MANUFACTURING DEFECTS IN
CORRUGATED BOARD/ BOXES,
THEIR CAUSES AND REMEDIES
BY
DEEPAK KILLAWALA
PRESENTED AT
32nd CERTIFICATE COURSE IN CORRUGATED
PACKAGING
WICMA AUDITORIUM,
237, MITTAL INDL. ESTATE NO.3,
M.V.ROAD, ANDHERI (E),
MUMBAI-400 059
AUGUST 01.2012
MANUFACTURING DEFECTS
IN CORRUGATED BOARD/
BOXES, THEIR CAUSES AND
REMEDIES
1.
INTRODUCTION
2.
CORRUGATOR DEFECTS
3.
CORRUGATOR ROLL DEFECTS
4.
PASTING OPERATION DEFECTS
5.
CREASING & CUTTING AND SLOTTING
OPERATION RELATED PROBLEMS
6.
DIE CUTTING PROBLEMS
7.
STITCHING RELATED PROBLEMS
8.
PRINTING DEFECTS
9.
CONCLUSION AND REFERENCES
BLISTERS
VARIOUS SHAPED LOOSE, UNBONDED AREAS IN EITHER LINER.
LINERS APPEAR TO BULGE IRREGULARLY AWAY FROM FLUTES.
CAUSES
REMEDIES
1. THIN STREAK IN LINER
1. CHANGE LINER
2. SPOTTY GLUE APPLICATION AT
FINGERS
3. LOOSE CORRUGATION
2. ADJUST FINGERS
4. WET STREAK IN LINER OR MEDIUM
3. CHECK MEDIUM MOISTURE
4. CHANGE ROLL IF CANNOT
BALANCE MOISTURE
COCKLES
APPEAR AS WRINKLES IN THE LINER BETWEEN THE FLUTE TIPS
CAUSES
REMEDIES
1. ADHESIVE APPLICATION TOO HEAVY
1. REDUCE ADHESIVE
2. TOO MUCH HEAT
2. RUN AT FASTER SPEEDS OR
BYPASS PRE-HEATERS WITH
MINIMUM POSSIBLE GLUELINE
CORRUGATIONS – CUT AT FINGERS
PERFORATIONS IN THE MEDIUM AT THE TIPS OF THE FLUTES IN LINE WITH THE
FINGERS.
CAUSES
1.
2.
3.
4.
5.
DIRTY FINGERS
FINGERS TOO TIGHT
BURR ON FINGERS
DIRTY CORRUGATING ROLLS (SILLICATE)
WET CORRUGATING MEDIUM
REMEDDIES
1.
2.
3.
4.
5.
CLEAN FINGERS
RELIEVE FINGERS
FILE OR CHANGE FINGERS
CLEAN ROLLS
INCREASE WRAP ON
PRECONDITIONER OR ADJUST
FINGERS FOR TYPE OF
MEDIUM
CORRUGATIONS – CUT OR FRACTURED
CORRUGATING MEDIUM WHICH HAS BEEN CUT OR FRACTURED ALONG SIDES OR
TIPS OF FLUTES.
CAUSES
1. HIGH TENSION ON MEDIUM
2. MEDIUM TOO WET OR DRY
3.
4.
5.
6.
CORRUGATING ROLLS TOO TIGHT
DIRTY OR WORN CORRU. ROLLS
ROLL MEDIUM OUT OF ROUNDNESS
CORRU. ROLLS NOT PARALLEL
REMEDIES
1. ADJUST BRAKE PRESSURE
2. INCREASE WRAP ON PRECONDIONER
OR ADJUST SHOWERS
3. REDUCE PRESSURE BETWEEN ROLLS
4. CHECK, CLEAN, REGRIND OR REPLACE
5. SLOW CORRUGATOR, CHANGE ROLL
6. ALLIGN CORRUGATING ROLLS
CORRUGATIONS – LEANING
CORRUGATIONS ARE LEANING OR TILTED TO ONE SIDE, BUT OTHERWISE WELL
FORMED.
CAUSES
REMEDIES
1. CORRUGATING ROLLS NOT PARALLEL
1. ADJUST ALIGNMENT OF
CORRUGATING ROLLS
2. WET MEDIUM
2. INCREASE WRAP OF MEDIUM
ON PRE-CONDITIONER
3. UNEVEN PRESSURE ON CORRUGATING
ROLLS
3. EQUALISE PRESSURE
WARPED BOARD
BOARD DOES NOT LIE FLAT ON THE LEVEL SURFACE.
