Impact of Compaction Treatments on PET Yarns Used for Vascular Prostheses Manufacturing

Textile cardiovascular prostheses are tubular structures made of polyester filaments. Woven prostheses are naturally tight but knitted ones are porous and can involve blood haemorrhage. Although compaction is necessary to reduce water permeability of knitted prostheses used for arterial replacement, it can induce degradation of mechanical properties of poly(ethylene terephthalate) (PET) yarns. We have studied the effect of chemical and thermal compaction process parameters on the physical and mechanical properties of PET yarns used for vascular prostheses manufacturing in order to find compaction systems that do not provoke important changes in the material characteristics. After chemical and thermal compactions, all yarn samples displayed longitudinal shrinkage accompanied by lateral swelling and a loss of mechanical properties. The analysis of chemical compaction results showed that fibre shrinkage and swelling are linked to the sizes of solvents molecules and immersion duration. Compaction performances in thermal process are widely linked to treatment temperature. The effect of the two compaction treatments on a PET single jersey fabric permeability was studied as well.