Two phase weaving machine
Multi phase weaving machines are described because the shedding is phased so that number of weft insertion device can traverse the warp simultaneously, the phase number of the weaving machine system indicating the number of weft insertion carriers inserting weft simultaneously. The nomenclature two phases is technically incorrect and double acting single phase is more technically accurate. The rigid rapier is driven from the centre and has a yarn clamp at both extremities. In one machine cycle of 360O the rapier inserts one pick alternatively in the right hand and left hand fabrics, the picks being inserted and beaten up phase opposed. The weft insertion system of a two phase weaving machine is shown in fig.
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| Fig: Weft insertion system of the saurer 500 two phase weaving machine. |
The advantage of such a system is high rapier utilization as there is no recovery stroke and the rapier never travels empty, a pick being inserting in the right hand section of the machine as it is withdrawn after inserting a pick in the left hand section. Phase opposed operation effectively restricts the machine to can shedding and the machine loses some width flexibility as an odd number of equal width fabrics cannot be produced. Cloth width flexibility is also somewhat restricted. In the 2×185 cm machine cloth width can be 175 cm, 87.5 cm and58.3 cm with normal weaving contraction if no loss of reed space is to be sustained. The two and three per side weaving widths are not commercially viable for most products and the machines most effective role is in the manufacture of two fabrics simultaneously in the range 150-175 cm .The widest two phase machine is the 2×185 cm weaving width.
