4. Denim is the oldest, most widely used, most fashionable and most
versatile fabric of the world. At present denim is mainly used for producing
garments particularly trousers for the young people. The gross production
of denim fabric is approximately 3,000 million metres per year.
Denims are produced from 4 oz. to 16 oz./ sq. yds in weight.
Technically Denim is defined as a 3/1 warp faced twill but also produced
from weaves like: Left hand twill, right hand twill, broken twill, cross
hatches, cords, dobby's, structures, etc .
Denims are made from yarn dyed warp and undyed weft.
Traditionally, denim was dyed with various shades of indigo, yarn-dyed,
different costs, and over-dyed with various types finishes at fabric as well
as garments state. Denims are manufactured different types of after
treatments or washes like stone wash, bleach wash, hand wash, acid wash,
over dyed, printed denims and even embossed.
Denim fabrics are used as jeans trousers both for men and ladies. It is
extensively used in the world as casual garments, Shirts, jackets, children
wears are also made of denim fabrics. Its versatility, finds applications in
furniture upholstery, bed covers, curtains, etc. Denim now-a-days is a
very demandable product. To make a denim fabric the required yarn for the
definite construction should be dyed then make a weavers beam to go to
weaving to make fabric.
7. Most of the denims are produced with 100% cotton and cotton-based blends with Lycra®,
Polyester, Tencel®, Bamboo, Jute, Nylon, and Linen etc. An ideal cotton mix for denim should
have the following quality parameters.
2.5% span length > 25mm
Strength (g/tex) >18
Micronaire > 4.5 to 5.0
Maturity Coefficient >0.75
Uniformity Ratio> 49%
Trash> 4.9%
In Bangladeshi mills, in most cases substantial quantity of waste yarns are used. This is
mainly done to reduce the cost of production. A well established mix for denim yarns are as
follows;
i. 80% waste, which consists of
(i) Dropping-1,
(ii) Dropping-2,
(iii) Flat strip,
(iv) Comber noil.
ii. 20% Fresh Cotton
FIBRE
8. YARN
(i) Rotor yams are the best and most widely used yarns in Denim production.
Because of their very high speed rotor yams are much cheaper than ring spun yams.
Off course rotor can only produce yarns of up to 30Ne. Though cheap rotor yarns are
associated with greater imperfections than corresponding ring yarns therefore knit
goods are produced from ring yarns.
(ii) Count range from 6 to 16 Ne but most widely used range is 7 to 12 Ne.
For slub yarn the range is 9 to 20 Ne.
(iii) Quality- Counf CV-<1.2, Single yarn strength> 12.8 gm/tex, Elongation>
6.0,U% <9.5.
(iv)As huge amount of slub yarns are used today the idea of too much strict
U% is not considered.
The diameter of slub varies froml.SD to 2.2D (Where D is the normal dia of yarn). The
periodicity of slub also varies widely. Test results show mat the distances between
two adjacent slubs varies within certain range. Some of the usual range distances
between two adjacent slubs are from 6cm to 10cm, 7 cm to 20 cm, 30cm to 60cm.
Some more information on yarns are given in weaving section later
12. Fig: Warpers beam
The thread from the packages in the creel is wound on to a beam to make warp beam.
13. PARTICULARS OF A DIRECT WARPING MACHINE
Setup parameter
>• *
Range Set value
Warping Length 1
-99,999m
Based on
quantity
yarn count, warping beam,
capacity
Cone/Cheese no. in the creel !
325-410
Based on customer fabric construction
Machine speed l-
800m/min
650
m/min;
Based on yarn count and
quality
Length correction % 1 156%
Stop motion I m-
second
Don't need
Supply Pressure 1-8 bar 5 bar
Beaming Pressure 1-160 40psi
Press Pressure 1-160 30psi
Carrier Pressure 1-160 50/55 psi
Hydraulic Pressure 0-40 16Psi
14.
15. Normally the process of dyeing dictates the technology of denim manufacturing.
The following twoDyeing methods are most popular processes for manufacture of
denim
SLASHER DYEING:
Slasher dyeing dyes the yarns in the warp beam form. It is a continuous
process which combines dyeing & sizing in a single operation. Dyeing is done by
continuously passing warp yarns through several (at least 5) troughs of indigo dye
liquor. The dyed yarns are then sized & wound onto a warp beam to be ready for use in
the weaving process. Slasher dyeing is usually of inferior quality as compared to rope
dyeing shade evenness or side-to-side shade variations. With the slasher dyeing, the
penetration of dyestuff is poorer, and it is easily reveals an uneven pick-up along its
width with the distortion of the pad-roll.
