PROCESS FLOW CHART - BUTYL TUBE
MANUFACTURE
SELECTION
OF RAW MATERIAL
INSPECTION
OF RAW MATERIAL
MASTER BATCH
MIXING
|
BLUE COMPAD MIXING |
STRAINING |
VALVE CEMENT COMPD
MIXING |
|
BLUE PAINT PREPA RATION |
FINAL MIXING |
CEMENT
PREPARATION
|
| |
EXTRUSION BEMENT
|
APPLICATION |
VALVE FIXING
SPLICING
SPLILCE CHILLING
FORMING & CURING
INSPECTION
VACUUM & VALVE
BENDING
PACKING
EXTRUSION
GREEM TURE
DIMENSIONS:-
|
FLAT WIDTH |
TOTAL
GAUGE |
|
CUT LENGTH |
TUBE WEIGHT=FLAT WIDTH X CUT LENGTH X TOTAL
GAUGE X SPECIAL GRAVITY
-GREE TUBE CIRCUMFERENCEþ95%
OF MOULD SECTIONAL PERIMETER
[FLAT WIDTH=CIRCUMFERENCE/2]
-CUT LENATH
þ3%
MORE OF MOULD CAVITY INNER CIRCUMFERENCE
TUBE WEIGHT
Q
TOTAL GAUGE=________________________________________________
SPEC.
GRAVITY FLAT WIDTH X CUT LENGTH X
GAUGES OF GREEN TUBE:-
|
TOP GAUGE |
- TOTAL GAUGE X 0.4 |
|
BOTTOM
|
- TOTAL GAUGE X 0.6 |
|
SIDE |
- TOTAL GAUGE
X |
þ VARITION IN TOTAL GAUGE - +
0.2mm (MAX)
þ AVERAGE CURED GAUGE
00.2mm
LESS THAN
EXPECTED TOP GAUGE ASSIGNED ABOVE
EXTRUSION (CONTS)
DIE AND CORE DIMEN SIONS:-
DIE:-
CIRCOMFERENCE
þ
88-92% OF GREEN TUBE CIRCUMFERENCE
LESS THAN 88%
þ
LESSER PRODUCTION OUTPUT
MORE THAN 92%
þ
MORE SHRINKAGE OF GREEN TUBE IN
STORAGE
DIE OPENING:-
-
DEPENDS ON BACK PRESSURE
-
HIGHER SIZE HAVE LESSER BACK
PRESSURE
-
DIE SWELL WILL BE + 65% (APPROX)
-
FOR SMALLER SIZES, +75 to 80% DUE
TO MORE BACK PRESSURE
-
DIE SWELL DEPENDS ON COMPOUND
VISCOSITY ADDITION OF REWORK COMPOUND AFFECRTS IT.
RECOMMANDED EXTRUDER:-
-
CONSTANT SCREW RPM
-
VARIABLE CONUEYOR SPEED
SPLING - AUTOMATIC MACHINE
MACHINE SET UP:-
LCV TRACK
4 4
PASS TRACTOR
_____ ____________
i). LOW CLAMP PRESOURE
(kg/cm²) - 5-25 25-35
ii) HIGH CLAMP PRESSURE
(kg/cm²) - 25-35 35-45
iii) BUTTING PRESSURE
(kg/cm²)- 35-45 45-55
iv) BUTTING TIME (Sec.) -
10 15
v) CUTTING OVER HANG (mm) -
0.8-1.0 1.0-1.2
vi) KNIFE TEMP. (ºC)
a) LOW HEAT
- 260±20 260±20
b) HIGH
HEAT- 600±20 600±20
CUTTING PATTERN:-
………….. ……………
15 15
®
mm ¬
®
mm ¬
ENTRY TUBE EXIT
HIGH SPEED RETURN
¾¾¾¾¾---------------------------------------------
- - - - - - - - -
MEDIUM SPEED
________________________________
|
HIGH CURRENT
LOW SPEED
LOW
HEAT
VLTIMATE OBJECT:- TO ACHIEVE UNIFORM
CUTTING SHADE THROUAHOUT THE CUT SURFACE.
SPLICING (CONTD)
CUTTING KNIVES:-
CUTTING
ANGLE þ
11° RE COMMANDED.
®SLIGHTLY
HORE ANGLE GIVE BETER RESULT
®INCREASE IN RUBBER
JAWS GAP LEADS TO INCREASE IN ANGLE
þCROSS
SEC. AREA OF KNIFE SHOULD BE
SAME FOR BOTH KNIVES
[CHECKING TO BE DONE BY
MEASURING 4 WEIGHING]
þ
KNIFE CLENING IS MUST BEFORE EVERY CUT
RUBBER
JAWS:-
-
FOR BETTER RESULT, SANDWITCH
COMPOUND JAWS
-
JAWS SET TO BE CHANGED AFTER
COMPLETION OF 50,000 CYCLES (OR 2 MONTHS)
-
JAWS ALIGHMENT SHOULD BE PERFECT
CHECK
LIST FOR GOOD JOINT IN GREEN TUBE:-
-
NO FLASH AT FOLD
-
THICKNING IS 10-15%, REQUIRED
-
FOLDS TO BE BLENDED WITH HOT KNIFE
-
CHECK FOR STEP AT FOLDS
-
CHECK FOR UNIFORM CLAMP IMPRESSION,
ON TUBE SURFACE.
