Warp knitting is by far the most versatile fabric production system in textiles . Warp knitted fabrics can be produced flat, tubular or three-dimensional, to be elastic or stable, and with an open or closed structure.
Fabric width can be over 6 m wide without seams (or a multiple of this width if it is a net construction). Warp knitting machines are divided in two categories: tricot machines and Raschel machines. Raschel machines are normally used for the production of technical textiles. Stitch-bonding machines are regarded as a special form of warp knitting machines, especially suited for the manufacture of technical textiles, non-wovens and composites. The principle of weft insertion in warp knitting involves the insertion of the reinforcement fibres in parallel across the whole width of machine . According to Raz , the advantages of weft insertion systems are:
Working width of up to 6.22 m (245 inches),
Production speed of up to 1,400 rpm, that is, a weft insertion rate of up to 7,560 m/min*
(on the basis of 24 yarn ends) *depending on the relevant product to be produced,
Weft take-up speeds of up to 320 m/min (on the basis of 24 yarn ends),
Flexible weft insertion system (weft repeat, number of weft yarn ends),
All yarn types including high-tenacity and fragile technical yarns can be inserted,
High flexibility of yarn counts,
Very high efficiency and productivity.
List of books: Warp,knitting