Impact of yarn and fabric

parameters on thermal comfort Dr Muhammad Mushtaq Mangat www.mushtaqmangat.org

Impact of yarn and fabric parameters on thermal comfort

  Thermal comfort depends upon the heat and moisture transfer properties of fabric

  Fabric composition plays a significant role in heat and mass transfer

  Yarn is basic building block of fabric

  Yarn structure defines the most of fabric characteristics

Yarn and its characteristics

  Yarn:

  “A continuous strand of twisted threads of natural or synthetic material, such as wool or nylon, used in weaving or knitting”. [The American Heritage® Dictionary of the English Language}

THERMAL COMFORT PROPERTIES OF SOME NEW YARNS

  Study about the thermal comfort properties of polyester yarn was conducted by Marmarali et al [1].

  A brief discussion is in the next pages:

  Researchers have used: A.  Tetra-channel polyester, B.  High functional polyester fiber designed with

slots conduct to siphon effect

C.  Patented blend of natural and synthetic fibres

Knitted fabric used for study

  Single jersey fabrics were knitted produced by using :

  A Type (150den), B Type (150den) and C Type (Ne30/1) yarns.

  Samples were produced in three different tightness values in order to obtain tight, medium and loose fabrics.

  Loop length values or stitch lengths (l) were kept at 4.2, 3.6 and 3.0 mm

  Properly washed without using any detergent

A, B, C yarn and medium tightness [1]

Measuring parameters

  Thermal conductivity,

  Thermal resistance,

  Thermal absorptivity,

  Water vapor permeability

  Air permeability

Measuring instruments

  Alambeta for thermal conductivity, fabric thickness, thermal resistance and thermal absorptivity values

  Permetest for water vapor permeability

  FX3300 for air permeability

Conclusion   Thermal conductivity, thermal resistance, thermal

absorptivity and air permeability are affected from tightness factor significantly.

  The looser fabrics possess high insulation and high air permeability values, also give warmer feelings.

  The comfort test results indicate that the fabrics knitted using C Type yarns have the highestair permeability besides better thermal resistance values and they give warmer feeling with lower absorptivity values.

  On the other hand A and B Type fabrics have similar thermal comfort properties with better relative water vapor permeability [1].

Comfort Characteristics of Fabrics Made of Compact Yarns

  This study was conducted by Das et al. [2] to compare EliTe compact yarns and normal yarns.

  A brief description of this study is given the following slides.

Measuring parameters 1.  Fabric Thickness was measured under specified pressure of 20

gf/cm2 by using Essdiel thickness tester.

2.  Fabric Weight per Unit Area by cutting and weighing of fabric

3.  Air Permeability was measured by TEXTEST Air permeability Tester (FX3300)

4.  Alambeta was used to measure:   Thermal conductivity   Thermal absorptivity   Thermal diffusivity   Thermal resistance Qmax   Sample thickness

Fabric parameters [2]

Results [2]

[2]

Conclusion [2] 1.  Fabrics developed from EliTe® compact yarns

are slightly

  thinner and better air permeability as compared to fabrics

  made from normal yarns.

  Fabrics developed from EliTe® yarns have higher values of thermal conductivity, thermal absorptivity, and qmax as compared to the fabrics developed from normal yarns where as the thermal resistance values are lowe

  Fabrics made from normal yarns shown slightly lesser values of MVTR than the fabrics made from EliTe® compact yarns.

  Wicking then fabrics made from EliTe® yarns show better wickability than the fabrics made from normal yarns except for fabric samples A and D.

  Over all if we analyze the contribution of the EliTe® compact yarns in the fabrics, then we find that the EliTe® yarns has certainly proved to be beneficial to improve the comfort of the cotton fabrics.[2]

References

  [1] Marmarali et al., Thermal Comfort Properties Of Some New Yarns Generation Knitted Fabrics in AUTEX 2009 World Textile Conference 2009: Izmir, Turkey

  [2] Das, A., Kothari, V. K., and Sadachar, A., Comfort Characteristics of Fabrics Made of Compact Yarns. Fibers and Polymers. 8, 2007. 1: p. 116-122.