| PROBLEM |
|
CAUSES |
|
SOLUTIONS |
| Poor Adhesion |
A. |
Contaminated substrate. |
A. |
Clean substrate. |
| Chemical |
| |
B. |
Insufficient solvency. |
B. |
(1) Consult supplier. |
| (2) Use stronger solvent. |
| |
C. |
Surface film on substrate either applied by substrate manufacture or inherent on the type of substrate. |
C. |
(1) Use recommended surface treatment procedures for the type of substrate. |
| (2) Consult substrate supplier. |
| Poor Adhesion |
A. |
Incompatible silicone additives. |
A. |
Reduce or change additives. |
| Intercoat |
| |
B. |
Substrate contaminated between coats. |
B. |
Clean substrate. |
| |
C. |
Base coat heated excessively producing hard surface to which succeeding coats will not adhere. |
C. |
Improve control of drying/curing process. |
| Poor Adhesion |
A. |
Separation and layering of materials in coating. |
A. |
(1) Coating material too thin. |
| Intracoat |
(2) Consult supplier. |
| |
B. |
Flooding and floating. |
B. |
Add wetting agent - consult supplier. |
| Poor Adhesion |
A. |
Flooding and floating. |
A. |
Add wetting agent consult supplier. |
| Mechanical |
| |
B. |
Coating too thin. |
B. |
(1) Use coarser printing screens. |
| (2) Reduce thinner. |
| (3) Add fumed silica. |
| |
C. |
Inadequate drying or curing. |
C. |
(1) Increase time and/or temperature for drying/curing. |
| (2) Increase air flow. |
| |
D. |
Dirty or contaminated substrate. |
D. |
Clean substrate. |
| |
E. |
Under or over catalyzed. |
E. |
Check for proper amounts of additives. |
| |
F. |
Excessive amounts of additives. |
F. |
Reduce amount of additives. |
| |
G. |
Improper choice of coating material for substrate being coated. |
G. |
Consult supplier. |
| |
H. |
Special substrate treated so as not to accept a finish. |
H. |
Consult supplier. |
| |
I. |
Coating material deteriorating with age. |
I. |
Discard. |
| Alligatoring |
A. |
Coating film too heavy. |
A. |
Apply thinner coat. |
| Also: |
| Cracking, Tearing |
| |
B. |
Incompatability of coating with substrate. |
B. |
Consult supplier. |
| |
C. |
Contaminated coating surface. |
C. |
Clean. |
| |
D. |
Insufficient dryer in coating material. |
D. |
Add dryer - consult supplier. |
| Backlap |
A. |
Coating pulls through screen behind squeegee during print stroke. |
A. |
(1) Reduce volume of coating material on screen. |
| Also: |
|
(2) Increase squeegee travel distance beyond image. |
| Backlash |
See: Screen sticking to printed substrate. |
|
| Backlash |
|
See Backlap. |
|
|
| Bleaching |
|
See Fading. |
|
|
| Bleeding |
A. |
Migration of color from the coating film onto or into a surface with which it comes in contact. |
A. |
(1) Change coating materials. |
| (2) Keep heat treated temperatures as low as possible. |
| Blister |
A. |
Solvent entrapment. |
A. |
Use faster evaporating solvent in air drying systems; slower evaporating solvent in baking systems. |
| Also: |
| Foam, Boiling, Bubbles |
| |
B. |
Poor solvent combinations. |
B. |
Add leveler - Consult supplier. |
| |
C. |
Oil or moisture on substrate. |
C. |
(1) Clean substrate. |
| (2) Keep substrate dry and at room temperature. |
| |
D. |
Dirt. |
D. |
(1) Clean substrate. |
| (2) Improve housekeeping practices. |
| |
E. |
Coating film too thick. |
E. |
Apply thinner coat. |
| Blocking |
A. |
Solvent is slowly released from the coating film. |
A. |
(1) Use faster drying solvent. |
| Also: |
(2) Consult supplier for suitable catalyst. |
| Pack-off |
(3) Longer drying/baking schedule. |
| Bloom |
A. |
Rapid evaporation of low boiling solvents cooling the surface and causing condensation. |
A. |
(1) Use slower evaporating solvent. |
| Also: |
(2) Reduce air flow over the film. |
| Blush |
(3) Lower the humidity. |
| Blur |
|
See Halo, Smear. |
|
|
| Blush |
|
See Bloom. |
|
|
| Boiling |
|
See Craters, Blister, Bubbles. |
|
|
| Bubbles |
A. |
Surface active substances in the vehicle or dispersing equipment. |
A. |
(1) Add defoamer - consult supplier. |
| Also: |
(2) Adjust speed of squeegee travel. |
| Foam, Blister, Boiling |
(3) Adjust off-contact. |
| |
B. |
