Fabric Manufacturing – II Lab ex-1,2,3,4,5,6,7,8
Experiment No. 01
Experiment Name: Study on passage diagram of ordinary power loom.
Theory:
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.
Objects:
1. To know about the different parts of loom machine.
2. To know about the passage diagram of loom machine.
3. To acquire knowledge about different types of motions which is needed to operate a loom machine.
Passage of warp and cloth through a ordinary power loom:
A warp sheet A from a weaver’s beam B passes around a back rest C and is led around lease rods D to heald shafts E & F which are responsible for separating the warp sheet into two layers to form a shed. The purpose of the back rest and the lease rods is to separate the warp yarns uniformly and precisely, and reduce entanglement and tension in the yarns during the opening of the warp shed.
A - Warp sheet
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B - Weaver's beam
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C - Back rest
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D - Lease rods
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E - Heald shaft
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F - Heald shaft
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G - Reed
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H - Cloth
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I - Weft yarn
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J - Temples
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K - Front rest
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L - Take-up roller
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M - Guide roller
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N - Cloth roller
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Figure: Passage of warp and cloth through a plain power loom
The warp yarns then pass through a reed G, which holds the yarns at uniform spacing and is also responsible for beating-up the weft yarn I into the fell of the cloth. After the weft is beaten up, the warp yarns interchange positions in the shed and thereby cause interlacing to be achieved. At this point, cloth is formed and is held firmly by temples J to assist in the formation of a uniform cloth. The cloth H then passes over a front rest K, around an emery roller or take-up roller L and a guide roller M and is finally wound on to a cloth roller N.
Experiment No. 02
Experiment Name: Study on shedding mechanism of an ordinary power loom.
Theory:
The shedding mechanism separates the warp threads into two layers or divisions to form a tunnel known as ‘shed’.
There are three types of shedding mechanism as below:
1. Tappet shedding mechanism
2. Dobby shedding mechanism
3. Jacquard shedding mechanism.
In our lab house dobby shedding mechanism is used to make shed which is placed on the top of a loom in order to produce figure patterns by using a larger no of healds than the capacity of tappet. Dobby is a mechanism which is attached with the loom to control the movement of heald shaft.
Objects:
4. To know about the different parts of shedding.
5. To learn the mechanism of dobby shedding.
6. To know about the gearing diagram of loom machine.
7. To know about the working sequence of dobby shedding process.
Main parts of dobby shedding mechanism:
1. Motor pulley
2. Motor
3. Machine pulley
4. Bottom shaft
5. Connecting rod
6. T-lever
7. Link rod
8. Jack lever
9. Heald shaft
10. Returning spring
Experiment No. 03
Experiment Name: Study on picking mechanism of an ordinary power loom.
Theory:
Pick is a single weft thread in a fabric as woven. It is the second primary motion in weaving. The process of passing weft thread through warp shed during weaving is called picking.
After the shedding mechanism opens the warp thread to form a shed, the picking motion comes into play to insert a weft thread (known as a pick) across the warp through the shed.
There are different types of picking mechanism. In our lab house bowl-and-shoe side lever underpick mechanism is used for picking.
Objects:
8. To know about the different parts of picking mechanism.
9. To learn the mechanism of picking mechanism.
10. To know about the gearing diagram of picking mechanism.
11. To know about the working sequence of picking mechanism.
12. To learn about different types of picking mechanism and their differences from each other.
Main parts of picking mechanism:
11. Motor
12. Motor pulley
13. Machine pulley
14. Bottom shaft
15. Picking tappet
16. Bowl
17. Shoe
18. Side lever
19. Picking stick
20. Picker
21. Return spring
Working Principle:
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.
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.
Experiment No. 04
Experiment Name: Study on beating mechanism of an ordinary power loom.
Theory:
It is the third primary motion in weaving. It is a process of pushing the newly inserted weft yarn to the already woven fabric at a point known as the “fell of the cloth” with the help of a reed fixed in the sley. The sley is given a sudden and quick movement towards the fell of the cloth by the cranks in the crank shaft.