17. FLOWCHART OF DYEING & SIZING:
Warper’s Beam
↓
Pretreatment (Scouring) bath
↓
Dryer- wash bath (1, 2, 3)
↓
Color box - 1
↓
Dryer - 1
↓
Color box- 2
↓
Dryer - 2 (Air oxidation is done here)
↓
Color box - 3
↓
Steam box
↓
Color box - 4
↓
Yarn pass between a set of guide roller for oxidation
↓
Color box - 5
18. ↓
Oxidation
↓
Color box - 6
↓
Guide Roller
↓
Color box - 7
↓
Oxidation
↓
Color box - 8
↓
Oxidation
↓
Wash box (1, 2, 3)
↓
Dryer
↓
Sizing box
↓
Dryer
↓
Accumulator
↓
Leasing
↓
Winding
↓
Weaver’s beam
•Type- Sliding creel
•Arrangement- Two creels are placed parallel to each others.
•Creel capacity-16 warp beams can be placed in each creel.
•Electronic motor is available to slide the creel as well as mount the beams.
Beam creel section:
19. Fig: Beam creel
Capacity of cooking tank: 1000
Ltr
Cooking Temperature: 85º
Cooking time: 25-50 mins
Pick up: 5-10%
Cylinder temperature: 110-
130ºc
Squeezing Pressure: By top
roller
Delivery squeeze pressure:
Lowest: 12-17 kN
Highest: 15-20 KN
Stretch: 0.7-1%
Refractro reading: 7-11%
Viscosity: 12-30 sec
Sizing Temperature: 85-90ºc
Sizing BATH:
No of dry cylinders used in this bath = 12
Sizing parameter:
20. Fig: Sizing Tank
Scouring:
Natural fibers contain oil, fats & waxes together with other impurities. During manufacturing oil & adventitious dirt
are collected. And these are affected the absorbency of the cloths & leads to uneven dyeing. Oil, fats & waxes are all insoluble
in water; they dissolve in organic solvents such as Chloroform, Ether and Petrol etc. Scouring is the process to remove all
these impurities to make a more absorbent, hydrophilic & clean fabric.
OBJECT:
1. 01. To remove natural & added impurities like oil, wax, gum, fatty material as completely as possible.
2. 02. To get a clean & even fabric surface for the next process.
3. 03. To increase the absorbency of the fabric, i.e. to make the fabric hydrophilic, so that it can absorb dye molecule,
water & other processing easily.
Scouring Recipe:
NaoH= 36-145 gpl or g/l
Wetting agent (Lionil EH) = 0.5g/l
Temperature=85ºc
Water = 1400 liter
Squeezing roller pressure = 4-5 bar
21. FUNCTION OF THE CHEMICALS USED IN SCOURING:
1. Alkali: It converts the oil into water soluble fatty acid & soap.
02. Wetting agent: A soluble or dispersible material that reduces the surface tension between the material & liquid. Detergency
effect helps to clean the material.
03. Sequestering agent: It reacts with metallic ions & thus makes the metallic compounds to become a part of complex anion.
DYEING:
Dyeing is consists of 2 dyes. The indigo blue & Sulphur black is used in the dyeing process of denim. Sometimes brown
color is used instead of indigo blue in the factory according to the requirement of buyer.
DYEING RECIPE:
For leuco preparation here is a ratio which is followed:
Indigo : 100 g/l
Caustic Soda : 73 g/l
Reducing agent : 93 g/l
Dispersing agent : 0.5 g/l
Sequestering agent : 0.5 g/l
Wetting agent : 0.3 g/l
22. For black preparation the following ratio is followed:
Black : 35 g/l
Caustic Soda : 15 g/l
Antioxidant : 15 g/l
Sequestering agent : 0.5 g/l
Wetting agent : 0.5 g/l
Dyeing Process:
Dyeing process that is maintained as follows:
Pure Indigo- Continuous Indigo Dyeing
Bottoming- Sulphur(Bottom) & Indigo(Topping)
Topping- Indigo(Bottoming) & Sulphur (Topping)
Black Denim-Continuous Sulphur Black Dyeing
Color Denim.
