Influence of mold pressurization on cycle time in rotational molding composites with welded ignimbrite as loading

Abstract

In the context of rising energy costs and climate emergencies, there is a need to incorporate novel procedures or materials to meet sustainability requirements and increase the efficiency of processes and use of resources. Although rotational molding might seem disadvantageous due to the long cycle times and high energy consumption, its inherent advantages, including the production of hollow parts of any size without wasting materials, with good surface reproducibility and no internal stresses, using cost-effective tooling remain noteworthy. To address energy consumption concerns, increase productivity, and enhance the environmental footprint of rotomolded products, this work proposes the incorporation of residual welded ignimbrite from quarries, a dusty material with over 60 % of SiO2, combined with the mold pressurization, finding a 4 % reduction of total cycle time with ignimbrite, which is further shortened to 12 % when pressure is applied. Particularly notable is the reduction 27 % reduction in oven time when using ignimbrite at 10 % under pressure. The thermomechanical and rheological characterizations revealno adverse effects either by the use of pressure or the mineral dust, thus establishing a viable alternative for energy (and cost) reduction. Besides, the obtained parts show good aesthetics, a stone-like aspect, which might provide additional features for applications such as outdoor furniture or storage tanks.