CURING
SPLICE
CHILLING:-
- ENSURE ICE FORMATION
-
LEAST CHILLING AREA ON GREEN TUBE
-
BASE CHILLING FOR LESSER SD/ID
RATIO SIZES
-
CROWN CHILLING FOR HIGHER SD/ID
RATIO SIZES.
SHAPING FORMER:-
(DESIGNING)
D- 3% MORE OF MOULD CAUITY
ID
R- RADIUS OF CONTOUR IS 2 X
MORE OF SECTION RADIUS OF MOULD
Q- INCLUDED ANGLE IS 98-100°
þ 100% SHAPING IN FORMER IS GOOD
þ
TEEKWOOD FORMERS AT HOT PLACES PREFERABLE.
DEFECT ANALYSIS IN FINISHED
PRODUCT
NATURE OF DEFECT
SUGGESTED REMEDIES
i) CIRCUMFEREVTIAL -ENSURE
100% SHAPING
INSIDE PUCKLE
(CIP) - ENSURE PROPER SHAPING TIME
ii) VERTICAL
INSIDE - ENSURE PROPER CUT LENGTH
PUCXLE
- CHECK FOR EXCESS FLAT WIDTH
-
DUST SHAPING FORMER
iii) VALVE PUCKER (VP)
- LOCATE VALVE ON GREEN TUBE AT
PROPER POSITION
-LOCATION OF
VALVE HOLE IN
FORMER SHOULD BE CORRECT
-
PROPER ALGNMENT OF CLIP/NOZZLE
IN MOULD
iv) SPLICE
CRACK - PROPER APPLICATION OF HOT KNIFE
AT SPLICING
PEFECT ANALYSIS OF FINISHED PRODUS (CONTD)
NATURE OF DEFEECT
SUGGESTED REMEDY
v) PINCH SPLICE -
CHECK SPLICING MACHINE FOR
SPECIFIED PRESSURES
- CHECK FOR STARVATION OF
POWDER AT FLODS INSIDE GREEN
TUBE
- CHECK FOR LESSER FLAT WIDTH
vi) BLISTERS
- CHECK FOR AIR ENTRAPMENT AT
(NEEDLE
TYPE) EXTRVSION
[REJECT SOME GREEN TUBE DURING
POWER FAILURE]
vii) AIR LOCK
-CHECK FOR LESSER SHAPING
[ROUGH SURFALE] -
CLEAN MOULD VENT LINES
-CHECK FOR MOISTURE ON MOULD
SURFACE
QUALITY CHECK UP OF FINISHED PRODUCT
(NON-DESTRUCTVE)
-
SPLICE APPEARANCE
-
NEAT VALVE AREA
-
UNIFORM GAUGE DISTRIBUTION
THROUGHOUT CIRCUMFERENCC
-
EQVAL GAUGE ON BASE AND CROWN
-
FREE FROM VISUAL DEFECTS
-
NEAT AND UNIFORM BLUE LINE
-
NO DIRTY MOULD MARKS ON TUBE
SURFACE
-
CLEAR MONTH CODE
-
FREE FROM BULGING
QUALITY CHECK UP OF FINISHED PRODUS:-
(DESTRUCTIVE)
-
SPLICE STRENGTH - 45 Kg/cm² (MIN)
-
UNIFORM BODY TENSILE STRENGTH
-
E.B% AT JOINT - 450% (MIN)
-
SPLICE FLEX TEST OF 2160 CYCLES
(MIN) WHEN TESTED IN DE-MATTIA M/C
-
VALVE ADAESSION STRENGTH, 6.0 kg/cm
(MIN) FOR TRUCK
-
5.0 kg/cm (MIN) FOR PASS.
-
TENSION SET OF 35% (M,AX) [50%
STRETCH/105°C/5HRB]
PERIODICAL CHECK UP OF
ACCELERATED AGEING PROPERTIES FOR CONSISTANCY AS PER STANDARDS OF 120°
-
FOR 24, 72 AND 96 HOURS.
