Showing posts with label Weaving. Show all posts
Showing posts with label Weaving. Show all posts
29 December 2012
Weaving and Knitting | Compare/Difference Between Weaving and Knitting
Weaving:
The
method or process of interlacing two yarns of similar materials so that
they cross each other at right angles to produce woven fabric. The warp
yarns, or ends, run lengthwise in the fabric, and the filling threads
(weft), or picks, run from side to side. Weaving can be done on a power or hand loom or by several hand methods.
Knitting:
Knitting:
A method of constructing fabric by interlocking series of loops of one or more yarns. The two major classes of knitting are warp knitting and weft knitting.
http://textilelearner.blogspot.com/2012/04/weaving-and-knitting-comparedifference.html#ixzz2OCbkfA8W
Difference Between Weaving and Knitting
Topics
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Weaving
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Knitting
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1.Definition
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The fabric forming process by interlacement of warp threads.
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The fabric forming process by intermeshing of loops.
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2.Elasticity
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Very less or no elasticity.
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The fabric shows high amount of stretch and elasticity due to loop structure.
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3.Dimentional stability
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Good dimensional stability which causes less shrinkage.
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Less dimensional stability.
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4.Durability
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More durable
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Less durable than woven Fabrics.
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5.Moisture absorption
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The fabric absorbs less moisture
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The knitted fabrics absorb more moisture because of their loose construction.
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6.Slacking and low sening
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The fabric provides good stability due to intersecting of yarns at right angle.
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It creates problem after wearing for along time.
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7.Air permeability
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Air is less permeable due to compact construction woven fabric.
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Air permeability is more due to voluminous structure of knitted fabric.
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8.Crease
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woven fabrics are more inclined to crease .So ironing and iron retention are better knitted fabric.
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Knitted fabrics are more resistant to crease. So it requires no ironing.
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9.Production cost
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Production cost is more due to warp preparation and desizing process
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Production cost is less due to modest manufacturing process.
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10.Yarn
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TPI of yarn is comparatively higher than knitting yarn.
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TPI of yarn is comparatively lower than woven fabric.
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http://textilelearner.blogspot.com/2012/04/weaving-and-knitting-comparedifference.html#ixzz2OCbkfA8W
25 December 2012
Parameters of Warp Yarns During Weaving
Parameters of Warp Yarns During Weaving
- Material characteristics.
- Fiber type, e.g., cotton, polyester, acetate.
- Yarn type & structure including blend composition, e.g. staple, ring, open
- end, air-jet, combed, carded, core spun, continuous filament.
- Yarn hairiness.
- Yarn preparation; winding, warping, slashing.
- Tension on yarn during sizing.
- Moisture content.
- Drying temperature.
- Slashing machine parameters.
- Slashing speed.
- Size box characteristics.
- High pressure squeeze rolls, including hardness of rolls.
- Amount of size.
- Yarn tension.
- Closeness of yarn.
- Loom parameters.
- Type of loom.
- Weave
- Loom speed.
- Warp tension.
10 October 2012
Different Parts of a Loom
Different Parts of a Loom
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| Different Parts of a Loom |
Short Description of Loom is Given Below:
Heald/Heddle: Wire or cords with eyelets that hold warp yarns in a place.
Function:
1. It helps in shed formation.
2. It is useful in identifying broken ends.
3. It determines the order or sequence of the warp threads.
4. It determines the warp thread density in a fabric.
Heald shaft/Harness: A wood or metal frame that holds the headl/heddles in position in the loom during weaving. It is usually more than one.
Shuttle: This is a vehicle for weft & passes through the divided warp for the interlacement of the warp & weft.
Shuttle box: Compartment of each end of the sley of a shuttle loom used to retain the shuttle between picking motion.
Picker: It is a piece of leather or other metal placed in grooves or on a spindle inside a shuttle box.
Beams:
A cylindrical body with end flanges on which a multiple of warp ends is
wound in such way to permit the removal of these yarns as a warp sheet.
Front rest:
It is a fixed roller placed in front of the loom above the cloth beam
& act as a guide for the cloth to wind on to the cloth beam.
Lease rods:
The division of warp yarn into one & one, two & two, & so
on is termed as lease. The two rods passed between the two successive
divisions of warp yarns are called lease rods.
Slay: It is the portion of loom that carries the reed and oscillates between the harness & the fell of the cloth.
Reed: A comb like wire or device used to separate yarns on a loom & to beat up the filling during weaving.
Treadle: The treadle is a paddle or lever under a loom with which a thread is connected by means of cords.
Temple: Roller device on a loom that hold the cloth at a proper width to prevent it from being drawn in too much by the filling.
23 September 2012
Study on under picking mechanism.
Experiment name: Study on under picking mechanism.
Introduction:
Picking is the second primary motion in weaving. The action of inserting weft yarn through the warp yarns is called picking.
Features of under picking mechanism:
1.Picker arm is placed under the race board.
2.Suitable for wider loom.
3.Under picking works less smoothly.
4.More direct action.
5.Rough in action.
6.More clean mechanism.
7.Consumes more power.
8.Used for heavy weight fabrics in silk and rayon looms.
Under picking mechanism:
In under picking mechanism a race board is situated over picking arm. Under picking is controlled by picking cam which is fixed on the bottom shaft. At first the motion comes from motor and m/c pulley.
Then the motion comes in to the bottom shaft and thus picking cam. When picking cam rotates and its nose portion comes in contact with treadle lever and pushes it then the treadle lever pushes the angular lever. The picking arm gets motion from angular lever which is connected with picking arm.
A picker is placed in the picking arm which pushes the shuttle. When shuttle gets motion by picking arm then shuttle begins to move to and fro on the race board. Thus picking is done.
A spring is situated which causes the picking arm and picker to move back after the delivery of the pick. At the two end of bottom shaft, two picking tappets are fixed. By increasing nose length picking speed may be increased.
How to increase PPM:
1.By increasing motor seed.
2.By increasing the nose shape of picking tappet.
3.By decreasing the length of picking arm.
Uses:
This mechanism is used in all non-automatic cotton looms. It is also used in jute looms.
Conclusion:
This picking mechanism is very important for loom. In the loom under picking is directly done by picker and picking arm. Again under picking is necessary for weft yarn insertion. So we should learn about this mechanism very carefully.
Introduction:
Picking is the second primary motion in weaving. The action of inserting weft yarn through the warp yarns is called picking.
The functions of picking mechanism are:
1.To deliver the shuttle along the correct flight length.
