Processing tubes from poly (l-lactic acid) (PLLA) by stretch blow moulding (SBM) is used in the manufacture of bioresorbable vascular scaffolds (BVS) to improve their mechanical performance. To better understand this processing technique, a novel experimental setup by free stretch blow inside a water bath was developed to visualise the tube forming process and analyse the deformation behaviour. PLLA tubes were heated, stretched and blown with no mould present inside a temperature-controlled water bath whilst recording the processing parameters (axial force, inflation pressure). The onset of pressure activation relative to the axial stretch was controlled deliberately to produce a simultaneous (SIM) or sequential (SEQ) mode of deformation. Real-time images of the tube during forming were captured using high speed cameras and the surface strain of the patterned tube was extracted using digital image correlation (DIC). The deformation characteristics of PLLA tubes in SBM was quantified by analysis of shape evolution, strain history and stress-strain relationship.
|Number of pages||15|
|Journal||International Journal of Material Forming|
|Early online date||17 Jan 2020|
|Publication status||Published - 1 May 2021|
Bibliographical noteCopyright The Author(s) 2020. Open Access - This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were
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Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 691238 involving Italian National Agency for New Technologies, Energy and Sustainable Economic Development (Italy), University of Warwick (UK), Queen’s University Belfast (UK) and California Institute of Technology (US). The PhD scholarship was funded by Queen’s University Belfast and China Scholarship Council.
- Experimental characterisation
- Free stretch blow
- Water bath