This study is about the effect of some mechanical properties on poly-cotton (PC) fabric produced by keeping cotton as constant warp and having cotton and PC blend in weft with different pick ratio. It was observed that fabric having PC and cotton in 1:1 ratio in weft shows the highest value in mechanical properties. It can be concluded that anatomical difference plays a very important role in fabric properties.

Introduction

In the Indian market, PC blends have obtained substantial vogue. Remarkable cost limiting by reduction of polyester content in PC fabrics is achievable without affecting consumer interest.1 Fibre type, crimp, blend type, contraction and yarn structure affect fabric frictional properties.2By increasing polyester content, breaking strength and extensibility of polyester-viscose blend can be increased.3According to a study, the effect of finishing stages, i.e. scouring, bleaching, mercerisation and dyeing, on mechanical properties of PC blend fabric results in softened fabric after scouring and dyeing, whereas it gets stiffened after mercerisation and heat setting. Bending hysteresis, shear hysteresis and bending rigidity values decrease after finishing.4

As far as the effect of yarn properties on mechanical properties of fabric are concerned, thread pulling out force is inversely proportional, whereas thread breaking strength is directly proportional to tearing strength of the fabric. Strength of the fabric is also influenced by cover factor.5 There is a statistical model for predicting the strength of PC blend.6 With increase in warp and weft insertion frequencies, weight of fabric also increases. And fibre-type influences change in fabric thickness7.

Materials and methods

Materials: Fabric is produced by using polyester-cotton blend in weft having a blend ratio of 65:35 of 34s count. The 38 mm staple polyester fibre has a linear mass density of 1.2 denier, whereas cotton is having a micronaire value of 4. The blend ratio of polyester to cotton in the yarn is 65:35.

Five samples were prepared with cotton in warp and cotton and PC in weft at different pick ratio and plain as weave. In sequence sample 1 has cotton to PC ratio is 1:1, sample 2 is made by taking cotton both in warp as well as in weft, sample 3 has cotton in warp and PC in weft, sample 4 has cotton to PC ratio of 1:2, and sample 5 has the same ratio of 2:1.

Methods: Testing is done by standard methods and at 270 C and 67 per cent RH.

Three mechanical tests were examined. Breaking strength and elongation at break were examined by ASTM D5035 and abrasion resistance was examined by ASTM D3884. ASTM International, formerly known as American Society for Testing and Materials, is an international standards organisation that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems and services.

  • Fabric breaking strength: Also known as tearing strength, it refers to the supreme tensile force when material is extended to smash. And it is used to assess the potential of fabric to withstand tensile harm.

  • Factors affecting strength are the strength of a single thread, structure-higher strength is observed in loosely-structured fabric, smooth yarns (show higher strength), thread movement (whose reduction results in a fall in strength), and special fabric finish like crease-resist (that reduce strength).