2.To throw the shuttle at a predetermined speed.
Main parts:
1.Picking arm
1.To deliver the shuttle along the correct flight length.
2.To throw the shuttle at a predetermined speed.
Main parts:
1.Picking arm
2.Picker
3.Picking cam
4.Picking bowl
5.Race board 6.Shuttle
7.Bottom shaft
8.Treadle lever
9.Angular lever
10.Crank shaft
3.Picking cam
4.Picking bowl
5.Race board 6.Shuttle
7.Bottom shaft
8.Treadle lever
9.Angular lever
10.Crank shaft
Features of under picking mechanism:
1.Picker arm is placed under the race board.
2.Suitable for wider loom.
3.Under picking works less smoothly.
4.More direct action.
5.Rough in action.
6.More clean mechanism.
7.Consumes more power.
8.Used for heavy weight fabrics in silk and rayon looms.
Under picking mechanism:
In under picking mechanism a race board is situated over picking arm. Under picking is controlled by picking cam which is fixed on the bottom shaft. At first the motion comes from motor and m/c pulley.
Then the motion comes in to the bottom shaft and thus picking cam. When picking cam rotates and its nose portion comes in contact with treadle lever and pushes it then the treadle lever pushes the angular lever. The picking arm gets motion from angular lever which is connected with picking arm.
A picker is placed in the picking arm which pushes the shuttle. When shuttle gets motion by picking arm then shuttle begins to move to and fro on the race board. Thus picking is done.
A spring is situated which causes the picking arm and picker to move back after the delivery of the pick. At the two end of bottom shaft, two picking tappets are fixed. By increasing nose length picking speed may be increased.
How to increase PPM:
1.By increasing motor seed.
2.By increasing the nose shape of picking tappet.
3.By decreasing the length of picking arm.
Uses:
This mechanism is used in all non-automatic cotton looms. It is also used in jute looms.
Conclusion:
This picking mechanism is very important for loom. In the loom under picking is directly done by picker and picking arm. Again under picking is necessary for weft yarn insertion. So we should learn about this mechanism very carefully.
7 August 2012
Weaving | Weaving Mechanism | Classification of Weaving Machines
The process of producing a fabric by
interlacing warp and weft threads is known as weaving. The machine used
for weaving is known as weaving machine or loom. Weaving is an art that
has been practiced for thousands of years. The earliest application of
weaving dates back to the Egyptian civilization. Over the years, both
the process as well as the machine has undergone phenomenal changes. As
of today, there is a wide range of looms being used, right from the
simplest handloom to the most sophisticated loom.
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Classification of Weaving Machines:
Weaving machines are classified according to their filling insertion mechanism. The classification is as follows:
Weaving machines are classified according to their filling insertion mechanism. The classification is as follows:
1. Shuttle
2. Shuttle-less
In shuttle weaving, a shuttle that traverses back and forth across the loom width, inserts the filling. Shuttles can be made of wood or plastic. Filling yarn is wound on the quill and the quill is placed in the shuttle. As the shuttle move across the loom, the filling yarn is unwound from the pirn and lay in the shed.
2. Shuttle-less
- Projectile
- Rapier
- Air-Jet
- Water-Jet
In shuttle weaving, a shuttle that traverses back and forth across the loom width, inserts the filling. Shuttles can be made of wood or plastic. Filling yarn is wound on the quill and the quill is placed in the shuttle. As the shuttle move across the loom, the filling yarn is unwound from the pirn and lay in the shed.
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| Fig: Basic Weaving Mechanism |
Projectile Weaving
Projectile weaving machines use a projectile equipped with a gripper to insert the filling yarn across the machine. The gripper projectile draws the filling yarn into the shed. The Projectile glides through the shed in a rake- shaped guide. Braked in the receiving unit, the Projectile is then conveyed to its original position by a transport device installed under the shed.
Projectile weaving machines use a projectile equipped with a gripper to insert the filling yarn across the machine. The gripper projectile draws the filling yarn into the shed. The Projectile glides through the shed in a rake- shaped guide. Braked in the receiving unit, the Projectile is then conveyed to its original position by a transport device installed under the shed.
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Fig: Projectile Weaving
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Rapier Weaving
In Rapier weaving, a flexible or rigid solid element, called rapier, is used to insert the filling yarn across the shed. The rapier head picks up the filling yarn and carries it through the shed. After reaching the destination, the rapier head returns empty to pick up the next filling yarn, which completes the cycle. A rapier performs a reciprocating motion.
In Rapier weaving, a flexible or rigid solid element, called rapier, is used to insert the filling yarn across the shed. The rapier head picks up the filling yarn and carries it through the shed. After reaching the destination, the rapier head returns empty to pick up the next filling yarn, which completes the cycle. A rapier performs a reciprocating motion.
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Picture: Weft insertion by rapier
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Rapier weaving machines can be of two types:
1. Single Rapier Machines:
A single, rigid rapier is used in these machines. The rigid rapier is a
metal or composite bar usually with a circular cross section. The
rapier enters the shed from one side, picks up the tip of the filling
yarn on the other side and passes it across the loom width while
retracting. Therefore, a single rapier carries the yarn in one way only
and half of the rapier movement is wasted. Also there is no yarn
transfer since there is only one rapier. The single rapier’s length is
equal to the width of the loom.
2. Double Rapier Machines: Two rapiers are used in these machines: one rapier, called the giver, takes the filling yarn from the yarn accumulator on one side of the loom, brings it to the center of the machine and transfers it to the second rapier which is called the taker. The taker retards and brings the filling yarn to the other side. Similar to the single rapier machines, only half of the rapier movements are used for filling insertion.
Air-Jet Weaving
The air jet weaving machines are the weaving machines with the highest weft insertion performance and are considered as the most productive in the manufacturing of light to medium weight fabrics, preferably made of cotton and certain man-made fibers (sheets, shirting fabrics, linings, taffetas and satins in staple yarns of man-made fibers); it has anyway to be pointed out that technically positive results are obtained at present also with heavy weight fabrics (denims) and that some manufacturers produce also machine models for terry production.
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Fig: Air-Jet Weaving
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These
machines are the ideal solution for those who want to produce bulk
quantities of customized fabric styles. The weaving widths range
generally from 190 to 400 cm. As regards the multicolor weft carrier, up
to 8 different wefts can be fed. It has however to be considered that
the air jet weaving machines require a high energy consumption to
prepare the compressed air and that this consumption rises definitely
with increasing loom width and running speed. The reduction in the
energy consumption is in fact one of the main concerns of the
manufacturers, and builds for the user an important selection criterion.
