Hair Severity: A new
yarn hairiness parameter
by V.Srinivasan & S.Balamurugan, Premier Evolvics
Pvt Ltd, India
The conventional
measurements of yarn hairiness are not its true
representation. Based on extensive studies, Premier has
introduced a new parameter - Hair Severity (HS). HS
represents the disturbing hairs. The Hair Severity can be
tested at 400 m/min in the Premier iQ Qualicenter- the
world’s most intelligent evenness tester and process control
equipment. The HS Statistics 2007 provides a useful tool for
the mills to benchmark the HS levels achieved over different
count and material.
Hairiness denotes the extent to which fibres protrude from
the yarn body. Hairiness is an important surface property
which has a direct impact on the performance of the yarn in
the subsequent processes. It also has a bearing on the feel
and appearance of the fabric. Certain minimum amount of
hairiness is desirable for converting the yarn into fabric.
However, when the length of the protruding hair crosses a
critical limit, it poses severe constraints during fabric
formation in Weaving and Knitting. The fabric quality also
gets degraded due to Pilling and Fuzzy appearance created by
the longer hairs.
Hairiness is a highly variable parameter which is
influenced by various factors like Raw material quality,
Process parameters in Spinning preparatory, Ring frame and
also at Winding. Controlling longer length hairs is of primary
importance for a yarn to perform better in subsequent
processes. Increased production rates and Compact Spinning
technology necessitates precise measurement of yarn hairiness
deviation. An innovative concept of estimating the “Hair
Severity” (HS) has been dealt here, as two yarn samples may
have similar Hairiness Index value, but they will have
different HS value based on the hairs distribution.

Hairiness is a highly variable parameter which is
influenced by various factors like Raw material quality,
Process parameters in Spinning preparatory, Ring frame and
also at Winding. Controlling longer length hairs is of primary
importance for a yarn to perform better in subsequent
processes. Increased production rates and Compact Spinning
technology necessitates precise measurement of yarn hairiness
deviation.
An innovative concept of estimating the “Hair Severity”
(HS) has been dealt here, as two yarn samples may have similar
Hairiness Index value, but they will have different HS value
based on the hairs distribution.
The need for a new Hairiness parameter
-
Improved
measurement of true hairs.
-
Selection of
suitable yarn for subsequent processes.
-
For easy
internal process control.
“Hairiness
index”, is not the true representation of Hair count
distribution, as hairs irrespective of its length are related
over one centimeter length of the yarn. This effectively means
that hairs of longer length are not significantly represented
here. Similarly “Hair Count” from 3mm to 10mm involves a
complex procedure to analyze and then relate it with practical
Spinning mill environment. “H3” the associated parameter with
Hair Count is also losing its importance as it is increasingly
getting difficult to monitor and analyse a 3~4 numeric digit
as the value changes to a great extent. Since the application
of both the Hair Count and H3 often calls for skilled
technicians to decide upon a comprehensive solution, Premier
has evolved a new parameter – Hair Severity (HS).
Two yarn
samples may have similar Hairiness Index value, but they will
have different HS value based on the hairs distribution. For
the spinner, HS serves as an excellent process control tool
For the yarn buyer, HS helps to distinguish yarns for a given
end use, whether it is for Knitting or Weaving . An example of
HS is given in table 1.

In the this example there is not much difference in the
Hairiness Index values. Although there is a difference in H3,
these values fluctuate to a great extent which makes it
difficult to monitor and use it as a tool. But there is
significant difference in the Hair Severity values.
Testing Hair Severity at high speeds
Studies on Hair Severity
Studies were conducted across the different Count and
Material. 73 mills participated in this study and Hair
Severity has been computed based on the mill’s information.
All samples were tested under controlled Lab environment.
Samples were tested at 400mpm and 50mpm. Good Co-relation has
been observed as shown in the Table 2.

Premier recommends testing of Hair Severity (HS) at 400mpm,
which is a universally acceptable testing speed for testing
Yarn Hairiness Index (HI) and Hair Count (HC), Evenness and
Imperfections simultaneously. Similarly controlled studies
have also been conducted to find out the effect of Ring frame
process parameters on HS and also the effect of HS on Knitting
and Weaving performance.
HS Statistics 2007
HS Statistics 2007 offer following.
- Distribution across count and material.
- Tool to understand the prevailing Quality level.
- Bench mark the quality against the best.
Count wise HS
Hair Severity has been arrived at and the ‘HS’ value has
been plotted across four different Count and Material. The
percentage level for Hair Severity has been plotted. The three
levels represent the levels achieved by 5%, 25% and 50% of the
mills who have participated in the study. The comparative
Hairiness Index and H3 values for these three levels are also
given in the numerical table. Hair Severity (HS) has a very
good Co-relation with the Raw material Quality, Process
parameters in the Spinning preparatory and the Ring frame.

More information on HS
The effect of HS on raw material properties and in-process
parameters has also been studied and collated. HS is an
intelligent solution that enables the spinner to optimize
critical parameters in spinning and post spinning such as
spacer selection, determining the life of the rings,
optimizing the singeing process and the tension level in the
winding. HS also influences the performance of key departments
in weaving and knitting such as the production efficiency.

For a detailed please contact Premier at mail@premier-1.com
or obtain a copy of Premier Intelligence Book on Hair
Severity.
About Authors
Mr. V Srinivasan is a B.Tech (Electronics and
Communication) and has been with Premier Evolvics for the last
twenty years. As the head of R&D for lab products, he is
responsible for the conceptualization, design and ongoing
technical support for Premier Lab Products. He is an active
member of the ITMF spinners committee and has presented
several papers at international forum like The Bremen Fibre
Conference. He also had 3 patents in his name.
Mr.S.Balamurugan is a Textile Technology graduate from PSG
with more than 18 years of experience .He has worked with
leading manufacturers / mills like Super Sales , Precot,
Hindupur and Isparta Textiles –Turkey.Having been with Premier
Evolvics for the last 5 years, he has contributed towards
development of hair severity parameter. His key area of
excellence includes quality and maintenance in spinning mills.
|