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July 31, 2012
Difference between Rib, interlock and plain
Comparison among plain single jersey, plain rib and plain interlock fabric:
points
|
Plain s/j fabric
|
Plain rib fabric
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Plain interlock fabric
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1.appearance
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Face and back side are different
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Face and back side are identical
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Face and back side are same
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2.visibility of Wales
|
Clearly visible on the face side
|
Face and back side are identical.
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Wales of each side are exactly opposite to each other and locked together
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3.extensibility
|
Widthwise extensibility is twice than lengthwise extensibility
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Width and lengthwise extensibility is twice than single jersey
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Elongation is same as single jersey
|
4.curling tendency
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Curling occurs at the edges
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No curling tendency
|
No curling tendency
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5.thickness
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Approximately twice of yarn diameter
|
Approximately twice than single jersey
|
twice than single jersey
|
7.series of loops
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One series of knitted loop for per course
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Two series of loops
|
Two series of loops
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8. Derivatives
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Single lacoste ,Double lacoste.,Single pique,Polo pique/Double pique,Two thread fleece,Three thread fleece,French terry etc.
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2×2 rib,Half cardigan or royal rib,Full cardigan or polka rib,Swiss double pique,French double pique
|
Single pique or cross tucks interlock,Jersey cord.Eight lock.
|
Comparison between RIB and INTERLOCK circular knitting machine:
RIB
|
Interlock
|
1.Rib has vertical cord appearance
|
1.it has the technical face of plain fabrics on both sides
|
2.one type of latch needle is used
|
2.two types of latch needle is used.
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3.one feeder is used at yarn feeding
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3.at least two feeders are used
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4.relaxation is less
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4.more relaxation
|
5.Dial and cylinder needles are opposite but placed in same sequence.
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5. Dial and cylinder needles are opposite and alternatively placed
|
6.it is not so thick and heavy structure
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6. it is so thick and heavy structure
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More production rate
|
7. less production rate
|
8.used to produce tops of socks, cuffs ,sleeves ,bottom edges of sweaters ,knit hats, means hosiery
|
8.used to produce underwear, shirts, suits, trousers suits, sports wear, dress
|
Machineries of blowroom....
HOPPER FEEDER:
The cotton coming from previous machine is deposited on creeper latticed Reserve bin. Creeper
lattice will deliver the cotton on feed Lattice of main bin. Feed
lattice will take cotton forward close to the inclined lattice. Swing
door is used to maintain the constant level of cotton on feed lattice Due to the spikes on the inclined lattice and direction of movement, lumps bf cotton will be
carried upwards by the inclined lattice. Hard pressed layers of cotton
are well combed by the spikes of inclined lattice.revolving spikes of the evener roller or lattice
beats and open the cotton.Due to the close space between evener lattice
and inclined lattice and rotation of evener roller in a opposite
direction, unopened excess lumps of cottons are thrown back into mixing
bin.Stripping roller strip the cotton from inclined lattice and projects
it over a grid bar system where sand, heavy trash are passed through the spacing of the grid.
From
stripping roller the cotton is deposited, layer by layer in. the
reserve box and is taken into next machine by lattice in the form of
uniform feeding across the full width of the scutcher.
Pneumatic Conveyor Air current setup by the fan with condenser in the blow room line suck the cotton tufts from one machine and transfer or convey to another through pneumatic conveyor and is fed to the next machine by condenser.
Object: The main object of hopper feeder is open and feed fiber properly for next process.
PORCUPINE OPENER
The
cotton fed by the previous opener is carried forward by the feed
lattice. The sheet of cotton now pass between pedal and pedal roller.
The weight of cotton fed per unit time is maintained constant by this pedal feed regulating motion.
Pedal
roller feed the sheet of cotton in between pair of feed roller which is
weighted to give necessary grip on the cotton.16 circular disc are
mounted on the shaft of this opener. 14 to 18 striker blades are
rivitted alternatively on each circular disc. Each striker is bent to a
slightly different angle.The compressed sheet of cotton delivered from
the feed roller is heavily beated by the rapidly revolving striker of
the porcupine beater against grid bar.Because of this beating action,
the cotton is effectively opened and extracted trash particles are
passed through the spacing of the grid bar.
At
the end of the grid bar, stripping rail is provided, this is a metal
bar which is set about 1/16 inch away from the end of the striker. This
small clearance between stripping rail and striker prevents bunches of cotton being carried around by the beater.
Step cleaner:
Condenser
is employed to feed cotton to the step cleaner. Photo-cell arrangement
in the reserve tower unit monitor the height of reserve fibre and
signals stop or start commands to the proceeding machine. Cotton is fed
from the reserve tower by pair of feed roller. According to the height
of cotton level, photo cell in the reserve tower of subsequent machine,
drive the feed Roller intermittently by motorised gear reduction unit.