Water-Jet Weaving
A water-jet weaving machine inserts the filling yarn by highly pressurized water. The relative velocity between the filling yarn and the water jet provides the attractive force. If there is no velocity difference, then there would be no tension on the yarn results in curling and snarling of the yarn. Water-jet weaving machine can only be used for hydrophobic fibers.
A water-jet weaving machine inserts the filling yarn by highly pressurized water. The relative velocity between the filling yarn and the water jet provides the attractive force. If there is no velocity difference, then there would be no tension on the yarn results in curling and snarling of the yarn. Water-jet weaving machine can only be used for hydrophobic fibers.
Fig: Water-Jet Weaving
28 July 2012
Warp and Weft Yarn Preparation | Necessity of Warp/Weft Yarn Preparation
Warp Preparation
Drawing-In
Provides each warp yam with its drop wire, heddle, and reed dent.
Tying- In
When mass producing the same fabric by simply typing each end of a new beam to its corresponding end of the old beam
Necessity of Warp Yarn Preparation
We need to prepare the warp yarn because of:
- Imperfection of yarn.
- Requirement to transfer the spun yarns in a conventional package.
- Extra treatment to make the yarn ready for weaving.
- Warp yarn must be able to withstand destructive forces to which it is subjected during the weaving process.
- Yarn hairiness must be decreases.
- Yarn must be aligned properly.
- Yarn elongation & flexibility must be sustained.
On conventional loom the filling yarn is inserted by means of a shuttle carrying a bobbin. This bobbin should be tapered at the end so that the yarn may be pulled without interruption through the eye of the shuttle as the shuttle travels from one side of the loom to the other.
Necessity of Weft Yarn Preparation
- Removal of slubs & weak places during processing which otherwise would impair the running of the loom.
- The production of the tighter packages having more yards per pirn. This reduces the number of pirn changes in the loom. This, in turn, reduces the possibilities of flaws & wastage.
- Greater uniformity of pirns used on the loom. This improves the uniformity of the fabric. The easy handling of small lots.
28 June 2012
3D-Weaving | Manufacturing Process of 3D-Weaving | Application of 3D Weaving Fabric
3D-Weaving
It cannot be performed with existing traditional methods and machines. It interlaces a multiple layer warp with multiple horizontal wefts and multiple vertical wefts producing directly shell, solid and tubular types of fully interlaced 3D fabrics with countless cross-sectional profiles.
First demonstrated in 1997, Dual-Directional (D-D) Shedding System is indispensable for performing 3D-weaving. This path breaking development has advanced the technology of weaving to a new dimension for the first time in its more than 27000 years of history.
Manufacturing Technology of 3D-Weaving
Special looms are required to operate the warp threads in 60o angle for weaving 3Dr-3 Directional fabrics. But the 3 Dimensional -3Dm- fabric can be woven by using ordinary loom with usual weaving principle-shedding, picking, beating - by having multi layers of warp and multi layers of weft. Even though the treble cloth with 3 series of warp and weft could be called 3Dm fabrics, in general, minimum 4 series of warp and weft are used in weaving to form several layers, one above the other to get the sufficient thickness resulting into 3 Dimensional fabric.
As per the principle of weft Tapestry fabric, to weave 3Dm fabrics, it is required to use one series of stitching warp and multi series of separating warp as per the number of layers to be formed.
As seen from the cross section, the stitching
warp passes from top to bottom and bottom to top but all the separating
warp lies almost straight and hence the stitching warp takes up more
length than the separating warp. Therefore, the stitching warp is
brought from a loose tension beam and the entire separating warp is
brought from another normal tension beam.
The following points are to be understood from both the cross sections: -
The first layer weft (Face) - shown as "a" - lies between the stitching warp (shown as 1) and first separating warp series (shown as 3).
The second layer of weft (Middle) - shown as "b"- lies between the first and second separating warp series (shown as 3 and 4).
Application of 3D Weaving Fabric
A new method has been developed for the manufacture of bifurcated prosthesis used in medical applications and they are used to replace the defective blood vessels in patients so as to improve blood circulation.
The 3D fabrics have recently entered the medical field. Their specific area of application is in the weaving of vascular prosthesis. Vascular prosthesis are surgically implantable materials. They are used to replace the defective blood vessels in patients so as to improve blood circulation. Conventional types of prosthesis were made from air corps parachute cloth, vignon sailcloth, and other types of clothing materials.
Materials such as nylon, Teflon, orlon, stainless steel, glass, and Dacron polyester fibre have been found to be highly suitable for the manufacture of prosthesis. These materials were found to be significantly stable with regard to resistance to degradation, strength, and were not adversely affected by other factors. Dacron polyester, which has bio-compatibility and high tensile strength, is being used over a period of time as suture thread or artificial ligaments.
3D-Weaving
is a complete new concept in case of weaving. The first method of 3D
woven fabric denotes 3 Dimensional fabrics, that is length, width and
breadth. In 3 Dimensional fabrics, the thickness is an important
criterion. Ordinary fabrics also have length, width and breadth, but in
the 3 Dimensional fabrics, the thickness is much more than ordinary
fabric. The thickness is achieved by forming multiplayer using multi
series of warp and multi series of weft, which are intersecting at
regular 90o angle as in usual cloth weaving principle.
It cannot be performed with existing traditional methods and machines. It interlaces a multiple layer warp with multiple horizontal wefts and multiple vertical wefts producing directly shell, solid and tubular types of fully interlaced 3D fabrics with countless cross-sectional profiles.
First demonstrated in 1997, Dual-Directional (D-D) Shedding System is indispensable for performing 3D-weaving. This path breaking development has advanced the technology of weaving to a new dimension for the first time in its more than 27000 years of history.
Manufacturing Technology of 3D-Weaving
Special looms are required to operate the warp threads in 60o angle for weaving 3Dr-3 Directional fabrics. But the 3 Dimensional -3Dm- fabric can be woven by using ordinary loom with usual weaving principle-shedding, picking, beating - by having multi layers of warp and multi layers of weft. Even though the treble cloth with 3 series of warp and weft could be called 3Dm fabrics, in general, minimum 4 series of warp and weft are used in weaving to form several layers, one above the other to get the sufficient thickness resulting into 3 Dimensional fabric.
As per the principle of weft Tapestry fabric, to weave 3Dm fabrics, it is required to use one series of stitching warp and multi series of separating warp as per the number of layers to be formed.
