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1

Analysis of Mechanical Behavior of Different Needle Tip Shapes During Puncture of Carbon Fiber Fabric

Yang Jingzhao, Dong Jiuzhi, Chen Yunjun, Jiang Xiuming

Autex Research Journal

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2022

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Vol. 22, no. 3

318--329

EN

In the present study, the fiber-bending around the needle during the piercing process of the carbon fabric is investigated. In this regard, a mathematical model is established to investigate the bending elongation of the carbon fiber around the needle and the interaction between the carbon fiber and the needle tip. Then the mechanical behavior of the carbon fabric when moving down the tip of the steel needle is analyzed. Based on the performed analysis, a shape curve equation that satisfies the puncture needle tip is established. Furthermore, the influence of different needle tip shapes on the mechanical behavior of the carbon fiber is analyzed. The performance of the needle tip is subjected to different loads, including the puncture template, horizontal tension of the fiber to the needle tip, frictional resistance between the fiber and the needle tip, sliding force, and the bending moment. The performed analysis shows that when the shape of the needle tip assumes the form of curve 10, the downward force, horizontal tension, friction resistance, sliding force, and bending moment are minimized. Accordingly, curve 10 is proposed as the optimal shape for the needle tip. The present study is expected to provide theoretical guidance for selecting overall puncture process parameters.

2

Geometric Characteristic of a Sewing Needle Applied in Clothing Manufacture Technology with Reference to Elastic Critical Statically Balance Loads – A Comparative Study

Hashima Wael A.

Fibres & Textiles in Eastern Europe

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2021

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Vol. 29, no. 3 (147)

86--90

EN

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 l = 60 mm, and ϕ = 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: Ι0 (Ι1) = 1.9615 (Ε – 12) m4 and (Ι2) = 2.0516 (Ε – 13) m4. The upper partial lenght a = 31.2 mm, while the lower partial lenght b = 28.2 mm. The value of the critical load is 110 N, while the Euler load Ρ e = 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 Ρ cr = 57 N, the Euler load Ρ e = 118 N, and γ = 3.13. For the line diagram of a sewing needle with a constant cross-section ϕ = 1.965 mm, l = 7.3185 (Ε – 13) m4, (formula) & η = 2.467. Then Ρ cr = 103 N, Ρ e = 413 N & (formula). For a sewing needle a constant cross-section and the penetration load is uniformly distributed, the geometric characterictic is found to be ῆ = 7.839, γ = 1.22, Ρ cr = Ρ cr(ql)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.

PL

W pracy badano igłę do szycia stosowaną w przemysłowej maszynie do szycia. Do badań użyto dwustopniowej igły do szycia o wymiarach: dł. = 60 mm, ϕ = 2.5 mm i średnicy 1.45 mm. Igłę potraktowano jako kolumnę z nieruchomym i wolnym końcem, z dwiema sekcjami: Ι0 (Ι1) = 1.9615 (E – 12) m4 oraz (I2) = 2.0516 (E – 13) m4. Górna długość częściowa wynosiła: a = 31.2 mm, podczas gdy dolna długość częściowa to: b = 28.2 mm. Celem pracy było otwarcie jeszcze nietkniętych obszarów dla bardziej intensywnych badań akademickich i eksperymentalnych w zakresie wpływu sił penetracji na obciążenia krytyczne.

3

Comparative Study of Needle Penetration Forces in Sewing Hems on Toweling Terry Fabrics: Influence of Needle Type and Size

Carvalho Manuel, Rocha Ana Maria, Carvalho Helder

Autex Research Journal

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2020

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Vol. 20, no. 2

194--202

EN

In this paper, an industrial case study comparing the use of different needles in the production of hems in towels is presented. The study aims to assess the sewability of the fabrics, quantified by needle penetration forces. The market offers an interesting range of options for the needle, regarding the geometry of the needle point, surface finishing, and sizes. However, in practice, the choice is difficult, namely due to the lack of quantitative data that may support the empirical evaluation made by the sewing technicians. The work aims to assess how the needle type and size relate to the resulting needle penetration forces. Three terry fabric structures, produced by a home textiles manufacturer, were tested using needles of different sizes, points, and coatings. Needle penetration forces were measured on a sewability tester prototype, previously designed and developed, based on an instrumented overedge sewing machine. It was found that needle penetration forces present very significant differences with small size increments, needle coating also influences forces significantly, and different needle points produce only slight differences, significant only on some of the fabrics that were tested.

4

(Bez)problemowa segregacja?

Masłowska-Bandosz M.

Recykling

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2016

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nr 2

73

5

Effect of thread structure on tension peaks during lock stitch sewing

Rengasamy R. S., Wesley D. S.

Autex Research Journal

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2011

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Vol. 11, no. 1

1--5

EN

A dynamic sewing tension study was carried out with a tension probe on sewing threads with different structures, physical and tensile characteristics in a single needle lock stitch sewing machine. The needle thread recorded four major tension peaks corresponding to events occurring during sewing; bobbin thread withdrawal, stitch tightening, needle piercing the fabric and tightening of the needle thread around the shuttle, among which stitch tightening caused the maximum tension for all threads. Polyester filament and spun polyester threads exhibited the highest and lowest tightening tension, respectively . Multiple regression analysis showed that pre-tension and elastic modulus show positive influences while tex, bending, rigidity and compressibility of threads show negative effects on tension peaks during tightening and needle piercing. Sewing speed shows a positive impact only on the tension peak due to needle piercing. Pre-tension showed a prominent influence on tension peaks on all threads while the number of fabric layers failed to show any effect.

6

Funkcje igły w procesie szycia

Decka S.

Przegląd Włókienniczy - Włókno, Odzież, Skóra

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2009

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nr 3

44-47