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Fused deposition modelling (FDM) process is one of popular 3D printing technologies, especially on printing polymer materials for a rapid prototyping. The process is well known for its resource saving, with no tooling cost required and minimum energy demand. However, the challenge is that the process performances are highly influenced by selection of parameters. From literature, consideration on material usage and process energy demand in FDM processes is still limited. This study used an L9 Taguchi orthogonal array design in investigating effect of build orientation, printing speed and layer thickness on process energy consumption and total material usage in FDM processes. The p-values from ANOVA analysis revealed that only layer thickness and build orientation had significant effect on the outputs. In minimising material usage, the strategy is to select the correct build orientation to avoid need of support structure. For reducing energy demand, optimum layer thickness needs to be determined by considering other factors such as mechanical properties and surface roughness. This study provides preliminary findings which will benefit FDM users in using resources efficiently. Further studies are required to complement the findings from the aspects of mechanical and physical properties of the printed products.

Recycled carbon fibre (rCF) is used in various applications as measures to reduce the carbon fibre waste in landfill. This study focuses on using rCF in powder form in injection moulded polypropylene (PP) products. The rCF was treated with 0.5 mol/L and 1.0 mol/L nitric acid. The tensile and flexural properties were evaluated and morphological surface of the samples was characterised using scanning electron microscopy (SEM). As the result, higher concentration of nitric acid increased the tensile strength but leads to lower flexural strength. Apart from that, the environmental assessment using OpenLCA software shows that the addition of RCF filler loading leads to reduction of climate change and acidification potential.

In this study, the main objective is to determine effect of recycled carbon fibre (RCF) on the mechanical properties of thermoplastics composites and associated environmental impacts. Such study is important to improve the strength of the composites as previous studies are limited on RCF composites, particularly in environmental aspects. In the compounding stage, extrusion process was carried out by using two different thermoplastics i.e. polypropylene (PP) and acrylonitrile butadience styrene (ABS) mixing with RCF. Particle size and weight loading of RCF were chosen as parameters to be studied. Bonding strength between the RCF and thermoplastics matrix was investigated through tensile and flexural properties. Lastly, the assessment of the products was carried out to determine the environmental impacts. Generally, the incorporation of RCF into PP and ABS plastic increases the tensile and flexural properties of the samples. It can be seen that the addition of rCF significantly improves tensile modulus and flexural strength up to 10 wt% filler loading. From the environmental impact assessment, the ABS products have greater impact in all categories. The usage of rCF reduce the amount of plastic hence leads to lower environmental impacts. The product has a potential to be used in mechanical demanding application particularly those require high flexural strength and tensile modulus properties.

Fibre reinforced composites are widely used in various sectors such as aerospace, wind energy and automotive. Due to its versatility and low cost for rapid prototyping and production applications, additive manufacturing technology has grown exponentially over the past few years. In this paper, performances of glass fibre and carbon fibre reinforced composites in additive manufacturing are reviewed from the perspective of mechanical properties. From the review, the reinforcements generally improve mechanical properties, in particular for tensile modulus and tensile strength. The paper presents a benchmark of additive manufacturing technologies for composite material as well as the spotlights of further research in the usage of carbon and glass fibres in rapid prototyping processes.