|
PROBLEM / DEFECTS |
CAUSES |
SOLUTIONS |
|
MIXING
UNDISPERSED CHEMICALS
POROSITY
SCORCH
|
IMPROPER MIXING CYCLE
LOW HEAT BUILD UP
IMPROPER BATCH WEIGHT
WRONG ADDITION OF
CURATIVES
CONTAMINATION
BY OTHER STOCK HIGH
DUMP
TEMPERATURE |
PROPER MIXING CYCLES
POLYMER
PRE-
MASTICATION
PROPER
BATCH
WEIGHT
PROPER
FOLLOW UP
CLEAN UP
BETWEEN
DIFF. STOCK
MIXING
EFFECTIVE
COOLING |
|
PROBLEM / DEFECTS |
CAUSES |
SOLUTIONS
|
|
MILLING
STICKING TO MILL ROLL
MILL BAGGING
STRAINING
MESH BLOCKAGE
|
EXCESS STICKY
COMPOUND
EXCESS BLACK / OIL
LOADING
MILL ROLL TEMP
DIFFERENCE
UNDISPERSED BLACK
|
ADD PROPER
DETACKIFIERS
(STEARIC ACID)
PROPER CONTROL IN
LOADING
EFFECTIVE MILL ROLL
RATIO
ENSURE PROPER COOLING
IMPROVE MIXING
TRY SOFTER PELLET
HARDNESS |
| PROBLEM / DEFECTS |
CAUSES |
SOLUTIONS |
|
EXTRUSION
SCORCH
BLILSTER
THINNING
GAUGE VARIATION
ADHESION OF INNER
WALLS |
HIGH BACK PRESSURE
UNDISPERSED CURTIVES
SCORCH SAFETY LOW
HIGH WORK AWAY
ADDITION
AIR TRAPS
UNDISPERSED CHEMICALS
WRONG DIE FIXING
MISMATCHING IN
CONVEYOR
SPEEDS
IMPROPER DIE / CORE
FIXNG
LOW QUANTITY OF TALC
|
PROPER DIE DESIGN /
LOWER SCREW SPEED
PROPER MIXING
CONTROLLING
ACELERATOR COMPOSITION
STRAIN & USE IN A
PROPER RATIO
HOMOGENEOUS
INGREDIENTS
PROPER DUMP
TEMPERATURE
AVOID LAPSES
CORRECT / CHECK AT
REGULAR INTERVALS
CORRECT FIXING
ENSURE PROPER TALC
USAGE |
| PROBLEM / DEFECTS |
CAUSES |
SOLUTIONS |
|
SPLICING
EXCESS OVERHANG
SMEAR, FLASH,
TRIMMING
BAND, STEP FORMATION
BREAKDOWN AT FOLD |
HIGH CLEARANCE
BETWEEN KNIFE & JAW
HIGH KNIFE HEAT
IMPROPER JAW
ALIGNMENT
IMPROPER BOBBIN BLOCK
ALIGNMENT
HIGH CLAMPING &
BUTTING PRESSURES
LESS CLEARANCE
BETWEEN JAWS |
USE PROPER TEMPLATE
FOR CHECKS
ENSURE PROPER LOW &
HIGH HEAT
ALIGN PREPERLY
OPTIMUM PRESSURE TO
BE MAINTAINED
PROPER CLEARANCE TO
BE MAINTAINED
|
| PROBLEM / DEFECTS |
CAUSES |
SOLUTIONS |
|
FLASH & EDGE BUILD UP
SPLICE OPENWITH |
UNEVEN CLAMPING OF JAWS DUE TO
WIDTH VARIATION IN TUBE ENDS
DURING DUAL SPLICING
TALC CONTAMINATION WAVY CUT
UNEVEN BUTTING
IMPROPER ALIGNMENT OF JAWS
GAUGE VARIATION |
GAUGE & WIDTH CONTROL
AVOID CONTAMINATION
SET KNIFE PROPERLY
ADJUST SETTINGS PROPERLY
GAUGE CONTROL
|
| PROBLEM / DEFECTS |
CAUSES |
SOLUTIONS |
|
FORMING
THINNING
OVERSHAPING
|
DAMAGE BY FOREING
MATERIAL
UNEVEN THICKNESS
HIGH INFLATION
PRESSURE
PEG SET DISTANCE
MORE |
AVOID CUTS / DAMAGE
BY FOREIGN MATERIALS
GAUGE UNIFORMITY
CONTROL
THROTTLE VALVE /
MONITOR PRESSURE
SET PEG AT SPEC
DISTANCE |
| PROBLEM / DEFECTS |
CAUSES |
SOLUTIONS |
|
CURING
ROUGH APPEARANCE
UNDER CURE
STICKING TO MOULDS
POROUS VALVE BASE
PINCHING / BUCKLING
|
DIRTY MOULDS
PRESSURE FLUCTUATION
WATER PARTICLE
INSIDE TUBE
STICKY COMPOUND
IMPROPER VALVE
FIXING
IMPROPER FORMING
IMPROPER SHAPING |
CLEAN MOULD
FREQUENTLY
CORRECT THE PROBLEM
AVOID SUCH LAPSES
REDUCE TACK
PROPER VALVE FIXING
TO BE FOLLOWED
PROPER FORMING /
SHAPING
TO BE FOLLOWED |
