Abstract
The relationship between knot characteristics and breaking mechanisms was investigated for the model filament of a poly(vinylidene fluoride) fishing line. The colouring procedure adopted in this study enabled us to define the accurate breaking position within the knots. Comparison of the breaking positions of a series of torus knots suggested that the breaking position gradually shifted from inside to outside the knots with increasing crossing number. Interestingly, a corresponding effect of knot geometry was also recognized as the synchronized decrease of tensile strength of the knotted filaments. The morphological observation of the fractured tips obtained after tensile breaking revealed that both squeezing and rotation identified for each knot predominantly determined the position and strength of the knot.