Elastic Modulus of Tangkin as the Indigenous Woven Back Pack from Dayak People in West Kalimantan

Tangkin is an indigenous woven bag produced by Dayak tribe in West Kalimantan, which usually used to carry heavy luggage from forest garden to take home and vice versa. This paper aims to predict the elasticity modulus of Tangkin and identify factors which influenced it. Modulus elasticity reduced from Hooke’s Law experiment, by using tensile test method, pulled by external force from 5.0 – 40 N. There is three Tangkin’s miniature assessed. They are made from bamboo, brace-less configuration, and have typical pattern of woven for each other. The pattern of woven has alliance with finite geometric series mathematics method by using Math Lab. The stress-strain graph presented the elasticity characterisation of Tangkin is still in Hooke’s Law area. Tangkin’s elastic modulus tends to increase in longer height of cylinder-like, but decrease on larger surface area. It means the toughness Tangkin will obtained with skinny but long shape. The elastic modulus value of Tangkin 1, Tangkin 2, and Tangkin 3 equal to 5909.1 Pa, 5267.4 Pa and 4550.8 Pa respectively. The weave pattern also influenced the elastic modulus, due to the force distribute direction. The pattern that have tendency to direct the force distribution oppositely from gravitational direction, will increase the strength of Tangkin. Meanwhile the slope of direction of force distribution will twisted the tangkin. This research can be useful for stage manage the alternative elasticity practical based on indigenous physics.