The following points are to be understood from both the cross sections: -
The first layer weft (Face) - shown as "a" - lies between the stitching warp (shown as 1) and first separating warp series (shown as 3).
The second layer of weft (Middle) - shown as "b"- lies between the first and second separating warp series (shown as 3 and 4).
Application of 3D Weaving Fabric
A new method has been developed for the manufacture of bifurcated prosthesis used in medical applications and they are used to replace the defective blood vessels in patients so as to improve blood circulation.
The 3D fabrics have recently entered the medical field. Their specific area of application is in the weaving of vascular prosthesis. Vascular prosthesis are surgically implantable materials. They are used to replace the defective blood vessels in patients so as to improve blood circulation. Conventional types of prosthesis were made from air corps parachute cloth, vignon sailcloth, and other types of clothing materials.
Materials such as nylon, Teflon, orlon, stainless steel, glass, and Dacron polyester fibre have been found to be highly suitable for the manufacture of prosthesis. These materials were found to be significantly stable with regard to resistance to degradation, strength, and were not adversely affected by other factors. Dacron polyester, which has bio-compatibility and high tensile strength, is being used over a period of time as suture thread or artificial ligaments.
23 June 2012
Basic Mechanisms in a Plain Power Loom
Basic Mechanisms in a Plain Power Loom
In order to interlace warp & weft threads to produce a fabric, the following weaving mechanisms are necessary on any type of loom:
In order to interlace warp & weft threads to produce a fabric, the following weaving mechanisms are necessary on any type of loom:
- Primary mechanism
- Secondary mechanism
- Auxiliary mechanism
Primary Mechanism
These are fundamental or essential mechanisms. Without these mechanisms, it is practically impossible to produce a fabric. The primary motions can further be divided as shedding, picking and beat up motions. The shedding opens the warp sheet into layers to facilitate passage of shuttle. The picking motion causes the shuttle carrying weft to be propelled from one end of loom to another. The beat up motion lays the previously laid weft to the fell of the cloth.It is for the reason that these mechanisms are called “Primary mechanisms”. The primary mechanisms are 3 in number.
These are fundamental or essential mechanisms. Without these mechanisms, it is practically impossible to produce a fabric. The primary motions can further be divided as shedding, picking and beat up motions. The shedding opens the warp sheet into layers to facilitate passage of shuttle. The picking motion causes the shuttle carrying weft to be propelled from one end of loom to another. The beat up motion lays the previously laid weft to the fell of the cloth.It is for the reason that these mechanisms are called “Primary mechanisms”. The primary mechanisms are 3 in number.
1. Shedding mechanism
2. Picking mechanism
3. Beat-up mechanism
Secondary Mechanism
These mechanisms are next in importance to the primary mechanisms. If weaving is to be continued, these mechanisms are essential. The secondary motions comprise of take up and let off motions. The take up motion helps to wind the cloth on to the cloth roller and also influences the pick density in the cloth. The let off motion helps to let the warp from the weaver’s beam at an uniform rate thus maintaining the warp tension constant throughout the weaving process.So they are called “Secondary mechanisms”. They are
1. Take-up motion
2. Let-off motion
Auxiliary Mechanism
To get high productivity & good quality of fabric, additional mechanisms, called “Auxiliary mechanisms” are added to a plain power loom. The auxiliary mechanisms are useful but not absolutely essential. The auxiliary motions consist of the warp stop motion, weft stop motion and warp protector motion. The warp stop motion is used to stop the loom in the event of warp breakages. This is necessary to prevent fabric defects such as missing ends and floats. The weft stop motion is used to stop the loom in the event of weft exhaustion or weft breakages. This is necessary to prevent missing weft threads called cracks, in the fabric. The warp protector is used to prevent multiple warp thread breakages in the event of shuttle getting trapped in the middle of the warp sheet. These are listed below:
1. Warp protector mechanism
2. Weft stop motion
3. Temples
4. Brake
5. Warp stop motion
9 May 2012
HISTORY OF WEAVING
HISTORY OF WEAVING
Evolution of Weaving
- Egyptians made woven fabrics some 6000years ago .
- Chinese made fine fabrics from silk over 4000 years ago.
- A shedding mechanism was originally invented in China in the 3rd century and introduced in Europe.
- In 12th century , completely wooden hand looms were used as standard designs in England.
- The developments in the design and performance of looms have taken place during the past 850 years.
- The fly shuttle , invented in 1733 by John Kay, was hand operated.
- It was an important cornerstone to improve the productivity.
- This shuttle, running on four wheels, was moving over the lower side of the warp sheet.
- Two wooden tenders connected to a small cord commanded by the hand were used to propel the shuttle. The weaver sitting in the middle of the loom threw the shuttle by pulling the cord very easily.
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| Hand loom |
Power Looms
http://textilelearner.blogspot.com/2012/06/history-of-weaving-in-according-with.html#ixzz2OCavGYyC- E.Cartwright invented the power loom in 1785
- In the early 1800s , looms made of cast iron were operated by power .
- In the 1830s, there were some 100,000 shuttle looms operating in England.
- In 1895, many looms, all driven by an electric engine were invented and then became spread.
- At the beginning of 1930's, eventually, each weaving machine driven individually by an electric motor was developed, this loom drive concept has remained in use until the present.
- The automatic loom stopping system was invented by R.Miller in England in 1796. The loom was automatically stopped when a short pick occurred.
- In 1894 Northrop devised a means for automatic weft replenishment without stopping the loom which was called automatic loom .
- The first dobby operated by a punched card was invented by B. Bouchone in 1725.
- A machine controlling bundles of harness cords with healds was constructed by J.M. Jacquard in 1801.
- The first shuttle change motion enabling weft threads of different colors to be inserted was constructed by J.P. Reid and T. Johnson in 1835.
- One significant invention in the field of design was that of Keighley dobby by Hattersley and Smith in 1867 .
- Rotary dobbies are manufactured in 1990s.
- Projectile w.m. was invented in 1924by an engineer named Rossmann became commercial in 1953.
- The first patent for the rapier w.m.was granted in 1898, then followed the Gabler system in 1925 and the Dewas system in 1930. Production of rapier w. m. started in 1972.
- The first air-jet system was invented in 1914 but it became important commercially after 1980’s.
- Continuous weft insertion on a circular w.m. was proposed before the end of the 19th century.
- After mid 90s, multi phase w.m. has showed new developments.
27 April 2012
Yarn Preparation for Weaving and Knitting
Definition
Yarn preparation involves those processes that improve the yarn’s weaveability or knittability.