CAUSES
1.
WET LINER
2. EXCESS MOISTURE ON SINGLE
FACE SIDE
REMEDIES
1. INCREASE WRAP ON
PRE-HEATER OR REDUCE
SPEED
2. a) INCREASE LINER PREHEATER WRAP
b) INCREASE OPERATING
SPEED IF PRACTICAL
c) USE MIN. ADHESIVE IN
SINGLE FACER
WASHBOARDING
REFERS TO APPEARANCE OF SINGLE FACE OR DOUBLE FACE LINER WHICH
STANDS TO FOLLOW FLUTE FORMATION (MOST PREVALENT IN LIGHT WEIGHT
LINERS.
CAUSES
1. EXCESSIVE ADHESIVE APPLICATION
2. IMPROPER VISCOSITY
3. GLUE ROLL SPEED NOT MATCHING
PAPER WEB SPEED
4. EXCESSIVE MOISTURE IN THE LINERN
REMEDIES
1. ADJUST DOCTORING ROLL
2. ADJUST VISCOSITY
3. ADJUST GLUE ROLL SPEED
4. INCREASE WRAP OF LINER
ON PRE-HEATER
WASHBOARDING IS CAUSED BY EXCESS ADHESIVE
ROLL IN PROPER ADJUSTMENT
FLUTE PATTERN GIVEN SHOWS ROLL IN CORRECT ALIGNMENT AND UNDER
UNIFORM PRESSURE.
OPERATOR SIDE
CENTER
DRIVE SIDE
IMPORTANCE OF TEETH PROFILE
GEAR TEETH IN CONTACT
GEAR TEETH PROFILE
PASTING OPERATION RELATED PROBLEMS
PASTING OPERATION IS CARRIED OUT TO JOIN CORRUGATE TO PAPER TO
PRODUCE 3-PLY, 5-PLY, 7-PLY SHEET.
CAUSES
1. CRUSHING OF FLUTES
2. EXCESSIVE ADHESIVE APPLICATION
3. LESS APPLICATION OF ADHESIVE
4. UNEVEN ADHESIVE APPLICATION
5. SHEET NOT MOVING STRAIGHT
6. CORRODED, WORN OUT AND
PITTED ROLLERS
REMEDIES
1. INCREASE GAP BETWEEN ROLLERS
2. a) ADJUST DOCTORING ROLL
b) REDUCE ADHESIVE VISCOSITY
3. INCREASE VISCOSITY
4. CHECK SURFACE OF APPLICATOR
ROLL
5. EQUALISE PRESSURE AT BOTH ENDS
6. MACHINE, GRIND AND ELECTROPLATE ROLLERS OR REPLACE
ROTARY CREASER RELATED PROBLEMS
CAUSES
1. SHEET CRACKING DUE TO DRY BOARD
REMEDIES
1. MAINTAIN MOISTURE IN THE
SHEETS
2. SHEET CRACKING DUE TO NOT USING
CORRECT CREASING HEAD
3. ROUGH CUTTING
4. MACHINE VIBRATIONS
2. USE RIGHT CREASING HEAD
3. a) SET GAP BETWEEN CUTTERS
b) GRIND OR CHANGE CUTTERS
4. a) CUTTERS JAMMED
b) DAMAGED BEARINGS OR GEARS
ECCENTRIC SLOTTING MACHINE RELATED PROBLEMS
CAUSES
1. RAGGED SLOTS OR ROUGH CUTTING
REMEDIES
1. IMPROPER LAMINATION OR WORN OUT
SLOTTING KNIFE AND SIDE CUTTERS,
ADJUST CUTTER SCREWS
PUNCHING OR DIE CUTTING RELATED PROBLEMS
CAUSES
REMEDIES
1. POOR PRINT PUNCH REGISTRATION
1. CORRECT PRINTING AND
PASTING REGISTRATION
2. TRIM NOT STRIPPING PROPERLY
2. PROVIDE PROPER NICK DEPTH
AND
GAP,
DAMAGED
CUTTING
RULE OR IMPROPER CORKING
3. PAPER CREASE FRACTURES
3. PROVIDE CREASING RULE OF
CORRECT THICKNESS,
REDUCE PRESSURE, IF EXCESS
DRY SHEET CAN ALSO CAUSE
FRACTURES
4. SHEET NOT EJECTING FROM DIE
5. TRIM SEPARATES IN MACHINE
4. PROVIDE CORK OF RIGHT
QUALITY AND IN QUANTITY
5. INCREASE NICKING
6. INACCURATE CREASING AND
CUTTING (DEFLECTION OF RULE)
6.
