Loepfe YarnMaster Zenit, Instruction Manual

Page: 12 / 83

12 ZENIT
YARN CLEARING GENERAL
As already mentioned, various types of yarn faults are distin-
guished according to their form. In the plane of coor dinates it
is possible to distinguish areas which relate to the following
types of faults (see figure 4).
Neps
Thick places / Short faults
Long faults and
Double ends
Thin places
Figure 4
Figure 5
D
iam
et
er
Length
RG
Yarn Clearing
Base Curve
The distinction between yarn faults which are to be cut out
and those which are to be left in the yarn (unacceptable and
acceptable yarn faults), which is made in the interest of win-
der efficiency, has already been pointed out. This di stinction
can be represented graphically on the plane of coordinates as
a line which separates the acceptable faults (below) from the
unacceptable ones (above). This line repre sents the
theo re­
tically­desirable base curve (RG)
. A concave base curve
(see figure 5) normally corresponds to the requirements in
practice.
The concave shape arises from the textile evaluation, where-
by the greater the deviation in diameter that is tolerated, the
smaller the length deviation that appears acceptable. Fur-
thermore, the base curve, thus, passes through fields of sim-
ilar fault frequencies, which meets the requirement of high
efficiency.
A distinction must be made between the theoretically-desir-
able base curve and the
practically­achievable base curve ,
which depends on the one hand on the clearing characteristic
typical of a clearer type, and, on the other hand, on its set-
ting flexi bility.