Preparation Requirement for Weaving Yarn:
Warp Yarns
Yarn preparation involves those processes that improve the yarn’s weaveability or knittability.
Preparation Requirement for Weaving Yarn:
Warp Yarns
- Yarns must be aligned properly
- Yarn strength must be increased
- Yarn hairiness must be decreased
- Yarn smoothness must be increased
- Yarn elongation and flexibility must be sustained
Filling Yarns
Yarn must be wound properly and on a suitable package for high speed unwinding
Preparation Requirement for Knitting Yarn:
Weft Knitting
Yarn must be wound properly and on a suitable package for high speed unwinding
Preparation Requirement for Knitting Yarn:
Weft Knitting
- Yarn friction must be decreased
- Fiber shedding must be decreased
- Yarn smoothness must be increased
- Yarn friction must be decreased
- Fiber shedding must be decreased
- Yarn smoothness must be increased
- Yarns must be properly aligned for introduction to knitting needles
7 April 2012
Yarn Preparation for Weaving and Knitting
Definition
Yarn preparation involves those processes that improve the yarn’s weaveability or knittability.
Preparation Requirement for Weaving Yarn:
Warp Yarns
Yarn preparation involves those processes that improve the yarn’s weaveability or knittability.
Preparation Requirement for Weaving Yarn:
Warp Yarns
- Yarns must be aligned properly
- Yarn strength must be increased
- Yarn hairiness must be decreased
- Yarn smoothness must be increased
- Yarn elongation and flexibility must be sustained
Filling Yarns
Yarn must be wound properly and on a suitable package for high speed unwinding
Preparation Requirement for Knitting Yarn:
Weft Knitting
Yarn must be wound properly and on a suitable package for high speed unwinding
Preparation Requirement for Knitting Yarn:
Weft Knitting
- Yarn friction must be decreased
- Fiber shedding must be decreased
- Yarn smoothness must be increased
- Yarn friction must be decreased
- Fiber shedding must be decreased
- Yarn smoothness must be increased
- Yarns must be properly aligned for introduction to knitting needles
4 January 2012
Weaving Resistance | Factors Affecting Weaving Resistance | The Effect of Loom Settings on Weaving Resistance
Weaving Resistance:
When warp and weft are interlaced in a fabric then they oppose to each other due to static electricity or other factors. This opposition or resistance is called weaving resistance. Weaving resistance or its counterpart, beat up force, is at the center of the relationship between pickspacing, yarn properties and loom settings.
Factors Affecting Weaving Resistance:
In case of pick spacing requires a larger beat up force or, for a given spacing, a thicker weft requires a larger force. It is suggested that a discontinuous relationship between pick spacing and weaving resistance but that has not been confirmed by experiment - possibly because irregularities in yarn properties would smooth the discontinuities. Loom settings are also known to influence the relationship.
There are some factors which affecting weaving resistance are given below:
There seems to be general agreement that increasing warp tension increases weaving resistance. Theoretically increased tension increases inter yarn forces and hence the effect of friction. . However, the influence seems to be fairly small, both indicating a rise of about 10% in weaving resistance for a doubling of the basic or average tension.
When warp and weft are interlaced in a fabric then they oppose to each other due to static electricity or other factors. This opposition or resistance is called weaving resistance. Weaving resistance or its counterpart, beat up force, is at the center of the relationship between pickspacing, yarn properties and loom settings.
Factors Affecting Weaving Resistance:
In case of pick spacing requires a larger beat up force or, for a given spacing, a thicker weft requires a larger force. It is suggested that a discontinuous relationship between pick spacing and weaving resistance but that has not been confirmed by experiment - possibly because irregularities in yarn properties would smooth the discontinuities. Loom settings are also known to influence the relationship.
 |
| Weaving resistance |
- The effect of warp tension
- The effect of shed balance
- The effect of shed timing
- The effect of cloth fell distance and beat-up force
- The effect of weave
There seems to be general agreement that increasing warp tension increases weaving resistance. Theoretically increased tension increases inter yarn forces and hence the effect of friction. . However, the influence seems to be fairly small, both indicating a rise of about 10% in weaving resistance for a doubling of the basic or average tension.
The Effect of Shed Balance:
They show a very significant effect of tension ratio in the two warp sheets on weaving resistance. It had earlier been reported by Bramma21 and Snowden8 that an unbalanced shed was helpful in achieving high setts. Jederan22 considered the effect on weaving resistance and, according to the English abstract of his Hungarian paper, found that "contrary to what is generally accepted" no reduction resulted. Mallah20 had reported that peak warp tension was reduced when the shed was unbalanced and both Yehia11 and Leung in their limited experiments, from which the present study has evolved, showed a significant reduction in beat up force when the shed was unbalanced. Yehia's work suggested that the effect was influenced by shed timing. Leung used a crude method of unbalancing that avoided Ito's "kinematic" effect and was incidentally independent of shed timing; he inserted a heavy roller like a lease rod in the warp so that each of the slacker and tighter sheets was always composed of the same threads. With the more normal arrangement, using a raised back rail to unbalance the shed, each yarn is alternately in the slack and tight sheet of the open shed; but when the shed is closed, i. e. crossing, it is by definition also balanced.So it would be expected that the timing of the shed relative to beat up would affect the weaving resistance.
The Effect of Shed Timing:
In view of what has already been said, it is not surprising to find contradicting statements about shed timing. Greenwood said the effect was so small that its significance must be doubted. Badve found a difference but not all his results show the effect consistently. Yehia's results suggested a "normal" timing gave least resistance. to a small extent. Theoretical studies suggested that it was not so much the effect of timing (and hence shed angle at beat up) on the actual beating up that mattered, but its effect in opposing slipping back. In industry it seems generally to be accepted that an early timing enables picks. to be beaten more closely. So a confused picture emerges and it is clear that a more detailed and more precisely defined range of settings should be used than the "late", "normal" and "early" often adopted.
Cloth Fell Distance and Beat-up Force:
Although cloth fell distance is not a basic or independent parameter (except when it is set at the start of a period of weaving) it is a visible feature that forms an important link in the relationships between other variables and so has received some attention. Badve set out to measure c. f. d. in order to test Greenwood's equations and pointed out that in developing the beat up force it is not the fell displacement in absolute terms that is related to beat up force, but the displacement relative to that which would occur due to shedding, back rail movements, etc., in the absence of beat up. When he had developed a means of measuring that relative movement, the modified c. f. d. or, as he termed it, the "interference" between reed and fell, was still often greater than seemed necessary for the force, even when true load/extension curves were used instead of constant moduli in the relationship. These results led him to suggest slipping back of picks might be responsible, so that the cloth fell was not clearly defined but was rather a region that was neither warp nor cloth. Greenwood found some evidence that c. f. d. was influenced by loom speed being slightly increased when the speed was reduced. That might be explained in the elastic moduli being slightly lower for slower rates of strain but it could also be an effect of fell movement rather than displacement by the reed.
