MANUFACTURING DEFECTS IN CORRUGATED BOARD/ BOXES, THEIR CAUSES AND REMEDIES

Transcription

1 MANUFACTURING DEFECTS IN CORRUGATED BOARD/ BOXES, THEIR AND BY DEEPAK KILLAWALA PRESENTED AT 32 nd CERTIFICATE COURSE IN CORRUGATED PACKAGING WICMA AUDITORIUM, 237, MITTAL INDL. ESTATE NO.3, M.V.ROAD, ANDHERI (E), MUMBAI AUGUST

2 MANUFACTURING DEFECTS IN CORRUGATED BOARD/ BOXES, THEIR AND

3 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

4 BLISTERS VARIOUS SHAPED LOOSE, UNBONDED AREAS IN EITHER LINER. LINERS APPEAR TO BULGE IRREGULARLY AWAY FROM FLUTES. 1. THIN STREAK IN LINER 1. CHANGE LINER 2. SPOTTY GLUE APPLICATION AT 2. ADJUST FINGERS FINGERS 3. LOOSE CORRUGATION 3. CHECK MEDIUM MOISTURE 4. WET STREAK IN LINER OR MEDIUM 4. CHANGE ROLL IF CANNOT BALANCE MOISTURE

5 COCKLES APPEAR AS WRINKLES IN THE LINER BETWEEN THE FLUTE TIPS 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

6 CORRUGATIONS CUT AT FINGERS PERFORATIONS IN THE MEDIUM AT THE TIPS OF THE FLUTES IN LINE WITH THE FINGERS. REMEDDIES 1. DIRTY FINGERS 1. CLEAN FINGERS 2. FINGERS TOO TIGHT 2. RELIEVE FINGERS 3. BURR ON FINGERS 3. FILE OR CHANGE FINGERS 4. DIRTY CORRUGATING ROLLS (SILLICATE) 4. CLEAN ROLLS 5. WET CORRUGATING MEDIUM 5. INCREASE WRAP ON PRECONDITIONER OR ADJUST FINGERS FOR TYPE OF MEDIUM

7 CORRUGATIONS CUT OR FRACTURED CORRUGATING MEDIUM WHICH HAS BEEN CUT OR FRACTURED ALONG SIDES OR TIPS OF FLUTES. 1. HIGH TENSION ON MEDIUM 1. ADJUST BRAKE PRESSURE 2. MEDIUM TOO WET OR DRY 2. INCREASE WRAP ON PRECONDIONER OR ADJUST SHOWERS 3. CORRUGATING ROLLS TOO TIGHT 3. REDUCE PRESSURE BETWEEN ROLLS 4. DIRTY OR WORN CORRU. ROLLS 4. CHECK, CLEAN, REGRIND OR REPLACE 5. ROLL MEDIUM OUT OF ROUNDNESS 5. SLOW CORRUGATOR, CHANGE ROLL 6. CORRU. ROLLS NOT PARALLEL 6. ALLIGN CORRUGATING ROLLS

8 CORRUGATIONS LEANING CORRUGATIONS ARE LEANING OR TILTED TO ONE SIDE, BUT OTHERWISE WELL FORMED. 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 3. EQUALISE PRESSURE ROLLS

9 WARPED BOARD BOARD DOES NOT LIE FLAT ON THE LEVEL SURFACE. 1. WET LINER 1. INCREASE WRAP ON PRE-HEATER OR REDUCE SPEED 2. EXCESS MOISTURE ON SINGLE 2. a) INCREASE LINER PRE- FACE SIDE HEATER WRAP b) INCREASE OPERATING SPEED IF PRACTICAL c) USE MIN. ADHESIVE IN SINGLE FACER

10 WASHBOARDING REFERS TO APPEARANCE OF SINGLE FACE OR DOUBLE FACE LINER WHICH STANDS TO FOLLOW FLUTE FORMATION (MOST PREVALENT IN LIGHT WEIGHT LINERS. 1. EXCESSIVE ADHESIVE APPLICATION 1. ADJUST DOCTORING ROLL 2. IMPROPER VISCOSITY 2. ADJUST VISCOSITY 3. GLUE ROLL SPEED NOT MATCHING 3. ADJUST GLUE ROLL SPEED PAPER WEB SPEED 4. EXCESSIVE MOISTURE IN THE LINERN 4. INCREASE WRAP OF LINER ON PRE-HEATER

