Recycled lignocellulosic materials for obtaining molded products. Part I: Evaluation of physical and mechanical properties

YANINA S. AGUERRE; GRACIELA B. GAVAZZO

Simposio; 3er Congreso Iberoamericano sobre Biorrefinería, 4to Congreso Latinoamericano sobre Biorrefinerías y 2do Simposio Internacional sobre Materiales Lignocelulósicos; 2015

This paper presents a study of the evaluation of physical and mechanical properties of recycled lignocellulosic materials with the ultimate objective of their use for the production of molded pulps. It is desired select the components that optimize the variables analyzed to use in the production of products moldings suitable for plants growing. These products, flower pots, allow replace the plastics materials, which are contaminants and hardly biodegradable. Their function is to contain the substrate and provide physical support to the plant during their stay in the nursery; enable mechanized production operations, and maintain adequate levels of moisture and aeration of the substrate, so they must have good strength properties to maintain the structural integrity and good permeability to control the temperature, the contained moisture and aeration of the set pot-substrate.For the development of the research, were used, two types of recycled lignocellulosic materials: Newspaper, office paper and old corrugated containers pulps and pine sawdust.The pulping were performed at medium consistency, and later cleaned. The sawdust was fractionated by manual screening and for experiences, was selected the fraction: "Pass-Retained 40-60 mesh". As of an experimental design type mixture of extreme vertices, were prepared, standard laboratory sheets weighing 150 g / m2. The pulp content is between 0 and 100%, and the content of sawdust between 0 and 40% by weight. Were evaluated, physical-mechanical properties (density, bulk, tensile, tear, burst, stiffness, compression ring and porosity), in accordance with TAPPI standards.It was observed that, with an increase in the percentage of office pulps, it is obtained, higher density value lower specific volume and consequently, higher value of porosity, and higher value of tensile, burst, and compression; with an increase in the percentage of old corrugated containers pulps are obtained, higher tear resistance properties, and, newspaper pulps higher stiffness properties. In all cases, an increase in the content of sawdust decreases resistance properties corresponding to a maximum of 20% in weight percentage of the possible use.Therefore it is concluded that, in the design of molded products, a higher content of pulps office papers improves most properties of strength and porosity, except tear and stiffness that is achieved to improve with the use of pulps old corrugated containers and pulps newspapers. As to the sawdust, it is possible to incorporate up to 20% of the mix of different pulps; higher percentages cause a marked decrease in the properties. The second part of this study, are used, mixtures that benefit, the development of compressive strength and stiffness of molded pulp. The results will form the basis for the reuse of other lignocellulosic materials from the farm in the production of products molded.