Lignocellulosic Recycled Materials to Design Molded Products: Optimization of Physical and Mechanical Properties

The object is to contribute to the reduction of environmental pollution, by reusing a fraction of urban solid waste, forestry and agroindustrial waste: newspaper (ONP), office paper (OWP), corrugated cardboard (OCC), pine sawdust, eucalyptus sawdust and sugar cane bagasse as raw material to design biocontainers suitable for growing plants, by applying pulp molding technology. The purpose is to evaluate the effects of the combination of these lignocellulosic materials on the physical-mechanical properties and optimize responses in order to select an ideal mixture on basis the product?s necessities. An experimental design of type mixture of extreme vertices was followed, considering secondary fibers as base material, in a 0-100% proportion, and pine sawdust, eucalyptus sawdust and bagasse fibers as reinforcement, in a 0-40% proportion. An experimental matrix by each reinforcing material was proposed. Properties were evaluated: density, tensile, bursting, tearing, compression, stiffness, wet tensile, permeability and water retention, testing handsheets weighing 150 g/m2. Responses were optimized using a statistical program. It was found that OWP pulps increase strength properties; OCC pulps increases tear and wet tensile; ONP pulps increase stiffness and reinforcement materials increase permeability. Factors that allow reaching the objectives are a mixture of pulp OWP/OCC in a 50/50 proportion.Fil: Aguerre, Yanina Susel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Gavazzo, Graciela Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; Argentin

Nanocellulose addition to recycled pulps in two scenarios emulating industrial processes for the production of paperboard

This study assesses the incorporation of nanocellulose in a paperboard feedstock emulating two scenarios of industrial processes. It included the production of 170 g/m2 paperboard, using mixtures of short-fiber and long-fiber fractions from recycled pulps with typical mill additives. In all cases, 3wt.% of nanocellulose was added to the pulp suspensions. The first scenario involved three types of nanocellulose addition in a mixture of 78 % long-fiber/22 % short-fiber pulps. The second scenario included the addition of two types of nanocellulose to an unrefined long fiber pulp to produce a multilayer paperboard. Drainage time and physical-mechanical properties of the handsheets were evaluated. Nanocellulose improved the mechanical properties in all cases. The tensile and burst indexes increased 19 % and 28 % in Scenario 1 and up to 60 % and 43 % in Scenario 2, respectively. The lower values in mechanical properties for Scenario 1 were attributed to the effect of the retention system. A new retention system using a cationic polymer with a high charge density produced decreases up to 79 % in the drainage time

Quality of Microfibrillated Cellulose Produced from Unbleached Pine Sawdust Pulp as an Environmentally Friendly Source

The implementation of biorefineries of sawmill residues is an opportunity in countries or regions with a high rate of afforestation. Microfibrillated cellulose (MFC) is a high-value product that can be obtained from the cellulosic fraction. However, many critical aspects involved in its production and characterization are not clarified yet. This study analyzes the physical and morphological properties of laboratory-obtained MFC from different sources, among them, hardwood and softwood industrial pulps and unbleached pine sawdust pulps from conventional and non-conventional processes, aiming to evaluate and predict the relationship between the characteristics of the pulps and those of MFC. MFC dimensions and the properties of the MFC suspensions (viscosity, transmittance, others) were determined. The results showed that unbleached pine sawdust pulp is a low-cost and environmentally friendly raw material for MFC production and that this MFC can be produced with less energy and on a small scale than MFC from industrial pulps. A principal component analysis was assessed, showing that pine pulps from sawdust produce MFC of similar characteristics to conventional pine pulps from chips (high relative transmittance, short microfibrils, and small widths visible with the optical microscope), so fiber length of the original pulp is not so relevant than high fiber width and fiber coarseness.Fil: González, Roxana Giselle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Ehman, Nanci Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Aguerre, Yanina Susel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Henríquez Gallegos, Sergio. Universidad de Concepción; ChileFil: da Fonte, Ana P. Namikata. Universidade Federal do Paraná; BrasilFil: Muniz, Graciela I. B.. Universidade Federal do Paraná; BrasilFil: Pereira, Martín Miguel. Universidad de Concepción; ChileFil: Carneiro, Mayara E.. Universidade Federal do Paraná; BrasilFil: Vallejos, María Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Felissia, Fernando Esteban. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales. Departamento de Medio Ambiente; ArgentinaFil: Area, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; Argentin