The Effect of Weave:
For given yarns it seems obvious that, just as maximum possible sett depends on the density of intersections in the weave, so weaving resistance would also depend on that density. Galuszinski, working on plain weave derivatives, claims to show a direct simple relationship between weaving resistance and setting formula. Chen Jui-lung had previously reported similar results but expressed in less precise terms.
For given yarns it seems obvious that, just as maximum possible sett depends on the density of intersections in the weave, so weaving resistance would also depend on that density. Galuszinski, working on plain weave derivatives, claims to show a direct simple relationship between weaving resistance and setting formula. Chen Jui-lung had previously reported similar results but expressed in less precise terms.
13 December 2011
STUDY ON POSITIVE LET-OFF MOTION.
EXPERIMENT NAME: STUDY ON POSITIVE LET-OFF MOTION.
INTRODUCTION:
A mechanism controlling the rotation of the beam on a weaving, warp knitting or other fabric is forming machine where the beam is driven mechanically.
MAIN PARTS:
1. Warp beam
2. Floating back rest
3. Feeler
4. Spring
5. Warm
6. Ratchet 7. Driving rod
8.Collar
9.Reciprocating collar
POSITIVE LET-OFF MECHANISM:
The beam turning mechanism is shown in the figure. The beam is driven by ratchet on a short vertical shaft, which also carries the worm, which drives the worm wheel.A pinion on the same shaft as the worm wheel drives the large beam wheel, which is fixed, to one of the beam flanges.
A pawl operator turns the ratchet wheel by the driving rod, which gets motion of the sley sword. Each time the sley comes forward the oscillating collar is connected to fixed collar & there is engagements of pawl with ratchet.As the tension in the warp sheet is increased, the floating rest will move downwards and the rod carrying the fixed collar will move to the right and the rod R1 will move to move the driving rod to the left.
This will bring the fixed collar to the oscillating collar.As a result, the force of imparted oscillating collar and fixed collar is more. The pawl drives so more ratchet wheel teeth. So the beam motion is more and more warp is withdrawn to the increased tension.
CONCLUSIION:
In this mechanism, constant tension can be maintained and any variation in tension can be detected. So it is used in modern power looms.
INTRODUCTION:
A mechanism controlling the rotation of the beam on a weaving, warp knitting or other fabric is forming machine where the beam is driven mechanically.
MAIN PARTS:
1. Warp beam
2. Floating back rest
3. Feeler
4. Spring
5. Warm
6. Ratchet 7. Driving rod
8.Collar
9.Reciprocating collar
10. Warm wheel
11. Large beam wheel
12. Adjusting rod
POSITIVE LET-OFF MECHANISM:
The beam turning mechanism is shown in the figure. The beam is driven by ratchet on a short vertical shaft, which also carries the worm, which drives the worm wheel.A pinion on the same shaft as the worm wheel drives the large beam wheel, which is fixed, to one of the beam flanges.
A pawl operator turns the ratchet wheel by the driving rod, which gets motion of the sley sword. Each time the sley comes forward the oscillating collar is connected to fixed collar & there is engagements of pawl with ratchet.As the tension in the warp sheet is increased, the floating rest will move downwards and the rod carrying the fixed collar will move to the right and the rod R1 will move to move the driving rod to the left.
This will bring the fixed collar to the oscillating collar.As a result, the force of imparted oscillating collar and fixed collar is more. The pawl drives so more ratchet wheel teeth. So the beam motion is more and more warp is withdrawn to the increased tension.
CONCLUSIION:
In this mechanism, constant tension can be maintained and any variation in tension can be detected. So it is used in modern power looms.
9 November 2011
Motions of Loom | Weaving Loom Motion | Primary Motions of Loom | Secondary Motions of Loom | Tertiary Motions of Loom
In order to interlace wrap and weft threads to produce a fabric, the following motions are necessary on any type of loom:
1. Primary motions
2. Secondary motions
3. Tertiary motions
1. Primary Motions:
These are fundamental or essential mechanisms. Without these mechanisms, it is practically impossible to produce a fabric. It is for this reason that these mechanisms are called ‘primary’ mechanisms. The primary mechanisms are three in number.
a. Shedding mechanism
b. Picking mechanism
c. Beat-up mechanism
a. Weft stop motion
b. Warp stop motion
c. Warp protector mechanism
d. Weft replenishment / Warp mixing motion
e. Cutter
f. Temples
g. Brake
h. Selvedge
1. Primary motions
2. Secondary motions
3. Tertiary motions
These are fundamental or essential mechanisms. Without these mechanisms, it is practically impossible to produce a fabric. It is for this reason that these mechanisms are called ‘primary’ mechanisms. The primary mechanisms are three in number.
a. Shedding mechanism
b. Picking mechanism
c. Beat-up mechanism
2. Secondary Motions:
These
mechanisms are next in importance to the primary mechanisms. If weaving
is to be continuous, these mechanisms are essential. So they are called
the ‘secondary’ mechanisms. They are: - Take-up motion
- Let-off motion
3. Tertiary Motions:
To
get high productivity and good quality of fabric, additional
mechanisms, called auxiliary mechanisms, are added to a loom. The
auxiliary mechanisms are useful but not absolutely essential. This is
why they are called the ‘auxiliary’ mechanisms. These are listed below. a. Weft stop motion
b. Warp stop motion
c. Warp protector mechanism
d. Weft replenishment / Warp mixing motion
e. Cutter
f. Temples
g. Brake
h. Selvedge
20 October 2011
Study on over picking mechanism.
Experiment name: Study on over picking mechanism.
Introduction:
Picking is the second primary motion in weaving. The action of inserting weft yarn through the warp yarns is called picking.
Introduction:
Picking is the second primary motion in weaving. The action of inserting weft yarn through the warp yarns is called picking.
The functions of picking mechanism are:
1.To deliver the shuttle along the correct flight length.
2.To throw the shuttle at a predetermined speed.
