Purpose: – The purpose of this paper is to investigate the adhesion of polymer materials printed directly onto fabrics using entry-level fused deposition modelling (FDM) machines. A series of functional and decorative parts were designed to explore the limitations and to identify potential applications.Design/methodology/approach: – A series of shapes and structures were designed as 3D computer-aided design (CAD) solids to determine whether complex parts could be printed directly onto the surface of fabrics. The structures were fabricated using an entry-level FDM printer with acrylonitrile butadiene styrene, polylactic acid (PLA) and nylon on eight different types of synthetic and man-made woven and knit fabrics. The results were recorded according to four parameters – the warp, bond, print quality and flex – before comparing the data sets.Findings: – Among the three polymers, PLA showed the best results when printed on the eight different types of fabrics, having extremely good adhesion with little warp, yet displaying a high quality of print with good flexural strength. For the fabrics, woven cotton, woven polywool and knit soy had excellent adhesion when the three polymers were deposited.Research limitations/implications: – Future work should cover a wider range of polymers and textiles and incorporate more functional features for testing. Other aspects include modifying the fibre surface through mechanical or chemical means to achieve a more efficient adhesion with the fibre and examining the deposition process in terms of temperature, pressure and build density. Future work should also investigate the feasibility for large-scale production.Practical implications: – This paper supports work on wearable electronics by integrating comfortable textiles with hard wearing parts without compromising on quality and fit and combining additive manufacturing processes with textiles to maintain the drape characteristics of the fabric. Polymer–textile deposition will contribute to new applications and functional products such as orthopaedic braces for medical use or for decorative features such as buttons and trimmings for garments.Originality/value: – This paper has contributed to new knowledge by providing a better understanding of polymer materials being printed directly onto fabrics using entry-level FDM machines.

Purpose: – The purpose of this article is to reviews state-of-the-art developments in four-dimensional (4D) printing, discuss what it is, investigate new applications that have been discovered and suggest its future impact. Design/methodology/approach: – The article clarifies the definition of 4D printing and describes notable examples covering material science, equipment and applications. Findings: – This article highlights an emerging technology cycle where 4D printing research has gained traction within additive manufacturing. The use of stimuli-responsive materials can be programmed and printed to enable pre-determined reactions when subject to external stimuli. Originality/value: – This article reviews state-of-the-art developments in 4D printing, discusses what it is, investigates new applications that have been discovered and suggests its future impact.

4D printing utilizes additive manufacturing methods to produce stimulus-responsive components that can change its shape from one to another when subject to appropriate stimuli. The use of 4D printing technology is expected to significantly become more widespread with more applications across bio-medical, aerospace, and defence industries. This paper discusses emerging applications for 4D printing and suitable stimulus-responsive materials for 4D printing. In terms of designing for 4D printing, aspects of the shape memory effect (SME) including one-way SMEs, two-way SMEs and three-way SMEs are presented. Materials and structures in the form of homogenous compositions and heterogeneous compositions are discussed, as well as different types of shape-shifting behaviours such as self-folding, self-assemblies, and self-dis-assemblies. Finally, current software and examples are presented together with the existing limitations that need to be overcome to achieve widespread adoption of 4D printing.

Material extrusion (ME) systems offer end-users with a more affordable and accessible additive manufacturing (AM) technology compared to other processes in the market. ME is often used to quickly produce low-cost prototyping with the freedom of scalability where parts can be produced in different geometries, quantities and sizes. As the use of desktop ME machines has gained widespread adoption, this review paper discusses the key design strategies and considerations to produce high quality ME parts, as well as providing actional advice to aid end-users in quickly identifying and efficiently troubleshooting issues since current information is often fragmented and incomplete. The systemic issues and solutions concerning desktop ME processes discussed are not machine-specific, covering categories according to printer-associated, deposition-associated and print quality problems. The findings show that the majority of issues are associated with incorrect printer calibration and parameters, hardware, material, Computer Aided Design (CAD) model and/or slicing settings. A chart for an overview of ME troubleshooting is presented allowing designers and engineers to straightforwardly determine the possible contributing factors to a particular problem.