheet opposite the side in contact with which finds the trellis, and by the fact that a bonding film is placed between the contrast sheet and the textile sheet to base of nonwoven fibers.

The invention relates, finally, to a composite article of the ski or snowboard type with a decoration complex previously described.

• la figure 1 montre le premier cycle de transfert par sublimation du procédé selon l'invention ;
• la figure 2 montre le second cycle d'assemblage à chaud et sous pression du procédé de l'invention ;
• la figure 3 est une coupe du complexe obtenu selon l'invention ;
• la figure 4 est une coupe schématique d'un ski recouvert du complexe de l'invention ;
• la figure 5 est un schéma en perspective éclatée du complexe selon l'invention.

Other characteristics and advantages of the invention will be better understood with the aid of the description which follows, with reference to the appended drawing illustrating, by a nonlimiting example, how the invention can be implemented, and in which:

• Figure 1 shows the first sublimation transfer cycle of the method according to the invention;
• FIG. 2 shows the second hot and pressurized assembly cycle of the process of the invention;
• Figure 3 is a section of the complex obtained according to the invention;
• Figure 4 is a schematic section of a ski covered with the complex of the invention;
• Figure 5 is an exploded perspective diagram of the complex according to the invention.

Carrying out the method according to the invention requires everything first use of a single layer plastic sheet 1 in transparent or translucent material; this sheet will called "transparent layer" in the description below.

As shown in Figure 1 we proceed, in a first step, to an impression of a decoration by transfer of dyes sublimable on one side 100 of layer 1.

This face 100 is intended to constitute the internal side transparent layer in the complex; as opposed to the opposite face 101 which is the outer side. The reason for decoration to be printed is in a manner known per se a sheet of backing paper 2 which is applied under a pressure P at a temperature T for a time t against the face 100 of the transparent layer. The transparent layer can be chosen from the sublimable plastics of Polyamides such as PA11, PA12, PA6.3, PA6.6, etc., Polycarbonates, ABS (Acrylonitrile Butadiene Styrene), AS (Acrylonitrile Styrene) transparent mixed with TPU (Thermoplastic urethane elastomer), Polyethylenes Terephthalates (PET).

The thickness of the transparent layer is between 0.2 and 1.1 mm. Sublimation is performed at a temperature between 160 and 180 ° C, and at a pressure of 1 to 3 bars for a time between 1mn30sec, and about 4mn. The depth of the ink migration front across the transparent layer on the inner side is around or slightly greater than 0.20 mm.

In a second step shown in Figure 2, we reconciles transparent layer 1 with a solid bonding film 3, a trellis 4 and a layer of contrast 5. The bonding film 3 is brought into contact with the predecorated face 100, the trellis 4 is brought into contact with the bonding film 3 on the side of film 3 opposite the contacting side with the transparent layer 1, and finally the contrast layer 5 is brought into contact with the trellis 4 on the side of the trellis 4 opposite the side in contact with the film 3.

We then proceed to an actual plating phase by increasing pressure and temperature to the point of softening at least of the film, in order to obtain the adhesion of the transparent layer 1 with the contrast layer 5 to through the trellis 4.

In the example illustrated, the bonding film 3 is chosen for its adhesion with the transparent layer 1 and with the contrast layer 5. This is a film thin hot melt between a few microns and a few tenths of a millimeter, the thickness preferred being close to 50 microns.

It is advantageous to use a film 3 based on polymer or copolymer grafted by action of carboxylic acid or carboxylic acid anhydride, for example by acid acrylic, methacrylic acid, or anhydride maleic.

Such a film 3 can in particular be made of polyethylene grafted, for example in polyethylene grafted with anhydride maleic.

This type of film allows the bonding of most sublimable materials constituting the transparent layer 1 cited above with the contrast layer 5.

But the film 3 can also consist of a copolymer ethylene and vinyl acetate (EVA), grafted by action carboxylic acid or carboxylic acid anhydride.

