New eco textiles from agroindustrial wastes: valorization of pineapple leaves fibres (PALF)

The general definition of sustainable economy is the ability of an economy to maintain defined levels of economic production indefinitely. This theme is closely linked to the introduction of environmental friendly processes, to the study of new materials obtainable from renewable sources and to the exploitation and minimization of by-products and wastes from industrial processes. The biorefinery concept match all these aspects: in a biorefinery biomass conversion processes are integrated and value-added chemicals, new materials, fuels, power, heat, can be obtained in a sustainable way with environmental friendly processes. For this purpose the employ of enzymes play a key role in biorefineries because they constitute an important alternative to the traditional and environmental impact chemical compounds and processes [1]. An interesting example is the case of Thailand, where agriculture and textile industry are working together to exploit the resources obtainable from pineapple cultivation [2]. This nation produce over 2.2 million t/y of pineapple fruits; connected to this cultivation, recently, is developing a new business resulting from the extraction of fibers from pineapple leaves (PALF), to be employed in the textile sector. These fibers are obtained from the leaves of the plant Ananas Comosus, which belongs to the Bromeliaceae family; they contain fibers (2.5 ÷ 3.5 %), pentosans (17.8 %), lignin (4.2 ÷ 12 %), fat and wax (3.3 %) and pectins (1.1 %) [3]. The presence of other constituents than fibers constitute an impurity that needs be removed, in particular lignin that act as a glue for the fibrillar structure of the fibers, is responsible of the non-wettability and consequently of the non-dyeing of the fibers. This fiber is silky, fine and has interesting textile properties, is capable of blending with jute, cotton, ramie and some other synthetic fibres: so it can capture an important position among natural fibers as potential commercial grade textile fiber [4]. In consideration of its properties, PALF is placed between jute and cotton or jute and ramie. This work propose the development of an industrial process for extraction of fibres and exploitation of other constituents, in order to reach a sustainable and economical profitable production process.