Tricot machines Characteristics
• Compound sinker bar (2-point knockover).
• Warp beams are placed mainly at the back of the machine or perhaps above the machine.
• Needles can be changed from the front side of the machine.
• Up to 5 guide bars are used at the moment.
• Use of compound needles.
• Starting-up without fabric take-up possible.
• Only pillar loops cannot be knitted (only by support through inlay motion),(lateral 2-point knock-over)
• Angle between incoming yarn sheet and fabric take-up is 90° (considerable needle stress).
• Simple machine construction.
• Short run-in of the threads because of the beam positions.
• High number of courses possible up to total stop of the beams (for pleats) because working without fabric take up is possible.
• High yarn run-in is possible (overfeed).
• Handling of the knitting elements from the knitter's side possible.
• Piles for terry effects are possible.
• Simple construction of pile fingers for plush.
• Soft fabric touch.
Disadvantages of Tricot machines
• Problems with small number of stitches and reduced yarn run-in (fabric take-up 90°) (high tension for the needle, loose selvedges lead to yarn twisting and fault).
• Processing of elastomeric yarn mainly possible only as loop.
• Net constructions are difficult to be made since the knock-over of the wales connection is not possible
(lateral 2-point knock-over).
• Processing of filler yarns is very difficult (see fabric take-up,90°).
• Common machine gauges from E 24 to E 40.
Raschel machines Characteristics
• Separate knock-over bar (trick plate) 3-1point knock-over and stitch comb bar.
• Warp beams are placed on the top of the machine.
• Needles have to be changed from the back side of the machine (due to the knock-over comb bar).
• Nowadays up to 78 guide bars are possible.
• Usage of compound needles and sometimes of latch needles.
• Loop formation without fabric take-up is not possible;main knockover at the front edge (take-up).
• Angle between incoming yarn sheet and fabric take-up is 170°(low needle stress).
• High take-up tension allows the production of open fabric structures and the manufacture of elastomeric inlays (powernet) as well as the production of elastic pleated fabrics.
• The high yarn tension does not affect the needles directly. Hence, low stitch densities and short yarn run-in possible at high fabric stability and low needle stress.
• Various materials can be used: film tapes, glass,aramide, carbon, metal wires.
• Wide range of gauges.
Disadvantages of Raschel machines
• Starting-up only with fabric take-up possible.
• Loose yarn run-in (overfeed) and high stitch densities(velvet, pleats) are not possible fabric touch less soft.
• Longer yarn path due to beam positions.
• Changing of needles only from the back side.