Printability of elastomer as a 3D printing material for additive manufacturing

Additive manufacturing (AM) involves creating prototypes by depositing and solidifying material by the placement of material in X, Y, and Z axes in a 3D space. The emergence of AM using elastomers has allowed the production of complex and customised parts with intricate geometries and modified properties as per specific needs of engineers cum designers. For successful 3D printing (3DP), it is crucial to use a material that is suitable for the specific application and printing process. Elastomers are unique polymers that are resilient, flexible and capable of deforming under stress. Fused deposition modelling, stereolithography and selective laser sintering printing are the most common 3DP techniques for elastomers. The use of elastomers in AM is limited due to technological, material and processing constraints. Despite challenges, elastomers have great potential in AM and can be applied in various industries namely automotive, aerospace, healthcare and consumer goods. However, there is a growing interest in expanding the range of elastomers that can be 3D printed. Researchers are experimenting with different approaches to enhance the printability of elastomers such as modifying material composition, material design, optimising printing parameters, control of chemical composition and 3DP techniques. Recent advancements in the structure, properties and printing techniques of elastomers show wide scope for improving their printability. Several elastomeric materials that can be 3D printed include thermoplastic elastomer, thermoplastic polyurethane, liquid silicone rubber, etc. This review paper aims at providing an overview of the current state of AM of elastomers, including the challenges and limitations. It discusses recent advancements and suggests ways to enhance the printability of elastomers in near future, which can help researchers and industry professionals to explore new and unique AM applications.