The trellis 4 is a honeycomb structure shown on the figures in the form of a flexible square mesh net. The net frame is formed by superimposed cords represented in section in Figure 2 by circles in the thickness of the mesh 4.

The cords are preferably made of fibers such as glass, carbon or other fibers. The thickness of the trellis can be between a few tenths of a micron and a few tenths of a millimeter, the preferred thickness being close to 0.1 mm. The width of meshes can be between a few tenths of millimeters and a few millimeters, the preferred width being of the order of 2 or 3 mm.

The contrast layer 5 is a sheet of aluminum not thin anodized 51 covered on each side with film of an ionomer type olefin copolymer (name SURLYN®).

The thickness of the aluminum foil is between 15 and 200 µm and the thickness of each film between 10 and 50 µm.

In the example illustrated, the use of a film 3 in polyethylene grafted with maleic anhydride allows bonding of a transparent layer 1 of polyamide on a layer of contrast 5 ionomer treated aluminum through the meshes of the net. The trellis 4 is therefore trapped between the layer transparent 1 and the contrast layer 5.

The adhesion of the film 3 is caused on the layer 1 by temperature increase to a higher value or equal to 160 ° C, and by hot pressing, by calendering or pressing, the film 3 against the first element 1 to ensure their joining together.

In the example illustrated, the assembly of the different layers 1, 3, 4, 5 in a single cycle heating and pressurizing. Mechanically, the heating cycle causes the film to soften collage 3. The trellis 4, by the cords forming the mesh, avoids the material of the bonding film 3 to flow in a direction substantially parallel to the side internal 100 of sheet 1. The only direction of creep possible for film 3 is a direction of crossing the trellis 4, of so that film 3 is in contact with both layer 1 and layer 5.

It follows that a dye that may have migrated into film 3, during temperature and pressure increases of the second step, can only be moved in one direction substantially parallel to the inner side 100 of the sheet 1.

This is why the precision of the initial decoration is not altered by creep of the bonding film 3.

As shown in Figures 2, 3, 4 and 5, the invention also provides for the use of a bonding film 6 for securing a layer of nonwoven fibers 7 to the layer of contrast 5 during the second stage or during a stage later.

Preferably, the film 6 and the layer 7 are assembled with layers 1, 3, 4, 5 as part of the single cycle heating and pressurization of the second stage. The film 6 is similar to film 3, and layer 7 is made from fibers such as glass, carbon or other fibers in thicknesses between 0.05 and 1 mm. Layer 7 used to reduce deformations appearing in the layer contrast 5 during the second stage due to the presence of trellis 4.

Indeed, the cords of the mesh 4 can cause locally deformations of the contrast layer 5 in the cases where the thickness of the layer 51 is too small, that is to say between 15 and 100 µm. By adding layer 7, the deformations of layer 5 are reduced and do not alter not the structure of layer 5 in terms of resistance mechanical or visual effect perceived through layer 1.

In the example illustrated, the assembly of the different layers 1, 3, 4, 5, 6, 7 in one operation.

Of course, it is possible to decompose this operation in a series of intermediate operations. In particular, we can proceed with the plating of a bonding film on one layer, then proceed to plating another layer on the other side of the collage film.

The complex formed, shown in Figure 3, is then ready for use in covering a composite article to decorate.

By composite article is meant essentially everything laminate object having a reinforcing structure. It is believed in particular, on skis, snowboards, snowboards roulette, etc.

Figure 4 shows schematically the section of a ski which comprises a complex obtained according to the method of the invention.

The joining of the complex with the rest of the ski structure can be made as part of processes very different. In all cases, one generally proceeds to a hot pressing cycle with the reinforcement structure 8 of the ski based on thermofluable resin. This reinforcement structure 8 may in particular consist of a textile sheet of reinforcement pre-impregnated with a thermosetting resin or a thermoplastic resin.

