Tensile strength and elongation of hemp and sisal ropes at different temperatures.

Temperature and humidity sensor-cables used in grain bins are currently made of steel or synthetic materials. The potential use of natural fibres as cables was tested. The natural fibres selected for this study were hemp and sisal. The tensile strength and extension of hemp and sisal ropes with diameters of 6, 8, or 10 mm were measured at various temperatures ranging from -40°C to +60°C. The hemp ropes had significantly higher tensile strength than the sisal ropes for all three tested diameters. The tensile strength of the fibres examined was not significantly affected by freezing temperatures but was significantly lowered at 60°C, and did not increase linearly with increase in diameter.