A WATER SPORTS BOARD STRUCTURE AND A METHOD FOR MAKING THE SAME

In a water sports board structure (3), a composite material shell (20) encloses a core (10) including a shaped body (11) made of a foam material obtained by a mixture of polylactic acid, preferably between 60% and 80% by weight, and of a polymer selected between an aliphatic polyester and an aliphatic / aromatic co-polyester. For the foam material, a biodegradable Ecovio EA material is preferably used, in particular Ecovio® EA200 or ECOVIO® 80EA2394EXP. In an exemplary embodiment, the shaped body (11) incorporates at least one, or preferably two cork longitudinal stringers (13) spaced apart from each other by about half the cross width of the core (10). The shell (20) can comprise a fibre layer (21,24), preferably of basalt fibres, impregnating with a resin, which can optionally form a resin layer (23,26) outside the fibre layers (21,24). A further resin-impregnated fabric layer (22) can be present between the core (10) and the fibre layer (21) of the shell (20). The above foam materials allow manufacturing boards that are at least 20% lighter than the conventional boards including polystyrene foam cores, and that have suitable elasticity while having excellent impact strength and/or resistance to abrasion, such a combination leading to high-performance water sports boards. Moreover, polylactic acid as well as the above aliphatic polyesters or aliphatic/aromatic co-polyesters are fully biodegradable, which allows environment-friendly disposal of the water sport boards of the invention, for instance, by composting, without forming any special waste. La présente invention concerne une structure de planche de sport nautique (3), dans laquelle une coque en matériau composite (20) renferme un noyau (10) comprenant un corps façonné (11) constitué d'un matériau en mousse obtenu par un mélange d'acide polylactique, de préférence entre 60 % et 80 % en poids, et d'un polymère choisi entre un polyester aliphatique et un co-polyester aliphatique/aromatique. Pour le matériau en mousse, on utilise de préférence un matériau Ecovio EA biodégradable, en particulier Ecovio® EA200 ou ECOVIO® 80 EA2394EXP. Dans un mode de réalisation donné à titre d'exemple, le corps façonné (11) incorpore au moins une, ou de préférence deux entretoises longitudinales en liège (13) espacées l'une de l'autre d'environ la moitié de la largeur transversale du noyau (10). La coque (20) peut comprendre une couche de fibres (21, 24), de préférence de fibres de basalte, imprégnant une résine, qui pe