23. LIST OF SOME CHEMICALS ARE USED & AND THEIR FUNCTION:
Pimazol ws:
Use as pre-wetting agent to reduce the surface tension of the liquor and allow to penetrated in to the fibers.
Sodium Hydrosulphite / Hydrose:
It is a reducing agent. It converts the insoluble vat dye to soluble leuco form & also to remove dissolved oxygen
from water.
Na2S2O4 + H2O + [O] = 2NaHSO3
Specification: ISO 9001, ISO 14001, OHSAS 18001
Purity = 90% min
Country = China
Caustic Soda:
It is scouring agent and removes impurities from the fiber. It is used here as pH controlling agent. NaHSO3 is
produced in the vatting bath which has the tendency to destroy leuco compound. To remove NaHSO3, alkali is used.
NaHSO3 + NaOH = Na2O3 + H2O
Specification:
“Caustic Soda Flakes’’
NaOH =96%min
Country = China
24. Ladiquest: It is a sequestering agent and use to remove the hardness of water.
Specification:
Name = 1097 – U liq
Country = Thailand
Setamol-Ws:
It is a dispersing agent. It is used to disperse the dye molecule properly in the dye solution.
Specification:
Manufacturer = BASF
Country = India
Persoftal BD (Paste):
It is a softener, used to soften the fabric in the finishing process.
Antioxidant:
It is used to protect oxidation of dye molecule in dye bath. It is used as reducing agent while Sulphur black is
used. It is also known as monohydrate glucose.
Acetic Acid:
It is used to reduce the percentage of pH in dye bath.
Specification:
Name = Acetic acid Glasiroyal
Composition:
Acery = 99%
Water = 0.7-1 %
Acetic anhydride = 0.3%
25. SIZING
Sizing Mills coat yarn with polyvinyl alcohol and starch for strength, and paraffin to make it easier to weave into
cloth and handle in sewing. It is a film- forming polymeric materials, which is applied to a warp sheet for the purpose of
protecting it during the weaving process.
Objects:-
•To increase the strength of yarn Up to 20% after the size application.
•To improve the hairiness, thick and thin places, Neps knots in the warp yarn.
•To protect the warp yarn from breakage during weaving process. Which is subjected to abrasion width varies loom parts
such as reed heald shaft Shuttle, Splitting rod.
Sizing composition depends on the following factors:
•Types of fibers
•Types of yarn
•Yarn quality
•Quality particulars of fabric to be woven
•M/c condition & ambient condition of the loom shade
•Cost of various ingredients
26. The Starch & Softener are used in the sizing bath are given below:
Starch: Emsland E-55 (Modified starch)
Emsland E-14
Softener: Mutton Tallow
Fin Fix
Trefin Wax
Starch:
These are products from grains & tubers. These are mixture of carbohydrate, oil, nitrogenous
substances & mineral matter. Carbohydrate is a polymer consisting of 25% amylase and 75% amylopectin.
Structurally it is a highly branched glucose polymer. Starches are cheap & easily available & have proved to valuable
adhesives over a many years especially for cellulosic yarns. This is manufactured mainly from maize, wheat, rice etc.
When starch is boiled with water, the starch granules swell & break up forming a smooth & homogenous gelatinous
mass.
27. EMSIZE E-55:
Application: is a low add –on starch sizing agent for spun yarns
Characteristics:
Application: is a low add –on starch sizing agent for spun yarns
Characteristics:
Kind of product: Potato starch derivatives
Appearance: Off white powder
Moisture content: < 20%
pH value (5% conc): 6-8
Viscosity:
Preparation of the solution:
The required quantity of product is added to cold water. Under stirring the slurry should be heated up till
95ºc and kept for at least 10 minutes at this temperature. Preparation in an autoclave has to be heated up to
110ºc and kept for at least 10 mins at this temperature.
28. EMSIZE E-14:
Application: Emsize is a starch sizing agent for spun
yarns
Characteristics:
Kind of product: High modified polymer
Appearance: Off white granules
Moisture content: 9-14%
pH value (5% conc): 9.5-11.5
Viscosity:
Preparation of the solution:
The required quantity of product is added to cold water. Under stirring the slurry should be heated
up till 95ºc and kept for at least 20 minutes at this temperature. Preparation in an autoclave has to be
heated up to 110ºc and kept for at least 10 mins at this temperature.
