TYPES OF SHADIND MOTIONS

TYPES OF SHADING:
There are three types of shading depending on the size of the cloth.
1. Tappet shedding.
2. Dobby shedding.
3. Jacquard shedding.

TAPPET SHEDDING:

 Tappet shedding is the simplest from the shedding.
 This type of method is used from the plain weave, simple twills and simple sateen and stain weave.
 It is used up to 10 frames.
 AA part from restricted patterning possibilities the chief disadvantage of tappet shedding is that we have to change the tappet at the completion of design.

MECHANISM OFF TAPPET SHEDDING:

The motions are drive from the two steel shaft one position above the other the top shaft is know as crank shaft while bottom is know as tapped shaft.
The motion drive is given from the motor to crank shaft and bottom shaft drives from crank.
When the bottom shaft revolves the tapped revolves on it these tappets are adjusted at different angles. At on time one tappet is pressing to the tappet treadle lever and other is lifting at second tapped liver.
Suppose the liver “B” is down hence the held frame will be up due to reversing system. This will from shed.
The shuttle and other mechanism carrying the weft threads will pass through the shed.

SHEDDING TIMING:
The shedding mechanism starts at above 60º at the crank shaft ay is completed about 120º.

SHEDDING MOTION PARTS:
1. Tappet.
2. Treadle liver.
3. Treadle liver blow.
4. Treadle liver bracket (fulcrum).
5. Adjustable card screw clip.
6. Bottom shaft gear.
7. Crank shaft gear.
8. Crank shaft arm.
9. Top reversing rollers.
10. Healed frame.
11. Top line warp sheet.
12. Bottom line warp sheet.


PICKING:
The processes of throughing shuttle shuttle from one side of the shaft to other side know as picking and this passage is known as pick.

PICKING MECHANISM:
This is second basic mechanism picking after come shading the purpose of this motions is to prepare the shuttle to carry pick into the shed from one side shuttle box to another side shuttle box.
Shuttle is the piece of wood about 14” long and weight about 14” once and automatic looms and 10-------12 once in non automatic loom. Shuttle is changed by workers manually the speed of a loom is no of picks per min.


TYPES OF PICKING MOTIONS:
There are two types of picking mechanism in conventional loom.

1. Over picking motion.
2. Under picking motion.

If the picking system is arranged above the loom, it is called over picking i.e. picking stick is the above the loom.

If the picking system is arranged below the loom, it is called under picking i.e. picking stick is below the loom.
UNDER PICKING MOTION:-
Under picking motion is shown in figure.
The picking stick is located below the shuttle box. There are two plates on bottom shaft having picking bowl. The side lever is fitted below the picking plate. The picking nose is fixed in the side lever.
The side lever up-side of the connecting rod of picking stick. And the picker attached to picking stick strikes the shuttle in the shuttle box. In this way shuttle passes through the shed. There is another same mechanism at the other end causes the shuttle to come back & in this way shuttle goes from one side to another.

PICKING MOTION PARTS:-
A- Picking Stick B- Stick Cam
C- Side Lever D- Crank Shaft
E- Buffer Strap F- Picker
G- Side Lever Bracket H- Adjustable Screw
K- Reed Cap L- Picking bowl
M- Picking Plate N- Picking Nose
O- Picking Shaft U- Slay Sword
P- Reed Q- Crank arm
R- Reed Fly Back S- Side From
T- Bumper

MAIN FEATURES OF UNDER PICKING:-
If is less forceful so it is used for slid loom & fine quality.
It is comparatively cheaper.
Less wears & tears of parts.
It is safe and secure.
It is mostly used for any type of loom and and is very simple mechanism.
Jet weft Insertion or Picking system:-

INTRODUCTION:-
This is one of the shuttles less weft insertion system. This is a very high speed weft insertion rate system. Commonly the weft insertion rate of this system from 2000 m/min to 30, 00 m/min. In this system the weft is inserted though the shed (opening b/w warp threads) from one side of the loom to the other either by using the pressurized air pressure or pressurized water pressure. On the basis of these two wefts insertion sources the looms have been designated as:
Air Jet Loom
Water Jet Loom
AIR JET WEFT INSERTION SYSTEM:-
This is one of the jet weft insertion system whose weft insertion rate is up to 3000 m/min.in this system, pressurized air pressure is used to insert the weft through the shed from one side of the loom to the other.

MECHANISM OF AIR JET WEFT INSERTION SYSTEM:-
There is a weft package creel or stand
(1)_on which the weft package
(2)_either cone or cheer is inserted. From the weft package the weft yarn accumulator which is positively driven by the motor.
(4)_From the yarn accumulator the yarn is fed into the tube of his main nozzle
(6)_There is an air chamber
(7)_around this tube of the main nozzle in which pressurized air is supplied from the air supply tank.
(8)_The yarn coming from the tube of the main nozzle is fed into the shed through teensier and scissor from one side of the loom to the other by the air pressure supplied to the main nozzle. There is a suction nozzle on the other end of the reed which sucks the weft yarn and in order to keep the weft yarn straight and under tension.