Abstract:

A production technology for agricultural biodegradable strings composed of polylactide (PLA) staple fibres was developed that uses the ring spinning method. During complete relaxation, strings with an unbalanced twist tend to detwist because of torque, which can be eliminated by thermal stabilisation. This study assessed the effects of fibre twist stabilisation on the PLA crystalline structure and also analysed the effect of those crystalline structure changes on strength. In addition, some strings were dyed a dark colour to analyse the effect of dyeing on the structural and physical properties. Dyeing at 80 - 90 ºC with a TERASIL Schwarz B, dyeing with a TERASIL Schwarz W-NS without a carrier and stabilising undyed strings in water at 80 ºC resulted in considerable reduction in unbalanced twist while maintaining a reasonable tenacity of 10 cN/tex. The quality of the strings processed met the requirements for application in horticulture.