Background: Jigat bark is a key important binding material in the agarbatti industry owing to its excellent adhesive property. However, owing to lack of mechanization, debarking is still mostly performed by manual operation, increasing human effort and decreasing the overall output. To support the design of a mechanized debarking machine, this study examined the effects of rake angle and blade thickness on piercing force, insertion depth and overall debarking efficiency. 
 
Methods: The experiments were conducted with the help of piercing force setup, it consisting of an S-type load cell, chisel, bark gauge/steel ruler and digital indicator with four rake angles (30&deg;, 40&deg;, 50&deg; and 90&deg;) and three blade thicknesses (1, 2 and 3 mm). 
 
Result: Two-way analysis of variance showed that the rake angle significantly influenced the piercing force [F (3,48) = 19.45, p = 2.16 x 10-8] and insertion depth [F (3,48) = 74.95, p = 3.95 x 10-18]. The blade thickness also significantly affected the piercing force [F (2,48) = 3.68, p = 0.0327] and insertion depth [F (2,48) = 4.60, p = 0.0149]. No significant interactions were detected during the evaluation, suggesting that both variables functioned independently. According to the regression analysis, observed that piercing force increased with blade thickness (c = 0.467, p = 0.015) and rake angle (b = 0.443, p = 0.039). The force-normalized insertion compliance (&ccedil; = D/F) declined as the thickness of the blade increased (c = -0.79, p = 0.013). Bark&rsquo;s hardness was measured at 490 N, 50% compression and 5 mm penetration and its average moisture content was 58.4%. For practical debarking, a 2 mm blade was chosen because it was more durability and better suited for repeated impact, even though a 1 mm blade with a 40&deg; rake angle needed less piercing force.

Optimization of Blade Geometry and its Orientation based on Piercing Force for Debarking Jigat Trees