EP0811401B1 - Complex covering for snowboards - Google Patents

Abstract

Complex for covering (1) mechanical structure of ski plate comprises at least one primary protective plastic layer (10) which makes up the external face of the ski which contains a secondary fabric layer of dry crosscut fibres (11). Secondary layer is stuck to primary layer and tertiary layer (12) which provides mechanical barrier between secondary layer and reinforcing resin of mechanical structure. Also claimed is plate coated with claimed complex.

Description

The present invention relates to a recovery complex intended to complete the mechanical reinforcement structure of a gliding board. It relates more particularly to articles in the form of laminates grouping together different composite materials such as skis in general, snowboards, monoskis and other similar objects.

In most cases, a gliding board consists of a mechanical assembly bringing together the essential elements for resist different stresses in bending, twisting and lateral deformations undergone by the board. These are generally reinforcing elements made of composite materials or metallic and filling elements serving as a core to keep the reinforcing elements at a distance.

In order to protect this complex from external aggressions and make the product more attractive, we cover the surface upper and the edges of the board by a top of protection and decoration generally consisting of one or several layers of plastic material, decorated or not, as described for example in document EP-A-0 606 556. However the role of this upper subset is limited to protection against scratching, edge blows, UV, cleaning, etc; but it does not bring improvement particular in the behavior of the ski.

The purpose of the present invention is to provide a improvement to the realization of a top of a board sliding which has in addition to its usual role, a role damping, participating in the attenuation of vibrations which disrupt the driving of the board.

In particular, one of the advantages of the invention is improve the vibratory behavior of the board by predominantly torsional damping. Most of added or integrated damping devices dampen especially the energy of the flexural deformations of the board; this which is not enough to maintain a powerful, precise contact and regular on snow. So, we found that damping must be greater in torsion than in pure bending to obtain better contact of the ends of snowboarding. The invention provides a report superior torsional / flexural damping to structures traditional gliding boards.

For this, the invention relates to a recovery complex a mechanical structure of a gliding board which includes at least a first protective plastic layer intended for constitute the outer face of the gliding board, a second layer of fabric of crossed dry fibers, said second layer being bonded to said first layer protective plastic, and finally a third barrier layer connected to the second layer by gluing and intended to constitute a mechanical barrier between said second layer and the resin reinforcements of said mechanical structure.

Surprisingly, we have been able to demonstrate that the second layer of fiber fabric was able to dissipate from energy from friction caused by crossed fibers between them, during deformations of the board; in particularly in torsion. The fiber is protected from the outside by the first plastic layer which covers it. Of the other side, the third layer is a barrier sealing that allows the woven fiber of the second layer to remain dry during the final assembly of the complex with the rest of the board structure, and especially when of the contact of the thermofluable resin of the elements of strengthening of the structure.

In addition to its cushioning role, the fiber fabric layer participates in the exterior decorative rendering of the complex.

According to another characteristic of the invention, the third layer is formed by at least one nonwoven textile web whose face, intended to be connected to the mechanical structure of the board, is impregnated with a low-temperature hot-melt polymer viscosity and low melting point. The polymer in the molten state fills the interstices of the nonwoven layer and makes the assembly waterproof to the thermofluable resin of the reinforcements. The non-woven layer has the advantage of significantly improving the bonding value between the complex and the rest of the structure gliding board.

According to an additional characteristic, the complex comprises a hot-melt adhesive film between the first layer protective plastic and the second layer of fiber fabric dryer and another hot melt bonding film between said second layer and the third barrier layer. The presence of films allows the bonding between the layers and thus offers a plus wide choice of materials forming the respective layers.

• la figure 1 montre une vue en coupe du complexe selon l'invention avant assemblage avec le reste de la structure de la planche,
• la figure 2 montre une vue écorchée de dessus du complexe en mettant en évidence les différentes couches le constituant,
• les figures 3 à 5 montrent un mode de réalisation du complexe selon l'invention,
• la figure 6 montre une planche de glisse recouvert d'un complexe selon l'invention,
• la figure 7 est une vue en coupe selon A-A de la figure 6,
• la figure 8 est une variante de la planche de glisse de la figure 6.

Other objects, characteristics and advantages of the invention will emerge from the following description of the particular modes, made in relation to the attached figures, among which:

• FIG. 1 shows a sectional view of the complex according to the invention before assembly with the rest of the structure of the board,
• FIG. 2 shows a cutaway view from above of the complex, highlighting the different layers making it up,
• FIGS. 3 to 5 show an embodiment of the complex according to the invention,
• FIG. 6 shows a sliding board covered with a complex according to the invention,
• FIG. 7 is a sectional view along AA of FIG. 6,
• FIG. 8 is a variant of the gliding board of FIG. 6.

Figures 1 and 2 show a complex 1 according to the invention intended to be attached to a mechanical structure 2 of a gliding board.

In this example, complex 1 is represented as of a strip composed of a plurality of layers assembled together to each other.

On the external side (EXT) is placed the first layer of protection 10 intended to constitute the external face of the complex. This layer is made of plastic and preferably of material thermoplastic.

