Loepfe YarnMaster Zenit, Instruction Manual

Page: 16 / 83

16 ZENIT
YARN CLEARING GENERAL
Imperfections
Frequent yarn faults are described as Imperfections in the
language of the textile industry. It is generally acknowledged
that the shorter the fault length, or the smaller the diameter
deviation respectively, the more frequent the event.
The source of these faults is found in the raw material or in a
non-perfect spinning process. The raw material, card wires,
eccentric top rollers/bottom rollers, defective aprons, rings
and ring travellers have a significant influence on the imper-
fections.
With a reliable analysis of the Imperfections it is not only
possible to optimize the production process but also con-
clusions can be drawn concerning the quality of the used
fibre material.
20 70 cm
0.5 1 2 4 8 cm
D 5.00
D 3.20
D 2.30
D 1.81
D 1.28
D 0.89
D 0.75
D 1.11
Surface Index SFI
The monitoring and evaluation of the surface structure of a
yarn (e.g. hairiness), is a further important criterion for qual-
ity assurance.
In order to predict yarn behavior during processing in weav-
ing or knitting, it is not sufficient to simply consider individual
quality characteristics (e.g. yarn irregularity) to assess a yarn.
Only a combination of different quality criteria (e.g. hairiness
and irregularity) supports making a definite conclusion.
These quality characteristics are combined in the surface in-
dex SFI enabling the user to monitor the quality level easily
and efficiently.
Frequent events Neps
Thick Places
Thin Places
Very frequent events Small