Abstract
υFor crêped yarn there establishes
in which ν the number of turns of yarn helix, α the inclination thereof, T the twist of yarn before crêping, _??_ the twist along crêped yarn and γ the radius of yarn helix. As to yarn helix, see Jour. Soc. Chem. Ind., Nippon, 37, No.4.
When _??_ calculated from the above relation (ν, α, γ and T are measurable directly) are compared with _??_ obtained from microscopical observations (after A. Herzog's method), there exist great discrepancies which are inexplicable as experimental errors.
On model experiments it is confirmed that the microscopical measurement of yarn twist is not reliable for hard twisted yarn. From this fact we must resort to the relation (1) to know _??_ so far as there is no direct measurement of it.