Preferably, it is a transparent sheet in thermoplastic material chosen from the group consisting of polyamides, polycarbonates, ABS, polyethylenes terephthalates (PET), polystyrenes. The diaper can wear a decorative pattern, for example a pattern made with inks sublimated 100 through the outer surface of layer 10.

This first layer must have sufficient thickness to protect the rest of the complex and absorb the deep ink thermal diffusion. She must be greater than or equal to 0.3 mm; preferably around 0.7 mm. Other decorating techniques can be used to replace sublimation. We can cite for example the use of screen printing, pad printing, hot stamping, etc.

Of course, it is conceivable that the complex includes several layers of protection. In this case, the layers can be assembled together beforehand by coextrusion or by any other means.

According to the invention, the second layer 11 of the complex is a dry fiber fabric. The fabric is preferably a textile weft and warp thread crossed with angles of crossing 90 degrees or less than 90 degrees (tissue multidirectional).

The fabric contains no impregnating resin, at most less at heart, so as to encourage friction between the wires or strands.

The thickness of this second layer can be between 0.2 and 0.7 mm. The grammage of the fabric can be between 200 and 1000 g.m -2.

This second layer may consist of a fabric of fibers synthetics chosen from glass, carbon, para-aramid, polyester or a mixture of these fibers.

The third layer 12 is a barrier layer whose role is, both to promote the bonding of the complex on the reinforcement structure and prevent the impregnation of the second layer by the thermofluable resin of the reinforcing layer 20 during the final assembly.

This layer 12 is therefore preferably formed by a sheet nonwoven fabric 120, the side of which is intended to be connected to the mechanical structure of the board is impregnated with a polymer hot melt 121 with low viscosity and low melting point. The polymer can fill the interstices of the nonwoven web and make it waterproof to the resin reinforcements.

Among the polymers likely to be suitable, preference will be given to choose from ionomers; especially those with a MFI (Melt Flow Index) value less than or equal to 7 and one point less than or equal to 110 degrees Celsius. The tablecloth nonwoven fabric also has the advantage of folding and stretch easily and without breaking.

The nonwoven textile layer associated with the polymer impregnation also constitutes an opaque background of revelation of the decor of the complex.

To achieve the cohesion of the complex, a collage film hot melt 130 is interposed between the first layer protective plastic 10 and the second layer 11 made of dry fiber and another hot melt adhesive film 131 between said second layer 11 and the third barrier layer 12.

The bonding films 130, 131 are preferably based on polymer or copolymer grafted by the action of carboxylic acid, carboxylic acid anhydride or carboxylic acid ester.

The film can advantageously be of grafted polyethylene, and more precisely, in polyethylene grafted with anhydride maleic.

Thanks to the choice of the nonwoven textile tablecloth and in it associating a hot-melt film of the type of that designated, we obtains bonding values much higher than those that can be obtained with any other substrate, such as plastic layer for example.

Resistance to sticking at the interface between the second layer 11 and the reinforcement structure 20 is of the order of 20 N in presence of the layer of nonwoven 120. The resistance is no longer only 4 N without the layer of nonwoven, however retaining the only presence of films 131 and 121 (and zero resistance after aging in an aqueous medium).

Resistance to sticking at the interface between the second layer 11 and the first plastic layer 10 is of the order of 12 N approximately with the presence of the bonding film 130.

In addition to its role as a barrier layer, the third layer 12 prevents the chemical modification of the bonding film 131 by the reinforcement resin when the film is in particular a ionomer capable of reacting with epoxides.

Figures 3 to 5 illustrate, by way of example, a method for manufacturing the complex 1 described above. According to Figure 3, we first print a decoration by hot transfer of sublimable dyes contained in a sheet of backing paper 3. The sheet is applied in contact with the surface of the plastic layer 10 and, in a manner known per se, heat and pressure are applied to obtain the diffusion of dyes through layer 10. The operating conditions of the decoration cycle are by example of 165 ° C for 2 min at 2 bars.

The next step is to stack the complex; respectively, of the first plastic layer 10 as well decorated with collage film 130, second fabric layer 11, then the other bonding film 131, the third layer formed from the nonwoven fabric 120 and the film of hot melt polymer 121.

A press cycle is then applied by applying a pressure of the order of 2 to 4 bars and at a temperature of 150 to 165 degrees for about 1 to 2 minutes.

A variant consists in carrying out the pre-assembly of a part of the complex by hot calendering. For example, the subset formed by the film 130, the second layer 11, the film 131, the third layer 12 can be calendered hot in first, then assembled to the plastic layer by pressing in a second step.

The complex thus formed is thus ready for use for final assembly with the rest of the board structure sliding which includes in particular the reinforcing elements prepregs.

The final assembly is an operation which consists in molding the structure to the desired shape while obtaining the adhesion of all the constituents between them. The operation is done in a mold of shape suitable for the desired final shape which is heated to sufficient temperature to cook the elements reinforcement in prepregs.

When baking in a mold, the resin in the reinforcements prepregs reaches a temperature of around 150 ° C and becomes fluid. Due to the pressure in the mold, of the order of 7-10 bars, the resin tends to creep in spaces and gaps left free. This creep is stopped in direction of the complex thanks to barrier layer 12. Resins most often used for prepregs in the field of the manufacture of skis and snowboards are resins thermosetting epoxy type.