The
rapid revolution of 6 beating cylinders (multiple beater)and beating of
the spikes on cotton against grid bar centrifugal force and gravity
combine effectively to open the cotton and remove the heavier
impurities.
Heavier
impurities, dust & dirt particles, short fibres, etc, from the
cotton are passed through the spacing of the bars and is collected
outside the grid bar.
KIRSCHNER BEATER :
Working principle:
Kirschner Beater has 3 arms like 3 Bladed beater but in place of blades there are wooden lag(5.5 inch wide) carrying a large no. of steel pins (24 Rows) and inclined in the direction of rotation and project about 3/8 inch from surface of wooden lag. So, instead of beating ,here combing
action is achieved.The sheet of cotton delivered from feed roll is
combed by the revolving steel pins of the beater against the grid across
the width of the machine. Lighter impurities are thoroughly extracted
from cotton and passed through the grid bars.
Object: To comb and extract the lighter impurities from cotton.
SCUTCHER:
In addition to the other functions of blowroom machines, the scutcher has to form a lap for supplying material to the cards.
Previously, most of these machines were double scutchers; they had two
beater positions and two pairs of perforated drums. Machines delivered
in recent years have been almost exclusively single scutchers: they have
only one beater position (Kirschner beater) and only one pair of
perforated drums or even a single drum.
Following are 3 types of scutcher:
1.Breaker scutcher
2.Finisher scutcher
3.single process scutcher.
Working system:
Tow way distributor distribute the cotton from opening andcleaning line of Blow room line into two scutcher equally. Condenser with fan Suck the material from two way distributor and feed it to the reserve bin of hopper feeder. Hopper feeder (with Reserve feed & delivery ) mix, comb, open and clean the cotton. At last it provide uniform feeding of cotton upon the lattice, across the full width of scutcher. Pedal feed motion control the feed and maintain the weight of cotton fed per unit time as constant for lap weight unitormity.3 Bladed Beater Open and clean the cotton.Cage with fan Suck the material from Bladed beater,
extract
the lighter impurities and it provide uniform feeding as a 3 sheet form
on lattice across the full width of the scutcher. Again one set of
pedal feed motion, 2 Bladed Beater & cage with fan is placed and above mentioned works are achieved/repeated.At last, calender Roller section Compress the sheet ofwhich
is delivered from cage.Compressed sheet of cotton now pass under the
dead roller. and is wound on lap roller, which is called lap.
Objects of the scutcher :
i) To further break down and clean the cotton tufts by a beater
ii) To convert the mass of cotton fibres into a uniform thick sheet of cotton both longitudinally and transversely and wound in the form of a compactly built lap.
CONDENSER:
Fan connected with Condenser suck the material from previous machine through pneumatic pipe and deposit it into the Reserve tower which feeds to the next machine in the blow room lineThis condensor is employed to feed cotton to Hopper feeder of scutcher, step cleaner, etc, Suction for conveying the fibre from machine to machine is created by the fan connected to the condenser.
The
fibre condensed on to the rotating surface of the cage is removed by
the wiper roller and deposited into the reserve feed tower.
The condenser and reserve tower unit provide sufficient production and reserve of fibre to meet all demands by the next machine.
Steps to be taken while changing the length & hank of the lap
Lap Hank= lap length in hanks/weight in lbs.
To change lap hank, the feeding to the sctucher is altered by following methods.
i)feed roller speed is changed by altering the position of the cone drum belt by trial & errer method to bring the required Lap weight & lap hank.
ii)front sheet & back sheet position of the reserve box of theHopper feeder & swing door position is altered i.e. weight/unit length fed to scutcher is altered depending on the required lap hank. For example, to get more wt/ yard of lap front sheet should be moved forward, to increase the volume of the reserve box to get heavier lap.
iii)
in automatic scutcher, press button switches are provided for the
regulation of the lap weight per yard and lap hank through a servomoter
on the P.I.V. drive. The current postion of the PIV drive and the
degree of regulation are clearly indicated on a scale. It is possible to determine the optimum.
Setting
very quickly in case of lap hank change overs. In case of automated
scutcher, only the basic lap weight per yard is set by using the
corresponding press button switches. All adjusments are automatically
carried out by the lap weigher.
Control system in Blow room
Following
control systems are used in the blow room line to control the feeding
and feed the cotton at uniform rate to the scutcher.
1. Photo electric cell is placed in the following places :-
i) Reserve feed tower of hopper feeder, step cleaner etc.
ii) Reserve trunk of automatic scutcher.
iii) Laminar trunk of ERM cleaner.
iv) Filling trunk of chute feeding system.
v) Piano feed regulating motion, in the scutcher.
vi) Front sheet position and swing door of hopper feeder.
vii) Pressure switch in feeding trunk of automatic scutcher.
viii)Solenoids, micro switch,limit switch and relays
Modern Blowroom
In processing the material, different types of machines are necessary, namely those suitable for opening, those for cleaning and those for blending.
