Ian Blanchonette

Tension Measurements in Weaving of Singles Worsted Wool Yarns

The variation of tension in weaving 25 tex singles worsted wool yarns is investigated using a commercial on-line tension measuring device. The maximum rate of tension change in warp yarns is 35 to 45 N/s (at beat-up) and in weft yarns 60 to 1000 N/s (depending on the system of weft insertion). Weft yarn failure rates are predicted from measured weft tensions and Uster Tensojet results. Clinging of warp yarns is shown to increase the average tension by up to 20% for a plain weave.

Moisture transfer properties of bifacial fabrics

Many biological plants have bifacial leaves with an adaxial surface and an abaxial surface. These two surfaces can often have different morphologies and properties, and they serve different functions in plant growth. This has inspired us to develop novel bifacial fabrics, with a knitted structure on one face and a woven structure on the other. Bifacial fabrics were produced on a purpose-built machine, using wool, acrylic and polyester yarns, with the woven structure being plain weave, and the knitted structure being single jersey. In this study, the moisture properties of these fabrics were compared with conventional woven and knitted fabrics. The water contact angles of the bifacial fabrics were similar to knitted and woven fabrics, but the absorption time on the woven fabric was much higher than the other fabrics. Liquid moisture transfer properties on both faces of the bifacial fabrics were different, with water spreading and absorption on the woven face being quicker than on the knitted face. These unique properties of bifacial fabrics show that these fabrics could be used as moisture management fabrics, without the need for any additional treatments.

Heat transfer properties of bifacial fabrics

Bifacial fabrics were produced on a purpose-built machine, using wool, acrylic and polyester yarns, with the woven structure being plain weave, and the knitted structure being single jersey. In this study, the heat transfer properties of these fabrics were compared with conventional woven and knitted fabrics. The bifacial fabrics had lower air permeability than knitted and woven fabrics, and they were warmer to touch. The thermal resistance of the bifacial fabrics was higher than the knitted and woven fabrics, and the thermal resistance of the two faces of the bifacial fabrics was statistically different.

Mechanical properties of bifacial fabrics

This study focuses on the qualitative evaluation of the mechanical properties of bifacial fabrics, which have a knitted structure on one face and a woven structure on the other. Woven, knitted, and bifacial fabrics were produced on a purpose-built machine, using wool/acrylic and polyester yarns. The bifacial fabric was manufactured with the woven structure being a plain weave and the knitted structure being a single jersey. The results of load–extension test showed unique tensile behavior, with two breakages in both the warp and weft directions, representing the woven and knitted structures. The bending length of the bifacial fabric in the weft direction with its knitted face up was smaller than that in the warp direction, and the bending length in the warp direction with its knitted face up was similar to that in two directions with the woven face up. The bifacial fabric demonstrated unique abrasion resistance on two faces, combining the performance of the knitted and woven fabrics in abrasion resistance. The abrasion resistance on the woven face was better than that on the knitted face. The knitted face of the bifacial fabric generally pilled less than the knitted fabric after abrasion over a certain number of cycles.

Thermal comfort properties of bifacial fabrics

Bifacial fabrics, with a single jersey on one face and a plain weave on the other, were produced on a purpose-built machine. Thermal comfort properties of bifacial fabrics were compared with conventional woven and knitted fabrics and the effect of weft density and loop length of bifacial fabrics on their thermal comfort properties was investigated. While different fabric structures were produced with the same wool, acrylic, and polyester yarns, the findings confirmed that the bifacial fabric is warmer (lower total heat loss) and more breathable (higher permeability index (im)) than the corresponding woven and knitted fabrics. Increasing the loop length of bifacial fabrics enhanced evaporative resistance, air permeability, warm feeling, thermal resistance, and water vapor permeability index, yet reduced total heat loss. An increase in the weft density of bifacial fabrics led to higher evaporative resistance, warmer feeling, higher thermal resistance, lower air permeability, and total heat loss. However, the permeability index did not change with an increase in weft density. This study suggests that thermal comfort properties of bifacial fabrics can be optimized by modifying structural parameters to engineer high-performance textiles.