PROVIDE RULE OF CORRECT
THICKNESS AND HEIGHT
7. NON-UNIFORM CUTTING AND
CREASING
7. DAMAGED CUTTING PLATE
NEEDS CHANGE
CAUSES
REMEDIES
8. EXCESSIVE MACHINE DEFLECTION
8. HIGH LOAD DUE TO MORE
CUTTING AND CREASING LENGTH
OR BLUNT CUTTING RULES.
CHANGE DIE OR CUTTING RULES
9. BLANK CONSISTENTLY UNCUT IN
ONE AREA
9.
10. SLOT IS STRIPPING DUE TO
IMPROPER SHAPE
10. PROVIDE TAPPER SLOTS
WARNING:
LESS MAC READY OR LOW RULE
HEIGHT
SAFETY GUARDS SHOULD NOT BE BY-PASSED AS IT CAN LEAD TO
SERIOUS ACCIDENT OF OPERATOR’S HAND.
STITCHING RELATED PROBLEMS
CAUSES
REMEDIES
1. CORROSION OF STITCHING WIRE
1. PROVIDE CORRECT ELECTRO
PLATING ON WIRE
2. BREAKING OF STITCHING WIRE
2. PROVIDE SOFT WIRE
3. STITCHING WIRE LEGS BUCKLED
OR DULL WIRE CUTTER
3. WIRE SIZE BEING USED
4. IMPROPER STITCH SPACING
4. TRAIN OPERATOR
5. WRONG PLACEMENT OF
END STITCH
5. MAINTAIN CORRECT GAP FROM
THE FLAP SCORE LINE
PRINTING DEFECTS
CAUSES
REMEDIES
1. INCORRECT INK FORMATION
1. CHECK EACH BATCH OF INK WITH
STANDARD COLOUR SWATCH
2. INK VISIBLE ON THE OTHER SIDE,
EXCESSIVE INK APPLICATION
2. REDUCE INK APPLICATION
3. POOR PRINTING DEFINITION
3. REPLACE DEFECTIVE PRINTING PLATES
4. IMPROPER PRINT REGISTRATION
4. COLOURS BEING OUT OF REGISTER,
ADJUST ONE COLOUR AT A TIME
5. INK OUT OF BOUNDARY (SMEAR)
5. EXCESSIVE INK APPLICATION OR
DIRTY PRINTING PLATES. REDUCE
INK OR CHANGE PRINTING PLATES
6. DIRTY PRINTING
6. DRY AND DUSTY BOARD. GET BOARD
WITH BETTER SURFACE FINISH
7. DISTORTED IMAGE DUE TO
HIGH PRINTING PRESSURE
7. REDUCE THE PRESSURE
8. IMAGE DISTORTION
8. DUE TO DAMAGED PRINTING PLATES,
REPLACE PLATES
THANKS ARE DUE TO
•
•
•
•
•
WICMA & FCBM
Mr. Pankaj D. Shah
Mr. Baldev Mehta
Mr. Y. M. Rao
All the Participants
LIST OF REFERENCES
1. CORRUGATED BOX MANUFACTURERS HAND BOOK BY S& S CORRUGATED PAPER
MACHINER CO. INC.
2. PAPER AND BOARD, ITS MANUFACTURING TECHNOLOGY, CONVERSION AND
USAGE BY ROBERT R.A. HIGHAM (VOL. 1 & 2).
3. STARCH PRODUCTION TECHNOLOGY BY J.A. RADLEY.
4. CORRUGATED SHIPPING CONTAINERS, AN ENGINEERING APPROACH BY GEORGE
G. MALTENFORT.
5. ROLL APPLICATION OF ADHESIVES BY RAYMOND R. MYRES.
6. PROBLEMS ENCOUNTERED DURING PRODUCTION AND ON-THE-SPOT
SOLUTIONS BY SURINDER SINGH BHURJEE.
7. CORRUGATING DEFECTS TERMINOLOGY BY TAPPI PRESS.