Glossary of terms for defects in knitted fabrics

In recent years, coated fabrics have become the major material used in membrane structures. Due to the special structure of base layer and mechanical properties, coated biaxial warp-knitted fabrics are increasingly applied in pneumatic structures. In this article, the mechanical properties of coated biaxial warp-knitted fabrics are investigated comprehensively. First, off-axial tensile tests are carried out in seven in-plane directions: 0°, 15°, 30°, 45°, 60°, 75°, and 90°. Based on the stress–strain relationship, tensile strengths are obtained and failure modes are studied. The adaptability of Tsai–Hill criterion is analyzed. Then, the uniaxial tensile creep test is performed under 24-h sustained load and the creep elongation is calculated. Besides, tearing strengths in warp and weft directions are obtained by tearing tests. Finally, the biaxial tensile tests under five different load ratios of 1:1, 2:1, 1:2, 1:0, and 0:1 are carried out, and the elastic constants and Poisson’s ratio are calculated using the least squares method based on linear orthotropic assumption. Moreover, biaxial specimens under four load ratios of 3:1, 1:3, 5:1, and 1:5 are further tensile tested to verify the adaptability of linear orthotropic model. These experimental data offer a deeper and comprehensive understanding of mechanical properties of coated biaxial warp-knitted fabrics and could be conveniently adopted in structural design.

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An evaluation and characterization study of knitted fabrics for use as telecommunication device substrate

Journal of Materials Research and Technology ◽

10.1016/j.jmrt.2021.04.002 ◽

2021 ◽

Author(s):

Marcos Aquino ◽

Juan Guerra ◽

Samanta Holanda ◽

Humberto Andrade ◽

Moises Melo ◽

...

Keyword(s):

Knitted Fabrics ◽

Characterization Study

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A New Geometric Model of Laid-in Weft-Knitted Fabrics

Textile Research Journal ◽

10.1177/0040517521992765 ◽

2021 ◽

pp. 004051752199276

Author(s):

Ki Wai Fong ◽

Si Qing Li ◽

Rong Liu

Keyword(s):

Cost Estimation ◽

Geometric Model ◽

Three Dimensional ◽

Wearable Electronics ◽

Material Consumption ◽

Knitted Fabrics ◽

Functional Textiles ◽

Loop Pattern ◽

Spatial Configurations ◽

Consumption Prediction

Inlay yarn and laid-in structures are important technical knitting elements that have been increasingly applied in the structural design of functional textiles in industrial, medical, and wearable electronics fields. However, there is no currently established geometric model to numerically analyze their spatial morphologies and structural properties. This study presents a new geometric model and numerical analysis approach to characterize spatial configurations of inlay yarn and ground yarn in a three-dimensional scenario for laid-in weft-knitted fabrics. Loop lengths of the inlay and ground yarn materials were calculated and analyzed under different contact and deformation conditions to estimate material consumption in this complex interlooping layout. Series of laid-in weft-knitted fabrics made of different combinations of ground and inlay yarns were fabricated with the 1 × 1 laid-in loop pattern and tested for the model validation. The comparisons between the experimental and calculated results indicated that the newly developed geometric model favorably agreed with the experimental measurements regarding the ground loop lengths and inlay loop lengths applied in the laid-in weft-knitted structures. The results indicated the applicability of the developed geometric model of laid-in weft-knitted fabrics with similar structural patterns in practical use. The output of this study provides a theoretical and practical reference for structural and physical properties analysis, material consumption prediction, even cost estimation of laid-in weft-knitted fabrics.

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