There have been continuing efforts toward improving printability and minimizing defects in 3D‐printed functional polymers and polymer nanocomposites (PNCs). While printability is essentially material related, and formation of defects is largely influenced by operational parameters, there is an interconnection between the factors influencing both. It is important to have a comprehensive insight on how these aspects interrelate to increase the prospect of improving part performance and widening the current range of applications of 3D‐printed polymer‐based functional materials. Therefore, this work first reviews various polymer 3D printing techniques and recent advances in 3D‐printed functional polymers and PNCs before discussing characterization and control of common defects in printed parts. Techniques for improving printability of polymer‐based functional materials are then discussed. Some opportunities for further developments in this area are highlighted in respect of polymer blending, immiscible blend nanocomposites, and a specific product development prospect.

This paper draws on previous work by the authors that aimed to use functional prototypes, produced using additive manufacturing (AM), as a means to draw customer input and preferences into the development of new products. This technique is referred to as Customer Interaction through Functional Prototypes (CIFP). The CIFP philosophy has been proven in both consumer and medical products. In recent years, the authors have developed further concepts of AM-enabled enhanced consumer involvement within their respective research teams. This paper discusses the extended use of CIFP to develop innovative new product concepts in the Vaal University of Technology, to support grantholders of the Industrial Development's Corporation (IDC) Support Programme for Industrial Innovation (SPII) and the Technology and Innovation Agency (TIA). The paper goes on to discuss a novel method of consumer interaction developed at Loughborough University, referred to as a Computer-aided Consumer Design (CaCODE). This technique allows nondesigners to take an existing product design (e.g., a pen) and modify its shape in real time, in order to create a customised version of the product that meets their needs. The modification is limited within pre-defined parameters to make sure that any final design is functional and can be produced using AM. OPSOMMINGHierdie artikel is geskoei op die gebruik van toevoegingsvervaardiging om kliënt insette en voorkeure in te sluit by die ontwikkeling van nuwe produkte. Die tegniek word die Kliënt Interaksie deur Funksionele Prototipes (CIFP) genoem. Die CIFP filosofie is al bewys in verbruikers-en mediese produkte. Verdere konsepte vir die gebruik van toevoegingsvervaardiging om kliënt betrokkenheid te bevorder is die die outeurs ontwikkel. Hierdie artikel bespreek die uitgebreide gebruik van CIFP om innoverende nuwe produkte te ontwikkel by die Vaal Universiteit van Tegnologie ter ondersteuning van navorsers wat steun van die Industriële Ontwikellings Korporasie (IDC) en die Tegnologie en Innovasie Agentskap (TIA) ontvang. Die artikel bespreek verder 'n nuwe metode vir verbruiker interaksie soos ontwikkel by Loughborough Universiteit, bekend as Rekenaar gesteunde Verbruiker Ontwerp (CaCode). Dié tegniek laat ontwerp-leke toe om 'n bestaande produk aan te pas om aan hulle vereistes te voldoen. Hierdie aanpassing is beperk binne voorafbepaalde parameters om te verseker dat die finale ontwerp funksioneel en vervaardigbaar is.

The development of an effective powder utilization is key to maximizing the potential of polyamide 12 (PA 12) for commercial laser‐based powder bed fusion of polymers (PBF‐LB/P). This requires an extensive study of relationships between the powder reuse extent, macroscopic properties of the powder, and mechanical properties of sintered parts. This work investigates the effects of the extent of PA 12 powder reuse during PBF‐LB/P on the powder's degradation degree and mechanical properties of the sintered parts. Powder reuse extent was expressed in terms of cumulative build time while degradation degree was assessed in terms of deviations in the properties of the reused powders from those of virgin powder. Increase in the powder reuse extent led to increased thickness of crystallite, melting temperature, and sintering window of the powder while the crystallization temperature, crystallinity degree, and melt flow rate decreased with increased reuse extent. The mechanical strength and modulus of the sintered parts initially decreased with an increase in number of build cycles to reach a minimum at the sixth build cycle, after which it increased. This study is a step further towards achieving an efficient PA 12 powder management and a systematic control of quality of sintered parts.

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The effects of cumulative build time during the reuse of polyamide 12 (PA 12) for laser sintering (LS) on the morphology, size and shape distribution of the feedstock powder and quality of printed parts were investigated in this study. Both the virgin and reused powders contain potato-shaped, elongated, and relatively few near-spherical particles. In agreement with the scanning electron microscope images, the circularity-roundness plots also indicate presence of near-spherical, potato-shape, and elongated particles in the virgin and reused powders. Particle size distributions of the powders revealed an increase in the proportion of fine particles at higher reuse cycles, which is due to cracking and fragmenting during repeated exposure to the high processing temperature during LS. Mild orange peel was observed at a cumulative build time of 36.4 h, which becomes more evident with increase of the build time. Moreover, the presence of surface defects could be observed at cumulative build times greater than 36.4 h, and all the parts exhibit deviation in average thickness and width from the desired values.