Both the starch has the following common properties:
excellent sizing effect
transparent flexible film
high adhesion power
compatible with other sizing agents
washed out quickly without enzymes
good biological degradability
29. Modified starch:
It is manufactured from natural starches mainly maize.
Advantage:
They are water soluble.
Can gelatinize easily & quickly
They penetrate well into the yarn because of their small particle Size, & pick up
percentage increases for this reason
Mutton tallow:
It is prepared from the sheep & is chemically composed of the glycerides of stearic,
oleic & palmitic acids.
30.
31. After warping, dyeing and sizing a weaver's beam is produced.
The
weaver's beam, after drawing and denting is then mounted in the
loom to produce the fabric. Weaving of denim fabric is not much
different from weaving all other fabric except the idea about the
warp and weft way shrinkage percent. It is well known that fabric
shrinks after relaxation and also after any wet process treatment.
In order to accommodate the aspect of both way shrinkages it is
necessary to use a very decisive EPI and PPI in the loom state so
that after relaxation and wet treatments the fabric will conform to
the customers supplied fabric details. It was found that in general
that the fabric shrinkage percent in the length direction varies
from I2%-15% while in the width direction the shrinkage percent
lies around 4.5% to 5.5 %. The higher shrinkage in the warp direction
is mainly due to greater warp tension during weaving and also due to
the coarser weft yams than that of the warp yarns. In order to comply
with the customer's requirements it will be necessary to choose both
EPI and PPI very precisely so that the final EPI and PPI of the
ultimate fabric conform to the buyer's requirement.
32. The typical reed and picks of some commonly produced fabric is given below;
Construction Finish
EPI
Loom
State
EPI
Finish
PPI
Loom
State
PPI
Finished
Cover
Factor
warp
Cover
factor
Weft
Cover
factor
9Rs+9R*7Rs+7R/
72*48
72 68 48 44/45 26.59 24 18.14
8Rs+9R*8Rs(MC)/68
*50
68 63 50 50 26.04 23.33 17.68
8Rs*10Rs+10R/76*5
4
76 71 54 50 27.56 26.87 17.08
9Rs+9OE*12Rs+10+
70D/
78*54
78 64 54 48/49 27.16 26 16.28
8Rs+10R*8Rs+7OE/
72*50
72 71 50 47/48 26 24 17.68
9OEs+9OE*10
OE/75*43
75 68 43 37/39 26.47 25 13.6
10Rs+10OE*6OE+70
D/
76*50
76 71 50 44/45 26.93 24.03 20.41
8Rs+7R+10R*9R/72
*48
72 66 48 41/44 26.69 24.94 16
33. We know
Cover factor, Kc =( K1 + K2 – K1*K2/28 )
Where, warp Cover factor, K1 = EPI/√ count
And weft Cover factor, K2 = PPI/√ count
Denim fabrics are highly sensitive to the fault incidence.
Therefore
maximum care is necessary at all levels to avoid fabric faults.
Normally the loom stoppages are regarded as a serious matter
in
accumulating fault level. Loom stoppages in turn depend on a
large
extent on the yarn quality. A recommendation based on
research
study has suggested the following yarn breakage norms in the
warping and sizing department;
34. Warping Ring
yarn
Rotor
yarn
Dyeing Ring
yam
Rotor
yarn
End break per
million metres
l<08 <0.5 End break per
million
metres
0.2 0.3
Loss of extension <0.5% <0.4% Loss of
extension
<1.3 <1.3
Imperfection also plays an important role in the production of a fault
free denim fabric. The norms for some of the important indicator of
yarn quality for denim are given below.
^
Parameter
Norms for Rotor
Yarns
Norms for Ring
Yarn
Count CV < 1.2% < 1.7%
Single Yam
Strength
> 12.8gm/tex > 14.0gin/tex
Elongation > 6.0 > 6%
U% j < 9.5 < 10%
Total
Imperfection
< 10 (at 280%) <35'9(At200%)
N:B: The CV% can not be applicable to the slub yarns.
