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1.  Presentation on:
 Controlling parameter of knit dyeing

2. Md. Al-Amin Masum
ID: 2015100400011
Batch: 29th
BSc in Textile Engineering
Southeast University
alaminmasum11@gmail.com

3.  Introduction: In which anything influence the
effective coloration of textile materials with dye
is called as parameters of dyeing. To obtain
uniform dyeing we need to control the dyeing
parameters carefully. We have different types of
dyeing such as woven dyeing, knit dyeing, fiber
dyeing, yarn dyeing, garments dyeing. Knit is
one of largest dyeing sector in Bangladesh. To
enrich quality of knit dyeing we need to control
following parameter.
 Machine parameter.
 Process parameter.
 Raw materials parameter.
 Chemicals parameter.

4.  To enrich quality of knit dyeing we need to
control following parameter.
 Machine parameter.
 Process parameter.
 Raw materials parameter.
 Chemicals parameter.

5.  During knit dyeing we used different types of
machine, such as winch, Jet dyeing, Compressor,
Stenter, Dryer etc. according to company and
model different machine have different feature.
When we used these machines we need to know
about the features of these machines and
control some parameters of these machines to
get effective dyeing performance, Parameters
such as
 Capacity.
 RPM.
 Time.
 Temperature.
 Pressure.
 M:L ratio.

6.  Capacity: Different machine have
different capacity. To get higher
and effective productivity we need
to produce a effective proportion
of machine. For example, If we
have 50 ton capacity of a dyeing
house we must prepare a effective
layout for higher production.
 RPM: Machine rpm is very
important fact during production
time. If machine is not run in its
setting rpm then production will
delay and productivity loss. We
need to take active action to run
machine in its required rpm. If any
problem found then we must solve
it.
 M:l ratio: During dyeing liquor ratio
must be uniform. Higher liquor
ratio higher chemicals and
auxiliaries waste. According to
machine and process we used
different liquor ratio.

7.  Temperature: During dyeing
temperature is very important stuff for
even and issue free dyeing. In case
temperature not notional then chemicals
will not effectively utilize. As a result
chemicals waste and more chemicals
required for expected dyeing. Machine
setting temperature can fall for
different problem we need to solve
these problems for uniform dyeing
 Pressure: Now in modern dyeing
machine pressure is an important stuff.
Dyeing perform in high pressure required
less time and temperature. By HTHP
machine we can dye polyester fabric
without carrier.
 Time: During dyeing time must be
control. Different process requires
different time. If process performs
overtime then fabric wills degradation
and strength loss. We must use effective
dyeing time.

8.  Knit dyeing is divided into several processes.
In every process we need to control the
requirements of this process to get efficient
dyeing.
Chemicals.
Material.
PH.
Water hardness.
Absorbency.
Rinsing.
M:L ratio.

9.  Gray fabric inspection.
 Sewing stitching.
 Singeing.
 Desizing.
 Scouring.
 Bleaching.
 Mercerizing.
 Dyeing/ printing.
 Finishing.
 Final inspection.
 Delivery.
For these processes the process parameters are different.
Main process parameters are pH, Temperature, Time, water
hardness, absorbency, rinsing, color selection, chemicals
selection.

10.  Chemicals: knit dyeing different process we used different
types of chemicals. Different chemicals have different
properties. To get high performance and reduce wastage
we need to know the properties of these chemicals.
Chemicals properties such as, purity, expire date, country
origin, concentration check, strength check, chemical
structure.
 Material: In knit fabric we used natural or manmade fiber.
For manmade fiber we can give the properties as we like,
but in case of natural fiber (cotton fiber) we cannot
control its properties, so we need to know the properties
of the fabric. Fiber properties such as, maturity, fiber
purity, color, country of origin, blend ratio, fabric GSM,
fabric yarn count etc.
 PH: PH is one of the most important parameter of dyeing.
Chemicals are active at a certain ph. Processes are
perform in different PH according to chemicals and
material. We must need to maintain the ph efficiently.

11.  Water hardness: For textile dyeing we need soft
water, otherwise chemicals and auxiliaries are waste
and dying will not desirable. So we need to remove
water hardness before dyeing.
 Absorbency: Fabric has different absorbency
according to fiber construction. Fabric absorbency
also depends on scouring process. We need to scour
the fabric well during scouring process.
 M:L ratio: Liquor ratio depends on chemicals,
material and process. Different process required
different liquor ratio. We must use effective liquor
ratio.
 Rinsing: After dyeing rinsing wash must be perform
effectively to remove the unfixed dye from the
surface of fabric.

12.  Textile dyeing processes require different types of
chemicals. According to process and materials, chemicals
are changed. Such chemicals have different concentration,
company of origin, strength, chemical structure. For
uniform dyeing need to utilize pure chemicals. Batter
chemicals give performance as well as low cost. As a result
dyeing cost will high. We can determine purity of chemicals
by titration process.

13.  Expire date check: Sometimes suppliers are issue
expire chemicals or mixed expire chemicals with
fresh chemicals. We must check expire date and
performance of chemicals. If chemicals are expiring
it can’t give desirable performance.
 Country of origin: Chemicals have different
properties according to country of origin. According
to country of origin chemical parameter will change.
So we must check country of origin according to
previous performance.
 Concentration & strength check: In market we can
got chemicals in different concentration. But we
need to cheek this for our safety and quest. We also
need to check the strength of chemicals. We can
check these by titration or ph measurement process.

14.  Physical origin: Different
chemicals have different
physical origin. We should
use its original physical
state because chemicals
are more pure in its
original physical state.
 Chemical structure:
Structure of chemicals is
change according to
company. During use a
chemicals we must check
its chemical structure.
Good quality dyes have
more unsaturated double
or triple bond.

15.  Fabrics are different
according to fiber,
design, GSM, yarn count
and structure. Fibers
have different
properties according to
types, country, and
origin. For those fabrics
properties are also
change. Different fiber
has affinity to various
dyes and chemicals. So
we need to know the
properties of fiber,
yarn, fabric before
dyeing process.

16.  Maturity check: Mature
fibers have good strength,
fastness, and lecture. If fiber
are immature then it can
degradation during dyeing
process. So we must need to
check maturity of fiber.
 Fiber impurities check: We
must determine the amount
impurities in fiber. We need
to remove these impurities
by scouring process.
 Cotton expire date check:
Though cotton fiber is a
natural material it has expire
date after that cotton will
lose its properties. So we
must need to check the
expire date.

17.  Country of origin: Cotton of
different country have different
properties, such as staple length,
strength, lecture etc, so we
obligingly check the country of
origin.
 Blend ratio: In case of blend fabric
we must check blend ratio.
Because according to blend ratio
fabric properties change. For that
dyeing parameter also change.
 Fabric GSM: During dyeing process
fabric degradation occurs. Fabric
can degrade up to (6-10)% . Before
dyeing fabric GSM must higher than
required GSM.
 Fabric shrinkage: Fabric can shrink
after dyeing so we need to check
and determine fabric shrink
percentage before dyeing and also
keep required allowance to got
required dimension of fabric.

18.  knit dyeing is one of the largest dyeing
sectors in Bangladesh. Different knit fabrics
are dyed by various processes. So dyeing
parameters are different for these processes.
To get uniform and effective dyeing we must
need to control the parameters. From the
above discussion we get a short knowledge
about knit dyeing parameters. This will help
us in our future job life.