Unit 3 Lecture 19 Topic 2 Flashcards
How does a single weft knit compare to a basic plain weave in the yearn structure?
Single weft knits have inter-looping yarns, while basic plain weaves have interlaced yarns.
What does quality and performance of knitted fabrics depend on?
The type of knitting used (warp or weft), fibre content, fineness, evenness and twist level of the yarns, closeness of the knitting (gauge), and extensibility of the finished fabric (stretchy/non-stretchy).
Why are knitted fabrics not used where high stability and tensile strength is needed?
Knitted fabric can stretch in all directions and loops widen or lengthen to accommodate stresses in use.
How do knits compare to weaves in terms of abrasion resistance?
Knits are generally better due to the increased yarn mobility. Knits are more likely to pill and snag than woven fabrics. Furthermore, bulkier knits tend to snag & pill more than
tighter, finer knits. Abrasion resistance is also greatly influenced
by yarn type, size and twist, as well as fibre toughness.
How do knits compare to weaves in terms of elasticity?
Knits generally have greater elasticity (stretch and recovery) than woven fabrics. This impacts comfort as knits provide greater freedom of movement. Fabrics with greater elasticity are generally made into close-fitting garments (underwear, socks, sportswear). Not all knits have equal recovery. Fibre and yarn properties will influence fabric recovery after stretching.
How do knits compare to weaves in terms of porosity?
Knits are generally lighter and more porous than woven fabrics. For a given quantity of yarn, more fabric can be produced from knitting than weaving. This porosity influences comfort as more air increases thermal insulation and a lighter weight is less of a burden to the wearer.
How do knits compare to weaves in terms of air permeability and wind resistance?
Knits have higher air permeability and lower wind resistance than woven fabrics. This is because the loops cannot be packed as tightly as woven structures.
How do knits compare to weaves in terms of resiliency?
Knits have better resiliency than woven fabrics. Their excellent wrinkle resistance influences appearance retention.
How do knits compare to weaves in terms of recovery?
Knit fabrics normally recover well from deformation as the loops attempt to return to their original positions in the knit structure. Recovery depends greatly on the fibre content and yarn structure. Sometimes loops don’t recover and a garment will become “stretched” out of shape. Washing and tumble drying often helps with the recovery. Some knits may lengthen due to the weight of the fabric (sometimes a problem with acrylic knits).
How do knits compare to weaves in terms of laundering?
More space in knitted structures allows yarns to swell and shrink in laundering. As a result, relaxation shrinkage is often greater for knits than woven fabrics because of the high tension placed on the yarns during knitting. This can be minimized by fabric finishing.
