Needles

Needles are the core stitch-forming components of a knitting machine. Positioned in individual grooves (slots or tricks) across the needle bed, they are manipulated by the carriage cams to catch yarn and draw it through existing loops to form fabric. Machine knitting needles are mechanical, self-acting units that differ significantly from hand-knitting needles.

Needle Anatomy

The standard needle used in domestic and bulky knitting machines is the latch needle, invented in 1849 by Matthew Townsend. Its anatomy consists of:

• Hook: The curved top that holds the yarn loop.
• Latch: A small, pivoted swing gate that opens and closes over the hook. It opens to let a stitch slide down onto the stem and closes to pull a new yarn loop through.
• Latch Spoon: The hollowed end of the latch that fits over the hook when closed.
• Hinge (Rivet): The pivot point of the latch. It must remain clean and lightly lubricated.
• Stem (Shank): The straight body of the needle.
• Butt: The raised protrusion that extends vertically out of the needle bed. The carriage cams push against the butts to slide the needles forward and backward.

Types of Knitting Machine Needles

• Latch Needles: The most common self-acting needles. The movement of the fabric loop itself opens and closes the latch.
• Slider Needles (Compound Needles): Used in Passap domestic machines and many high-speed industrial circular and flatbed machines (like Shima Seiki and Stoll). They consist of a separate hook and a sliding tongue that moves independently to open and close the hook, offering precise control at high speeds.
• Spring Beard Needles: Used in vintage loop-wheel industrial circular machines. They require an external presser foot to close the flexible "beard" hook.

Needle Maintenance & Replacement

Bent or stiff needles are a primary cause of dropped stitches, tucking errors, and fabric snags.

• Inspection: Run a needle pusher across the bed to align the needles in holding position (E/D position). Check if the hooks are aligned, butts are straight, and latches swing freely.
• Replacing standard flatbed needles:

1. Slide out the sponge bar (needle retainer bar) from the side of the machine.
2. Push the damaged needle forward into the holding position, then lift the needle butt up and slide the needle forward out of the bed groove.
3. Slide the new needle into the slot, butt first.
4. Re-insert the sponge bar over the needle shanks to secure them flat.