Biocomposites are defined as eco-friendly materials from an environmental point of view. Because of the importance of this class of materials, their study is important, especially in moist and heated conditions. In this sense, this work aims to evaluate the transient behavior of moisture absorption and mechanical performance of biocomposites composed of a matrix of high-density biopolyethylene (originated from ethanol produced from sugarcane) filled with curauá vegetable fiber and organophilic montmorillonite clay. For this purpose, dry biocomposites filled with organophilic montmorillonite clay and curauá fiber (1, 3, and 5 wt.%) were prepared using a hand lay-up technique and subjected to moisture absorption and mechanical (flexural and impact tests) characterizations at different times. The experiments were carried out at water bath temperatures of 30 °C and 70 °C. The results have proven the strong influence of chemical composition and temperature on the moisture absorption behavior of biocomposites across time. For a higher percentage of reinforcement on the polymeric matrix, a higher moisture migration rate was verified, reaching a higher hygroscopic equilibrium condition at 16.9% for 5 wt.% of curauá fiber and 10.25% for 5 wt.% of montmorillonite clay particles. In contrast, the mechanical properties of all of the biocomposites were strongly reduced with an increasing moisture content, especially at higher fiber content and water bath temperature conditions. The innovative aspects of this research are related to the study of a new material and its transient mechanical behavior in dry and wet conditions.

Recently, the liquid composite molding technique (LCM) has been used for producing fiber-reinforced polymer composites, since it allows the molding of complex parts, presenting good surface finishing and control of the mechanical properties of the product at the end of the process. Studies in this area have been focused on resin transfer molding (RTM), specifically on the resin rectilinear infiltration through the porous preform inserted in the closed cavity neglecting the sorption effect of the polymeric fluid by the reinforcement. Thus, the objective of this work is to predict resin radial flow in porous media (fibrous preform), including the effect of resin sorption by fibers considering a one-dimensional approach. For correct prediction of the flow behavior inside the porous media, an advanced modeling approach composed of the mass conservation equation and Darcy’s law is used, and the solution of the coupled equation is obtained. Transient results of the flow front location, velocity and pressure within the mold during the resin infiltration are shown, the effects of different parameters for resin (viscosity), reinforcement (sorption term, permeability and porosity) and process (injection pressure and injection radius) are analyzed, and an in-depth discussion is performed.

With the growing human awareness of trying to reduce the environmental impact in today’s world, the development of new sustainably based materials has been the increasing focus of industry and academia. Biocomposites are environmentally friendly materials produced from raw materials synthesized from renewable sources. In this sense, this work aims to characterize and evaluate the mechanical and thermal performances of biocomposites manufactured from a thermoplastic matrix of high-density bioethylene and obtained from ethanol produced from sugarcane and reinforced with organophilic montmorillonite clay. For this, polyethylene grafted with maleic anhydride (PE-g-MA) was used as a compatibilizer. Dry biocomposites with 1, 3, and 5% organophilic montmorillonite clay, by weight, were subjected to structural (FTIR and DRX), thermal (DSC), thermogravimetric (TG/DTG), thermodynamic–mechanical (DMA), morphological (SEM and MET), and mechanical (tensile, flexural, impact, and shore D hardness tests) characterizations. The DMA experiments were carried out within the viscoelastic region of the polymer. From the obtained results, we notice that, in general, there was an increase in the properties of high-density biopolyethylene (B-HDPE) (without compromising its processability), and therefore, the automotive application of biocomposites compatible with PE-g-MA, containing low levels of organophilic montmorillonite clay, is recommended.

Currently, several researches have been developed on the drying of ceramic materials, most of which are carried out experimentally. This process requires high investments and energy consumption, resulting in high costs for companies in the sector. The drying process can be defined as a unit operation that consists of removing water from porous materials through heat transfer. So, aiming at a better cost benefit, it is common to use theoretical solutions that allow, with relative ease of replication and low cost, to change operational and geometric conditions of the dryer or drying object. In this sense, this work aims to predict the drying process of a ceramic tile in a kiln via computational fluid dynamics (CFD). To carry out the simulations, the commercial package Ansys CFX® 22.R1 was used. For a drying temperature of 82,7 °C, the results of drying and heating kinetics, product moisture content, oven air velocity and pressure are displayed and analyzed. A comparison between predicted and experimental data of the average moisture content of the tile throughout the process was performed and a good agreement was obtained.

Devido a sua importância econômica, tem-se estudado o processo de secagem das cerâmicas devido à ocorrência de inúmeros fenômenos, além de um alto consumo de energia que ocorre nesta etapa de fabricação. O uso de tecnologias de simulação numérica permite alterar condições operacionais e geométricas do objeto de secagem, com baixo custo e facilidade. Este trabalho foi realizado com a finalidade de estudar esse processo para tijolos maciços, considerando-o um meio sólido por Fluidodinâmica Computacional (CFD), nas seguintes condições experimentais: temperatura de secagem de 60°C e 80°C, teor de umidade inicial de 0,001734 e 0,00158 (kg/kg, bs) e umidade relativa de 10,1% e 5%, respectivamente. O fenômeno de secagem do tijolo maciço foi estudado isoladamente, considerando o modelo de secagem por difusão líquida. Os resultados da temperatura e fração volumétrica de água no interior do tijolo foram obtidos pelo pacote de software ANSYS CFX®. A comparação da umidade e temperatura simuladas com dados experimentais pode validar os resultados numéricos, estimando o coeficiente de difusão de massa e o coeficiente de transferência de calor da superfície do material. Os resultados obtidos nas simulações mostram a existência de importantes gradientes de temperatura e umidade, cujas áreas podem apresentar patologias.