On the process capability of the solid free-form fabrication: A case study of scaffold moulds for tissue engineering

Abstract

This study applies the methodology and procedure of process capability to investigate a solid free-form fabrication technique as a manufacturing method to produce scaffold moulds for tissue engineering. The process capability Cpk and process performance Ppk of scaffold mould manufacture using a solid free-form fabrication technique has been analysed with respect to the dimension deviations. A solid free-form fabrication machine T66 was used to fabricate scaffold moulds in this study and is able to create features that ranged from 200 microm to 1000 microm. The analysis showed that the printing process under the normal cooling conditions of the printing chamber was in statistical control but gave low process capability indices, indicating that the process was 'inadequate' for production of 'dimension-consistent' scaffold moulds. The study demonstrates that, by lowering the temperature of the cooling conditions, the capability Cpk of the printing process can be improved (about threefold) sufficiently to ensure the consistent production of scaffold moulds with dimension characteristics within their specification limits.

A combined additive layer manufacturing / indirect replication method to prototype 3D vascular-like structures of soft tissue and endocrine organs

“…The minimum feature size is classically guaranteed around 0.01 mm by machine manufacturers, but this value can vary consistently depending on the feature orientation in the building volume (Sachlos et al 2003, Liu et al 2008. If the small feature is not a thin laying on a bulky substrate, like a hole or a step, but a self-standing branch in a ramified structure, our results show that the minimal dimension for reconstruction may rise up to approximately 0.5 mm.…”

Human cell culture process capability: a comparison of manual and automated production

“…Process capability analysis approaches have been widely used in mature industry sectors such as the electronics, pharmaceutical and medical devices sectors, typically within quality-by-design frameworks and continuous quality improvement programmes (US FDA, 2004b;Yang and Liu, 2005;Pearn and Wu, 2005;Liu et al, 2008;Cogdill and Drennen, 2008). In accordance with current regulatory drivers under Good Manufacturing Practice and the new European Union Tissues and Cells Directives (ATMP, 2007), these approaches, as part of a quality function early in development, are likely to be equally important to gaining better process understanding and control of emerging cell-based therapy products and their manufacturing processes, particularly to minimize product quality variation, non-conformance and delays in product approval.…”