Characterisation of heterogeneous Dorper fleece and comparative performance of Dorper and Merino felted textiles

Purpose This study aims to characterise heterogeneous Dorper fleece and compare the properties of wet-felted textiles manufactured separately from unseparated Dorper fleece and Merino wool. Design/methodology/approach Surface and cross-sectional morphology, bulk mean fibre diameter, fibre length and crimp frequency were evaluated. Wet-felt panels were manufactured independently from each pooled fibre lot under matched conditions and tested for thickness, bending stiffness, moisture regain, tensile behaviour, relative water-vapour permeability and thermal resistance. Findings Dorper fleece comprised non-medullated wool fibres and medullated hair fibres with distinct morphological and crimp characteristics. The unseparated fleece was successfully converted into coherent wet felt. Dorper felt was found to have greater thickness, bending length and flexural rigidity than Merino felt. It also exhibited higher thermal resistance and greater displacement at maximum load. However, its relative water-vapour permeability and maximum load at rupture were lower. Moisture regains did not differ significantly between the felts. The greater thermal resistance of Dorper felt was consistent with its greater thickness and could not be attributed solely to fibre composition. Originality/value This study links the heterogeneity of unseparated Dorper fleece to the measured performance of a wet-felted textile and compares this performance with that of Merino felt produced under matched conditions. It provides evidence for valorising an underused agricultural by-product while identifying the testing needed for specific end uses.