35. GSM Calculation
Yarn count = Length (cm) X 0.0059
Wt(gm)
Yarn weight =
Sample weight X 100X100 / Sample Length X SampleWidthX 33.9063
For example,
Construction = 71 X 51
Total yarn = 11
Length of fabric = 3.45cm
Weight of fabric = 0.03 gm
Count =11X3.45X0.0059 / 0.03
=7.46
Weight = 0.4 X 100 X 1OO X 3.45X2.886X33,9063
=11.83 oz / yd2
Crimp % :
Warp Length – Actual Warp Length Production / Warp Length * 100
36. Shrinkage % :
Actual Production – Finishing Production / Actual Production * 100
Fig: Front view of a weaving mc
46. After weaving, the woven denim fabrics undergo for various finishing
processes depending on the end uses. This is because denim fabric
produced in a loom is somewhat dirty and very stiff and difficult to make
garment from them. Apart from this, the technical specification like width
and threads per inch cannot always be achieved straightway from the loom.
Therefore some physical and chemical treatments are carried out before
delivering the fabric to the customer/garment factory. These processes
are discussed under finishing section. Finishing of denim is carried out in
both fabrics as well as garment state. The fabric finishing is carried out in
the weaving factory where the fabric is produced but the garment state
finishing is carried out in the garments washing plant.
47. Finishing section placed along a line:
Finishing Line
Fabric Finishing
The typical flowchart of the denim fabric finishing is as below
Loom state fabric
↓
Brushing
↓
Singeing
↓
Brushing
↓
Softening
↓
Correction of skewing
↓
Compressive shrinkage
↓
Palmer (Calendaring cum drying)
↓
Inspection
↓
folding
48. Description of the processes:
Brushing:
The purpose of this process is to remove the lint, fluffs and
loose impurities. This is achieved by subjecting the fabric to
kind
of roller beating action.Singeing:
The objective of this process is to burn out the protruding
fibres
from the surface of the fabric. Only blue side singed and it is
done
twice.
Softening:
The aim of this process is to modify the feel of denim fabric and
to
facilitate the movement of the threads during skewing and
shrinkage
process. This is just a softening process where the fabric is
passed
continuously through a solution containing 5gm/Htre softener.
Sometimes softener is used as foam form. Use of foam
reduces the
quantity of heat required to dry the fabric.
49. CORRECTION OF SKEWING:
The 3/1 twill weave is in the classical denim fabric is inherently
unstable weave and has a tendency to twist anticlockwise
considering blue side as face side to stable configuration when it
is
put in water. Due to this unstable condition the weft yarns lies with
warp yarn at an angle different from 90°. This is regarded as
skewing
and if it is not corrected then there will be deformation and leg
twisting in the jeans made out of it. Therefore skewing is corrected
in this section where the fabric is basically passed either over a
roller
or through two sets of rollers. The basic idea of correction the
skewing
is that warp yarns deliberately pulled at one end so that the weft
yarn
can lie with warp at 90° .In the former case the fabric is pulled by
a
pair of squeeze rollers and the correction roller is either pushed up
or down. In the later case two sets of rollers are set at the two
extreme ends, the rollers are capable of pulling fabric at different
speeds. What ever is the method of correcting the skew ness, in
all
cases attempt is made to compact the fabric sufficiently so that
the
tendency of skewing is eliminated.
50. Compressive shrinkage:
The lengthwise shrinkage potential of denim fabric varies from 12% to
18% depending on the quality and construction. It is necessary to
correct this type of high potential shrinkage before making a
garment. Compressive shrinkage is a very widely used finishing
process used for shrinking the denim fabrics deliberately. This is
basically a mechanical finishing treatment. The basic working
principle of this process is that if a strip of elastic rubber is extended
and then a fabric strip is held pressed against the extended rubber. If, now
the rubber is allowed to relax, it will relax while the fabric strip will
also relax as it is held pressed against the rubber. In the real case, an
endless rubber sheet is pressed by a large circular cylinder. The fabric
is fed between the cylinder and the rubber sheet. By varying the
amount of feed it is possible to control the amount of shrinkage.
The extent of relaxation of the fabric can be controlled by controlling the amount
of feed.
