Warp Knitting Explained: Machine Families, Systems and Parts

November 9, 2022

Warp knitting is a way of making fabric in which the yarns run lengthwise, every needle is fed by its own guide, and loops are formed across the whole width at the same moment. That one idea is shared by machines that otherwise have very little in common, from fine tricot to heavy reinforcement equipment.

This page is the map of the field: which machine family handles which job, which control systems attach to them, which parts decide fabric quality, and where to go next for detail. Grand Star Technology has built in this field since 2012 from Fujian, China.

How warp knitting is organised: the machine families

If you came here to tell the machines apart rather than to understand the process, the classification by needle bed, needle and take-off direction is set out in types of warp knitting machines.

Choosing a family starts from the fabric

Picking a family is usually decided by the fabric, not by preference.

If the end product is on the fine and fast side, then the question is which tricot configuration.

If it is structural, open or heavy, then the question is which raschel or composite build.

If you know the fabric you must deliver but not the machine that makes it, then start from the application pages and work backwards: automotive textiles, apparel textiles, home textiles and sports textiles.

This shortcut does not apply to the warping stage, which every family needs. It is easy to underestimate when quotations are compared and hard to fix later, because beam quality follows the fabric all the way to the roll.

Systems that attach to the machine

Most of what separates two machines of the same family is the systems bolted to them. Four are worth knowing by name before you compare offers.

• Let-off system: controls how yarn is delivered from the beams, and therefore how stable tension is across a run.
• EL system: electronic control over yarn delivery, for constructions that will not tolerate mechanical approximation.
• Jacquard system: patterning capability, the difference between a plain fabric and a designed one.
• Detect-scan system: fault detection during production, so a defect stops the machine instead of filling a roll.

There is a fifth path that gets overlooked: an existing machine can be brought back into service instead of replaced. That work is listed under machine reconditioning, and for plants with a sound frame and tired electronics it is often the shorter route to capacity.

The parts that decide fabric quality

Machines get the attention; elements and parts decide what comes off the roll. Loop formation happens at the needle, so knitting needles and the bars around them are where quality problems usually start and where any wear investigation should begin. Yarn arrives through ceramic guiding parts and off the warp beam, and leaves through the take-up. The rest divides into mechanical parts, electronic parts and warping parts.

One check that saves dismantling

When a fabric fault appears, establish first whether it stays in the same needle band down the length of the roll or wanders across the width. A fault that stays put points at elements. A fault that moves points at tension, yarn or beam. Ask that one question before a single cover comes off.

Service footprint and next steps

Our machines run in the United States, Japan, Turkey, Vietnam, Indonesia, India, Colombia and Mexico among other markets, and service is organised around that footprint: local teams where we have them, real-time online support first where we do not, and engineers dispatched from the nearest hub when the fault needs hands on it.

For commercial terms and the wider group range, grandstarcn.com is the place to go. For a technical question about a specific construction, send the fabric specification and the machine you currently run through our contact page; that pairing answers more than a general enquiry does.

Frequently Asked Questions

What is warp knitting?

It is a fabric-forming process in which yarns run lengthwise, each needle is fed by its own guide, and loops are made across the full width at the same time. Tricot, raschel, double needle bar, lace, net and composite machines all work on that principle, with warping equipment preparing the beams.

Which warp knitting machine family suits which fabric?

Tricot covers fine, fast production for apparel, linings, automotive and sports textiles. Raschel spans open structures through heavier technical cloth. Double needle bar builds spacer and pile constructions, lace models handle patterned work, net equipment serves agriculture, packaging, construction and fishing, and composite lines make reinforcement.

Which systems can be added to the machine?

Four main ones: let-off for yarn delivery from the beams, EL for electronic control of that delivery, jacquard for patterning, and detect-scan for fault detection during production. An existing unit can also be reconditioned instead of replaced, often the quicker route when the frame is sound.

Where should I start when a fabric fault appears?

Check whether the defect stays in the same needle band down the roll or wanders across the width. A defect that stays put points at the knitting elements. One that moves points at tension, yarn or beam. That single observation narrows the search before anything is dismantled.