Main Parts:
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| Over picking |
- Picking arm
- Picking strap
- Picker
- Bottom shaft
- Picking spindle
- Shuttle
- Picking cam
- Vertical shaft
- Cone
- Bowl
- Angular
- Crank shaft
Features of Over Picking Mechanism:
1.Picking arm is over shuttle.
2.Suitable for narrow loom.
3.Higher picks per minute.
4.Less power required.
5.Works more smoothly.
6.Shortening the picking strap and changing the shape of the cam can increase picking force.
Mechanism of Over Picking:
Over picking mechanism is used on cotton and jute loom. It is robust and easy to adjust and maintain. The spindle is situated over the shuttle box and is essential to guide the shuttle along the correct path. It is normally set slightly up and slightly towards the front of the loom and its inner end.
The back end of the shuttle will thus receive a similar lift at the end of the stroke, so that its leading end will receive correct delivery down and into the shed. A flexible leather-picking strap is used to control the picker, which has tendency to stretched slowly in use, and vary with regard to its elastic property.
The cone over pick motion consists a vertical shaft placed either inside or outside the loom framing. The shaft serves as fulcrum of the picking arm, it is held against the loom frame. There is a spiral spring at the picking shaft, which causes the picking arm and picker to move back after the delivery of the pick.
At the two end of the bottom shaft, two picking cams are fixed. In revolving its nose the tappet strikes the cone shaped ant frictional roller strut, positively rotates the shaft and causes the pick to move inward with sufficient velocity to drive the shuttle across the loom. The timing of the picker begins to move can be attend by turning the picking tappet on its boss.
How to Increase PPM:
1.By increasing motor speed.
2.By setting the cone stud nearer to the picking tappet.
3.By decreasing the picking strap.
4.By altering the position of picking arm towards the centre of the loom.
5.By decreasing the length of the stroke of picking tappet.
Uses:
This is used for narrow and fast running looms, weaving light and medium weight fabrics and for many narrow and wide looms for weaving heavy fabrics.
Conclusion:
The over picking motion is negative one; the exact amount of power is required to drive a shuttle. By this experiment we learned about the over picking mechanism and how it works. This experience will help us in our future practical life.
1.Picking arm is over shuttle.
2.Suitable for narrow loom.
3.Higher picks per minute.
4.Less power required.
5.Works more smoothly.
6.Shortening the picking strap and changing the shape of the cam can increase picking force.
Mechanism of Over Picking:
Over picking mechanism is used on cotton and jute loom. It is robust and easy to adjust and maintain. The spindle is situated over the shuttle box and is essential to guide the shuttle along the correct path. It is normally set slightly up and slightly towards the front of the loom and its inner end.
The back end of the shuttle will thus receive a similar lift at the end of the stroke, so that its leading end will receive correct delivery down and into the shed. A flexible leather-picking strap is used to control the picker, which has tendency to stretched slowly in use, and vary with regard to its elastic property.
The cone over pick motion consists a vertical shaft placed either inside or outside the loom framing. The shaft serves as fulcrum of the picking arm, it is held against the loom frame. There is a spiral spring at the picking shaft, which causes the picking arm and picker to move back after the delivery of the pick.
At the two end of the bottom shaft, two picking cams are fixed. In revolving its nose the tappet strikes the cone shaped ant frictional roller strut, positively rotates the shaft and causes the pick to move inward with sufficient velocity to drive the shuttle across the loom. The timing of the picker begins to move can be attend by turning the picking tappet on its boss.
How to Increase PPM:
1.By increasing motor speed.
2.By setting the cone stud nearer to the picking tappet.
3.By decreasing the picking strap.
4.By altering the position of picking arm towards the centre of the loom.
5.By decreasing the length of the stroke of picking tappet.
Uses:
This is used for narrow and fast running looms, weaving light and medium weight fabrics and for many narrow and wide looms for weaving heavy fabrics.
Conclusion:
The over picking motion is negative one; the exact amount of power is required to drive a shuttle. By this experiment we learned about the over picking mechanism and how it works. This experience will help us in our future practical life.
15 September 2011
Take-up Motion | Let-off Motion | Secondary Motions of Weaving Loom Mechanism
Secondary Motions:
These mechanisms are next in
importance to the primary mechanisms. If weaving is to be continuous,
these mechanisms are essential. So they are called the ‘secondary’
mechanisms. They are:
- Take-up motion
- Let-off motiona.
Take-up motion
The take-up motion withdraws the cloth from the weaving area at a constant rate so as to give the required pick-spacing (in picks/inch or picks/cm) and then winds it on to a cloth roller.
The main part of the mechanism is the take up rollers, which draws the cloth at the regular rate, and the number of picks per inch decides this rate. The take up roller is covered with emery cloth or hard rubber depending upon the type of cloth woven. The drive to the take up roller is by a train of gear wheels put into motion directly from the main shaft.
The take-up motion withdraws the cloth from the weaving area at a constant rate so as to give the required pick-spacing (in picks/inch or picks/cm) and then winds it on to a cloth roller.
The main part of the mechanism is the take up rollers, which draws the cloth at the regular rate, and the number of picks per inch decides this rate. The take up roller is covered with emery cloth or hard rubber depending upon the type of cloth woven. The drive to the take up roller is by a train of gear wheels put into motion directly from the main shaft.
 |
| Picture: Fabric take-up motion. |
Let-off motion
The let-off motion delivers the warp to the weaving area at the required rate and at constant tension by unwinding it from the weaver’s beam. The secondary motions are carried out simultaneously. The speed of the servo motor is transmitted to warp beam gear via reduction gear, thus driving beam.
The let-off motion delivers the warp to the weaving area at the required rate and at constant tension by unwinding it from the weaver’s beam. The secondary motions are carried out simultaneously. The speed of the servo motor is transmitted to warp beam gear via reduction gear, thus driving beam.
21 August 2011
Study on seven wheel take up mechanism (Cotton Weaving).
Experiment name: Study on seven wheel take up mechanism (Cotton Weaving).
Introduction:
Take-up is to draw a fabric to the cloth roller regularly as it is woven. Texture of a fabric largely depends upon the number of ends and picks per centimeter or inch. This motion determines the number of picks of weft per inch or centimeter and contributes to the uniform texture of the fabric. It is the work of the weaver for accurately fixing the position of the fell of the cloth before starting a loom.
Objects:
1.To know about the construction of the mechanism.
2.To know about drive of the take-up motion.
Take up motion:
The process of withdrawing fabric from weaving zone at a constant rate and then winding the woven cloth on the cloth roller with the continuous progress of weaving is called take up motion.