51. Machine that are used in Tube line are given below:
J - Box
Brushing Unit
Singing / Burning
Washing / Softing
Skew Roller
Dry Cylinder
Shrinkage by rubber belt with 33º pressure
Calendering / Palmer
Folding
Softening Agent
Softener (Persaftier ISD)
Wetting Agent ( Lionil )
Acetic acid
52. Machine Specification :
Machine name: Morrison
Company Name : Morrison Textile Machinery Company
Origin : USA
Maximum Capacity : 40000 yds / day
Manufacturing Date : 2005
53.
54. Inspection Procedure
As the fabric is produced by the Air jet loom it is then collected by the quality
inspector and the fabric is thoroughly inspected in front of a white light board. During
this inspection the holes, oil marks, reed marks, loom bar, temple mark, double end,
double pick, tight warp, loose warp, faulty denting, faulty drawing are checked. If the
fabric is within the acceptance level (by the four point system) then it is sent to the
garments section for further treatment.
Quality Standard
Sinha Denims Ltd. Follows the four point grading system to inspect the body of the
fabric. In the four point system the faults are found by inspection and are given
points against the fault. Then the total no. is calculated. The following table shows
the four point system.
56. Four Point Grading System
Size of defects Penalty Points
3 inches or less 1
Over 3 inch but not over 6 inch 2
Over 6 inch but not over 9 inch 3
Over 9 inch 4
Following Table shows common faults and response by inspection section at Sinha
Denims Ltd
57. No. Faults Response
1. Reed Mark Uneven warp & weft tension
2. Mis pick Uneven weft yarn tension
3. Snarl Uneven air pressure
4. Hole Uneven knotting
5. Slubs Yarn fault
6. Thick thin place Uneven tension
7. Weft contamination Wrong weft yarn supply
8. Double end Wrong denting
9. Wrong denting Double end
10. Double pick Wrong air tension
11. Wrong drawing Operator fault
12. Loose warp Wrong beam winding
13. Tight warp Do
14. Oil line/ stain Carelessness
15. Chemical Do
16. Dirt stain Do
17. Crease mark Do
18. Uneven tension Wrong operational set up
58. MACHINE SPECIFICATION:
Machine Name : Modular Design Inspection Winding M/C
Company Name : S T T Machinery Co Ltd
(S T T = Shiaw Tai Tong )
Model : S T T - I E W 10272
Patent No : 187203
Serial No : 2987-2
Manufacturing Date : 2006
Origin : Taiwan
59.
60. Quality assurance:
Quality assurance is defined as all those possible planned and systematic actions
necessary to provide adequate confidence than a product or service will satisfy
given requirements for quality. The Quality Assurance Department is assigned to
maintain consistently uniform quality of the material in process and various stages
of manufacturing.
Objects of Quality Control:
Specification test
Raw material control
Process control
Process development
Product testing
Research
61. Quality Assurance System:
Quality assurance procedure may be divided into two major parts
Online quality control
Offline quality control
Online Quality Control:
Online quality control comprises with the raw material control, process
control & finish fabric inspection.
Raw material control:
As the quality product depends upon the raw material quality, quality assurance
department must ensure the best qualities of raw material (with economical consideration) are used
in production.
The yarn should be with a known concentration and high degree of purity
The dyes and chemical should be compatible with each other
The fabric must be without faults, with proper absorbency, whiteness as per requirement of the
subsequent process.
62. Process Control:
The method chosen for process must be provided with necessary parameters.
During weaving samples should be checked at each stage of process.
During finishing, temperature, speed, padder pressure, overfeed should be controlled a per requirement
GSM, width, shrinkage (both length & width) should be maintaining as per buyer requirement.
Finish Fabric Inspection:
Purpose:
To ensure that an acceptable quality fabric is used for producing garments and proper quality of
shipment is received from the supplier.
Scope: All produced and incoming fabrics of Sinha Denims Ltd.
Procedure:
•Store in charge will check the received fabric with the report length and type of fabric with the stated
shipment document quantity and the actual order quantity.
•The finding will be recorder in inventory report and discrepancy regarding fabric type, color and length
will be notified to the GM/ASTT> Manager.
•For in-house products quality control officer will guide all over inspection.
•Quality inspector (fabric) shall check 100% receive fabric for quality. He will identify any defect, hole or
stain in the fabric and make calculating given below-
63. Point calculation system
Defect area Point
1” to 3” 1
3” to 6” 2
6” to 9” 3
Above 9” 4
For any hole in fabric 4
Calculations of points is done by-
= Actual Point Grade
64. •If point grade is 40 or below then the fabric is ok. If the result is more than 40 points, then
inform it to GM or respective merchandiser
•The fabric is also checked for shading defect in side by side and length. Any non-
conformities/ shading will be notified to asst. manager using inspected reports. Roll wise color
uniformly card is maintained for identification of shade variations.