Different intensities of processing are also required, because the
tufts continually become smaller as they pass from stage to stage.
Accordingly, while a coarsely clothed cleaning assembly is ideal after
the bale opener, for example, it is inappropriate at the end of the
line. Therefore, there are no universal machines, and a blowroom line is
a sequence of different machines arranged in series and connected by
transport ducts. In its own position in the line, each machine gives
optimum performance at any other position it gives less than its
optimum. Also there may be advantages in different modes of transport,
feeding, processing, cleaning and so on from one machine to another
along the line. Finally, the assembly of a blowroom line depends among
other things on:
1.The type of raw material;
2.The characteristics of the raw material;
3.Waste content;
4.Dirt content;
5.Material throughput;
the number of different origins of the material in a given blend.
In
most cases a modern blowroom line consists of the following machines,
as shown in (Rieter) and (Trützschler), illustrating two
typical blowroom lines.
8. Rieter blowroom line; 1. Bale opener UNIfloc A 11; 2. Pre-cleaner
UNIclean B 12; 3. Homogenous mixer UNImix B 75; 4. Storage and feeding
machine UNIstore A 78; 5. Condenser A 21; 6. Card C 60; 7. Sliver Coiler
CBA 4
9. Trützschler blowroom line; (conventional, for combed cotton. One line with a number of variations.)
Advantages of modern Blow room line
Modern Blow Room line or latest developments in the B/R machinery consists
1.Modern mixing machine (Automixer, Multimixer, Aeromixer, Latest mixing bale opener etc.,)
2.Improved opener & Beater (ERM cleaner, mono cylinder, axiflo cleaner, Airjet cleaner, etc.)
3.Automatic scutcher.
4.Automatic lap doffing device.
Fabric inspection Faults and their causes
Defects | Causes |
Holes | Bad needle, take down mechanism too tight, high tension on yarn, bad yarn needle too tight in their slots, dial height too low or too high, badly tied knots, improper stitch setting. |
Drop stitches | Takedown mechanism too loose, defective needles, too loose yarn tension not sufficient, wrong needle timing set, needle tricks closed. |
Vertical lines | Defective needle, dirt in needle slots, needle too loose or too tight in the tricks, needles not enough lubricated. |
Soiled yarn | Contamination of cones due to miss handling, knot tying with dirty hand. |
Rust mark | Rusty needle, rust in tricks. |
Slub | Broken filaments being pushed back along the thread line excessive tails of knitter knot. |
Loop distortion | Bad and bent needles, bent trick walls, uneven yarn tension, needle timing set wrong, yarn carriers set wrong. |
Difference between weaving and knitting
Topics
|
Weaving
|
knitting
|
1.Definition
|
The fabric forming process by interlacement of warp threads.
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The fabric forming process by intermeshing of loops.
|
2.Elasticity
|
Very less or no elasticity.
|
The fabric shows high amount of stretch and elasticity due to loop structure.
|
3.Dimentional stability
|
Good dimensional stability which causes less shrinkage.
|
Less dimensional stability
|
4.Durability
|
More durable
|
Less durable than woven Fabrics.
|
5.Moisture absorption
| The fabric absorbs less moisture |
The knitted fabrics absorb more moisture because of their loose construction.
|
6.Slacking and low sening
|
The fabric provides good stability due to intersecting of yarns at right angle.
|
It creates problem after wearing for along time.
|
7.Air permeability
|
Air is less permeable due to compact construction woven fabric.
|
Air permeability is more due to voluminous structure of knitted fabric.
|
8.Crease
|
woven fabrics are more inclined to crease .So ironing and iron retention are better knitted fabric.
|
Knitted fabrics are more resistant to crease. So it requires no ironing.
|
9.Production cost
|
Production cost is more due to warp preparation and desizing process
|
Production cost is less due to modest manufacturing process.
|
10.Yarn
|
TPI of yarn is comparatively higher than knitting yarn.
|
TPI of yarn is comparatively lower than woven fabric.
|
May 1, 2012
April 23, 2012
What is organic cotton and how is it grown?
Organic
cotton is cotton that has been grown for at least three years without chemical
pesticides, defoliants, or fertilizers. Natural fertilizers and fertilizing
techniques are used instead, including compost, manure, naturally derived
mineral and plant fertilizers, and crop rotation. Third-party certification organizations
verify that organic producers employ only approved natural methods and
materials in organic production
How should organic cotton be labelled in the United States?
Labelling requirements for
organic fibers are as follows:
●Organic" - at least 95%
of the ingredients must be organic.
●Made With" – 70 to 95%
of the ingredients must be organic.
●Below 70 %"- US allows
identification of organic ingredients on the information panel in products
containing 50% or more
organic ingredients.
●Percent organic declarations
in the US
are not mandatory.
●Transition to organic"
- is not allowed.
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