Warp Knitting Machines Overview

Study Notes

Compound needles are used in warp knitting machines to increase productivity, replacing beard or latch needles.

Compound Needle (main Body): A crucial part of the machine's structure.
Compound Needle (Closing Element): An essential component in the closing process.
Trick Plate: A component in the mechanism.
Sinker: A component that controls the fabric.
Yarn End: The yarn supply.
Yarn Guide: Directs the yarn.
Fabric: The final product.

Step 1: Needles rise, guide bars swing; sinkers hold fabric down, hooks and tongues rise up, hook rises faster than tongue until it aligns with guide holes. Guides then swing to the back of the machine.
Step 2: Guides overlap, return swing; hooks and tongues descend, tongues descend slower closing hooks.
Step 3: Landing and knock-over; sinkers withdraw, needles descend, loop lands on closed hook, then knocked over as it descends below the sinker belly. Underlap occurs before needles rise and sinkers hold fabric down.

Tricot:
- Uses bearded needles or compound needles.
- Typically finer gauge (28-32 needles per inch).
- Suitable for finer filaments.
- Fewer guide bars (2-4).
- Fewer warp beams.
- Sinkers control fabric throughout knitting cycle.
- Needle-fabric angle 90°.
- Produces simple fabrics.
- Higher machine speed.
- Lower knitting tension.
- Wider machine.
- Lighter fabric
- More resilient, better drape, higher bursting strength, better dimensional stability, soft hand, and even opaque and tight.
Raschel:
- Uses latch needles.
- Coarser gauge (8-16 needles per inch).
- Suitable for spun yarn, coarser filaments, or decorative staple spun yarn.
- More guide bars (6-48).
- More warp beams.
- Sinkers only ensure fabric stays down.
- Needle-fabric angle 160°.
- Produces more complex fabrics.
- Lower machine speed.
- Higher knitting tension
- Narrower machine.
- Heavier fabric
- Less resilient, poor drape, lower bursting strength, and poor dimensional stability, hard hand, uneven and loose.

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