Objects:
13. To know about the different parts of beating mechanism.
14. To learn the mechanism of beating mechanism.
15. To know about the gearing diagram of beating mechanism.
16. To know about the working sequence of beating mechanism.
17. To learn about different types of beating mechanism and their functions.
Main parts of beating mechanism:
22. Motor
23. Motor pulley
24. Machine pulley
25. Crank shaft
26. Connecting arm
27. Race board
28. Rocking shaft
Working Principle:
The crankshaft gets drive from motor via motor pulley and m/c pulley. The crankshaft has two cranks. These cranks transform the rotary motion into swinging motion. The reed cap is connected by crank arm to crank of the crankshaft. Again the reed is connected between reed cap and sley. There is sleysword under the sley that is bolted to the rocking shaft. There is also shuttle box on the sley. Now the crank gives the swinging motion to the sley by crank arm. When the sley is moving towards the healdshaft at certain position the shuttle passes through warp shed. Again when the sley is coming towards the front rest at last position the reed pushes the last pick to the previous pick of cloth. This is the beating-up motion and the cloth increases in lengthwise in this way.
Experiment No. 05
Experiment Name: Study on 7-wheel take-up mechanism of an ordinary power loom.
Theory:
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.
3. 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
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.Change wheel(1-Let)
9. Sewing wheel/Pinion (24)
10. Stud/Compound wheel (89)
11. Stud/Compound Pinion (14)
12. Take up wheel (89)
13. Take up roller (dia:15.5 inch)
14. Cloth roller
Fig: 7-Wheel Take Up Mechanism
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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:
Working Principle:
This positive take-up mechanism consists of seven wheels. These are
1. Rachet,
2. Standard wheel,
3. Change pinion,
4. Stud pinion,
5. Stud wheel,
6. Swing pinion and
7. 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.
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.
Experiment No. 06
Experiment Name: Study on negative let-off mechanism of an ordinary power loom.
Theory:
Let-off is to supply warp thread in the weaving zone at a predetermined rate. Negative let-off is a mechanism for controlling the rotation of the beam on a weaving, warp knitting or other fabric forming machine where the beam is pulled round by the warp against a breaking force applied to the beam.
Objects:
1. To know about the construction of the mechanism.
2. To know about drive motion of the let-off motion.
Main parts & Specifications:
1. Warp beam.
2. Beam ruffle.
3. Chain.
4. Machine frame.
5. Weight lever.
6. Pivot.
7. Fulcrum.
8. Weight.
2. Beam ruffle.
3. Chain.
4. Machine frame.
5. Weight lever.
6. Pivot.
7. Fulcrum.
8. Weight.
Working Principle:
The warp beam ruffle is wrapped around by chain. The one end of the chain is fixed at . i.e. at the m/c frame whereas the other end is connected to fulcrummed device to the weight lever , which is pivoted and a dead weight is placed which can be moved along the length of the weight lever.
In this system the tension of the warp is regulated by the friction between chain and the beam ruffle. The friction is controlled by dead weight on the weight lever and the distance of deadweight from the pivot. Heavier the dead weight and longer the distance of it from the pivot lesser the let-off.
The warp beam dia gradually decreases as weaving proceeds. So it’s necessary to increase the let-off rate. If the dead weight is kept on the same place, the let-off rate will remain unchanged. So an experienced worker is required to change the dead weight gradually with the change of the warp beam dia. As a result irregular tension occurs and the rate of yarn breakage may increase.
In this system the tension of the warp is regulated by the friction between chain and the beam ruffle. The friction is controlled by dead weight on the weight lever and the distance of deadweight from the pivot. Heavier the dead weight and longer the distance of it from the pivot lesser the let-off.
The warp beam dia gradually decreases as weaving proceeds. So it’s necessary to increase the let-off rate. If the dead weight is kept on the same place, the let-off rate will remain unchanged. So an experienced worker is required to change the dead weight gradually with the change of the warp beam dia. As a result irregular tension occurs and the rate of yarn breakage may increase.
Negative let-off mechanism is a very simple and manual mechanism. It is suitable for light and medium weight fabrics. It is mainly used in old looms and for weaving of plain cotton fabric.
Experiment No. 07
Experiment Name: Study of Single Truck Single Jersey Circular Knitting Machine.
Objectives:
1. To know about the different parts of this machine.
Objectives:
1. To know about the different parts of this machine.
2. To learn the functions of these parts.
Different parts of this machine is given below:
1. Latch needle: This type of needle has a special sliding latch with other common features. This part is used to form loops.
