If degree of sizing is too high or low, risk of thread breaks is increased. Degree of sizing(%) = [Sa(%) * K(%)] / (100%) ; where
Sa = Sizing liquor take up. It is the ratio of the liquor taken up to the weight of untreated yarn.
K = Concentration. It is measured by a refractometer.
REFRACTOMETER MEASURING CUP
FACTORS AFECTING DEGREE OF SIZING: i) Concentration
ii) Viscosity of sizing liquor iii)Temperature of sizing liquor iv) Speed
v) Squeezing pressure ENERGY CONNECTIONS
Steam pressure:
Operating pressure = 0.5 to 3.5 bar
Steam quantity:
SE-C = 50 kg/h SD-C = 80 kg/h
Condensate : must drain without back press.
Air pressure :
With squeezing pressure upto:-
60 KN => 6,5 bar 100KN => 8,5 bar
Air quantity:
SE-C = 1.15 cubic mt/h (intake) SE-D = 1.65 cubic mt/h
Air must be free of water, dust and oil. WAXING DEVICE (PVD)
This is used to apply various oils or waxes to the warp after sizing. It is fitted at the beginning of the dry splitting zone immediately after the dancing roller, where the warp is still undivided.
This device consists of:
i) A melting funnel for solid media (waxes). ii) A tray to contain the lubricant:
a) Tray is made of stainless steel and protected from fiber fly and other impurities with cover plates.
b) The tray has a heating coil for internal heating.
c) Wax temperature in tray is controlled by a temperature controller and a pneumatic valve.
d) Lubricant can only be removed via drain cock iii) An applicator roll:
a) Made of stainless steel with a specially treated surface.
b) Driven in properly to the sizing machine’s warp speed by a frequency – regulated 3- phase a.c. motor with a worm gear.
iv) if liquid media (oils) are used, it is fed via a transparent bottle with a capacity of 10 liters.
4. DENTING AND DRAWING – IN
All the warp threads have to be threaded through the heald eyelet and its gap in the reed prior to weaving. The heald is the part of the loom that is used to move the warp threads up and down. The threads pass through eyelets on the heald. For a simple weave pattern alternate eyelets are moved up to raise the corresponding warp threads, and the threads between are moved down. When the shuttle travels back their positions are reversed. The reed is like a comb and its purpose is to control the separation of the warp threads.
PREPATORY PROCESS FOR DRAWING-IN: The open space between each wire of the hook is called dent. A warp end is passed through a dent with the help of the reed hook, after it passes through the heald. This process is called denting.
Automatic drawing-in machines multiply the productivity of each drawing-in operation 5- to 10- times in relation to manual drawing-in thus enabling the required level of processing flexibility.
MACHINERY:
1) STAUBLI DELTA 200 : The DELTA 200 is a high-performance drawing-in installation. It is used wherever high production performance, a wide field of applications, and maximum flexibility are required. The DELTA 200 draws-in warp yarns directly from the warp beam with 1 or 2 sheets, and optionally up to 4 sheets.
2) STAUBLI DELTA 110 : These drawing-in installations are designed for weaving mills
with medium drawing-in requirements. The DELTA 110 also handles drop wires and is a universal installation. Furthermore, a module is available that is specially designed for drawing-in course yarns. Drawing-in takes place directly from the warp beam with 1 warp sheet, or optionally with 2 warp sheets.
Main characteristics:
DELTA 110 200
Drawing-in speed (ends/min) 100/140* 200
Number of warps in 8h (ca. ) 2-5 4-8
Warp widths (m) 2.3/ 4.0/ 6.0 2.2/ 2.8/ 4.0
Number of warp sheets 1 (2*) 2 (4*)
Reed density( teeth/ dm) 500 500
Max. number of frames (O-healds) 16 20
Max. rows of dropwires ____ 8
Number of dropwire paths ____ 2
Drawing-in element Hook Rapier
Yarn count range (tex) 3-250 3-330
MACHINE CONCEPT: Modular system
The different modules of these machines are as follows:
1) Main Module Basic Equipment:
Part modules:
• Control cabinet and electrics.
• Base Frame
Function:
i) Static auxiliary function
ii) Supporting unit for the machine infrastructure iii) Holds electrics and pneumatics.
2) Yarn Drawn –in Module: Function:
Serves to guide the separated warp ends through the heald, drop wire and reed.
3) Yarn Supply Module: Part modules:
• Thread Frame
• Yarn Separation
• Yarn Supply
Function:
i) Handling the warp beam and thread sheet
ii) Separating and preparing the warp end for drawn- in. 4) Heald Module:
Part modules:
• Heald Magazine
• Heald Separation
• Heald Distribution
• Shaft holder\ Stave holder (harness truck)
Function:
i) Handling the healds from the magazine stack ii) Distribution between the shafts
5) Reed Module:
Part module: Reed Transport Function: Reed Handling 6) Drop Wire Module: Part modules:
• Drop Wire Magazine
• Drop Wire Separating
• Drop Wire Distribution
• Drop Wire Transport( Harness Truck)
Function:
i) Magazing the drop wires.
7) Control Module Part modules:
• Function Keyboard
• Control Keyboard
Function: Controls and co-ordinates the module computers assigned to the main module.
8) Master System Module Part modules: • Keyboard • Monitor • Master computer • Printer Function:
i) Accepts the drawn-in data from the operator ii) Transmits it to the control computer.
iii) Manages the operating data. iv) Visualizes the process sequence.