Preparation of 3D Printable HAp-based Composite Powder for Binder Jetting Process

Abstract

The purpose of this study was to prepare a 3D printable powder composed of hydroxyapatite and biocompatible polymers such as chitosan, dextrin, and polyvinylpyrrolidone for the binder jetting process. The relationship between powder properties such as flowability and particle size distribution, as well as printing quality were investigated in the binder jetting process. For this purpose, 3D printable powder and an appropriate solvent were designed and demonstrated by hydroxyapatite and water-soluble polymers such as carboxymethyl chitosan, dextrin, and PVP. Results showed that a combination of 60%wt. hydroxyapatite, 28%wt. carboxymethyl chitosan, 10% wt. dextrin, and 2% wt. PVP, with controlled particle size distribution according to the Dinger-Funk equation led to the best print quality. Finally, flash dipping of the 3D printed parts in chitosan solution resulted in increases of compressive and Young's modulus from 1.3 and 10 MPa to 7.4 and 125 MPa, respectively.

Mechanical characterization of additively manufactured polymer composites: A state‐of‐the‐art review and future scope

“…After dipping the specimens in chitosan solution, the average porosity and density decreased, enhancing overall strength. [ 153 ] The geometrical accuracy of the samples produced from the formulation having a mixture of HA powder with 30 wt% PVA was greater than 85%, and they had a green compressive strength of 5.63 ± 0.27 MPa, which was 500% higher than the standard binder jetting powders. The polyvinyl alcohol (PVOH) powder, which has good adhesive properties, improves the specimens' bonding, increasing the strength.…”

“…Table 6 shows several studies have been conducted on the parameters of the printers to observe their effect on the mechanical properties of printed parts. [153][154][155][156][157][158][159][160]162] The best print quality was achieved by Dini et al [153] using a blend of 60 wt %, HA, 28 wt%, carboxymethyl chitosan, 10 wt%, dextrin, and 2wt%, polyvinylpyrrolidone, with regulated particle size distribution. Finally, after being dipped in a chitosan solution, the compressive strength Young's moduli of the 3D printed pieces increased from 1.3 and 10 MPa to 7.4 and 125 MPa, respectively.…”