Yarn & Twist What is wound into the strand

Yarn Linear Density tex

Twist tpm

Yarn Bulk Density g/cm3

Snarl Test & Setting How much of the twist gets out

Test Loop Length m

Twist Released as Snarl %

Empirical, from the yarn and the test method

Setting Efficiency %

Steam or heat setting applied before the test

Snarls in the Test Loop

— turns

Turns a doubled loop of this length will form

Twist Geometry & Residual Energy

Twist Multiplier (Ne basis): —
Surface Twist Angle: — deg
Twist Still Free to Release: — %
Twist per Inch: — tpi
Snarls per Metre of Loop: — 1/m
Yarn Diameter: — um
Yarn Count: — Ne
Twist Energy Index: —

The snarl prediction is semi-empirical: the geometry is exact but the released fraction is a measured input that varies with fibre, moisture, time since spinning and the test method, so the snarl count should be treated as a comparison between yarns rather than an absolute prediction. Moisture matters more than most people expect - the same yarn tested at 45% and 75% relative humidity gives noticeably different liveliness, which is why the test belongs in a conditioned laboratory. Setting efficiency is entered as a single figure but real setting is time, temperature and moisture dependent and partially reverses on ageing, so a yarn set weeks ago is livelier than the same yarn set yesterday. The twist energy index is a ranking device with no units, not a physical energy.

Yarn Twist Liveliness, Snarling & Residual Torque — free, with the formula and a worked example, at Textile School.