Types:
(1)According to drive:
(a) Positive take up.
(b)Negative take up.
(2)According to motion of the cloth/Rate of take up:
(a)Continuous
(b)Intermittent
(3)According to drive given to the cloth roller:
(a)Direct drive
(b)Indirect drive
(4)According to number of gear train:
(a)5-Wheel
(b)6-Wheel
(c)7-Wheel
(5)According to brand name:
(a)Sulzer
(b)Pickanol
(c)Toyota
Main parts& Specifications:
1.Sley
2.Sleysword
3.Connecting rod
4.Monkey tail
5.Holding/Catching/Locking pawl.
6.Pulling pawl
7.Rachet Wheel(24)
8.Standard wheel(36). 9.Changewheel(1-Let)
10.Sewing wheel/Pinion(24)
11.Stud/Compound wheel(89)
12.Stud/Compound Pinion(14)
Introduction:
Take-up is to draw a fabric to the cloth roller regularly as it is woven. Texture of a fabric largely depends upon the number of ends and picks per centimeter or inch. This motion determines the number of picks of weft per inch or centimeter and contributes to the uniform texture of the fabric. It is the work of the weaver for accurately fixing the position of the fell of the cloth before starting a loom.
Objects:
1.To know about the construction of the mechanism.
2.To know about drive of the take-up motion.
Take up motion:
The process of withdrawing fabric from weaving zone at a constant rate and then winding the woven cloth on the cloth roller with the continuous progress of weaving is called take up motion.
Types:
(1)According to drive:
(a) Positive take up.
(b)Negative take up.
(2)According to motion of the cloth/Rate of take up:
(a)Continuous
(b)Intermittent
(3)According to drive given to the cloth roller:
(a)Direct drive
(b)Indirect drive
(4)According to number of gear train:
(a)5-Wheel
(b)6-Wheel
(c)7-Wheel
(5)According to brand name:
(a)Sulzer
(b)Pickanol
(c)Toyota
Main parts& Specifications:
1.Sley
2.Sleysword
3.Connecting rod
4.Monkey tail
5.Holding/Catching/Locking pawl.
6.Pulling pawl
7.Rachet Wheel(24)
8.Standard wheel(36). 9.Changewheel(1-Let)
10.Sewing wheel/Pinion(24)
11.Stud/Compound wheel(89)
12.Stud/Compound Pinion(14)
13.Take up wheel(89)
14.Take up roller(dia:15.5 inch)
15.Cloth roller
Motion Transfer:
Sley sword to connecting rod. Connecting rod to monkey tail. Monkey tail to pawl. Pawl to rochet wheel. Rochet wheel to standard wheel. Standard wheel to change wheel. Change wheel to sewing wheel. Sewing wheel to stud wheel. Stud wheel to stud pinion Stud pinion to take up wheel. Take up wheel to take up.
Working principle:
This positive take-up mechanism consists of seven wheels. These are
i)Rachet,
ii)Standard wheel,
iii)Change pinion,
iv)Stud pinion,
v)Stud wheel,
vi)Swing pinion and
vii)Take-up roller wheel.
The
motion is primarily imparted from the sleysword. The sleysword is
connected to the slay that gets motion from crank shaft and the crank
shaft gets motion from motor by gearing. At the bottom of sleysword a
connecting rod is connected which passes the motion to the monkey tail.
The monkey tail is fulcrum with two pawls: the upper is holding pawl and lower is pulling pawl. These two pawls are mounted freely to the ratchet wheel which is connected with the standard wheel by shaft. Over the standard wheel the change pinion is geared. The change pinion is connected with the stud pinion by shaft and the stud wheel is geared with the stud pinion upon it. The swing pinion is connected with the stud wheel and the cloth take-up roller wheel is geared with the swing pinion.
The cylinder upon which the woven fabric is wound, is connected with this wheel by shaft. Now when the sley moves one time after one pick insertion the connecting rod pass this motion to the monkey tail and as the pawls are fulcrum with monkey tail they get downward motion. Using this downward motion the pushing pawl pulls the rachet wheel one time and the holding pawl holds the rachet in this position. Finally the cloth roller gets the motion by gear train and thus fabric is wound on cloth roller continuously with the weaving of fabric.
Advantages of 7 take-up wheel over 5 wheel take-up mechanism:
1.It can give a larger number of picks per inch in cloth from a small stock of wheels by changing two wheels in the train,
2.It can give even a fraction of a pick per inch in cloth and
3.The number of teeth in the change wheel and the number of picks per quarter-inch has been simplified.
Remarks:
By this experiment we know about how to cloth is collected by take up mechanism. This is an interesting experiment too. We hope this will be very helpful in our practica life.
The monkey tail is fulcrum with two pawls: the upper is holding pawl and lower is pulling pawl. These two pawls are mounted freely to the ratchet wheel which is connected with the standard wheel by shaft. Over the standard wheel the change pinion is geared. The change pinion is connected with the stud pinion by shaft and the stud wheel is geared with the stud pinion upon it. The swing pinion is connected with the stud wheel and the cloth take-up roller wheel is geared with the swing pinion.
The cylinder upon which the woven fabric is wound, is connected with this wheel by shaft. Now when the sley moves one time after one pick insertion the connecting rod pass this motion to the monkey tail and as the pawls are fulcrum with monkey tail they get downward motion. Using this downward motion the pushing pawl pulls the rachet wheel one time and the holding pawl holds the rachet in this position. Finally the cloth roller gets the motion by gear train and thus fabric is wound on cloth roller continuously with the weaving of fabric.
Advantages of 7 take-up wheel over 5 wheel take-up mechanism:
1.It can give a larger number of picks per inch in cloth from a small stock of wheels by changing two wheels in the train,
2.It can give even a fraction of a pick per inch in cloth and
3.The number of teeth in the change wheel and the number of picks per quarter-inch has been simplified.
Remarks:
By this experiment we know about how to cloth is collected by take up mechanism. This is an interesting experiment too. We hope this will be very helpful in our practica life.
5 March 2011
Weaving | Weaving Mechanism | Classification of Weaving Machines
The process of producing a fabric by
interlacing warp and weft threads is known as weaving. The machine used
for weaving is known as weaving machine or loom. Weaving is an art that
has been practiced for thousands of years. The earliest application of
weaving dates back to the Egyptian civilization. Over the years, both
the process as well as the machine has undergone phenomenal changes. As
of today, there is a wide range of looms being used, right from the
simplest handloom to the most sophisticated loom.
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