PRESS FUNCTION IN TIELS

PRESSING SECTION IN TIELS FUNCTION OF PRESS

The main function of the press department is to shape a tile from the dust obtained from the spray dryer storage silo in order to provide it good green strength.

OPERATION OF PRESS

First the material in silo in dust form fill in the pushers net & require amount of dust material is going in the die & than the hydraulic press machine is press & the tile is prepared. The pressure of the press is depends on the tile size, because the green strength is depend upon the tiles pressure. In B.C.L. there are four presser, 8000tones for 12”*12”floor tiles. 1200tones for 12”*12”floor tiles. 800tone for 12”*12”floor tiles. 1205tone for 8” 12”wall tiles.

QUALITY OF DUST

The quality of dust is important. It is passed through 10 or15 mesh sieve. After silo put the dust into the pushes net & then the hydraulic press is running. The press takes require amount of dust. The moisture of dust is kept 0 to 65%.

QUALITY CHECKING AT DIFFERENT STAGES

The quality is checking at the different types of pressing like moisture, thickness, size & bulk density (hardness).Before the pressing the moisture checking of dust done. It should be 5 to 6% after pressing like thickness, size & hardness. The thickness depends upon the punch & the die mould then the pressure is applied as per their size of tiles. After mangle dryer is residual moisture must be checked. If the tile has high moisture there is possibility of pinholes on the tile surface in the kiln. After mangle dryer tile temperature should be checked.

MAIN PARTS OF THE PRESS

Frame Pusher Fixed cross piece

1) Cylinder & hydraulic piston

2) Pre filling tank

3) Multiplier

4) Logic element board

5) Drawer

6) Support & hopper

7) Drawer gear motor

8) Drawer fixed part

9) Hydraulic lifting switch box & thickness checking

10) Mech-locking unit

11) Spring stock absorber

12) Acupilator

13) Injector hydraulics

14) Piston pump

15) Lower punch & upper punch

16) Magnet

17) Filter

PARAMETERS OF PRESS

FOR 12”*12”FLOOR TILE:-

Pressure -------------- 230 bar to 240 bars

Apparent Density ------------- 2.05 to 2.07gms/cc

Thickness -------------- 7.7mm to 7.9mm

Tile temp. --------------- 90degreeC to 100degreeC FOR 8”*12

WALL TILES:-

Pressure ----------------- 250bar

Apparent Density ----------------- 2.03 to 2.05gms/cc

Thickness ----------------- 6.7 to 6.9mm

Tile ----------------- 100degreeC to 100degreeC

MAGNET SHOULD BE CLEANED EVERY 2 HOURS:-

Oil temp -------------- 40degreeC

Upper mould dies temp ------------- 65degreeC

Lower mould die temp ------------ 65degreeC

Die frame (box) temp ------------ 45degreeC

OIL SHOULD BE CHANGED AFTER 1500 HOURS.

DIE SHOULD BE CHANGED AFTER 5 TO 6 LAKHS STOCKS.

DEFECT ARRIVED AT THE PRESS CAUSES

1) High moisture content in the powder.

2) Insufficient heating of die-set.

3) If the fine dust particles present in the powder, it locked in the tiles.

REMEDIES

1) By maintain the correct moisture range.

2) By giving the sufficient heating to die set.

3) By controlling the fine dust particle in the powder.

4) By adjusting the duration period this problem will rectify.

OIL DROPS

The hydraulic cylinder worked by using oil. If this oil mixed in the powder by drops, after firing these drops are coming as the bubbles. If the oil is evaporate in firing the bubbles are not coming on the surface of the tile.

CAUSES OF CHIPPING

The tile passing on the belt conveyor & on the both sides steel guiders are arranges. If the tile is touching the guiders the soft edges of tiles will getting chipped. This defect also comes by band compensator columns. This & unloading. This defect is rectified by taking case in all these places.

PINHOLES

The moisture in the body after drying will liberate during firing. This liberation causes to pinholes.

CAUSES FOR CRACK

1) After pressing the tiles are pushed by a withdrawer. If it pushed speedily the tile it will be cause to form the crack. 2) Improper pushing of pushes feed from the rods to baskets in the vertical dryer.

3) Due to the high moisture contain in the powder.

4) Due to the pressure variation.

5) Cars vibration between stocks making to kiln. MANGLE DRYER There are four mangle dryers in BCL One is horizontal mangle dryer & the others are vertical mangle dryer. These are 77 Jhula in horizontal M.D at press

A. There are 20 Jhula in mangle dryer at press B, in press C at mangle dryer there are 22 Jhula.And in press D in mangle dryer takes a cycle of mangle dryer. In mangle dryer the burner temp is near 135o C. Air temp at the generation exit

Adjustable from 100 to 200c Tile moisture at the dryer entry

6 to 7% Tile moisture at the dryer exit

Inferior to 1%

Feel the reducer up to the level.

After soon of operation empty 7 replace by the same type of oil.

Keep the level constant with some eventual topping up.

Change the oil after 1500 to 2000 hours of operation.