•During the fabric inspection if the yardage of any roll is reported more or less by the fabric
inspection machine then the one specified in the roll, the roll will be measured manually using
measuring tapes. Only calibrated measuring tape should be used.
•The result of fabric inspection shall be recorded in fabric inspection report.
Defects found in the final inspection:
Uneven shade
Oil spot
Neps
Crease mark
Machine stoppage mark
Reed mark
Pick missing
Double end
Hole
65. Offline quality control:
Offline quality control generally comprises different tests of final product so that it is
possible to identify whether it pass against the norms given by buyer, the following
test are generally done-
GSM test
Shrinkage test
Shade Check
Wash fastness test
Fastness to water
Rubbing fastness test
Perspiration test
Durability test
Dimensional stability
66.
67. Basic Procedure of Production Planning & Control
A planned work brings success. Without planning nothing is complete
within the required time. So planning has its own importance which is intolerable.
Planning gives a schedule task and control controls it successfully. But
production planning and control is not an easy task. Its basic working procedure
is as follows-
Taking order form marketing division
Analyzing the orders
Planning for dyeing the yarn
Planning for weaving the fabric
Planning for finishing the fabric
It is only a basic procedure. It may change according to the type of order.
Sometimes the order is planned only for finishing the materials or only for
weaving the goods. Then some steps are minimizing for planning.
68. a)Taking order from the marketing division:
Sinha Denims Ltd. Marketing division supplied fabric orders to the planning
and control division by a specific format.
b) Analyzing the orders:
After getting the fabric order, this section analyzes the orders according to buyers
order quantity, type of orders (i.e. type of fabric) delivery date etc. This section
plans for required quantity of fabric to be weaved, delivery fabric.
c) Planning for weaving of the fabric:
Production planning for weaving is called ‘” Beam Plan”. Weavers beam is
prepared according to m/c capacity, reed count, fabric construction, width, GSM
and priority of delivery etc and written in a pattern card.
d) Planning for finishing of the fabric:
Finishing schedule is same as weaving. After weaving, materials go to the
finishing section. The fabric can be finished in the regular finishing m/c. Finishing
will be selected according to the type of the fabric to be finished. Finishing data
is written to the pattern card and is informed to the planning section. However
this section always forces to all the departments to finish all the work within the
delivery time given by the buyers. Thus, it plays a very important role in the
success of the company.
69.
70. Costing of the product
Costing system mainly describe how the cost of the final product is fixed by the
company top managements. As it is a fabric manufacturing factory, so according to
the buyer/ customer requirements of final garments, merchandiser gives the
consumption of fabric with specifications. Then it is calculated how much yarns are
required for processing. After that, the final cost is fixed including some profit. Then
the unit price is offered to the buyer for the approval.
Costing of a product includes:
Yarn cost
weaving cost
Dyes and chemical cost
Cost of dyeing
Cost of finishing
Cost of cutting
Labor cost (direct & indirect)
Factory cost
Office and administrative cost
Others cost
Profit,etc.
71. Comments:
Costing of a unit product is the most secret matter of the industry. The company
policy does not allow flashing this out. So we could not collect the price of the
product.
72.
73. Marketing Information:
Sinha Denims Ltd. Is a 100% export oriented denim fabric
manufacturer. So they sell their product to export market. They also
take some initiative for market development through communicating
with new buyer and taking part in different international garments fair
Product & Customer:
As it is a denim industry, its main products are 3/1, 2/1, 2/2, 1/1 L.H.T &
R.H.T and 3/1 broken twill. The factory ensures faults free fabrics as per
customer requirements, through practice of faults free control procedures
76. Maintenance:
Machine, Building & facilities are subjected to deterioration due to their use
& exposure to environmental condition. Process of deterioration ,if unchecked,
culminates in rendering these service facilities unserviceable & brings them to a
standstill .In Industry ,therefore has no choice but to attend them from time to time
to repair & recondition them so as to elongate their life to extent it is economically &
physically possible to do so.