11 WASHBOARDING IS CAUSED BY EXCESS ADHESIVE

12 ROLL IN PROPER ADJUSTMENT FLUTE PATTERN GIVEN SHOWS ROLL IN CORRECT ALIGNMENT AND UNDER UNIFORM PRESSURE. OPERATOR SIDE CENTER DRIVE SIDE

13 IMPORTANCE OF TEETH PROFILE GEAR TEETH IN CONTACT GEAR TEETH PROFILE

14 PASTING OPERATION RELATED PROBLEMS PASTING OPERATION IS CARRIED OUT TO JOIN CORRUGATE TO PAPER TO PRODUCE 3-PLY, 5-PLY, 7-PLY SHEET. 1. CRUSHING OF FLUTES 1. INCREASE GAP BETWEEN ROLLERS 2. EXCESSIVE ADHESIVE APPLICATION 2. a) ADJUST DOCTORING ROLL b) REDUCE ADHESIVE VISCOSITY 3. LESS APPLICATION OF ADHESIVE 3. INCREASE VISCOSITY 4. UNEVEN ADHESIVE APPLICATION 4. CHECK SURFACE OF APPLICATOR ROLL 5. SHEET NOT MOVING STRAIGHT 5. EQUALISE PRESSURE AT BOTH ENDS 6. CORRODED, WORN OUT AND 6. MACHINE, GRIND AND ELECTRO- PITTED ROLLERS PLATE ROLLERS OR REPLACE

15 ROTARY CREASER RELATED PROBLEMS 1. SHEET CRACKING DUE TO DRY BOARD 1. MAINTAIN MOISTURE IN THE SHEETS 2. SHEET CRACKING DUE TO NOT USING 2. USE RIGHT CREASING HEAD CORRECT CREASING HEAD 3. ROUGH CUTTING 3. a) SET GAP BETWEEN CUTTERS b) GRIND OR CHANGE CUTTERS 4. MACHINE VIBRATIONS 4. a) CUTTERS JAMMED b) DAMAGED BEARINGS OR GEARS

16 ECCENTRIC SLOTTING MACHINE RELATED PROBLEMS 1. RAGGED SLOTS OR ROUGH CUTTING 1. IMPROPER LAMINATION OR WORN OUT SLOTTING KNIFE AND SIDE CUTTERS, ADJUST CUTTER SCREWS

17 PUNCHING OR DIE CUTTING RELATED PROBLEMS 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 4. PROVIDE CORK OF RIGHT QUALITY AND IN QUANTITY 5. TRIM SEPARATES IN MACHINE 5. INCREASE NICKING 6. INACCURATE CREASING AND 6. PROVIDE RULE OF CORRECT CUTTING (DEFLECTION OF RULE) THICKNESS AND HEIGHT 7. NON-UNIFORM CUTTING AND 7. DAMAGED CUTTING PLATE CREASING NEEDS CHANGE

18 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 9. LESS MAC READY OR LOW RULE ONE AREA HEIGHT 10. SLOT IS STRIPPING DUE TO 10. PROVIDE TAPPER SLOTS IMPROPER SHAPE WARNING: SAFETY GUARDS SHOULD NOT BE BY-PASSED AS IT CAN LEAD TO SERIOUS ACCIDENT OF OPERATOR S HAND.

19 STITCHING RELATED PROBLEMS 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 3. WIRE SIZE BEING USED OR DULL WIRE CUTTER 4. IMPROPER STITCH SPACING 4. TRAIN OPERATOR 5. WRONG PLACEMENT OF 5. MAINTAIN CORRECT GAP FROM END STITCH THE FLAP SCORE LINE

20 PRINTING DEFECTS 1. INCORRECT INK FORMATION 1. CHECK EACH BATCH OF INK WITH STANDARD COLOUR SWATCH 2. INK VISIBLE ON THE OTHER SIDE, 2. REDUCE INK APPLICATION EXCESSIVE 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 7. REDUCE THE PRESSURE HIGH PRINTING PRESSURE 8. IMAGE DISTORTION 8. DUE TO DAMAGED PRINTING PLATES, REPLACE PLATES

21 THANKS ARE DUE TO WICMA & FCBM Mr. Pankaj D. Shah Mr. Baldev Mehta Mr. Y. M. Rao All the Participants

22 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.