The Thermal and Mechanical Behaviour of Wood-PLA Composites Processed by Additive Manufacturing for Building Insulation

Influence of Carbonyl Iron Particles (CIP) and Glass Microspheres on Thermal Properties of Poly(lactic acid) (PLA)

In this investigation, composite poly(lactic acid) (PLA) systems of hollow glass microspheres (MS) and carbonyl iron particles (CIP) were processed and characterized to investigate the effects of using conductive and insulating particles as additives in a polymer system. PLA-MS and PLA-CIP were set at the two levels of 3.94 and 7.77 vol.% for each particle type to study the effects of the particle material type and loading on neat PLA's thermal properties. It was observed during the twin-screw extrusion that the addition of CIP greatly decreased the viscosity of the PLA melt during processing. Correlations determined using thermogravimetric analysis, differential scanning calorimetry, thermal conductivity, and shear rheology provided insights into how thermal stability was affected. The incorporation of MS and CIP altered thermal properties such as the glass transition temperature (Tg), melting temperature (Tm), and cold crystallization temperature (Tcc). The metal CIP-filled systems had large increases in their thermal conductivity values and viscoelastic transitions compared to those with PLA that were correlated with the observed overheating during extrusion.

Improving the Physical and Mechanical Properties of Mycelium-Based Green Composites Using Paper Waste

The growing demand for environmentally friendly and sustainable materials has led to the invention of innovative solutions aiming to reduce negative impacts on the environment. Mycelium-based green composites (MBCs) have become an alternative to traditional materials due to their biodegradability and various potential uses. Although MBCs are accepted as modern materials, there are concerns related to some of their physical and mechanical properties that might have limitations when they are used. This study investigates the effects of using paper waste to improve MBC properties. In this study, we investigated the physical and mechanical properties of MBCs produced from lignocellulosic materials (corn husk and sawdust) and mushroom mycelia of the genus Lentinus sajor-caju TBRC 6266, with varying amounts of paper waste added. Adding paper waste increases the density of MBCs. Incorporating 20% paper waste into corn husks led to the enhancement of the compression, bending, and impact strength of MBCs by over 20%. Additionally, it was also found that the MBCs produced from corn husk and 10% paper waste could help in reducing the amount of water absorbed into the material. Adding paper waste to sawdust did not improve MBC properties. At the same time, some properties of MBCs, such as low tensile strength and high shrinkage, might need to be further improved in the future to unlock their full potential, for which there are many interesting approaches. Moreover, the research findings presented in this publication provide a wealth of insightful information on the possibility of using paper waste to improve MBC performance and expand their suitability for a range of applications in sustainable packaging materials and various home decorative items. This innovative approach not only promotes the efficient utilization of lignocellulosic biomass but also contributes to the development of environmentally friendly and biodegradable alternatives to traditional materials.

Experimental and Numerical Study of Printing Strategy Impact on the Mechanical Properties of Sustainable PLA Materials

This article is focused on a mechanical properties investigation of three types of sustainable poly lactic acid materials manufactured using the fused filament fabrication process. The purpose of this work was to study the impact of printing strategies on the mechanical properties and predict mechanical behavior under tensile loading using finite element analysis. The testing of mechanical properties was conducted according to the ISO 527 standard. The numerical simulations were conducted in Simufact Forming 2022 software. Analysis of the experimental data showed a dependance of mechanical properties on the used printing strategy. The Clear PLA samples printed in the XY plane exhibited a 43% reduction in tensile strength and a 49% reduction in elongation compared to samples printed from the same material in YZ plane. The experimental results show the influence of the printing orientation on the mechanical properties of 3D-printed samples.