An Investigation of the Penetration Force Profile of the Sewing Machine Needle Point

The distributions of the tangential and radial stresses acting on the yam of a fabric during sewing as the sewing needle is inserted into the fabric have been discussed by means of the mechanical principles of elasticity. The influence on the needle penetration force caused by the shape of the cross section and the profile curve at the needle point has also been investigated. It is suggested that five parameters. i.e., the mechanical properties of the textile material k, the variation ratio y' of the needle radius, the contacting arc length θ. the frictional coefficient μ and the sewing machine speed v are the main factors that determine the penetration force of the sewing needle. The variation ratio y', or the slope at any point of the needle profile, is the most important factor for needle design. Depending on the analysis of the forces acting on the needle surface, an optimum profile curve has been obtained. If this curve is used as a new sewing needle profile, the penetration force can possibly be reduced by up to 20%.