The invention also relates to the gliding board provided with a complex as described above. In the case of figure 6 and 7, the gliding board is provided over its entire length with the complex 1 which covers the mechanical structure 2.

This structure 2 comprises a reinforcing element or layer upper 20, a central core 21, an element or layer of lower reinforcement 22, lateral metal edges 230, 231 and a sliding sole 24, generally made of polyethylene. The elements 20, 22 are advantageously based on fibers of reinforcement and epoxy thermosetting resin.

The core is made of a low density material but compression resistant such as foam, wood or nest bee.

According to the invention, the complex is assembled on the structure 2 so that the third layer 12 constituting the barrier mechanical is bonded by contact with the layer of reinforcement 20 based on fibers impregnated with a flowable resin hot belonging to the mechanical structure 2.

In the example of FIG. 6, the fibers or threads of the layer in fabric occupying the entire length of the board are oriented and crossed substantially in a direction inclined at + and - 45 degrees relative to the longitudinal direction I-I 'of the board.

Depreciation measurement tests have shown that the relationship between the first of twist and the third of bending in the corresponding frequency range; of the order of 200 Hertz, is more important for boards using the complex of the invention only for planks of traditional structure. We measure that this ratio is in all case greater than 1 and of the order of 1.05 for a ski with structure in a box with all-fiber reinforcements and around 1.42 for a ski with a fibro-metal box structure. For a structure traditional, the ratio is around 0.75 for a ski of type with all fiber reinforcements and around 0.70 for a ski with fibro-metal reinforcement. We see that these skis which have a greater than 1 have a behavior on snow that one can be described as softer thanks to better surface contact sliding / snow.

In the example of figure 8, the gliding board shown is a ski which has a central portion 30 corresponding to the mounting area of the fasteners, a front area 31 extending between the front limit of the central portion 30 and the spatula and a rear zone 32 extending between the limit rear of the central portion 30 and the heel of the ski.

In this case, it is expected that the second layer of dry fibers 11 is only present in the front zone 31 and the rear zone 32 to provide predominantly torsional damping in those areas that are particularly stressed and more than the central portion. In the central portion, layer 11 can be replaced by an additional plastic layer similarly thickness in the complex for example. In a variant, the layer 11 can also not be replaced by a layer additional.

Of course, the invention is not limited to the modes of as described and includes all equivalents techniques which may fall within the scope of the claims which follow.

Claims (11)

1. Coating complex (1) for a mechanical structure (2) of a glide board having at least one first protective plastic layer (10) adapted to constitute the external surface of the glide board, a second layer made up of criss-crossed dry fiber fabric (11), said second layer being connected by adhesion to said first protective plastic layer (10), and a third barrier layer (12) connected to the second layer (11) by adhesion, and adapted to constitute a mechanical barrier between said second layer (11) and the resin of the reinforcements of said mechanical structure.
2. Coating complex according to claim 1, characterized in that the third layer (12) is constituted of at least one non-woven textile sheet (120), whose surface that is intended to be connected to the mechanical structure of the board is impregnated with a heat meltable polymer (121) having low viscosity and a low melting point.
3. Coating complex according to claim 2, characterized in that the heat meltable polymer (121) is selected from among ionomers.
4. Coating complex according to claim 1, 2, or 3 characterized in that it has a heat meltable adhesive film (130) between the first protective plastic layer (10) and the second dry fiber fabric layer (11), and another heat meltable adhesive film (131) between said second layer (11) and the third barrier layer (12).
5. Coating complex according to claim 4 characterized in that the adhesive films (130, 131) are polymer or copolymer based, grafted by the action of carboxylic acid, anhydrous carboxylic acid or carboxylic acid ester.
6. Coating complex according to any of the preceding claims, chaxacterized in that the first layer (10) is a transparent sheet made of a thermoplastic material selected from among the group constituted of polyamides, polycarbonates, ABS, polystyrenes and polyethylene terephtalates (PET).
7. Coating complex according to any of the preceding claims, characterized in that the second layer (11) is constituted of a fabric made of synthetic fibers selected from among glass, carbon, para-aramide, polyester or a mixture of these fibers.
8. Glide board having a mechanical reinforcement structure (2) made of hot flowable resin, equipped with a coating complex (1) according to any of the preceding claims over at least a portion of its length; the third layer (12) constituting the mechanical barrier, that is connected by contact adhesion to a reinforcement layer (20) made of fibers impregnated with a thennoflowable resin belonging to the mechanical structure (2).
9. , Glide board according to claim 8, characterized in that the fibers of the second layer (10) are oriented and substantially criss-crossed along a direction inclined at + and - 45 degrees with respect to the longitudinal direction of the board.
10. Glide board according to claim 9, characterized in that the second layer made up of dry fiber fabric (11) is present in the complex only along a portion of the length of the board.
11. Glide board according to claim 10, characterized in that the second layer made up of dry fiber (11) is present in the front zone (31) and the rear zone (32) outside the central portion (30) which corresponds to the binding mounting zone.

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