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.

通过拉伸吹塑（SBM）对聚（l-乳酸）（PLLA）进行处理的管用于制造可生物吸收的血管支架（BVS），以提高其机械性能。为了更好地理解这种加工技术，开发了一种通过在水浴中自由拉伸吹制的新型实验装置，以可视化管形成过程并分析变形行为。将PLLA管加热，拉伸和吹塑，在温度受控的水浴槽内不留霉菌，同时记录加工参数（轴向力，膨胀压力）。故意控制相对于轴向拉伸的压力激活的开始，以产生同时的（SIM）或顺序的（SEQ）变形模式。使用高速相机捕获管在成型过程中的实时图像，并使用数字图像相关性（DIC）提取图案化管的表面应变。通过分析形状演变，应变历史和应力应变关系，定量分析了SLA中PLLA管的变形特征。