Modern Developments in Textile Manufacture

Spinning

Compact Spinning
Protruding fibres from the body, known as hairiness, is a characteristic feature of staple fibre yarns. This gives the yarns and fabrics made from them a softer and comfortable feel. At the same time hairiness has some undesirable effects as pointed below
- Full ralisation of strength of fibres is not realised as part of the fibres are not integrated in the yarn
- Rough feel is given to yarns
- Variation in hairniess is a source of weft bars and warp way streaks in fabric.
- Long protruding hairs from yarn contribute to multiple breaks in weaving and fabric faults like stitches and floats.
Compact spinning is designed to reduce hairiness in yarn. In traditional spinning fibres in the selvedge of strand emerging from front roller nip do not get fully integrated into yarn because of restriction to twist flow by the spinning triangle. These fibres therefore show up partly as protruding hairs or wild fibres. To overcome this effect, the spinning triangle is nearly eliminated in compact spinning by incorporating a condensing zone after main drafting zone. The condensing zone has a revolving perforated apron with suction underneath. The fibres are collected on the perforated track and thus get condensed. The width of strand under front roller nip is substantially reduced and this enables twist to flow right up to nip. As a result hairiness is substantially reduced. Compact spinning systems are offered by Rieter(Comforspin), Suessen(Elite) and ITV-Zinser among others. Benefits claimed from comfort spinning are
- 15-20% reduction in hairiness of yarn, the reduction being more pronounced in long length hairs
- 10-15% improvement in yarn tenacity
- Twist in yarn can be reduced by 10% while maintaining same yarn strength
- Better evennes of diameter and hairiness.
- Better abrasion resistance of yarn leading to less end breaks in weaving. Loom shed droppings and linting in knitting are reduced
- Size% can be reduced by 30-50%
- Singeing can be omitted
- Reduced pilling and better dye uptake in fabric
Nonwovens
- 3 layer sandwiched wipes
  3 layer sandwich with wood pulp sanwiched between 2 layers of staple fibre and cosolidated by hydroentanglement, represents an attractive proposition for making cost effective wipes and medical products. This is patent by Georgia Pacific and made by Fleissner under agreement. Hydroentanglement is achieved by fine water jets directed on the web supported by by a conveyarbelt or similar means. Entanglement occurs when the water strikes the web and deflects the fibres. This technology accurately translates the characteristics of fibres into final product and produces more durable goods. The products look similar to wovens and knits.Wood pulp sandwiched and hydroentangled with a staple fibre web is cheaper compared to 100% staple fibre nonwoven wipes, has a higher thickness and absorbancy and comparable strength. Further the product has more uniformity as pulp levels out card web irregularities. Production rates upto 400 m/min are claimed. Though higher investment is involved in this technology, it pays back rapidly because of low raw material cost, higher productivity and improved properties. Similar sandwiched products are also made with wood pulp sandwiched between 2layers of spun bonded nonwoven
- Hyper punch Needling
  During needle punching the web is stopped by needles from moving forward upon penetration but needled felt is pulled forward during this period by take up rollers and this leads to stretching of material and weight variations in outgoing needle punched material. To overcome this, elliptical movement of needle board is developed by Dilo and other manufacturers.Eliptical movement consists of a horizontal and vertical component. The horizontal component reduces speed difference between needle and web and reduces draft.

Modern Developments in Textile Manufacture

Spinning

Nonwovens