Deformation Properties of 3D Printed Shape Memory Polymer

Abstract

Recently, the 3D printer which can make products in a short time without cutting or casting has been attracted worldwide attention. If we use the 3D printer, it is possible that a customized product which is well suited to the individual is fabricated with low cost and in a short time. On the other hand, in the intelligent materials, shape memory polymer (SMP) has been practically used. In SMP, shape fixity and shape recovery appear based on the difference of properties of molecular motion between above and below the glass transition temperature in temperature variation. The thermomechanical property of SMP is close to that of the human body around glass the transition temperature. Since SMP has these characteristics, it can be applied to the elements coming into contact with body as a nursing-care robot in the medical field. Hence, if we make a product with SMP using the 3D printer, the new device which is well suited to the individual can be developed. In the present paper, the deformation properties of SMP made by the fused deposition modeling (FDM) 3D printer were investigated. The results obtained are as follows. (1) The deformation resistance and recovery strain in unloading of the 3D printed SMP under a low printing rate are higher and larger than these of the high printing rate. (2) If we heat the 3D printed SMP under a high printing rate, it does not recover the original shape perfectly since the residual stress appears during printing.