One can in particular use a textile reinforcement ply to base of woven or non-woven fibers of glass, carbon or made of polyaramid, impregnated with a thermosetting resin wet or partially crosslinked chosen from the group consisting of polyester, epoxies, polyurethanes.

Alternatively, a textile tablecloth can be used. reinforcement based on woven or non-woven fibers of glass or carbon impregnated with a thermoplastic resin chosen from the group consisting of polyamides, polycarbonates, PEI (Polyether Imide).

The invention is not limited to the embodiment thus describes, and includes all technical equivalents that can to enter into the scope of the claims which will follow.

In particular, one can plan to use any metal or metal alloy to make the contrast layer 5.

We can also provide any structure to achieve a lattice 4 which may include meshes of different shapes like triangles, hexagons, various polygons regular or irregular.

The mesh 4 could be a uniform layer pierced by circular or non-circular holes.

Claims (11)

Method for decorating a composite article comprising preparing a decorated complex to be assembled with a reinforcing structure (8) of the resin-based article hot melt during a subsequent hot pressing cycle, the process comprising at least two cycles, a first cycle during which the decoration is transferred by the method of printing sublimable ink (s) on the first face (100) of a transparent plastic layer or translucent (1), and a second cycle, characterized in that proceeds in the second cycle by means of a bonding film (3) hot assembly and pressure on the first side (100) thus decorated, with a contrast sheet (5) in material chosen from the group consisting of metals or metal alloys, and in that, in one step prior to assembly of the contrast sheet (5) on the first face (100), there is a trellis (4) between the contrast sheet (5) and the first side (100). Decoration method according to claim 1, characterized in that the contrast sheet (5) is a non-anodized aluminum foil covered on each side a film of an ionomer-type olefin copolymer. Decoration process according to claim 1 or 2, characterized in that there is a textile web (7) based non-woven fibers in contact with the contrast sheet (5) on the side of the contrast sheet (5) opposite the side to contact of which is the trellis (4). Decoration process according to claim 3, characterized in that a bonding film (6) is arranged between the contrast sheet (5) and the textile sheet (7) based on non-woven fibers. Decoration process according to any one of Claims 1 to 4, characterized in that the mesh (4) is an arrangement of glass fiber cords forming a grid with square openings. Decoration process according to claim 4 or 5, characterized in that the plastic layer transparent or translucent (1), the first bonding film (3), the trellis (4), the contrast sheet (5), the second bonding film (6), and the fiber-based textile web (7) non-woven, are joined together in a single surgery. Decoration complex intended to be assembled with a reinforcement structure based on hot-melt resin composite article, said complex comprising a layer of transparent plastic (1) including a first face (100) wears a decoration obtained by the printing method sublimable ink (s), characterized in that a sheet of contrast (5) which covers the first face (100) of the layer transparent plastic (1) is assembled on the face (100) of the plastic layer (1) by means of a bonding film (3), what the contrast sheet (5) is chosen from the group consisting of metals or metal alloys, and that a trellis (4) is arranged between the contrast sheet (5) and the first face (100) in a step prior to assembly of the contrast sheet (5) on the face internal (100). Decoration complex according to claim 1, characterized in that the contrast sheet (5) is a non-anodized aluminum foil covered on each side a film of an ionomer-type olefin copolymer. Decoration complex according to claim 1 or 2, characterized in that a textile sheet (7) based on fibers nonwoven is arranged in contact with the contrast sheet (5) on the side of the contrast sheet (5) opposite the side to contact of which is the trellis (4), and by the fact that a bonding film (6) is arranged between the contrast sheet (5) and the textile sheet (7) based on non-woven fibers. Decoration complex according to any one of Claims 1 to 3, characterized in that the mesh (4) is an arrangement of glass fiber cords forming a grid with square openings. Composite article of the ski or snowboard type provided a decoration complex according to claim 7 or 8.

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