34-Inch 28G Pneumatic High-Foot Open-Width Knitting Machine

Three systems must work together

This model combines a 34-inch, 28G and 72-feeder double-side knitting configuration with a pneumatic high-foot feature and an open-width handling route. The archive records 18 RPM and mentions school-uniform and durable functional fabrics. The correct trial must cover all three systems: loop formation, pneumatic operation and the slit/spread/take-up path.

Do not treat “high-foot opening” as one vague benefit. Ask Kunyuan to show where the pneumatic high-foot mechanism acts, where the tube is slit, how the edges are guided and how the flat roll is wound. Define which features are standard on the quoted model.

Start from the uniform fabric specification

For school-uniform or similar fabric, provide the double-knit structure, yarn composition/count, color/dyeing route, target weight, finished width, hand and durability tests. If elastane is used, include its position and recovery requirement. The 28G setup supports a finer surface, but it does not prove breathability, abrasion or colorfastness without finished-fabric tests.

The supplier should state the 72-feeder yarn map and expected roll format. Pneumatic pressure/flow, slitting location, edge control and maximum roll size belong in the same technical boundary.

Integrated acceptance sheet

Trial from first loop to finished roll

Run production yarn, document feeder positions and inspect both fabric faces before slitting. Measure tubular width, then follow the fabric through the cutting and spreader path. Check slit position, edge damage, open width, diagonal wrinkles and roll alignment at the start, middle and end.

Send a labelled portion through the intended dyeing and finishing process. Recheck weight, width, shrinkage, hand and required uniform tests. Keep pneumatic, slitter and winding settings with the knitting recipe. This makes a complaint traceable to the right system instead of blaming the whole machine.

Maintenance without cross-adjusting systems

Log pneumatic pressure/leak checks, blade/edge-guide condition and take-up tension separately from needles, dial and feeders. A roll-handling problem should not trigger random cam changes. A fixed needle line should not be hidden by changing winding tension.

Before service, isolate power and release stored air. Protect the blade and follow the manufacturer’s access procedure. After work, make a short marked roll and verify all three systems before production release.

Define the handoff to dyeing and finishing

Agree the roll direction, maximum roll diameter/weight, core size, edge allowance and identification label expected by the next department. A clean open-width roll can still create downtime if it is wound in the wrong direction or cannot fit the finishing line. Include these details in the acceptance record rather than leaving them to the first production shift.

The installation review should cover machine and service footprint, blade access, lifting route, compressed air, electrical supply and space for doffing a flat roll. Ask which settings are locked, which operators may change, and how a slit-edge alarm or pressure loss is handled. These operational boundaries are part of the delivered system.