It is in this in the context that maintenance assumes important as an
engineering function .It is made responsible for provision of a condition of these
machines, buildings, & service that permit uninterrupted implementation of plans
requiring their use.
77. Objectives of maintenance:
•To keep the factory plants, equipments, machine, tools in an optimum working
condition.
•To ensure specified accuracy to product & time schedule of delivery to customer.
•To keep the down time of machines to the minimum thus to have control over the
production program.
•To keep the production cycle within the stipulated range.
•To modify the machine tools to meet the need for production
Types of maintenance:
78. Break Down MaintenancePreventive Maintenance
Maintenance
Electrical
Maintenance
Mechanical
Maintenance
Electrical
Maintenance
Mechanical
Maintenance
Types of maintenance:
79. Preventive Maintenance:
Preventive maintenance is a predetermined routine actively to ensure on time
inspection/ checking of facilities to uncover conditions that may lead to production
break downs or harmful description.
Breakdown Maintenance:
In this case, repairs are made after the equipment is out of order and it cannot
perform its normal functions.
Routine Maintenance:
Maintenance of different machines is prepared by expert engineer of
maintenance department. Normally in case of weaving machine maintenance is
done after every 7 days for complete checking of different important parts are
done.
80. Maintenance Procedure of Different machine:
•Weaving Machine
Maintenance: Mechanical
Items need to be checked & Service
Grease the bearing.
Complete cleaning of machine.
Cleaning of relay valves, replace scale if required.
Checking air supply filters, regulators, and auto drain scales.
Cleaning filter element and blow out.
Greasing the unloading roller bearings.
Checking oil level and bolts of unloading roller gearbox.
Checking of unloading roller couple and packing.
Checking and cleaning of main vessel level indicator.
Check the oil level of pump bearing and refill if required.
Check the function of heat and cool modulating valves.
Check all belts and belt tension.
81. •Finishing machine:
Maintenance: Mechanical
Items need to be checked & service
Grease padder bearing & expender device unit by Staburg NBU.
Complete cleaning of m/c.
Checking oil level and bolts of unloading roller gear box.
Check oil level of hydraulic system.
Check all belts, all chain and belt tension.
Check gear box plotting and its oil.
Check main line air pressure and air pressure gauge.
Check pneumatic belts, brushes, if required tight them properly.
Check in feed motor.
Check squeeze roller hydraulic cylinder.
Check turn table, belt tension, and gearing.
82. Conclusion
Findings:
Project is an essential part for textile education because it minimizes the gap between theoretical and
practical knowledge. Undoubtedly, this Project taught us lot about textile technology, production
processes, textile machineries, industrial management, and made us comfortable to industrial life.
Besides it gave us the first opportunity to work in industry.
Limitations:
Because of secrecy act, the data of costing and marketing activities have not been supplied
We did not get enough supervision form the responsible persons of different section due to their
busy schedule. So there may some limitation of data of different section in this report.
We had a very limited time. In spite of willingness to study in more details it was not possible to do
so.
Some of the points in different chapters are not include as these were not available.
It is not possible to in compass the whole process in such a small frame as this report.
83. Suggestions:
Due to shortage of technical persons (Textile Engineers) sometimes quality level drops which need to be
minimize by employing technical person. Especially at night shift.
During our project preparing period, most of the time the product were not first time right and need to be re
processed, increasing the production cost this problem has to be overcome.
We observe that there is lack of understanding between the top level personnel and floor level workforce,
weakening the chain of command.
Supervisor or floor in-charge did not properly follow the program. So sometimes operators deviate from the
set procedure which may hamper the quality of the product.
The machine in weaving and finishing section should be modernized to control all the parameters properly to
minimize the rejection percentage.
Weaving production needs to increase as well as technical persons need to employed there.
The machine stoppage time should be analyzed and minimized. The maintenance should be carried out
when the machine is out of action and routine maintenance should be carried out regularly.
More skilled labor should be used in the project to improve productivity.
84. BIBLIOGRAPHY:
Technical Solutions: Weaving from Mr. Younus
Technical Solutions: Weaving from Mr Tareq
Technical Solutions: Weaving from Mr Zahid
Technical Solutions: Quality Assurance & Control From Mr. Taufiq
Maintenance & Utilities: from Mr. Shahadath Hossain
Laboratory Tests: from SDL Document