Pneumatic Open-Width Double Jersey Circular Knitting Machine

Open width changes what happens after knitting

Double-jersey fabric normally leaves the knitting zone as a tube. On an open-width machine, the fabric is slit, spread and wound flat so the mill can inspect the full width and prepare the roll for finishing. Kunyuan’s cleaned product record identifies a 34-inch, 28G, 72-feeder configuration for this model family. That exact row should lead the quotation; older broad ranges on the page should not be mixed into the offered setup.

The pneumatic system supports the opening and take-up path. Its value is not “air makes better fabric” but controlled handling: the slit line must stay where intended, both edges must travel without folding, and winding tension must not create a hard centre, loose edge or repeating mark.

Follow the fabric from needle bed to flat roll

The double-knit structure is formed by the cylinder and dial. After the tube leaves the knitting zone, the slitting device opens it and the spreader guides it into a flat roll. Each step can create a different defect. A needle or yarn-feed problem appears in the knitted structure; a wandering slit or damaged edge points to the opening route; diagonal wrinkles or roll telescoping deserve a take-up review.

Give Kunyuan the construction, yarn and elastane plan, target greige/finished width and the finishing machine’s entry requirement. Ask for the pneumatic pressure and air-quality requirement, the slitting location, edge-guiding method and maximum acceptable roll diameter/weight for the offered take-up.

Configuration and roll-acceptance record

Trial the whole handling path

Use production yarn and knit a stable double-jersey structure before judging the opening equipment. Measure tubular width before slitting, then inspect the opened width at the beginning, middle and end of the roll. Check slit-edge damage, curled or folded edges, wrinkles, width drift, diagonal tension lines and roll alignment.

Process a trial roll through the buyer’s next finishing step when possible. A flat roll that looks acceptable beside the knitting machine can still feed poorly if it is too hard, telescoped or uneven at the edge. Keep the knitting settings, pneumatic settings, slitter position and take-up tension with the accepted roll.

Maintenance by defect location

Clean the needle/dial zone according to the machine procedure, but maintain the slitter, spreader and take-up as separate inspection points. A dull blade can pull rather than cut; contaminated edge sensors or guides can let the slit wander; unstable air supply can change the handling response. Record these observations instead of making unrelated knitting adjustments.

Isolate the equipment before blade, spreader or take-up work and release pneumatic energy safely. After maintenance, confirm the slit path on a short marked run before resuming full-roll production.