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In this work a sewing needle of an industrial commercial sewing machine is investigated from the different points of view of geometrical and critical elastic statistical balance. The dimensions of the sewing needle are = 60 mm, and = 2.5 mm and 1.45 mm diameter for the two stepped needle. The needle is treated as a fixed – free end column, with two sections: I0 (I1) = 1.9615 (E – 12) m4 and (I2) = 2.0516 (E – 13) m4. The upper partial length a = 31.2 mm, while the lower partial length b = 28.2 mm. The value of the critical load is 110 N, while the Euler load Pe = 1112 N, then γ = 3.1796. Another approach was used for a line diagram of the truncated cone of the sewing needle, where the critical load Pcr = 57 N, the Euler load Pe = 118 N, and γ = 3.13. For the line diagram of a sewing needle with a constant cross-section = 1.965 mm, I = 7.3185 (E – 13) m4, = 41.8778 N & η = 2.467. Then Pcr = 103 N, Pe = 413 N & γ = = 2. For a sewing needle with a constant cross-section and the penetration load is uniformly distributed, the geometric characteristic is found to be = 7.839, γ = 1.22, Pcr = Pcr()cr = 328 N & q = 5472 N/m (6 N/mm). The present work aims to open as yet untouched areas for more and intensive academic and experimental studies, in the field of how penetration forces affect critical loads. The work is the first step in the evaluation of the mechanics of the industrial sewing needle.

The factors of increasing productivity, reducing the cost and the quality improvement are the most important research concerns in weaving machinery. Increasing the effectiveness and productivity of production were achieved by increasing the operating time and efficiency of weaving looms. Thus, the manufacturers of weaving equipment attempt to minimize factors that limit production speed and production conditions. Heald frame is one of the known parts of the weaving machine that causes vibrations and noise which are important factors that influence high-speed development of looms. In this research work, study of mechanical factors (stresses and vibration) has been investigated for heald shaft. Finite element model of the heald frame was constructed to simulate different type of material. Then some important natural frequencies and vibration modes are calculated and the results. Results show a major improvement with the usage of these different material. As well as the failure of heald shaft is mainly due to friction and vibration and not due to the stresses or weight.

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