2. Cams: There are three types of cams:
a. Knit cam: This cam helps needle to form knit loops.
b. Tuck cam: This cam helps needle to form tuck loops.
c. Miss cam: This cam helps needle to form miss loops.
Different parts of this machine is given below:
1. Latch needle: This type of needle has a special sliding latch with other common features. This part is used to form loops.
2. Cams: There are three types of cams:
a. Knit cam: This cam helps needle to form knit loops.
b. Tuck cam: This cam helps needle to form tuck loops.
c. Miss cam: This cam helps needle to form miss loops.
3. Sinker: There are three types of sinkers:
a. Loop forming sinker: This sinker is used to sink or kink the newly laid yarn.
b. Holding down sinker: This sinker is used to hold down the old loops.
c. Knocking-over sinker: This sinker supports the old loop as the new loop is drawn through it.
4. Feeding unit :- A feeder supplies yarn to needles. A positive feeder contains the following parts:
a. Knot catcher: This part finds any fault in yarn.
b. Yarn tensioner: This part gives proper tension to yarn for proper knitting.
5. Timing belt/Tooth belt: This part helps machine to stop immediately.
a. Loop forming sinker: This sinker is used to sink or kink the newly laid yarn.
b. Holding down sinker: This sinker is used to hold down the old loops.
c. Knocking-over sinker: This sinker supports the old loop as the new loop is drawn through it.
4. Feeding unit :- A feeder supplies yarn to needles. A positive feeder contains the following parts:
a. Knot catcher: This part finds any fault in yarn.
b. Yarn tensioner: This part gives proper tension to yarn for proper knitting.
5. Timing belt/Tooth belt: This part helps machine to stop immediately.
6. VDQ Pulley: This part is used to control stitch length of the knitted fabric.
7. Cylinder: This frame contains needles, cams, jacks and sinkers.
8. Sinker Ring: Sinkers are placed on the sinker cam in the sinker ring.
9. Needle Detector: This part detects the any type of faults of needles.
10. Fabric Detector: This part detects any fault of fabric.
11. Adjustable Fan: This part removes lint, hairy fibre from yarn and others.
12. Take up Roller: This part is used to take up the fabric from cylinder.
13. Cloth Roller: The final product i.e. cloth is wound on this roller.
14. Expander: This part is used to control the width of fabric.
15. Creel: This part is used to contain yarn packages.
7. Cylinder: This frame contains needles, cams, jacks and sinkers.
8. Sinker Ring: Sinkers are placed on the sinker cam in the sinker ring.
9. Needle Detector: This part detects the any type of faults of needles.
10. Fabric Detector: This part detects any fault of fabric.
11. Adjustable Fan: This part removes lint, hairy fibre from yarn and others.
12. Take up Roller: This part is used to take up the fabric from cylinder.
13. Cloth Roller: The final product i.e. cloth is wound on this roller.
14. Expander: This part is used to control the width of fabric.
15. Creel: This part is used to contain yarn packages.
Experiment No. 08
Experiment Name: Study on passage diagram of rib circular machine.
Objectives:
Objectives:
1. To know rib circular knitting machine.
2. To know similarities between single and double jersey machine.
3. To know this machine are synchronized timing & side creel used in this machine.
4. To know cylinder & dial are used in this machine & two set needle used one for cylinder and one for dial.
Description of the Machine:
In a dial cylinder rib machine there is one set of needles on the circumference of the vertical cylinder and another set of needles on a horizontal dial. So two sets of needles remain at the right angle with each other. In dial cylinder machines the dial and cylinder rotates but the cam systems with the feeders remain stationary.
The dial needles get its motion from its butt that is placed on the cam truck. This cam truck is formed by different cam placed on a cam plate.
During the rotation of the cylinder, cylinder needles moves vertically and dial needles moves horizontally. Cylinder needles also get its motion from it. There is a cloth tale up roller which also rotates with unison to dial and cylinder and fabric is wound on it.
The dial needles get its motion from its butt that is placed on the cam truck. This cam truck is formed by different cam placed on a cam plate.
During the rotation of the cylinder, cylinder needles moves vertically and dial needles moves horizontally. Cylinder needles also get its motion from it. There is a cloth tale up roller which also rotates with unison to dial and cylinder and fabric is wound on it.
