How to Choose a Selvedge Uncurler

Why the Edge Has to Be Open

A selvedge uncurler opens and flattens the edges of fabric during dyeing, finishing or printing. On a stenter it does one specific job: it makes sure the edge arrives at the pinning point flat instead of rolled.

An edge that arrives rolled gets gripped double. The pins go through two thicknesses, the fabric tears at the selvedge, and the width control the machine exists to provide is gone. Rolled or curled selvedges also cause uneven stretching and defects further down the line.

Four Options in Order of Gentleness

Uncurlers work either mechanically, by physical contact, or pneumatically, which is contactless and suits delicate fabrics such as denim. Roller types come in two, three and four finger designs.

In practice you are choosing between four things. A flat nylon guide is the gentlest passive option. A three finger uncurler gives more positive control for moderate curl. A four finger uncurler spreads the flattening over a longer length for edges that roll hard. And a pneumatic spreader is the gentlest of all, for elastic knits and spandex blends that mechanical contact would ladder.

Flat Nylon for Delicate Goods

A flat nylon selvedge uncurler is made from high-wear nylon or polymer, so it handles fabric smoothly. It is non-abrasive, which reduces friction and edge damage, and it resists the heat and chemicals used in finishing.

The profile is flat or slightly curved so it opens the edge gently, and it is usually adjustable in height and angle for different fabric types. It can replace a metal uncurler anywhere softer handling is needed.

Fingers for Positive Control

A finger uncurler has adjustable fingers that flatten the fabric edges as they enter the stenter. The fingers can be moved horizontally or vertically to suit different fabric types and widths, which is what makes them useful on a machine taking varied work.

Three fingers suit moderate curl. Four fingers spread the contact over a longer length of edge, which is what heavily curling knitted goods need. Both keep the fabric width consistent and the edge properly aligned into the chain clips or pins.

Pneumatic for Elastic Knits

The E+L ELSPREADER LPA 03 is a pneumatic selvedge spreading device from Erhardt+Leimer of Germany. It flattens, uncurls and smooths curled, folded or frayed selvedges right before pinning on stenter frames, sanforizing lines and finishing ranges.

Being air powered, the edge opening is gentle, which is what ultra-delicate elastic knits, jersey, spandex blends and lightweight wovens need. It costs far more than a passive uncurler, and on the fabrics it is made for it earns the difference.

Look After the Rollers

Whatever device you choose, the part that touches the fabric is a wear part. PEEK rollers are the usual choice because PEEK is self-lubricating, so the roller turns freely against the edge without grease anywhere near the cloth.

Inspect the working surface at every service. Once it has grooved, it stops turning cleanly and starts marking the fabric it was fitted to protect.