High speed mixing or dispersing equipment. |
B. |
(1) Add defoamer - consult supplier. |
| (2) Use slower speed mixer. |
| (3) Use paint shaker. |
| (4) Hand stir. |
| Chalking |
A. |
Coating material not properly bonded to substrate. |
A. |
(1) Clean substrate. |
| (2) Check cure cycle. |
| |
B. |
Exposure. |
B. |
(1) Improper coating material for job requirement. |
| (2) Consult supplier. |
| (3) Apply protective overcoat. |
| |
C. |
Improper coating material for job. |
C. |
Consult suppliers. |
| Checking |
A. |
Overbaked or overcured. |
A. |
Check baking/curing cycle. |
| Also: |
| Cracking, Crazing, Tearing |
| |
B. |
Underbaked or undercured. |
B. |
Check baking/curing cycle. |
| |
C. |
Coating too heavy. |
C. |
Apply thinner coating. |
| Clogging |
A. |
Coating material is drying out in the screen or application equipment. |
A. |
(1) Clean screen applicator. |
| (2) Filter coating material. |
| (3) Add retarder. |
| (4) Sharpen squeegee. |
| (5) Add fresh coating to screen on a more frequent time schedule. |
| |
B. |
Coating material is too coarse for adequate passage through the coating equipment. |
B. |
(1) Consult supplier. |
| (2) Use coarser screens or other flow restricing devices. |
| Cobwebbing |
A. |
Static electricity, low humidity, low boiling solvent. |
A. |
(1) Add retarder or more thinner. |
| (2) Use humidifier. |
| (3) Use higher boiling solvent. |
| (4) Reduce squeegee speed. |
| (5) Ground equipment. |
| Color variation on finished film |
A. |
Flooding and floating. |
A. |
(1) Add wetting agent - consult supplier. |
| (2) Too much thinner. |
| |
B. |
Too much heat in drying/curing operation. |
B. |
Reduce temperature and/or increase speed. |
| |
C. |
Uneven application. |
C. |
Check coating equipment. |
| Cracking |
A. |
Coating too heavy. |
A. |
Apply thinner coat. |
| Also: |
| Alligatoring, Checking, Crazing |
| |
B. |
Over baked/cured. |
B. |
Check baking/curing cycle. |
| |
C. |
Under baked/cured. |
C. |
Check baking/curing cycle. |
| |
D. |
Film shrinkage due to poor intercoat wetting. |
D. |
(1) Clean before overcoating. |
| (2) Add wetting agent - consult supplier. |
| (3) Consult supplier for proper coating materials. |
| |
E. |
Contaminated substrate. |
E. |
Clean or replace substrate. |
| |
F. |
Overcoat is less flexible than undercoat. |
F. |
Consult supplier for proper coating materials. |
| |
G. |
Coating is not as plastic as the substrate. |
G. |
Use more flexible coating material. |
| |
H. |
Incompatibility of coating with substrate. |
H. |
Consult supplier. |
| Craters |
A. |
Bubbles in film. |
A. |
(1) Add defoamer and/or thinner. |
| Also: |
(2) Add flattening agent - consult supplier. |
| Dimples |
|
| |
B. |
Solvent entrapment. |
B. |
Use faster evaporating solvent. |
| |
C. |
Poor solvent combinations. |
C. |
(1) Consult supplier. |
| (2) Add leveling agent. |
| |
D. |
Surface contamination. |
D. |
Clean. |
| |
E. |
Containation of coating material. |
E. |
Keep covered. |
| Crawl |
A. |
Contaminated substrate. |
A. |
Clean substrate. |
| Also: |
| Scallop, Creep, Fish eyes, Pull-back |
| Crazing |
|
See Checking, Cracking. |
|
|
| Creep |
|
See Crawl. |
|
|
| Dark Reaction |
A. |
Coating material has exceeded shelf life. |
A. |
Replace with new material. |
| (U.V. Ink) |
| |
B. |
Coating material was stored at elevated temperature. |
B. |
Change storage area to cooler (-room temperature) location. |
| Delamination |
A. |
Contaminated substrate. |
A. |
Clean or replace substrate. |
| |
B. |
Overcured base coat. |
B. |
Reduce cure time. |
| |
C. |
Gross mismatch in expansion between layers. |
C. |
Consult supplier. |
| Digs |
A. |
Impact with a foreign object. |
A. |
Change storage location to a safer, protected area. Instruction on safe handling. Use a cover plate during storage. |
| Dimples |
|
See Craters. |
|
|
| Distrorted image |
A. |
Too much squeegee pressure. |
A. |
Reduce squeegee pressure. |
| Also: |
| Ragged lines, Sawtooth |
| |
B. |
Insufficient screen tension. |
B. |
Replace screen. |
| |
C. |
Weak screen frame structure. |
C. |
Obtain more rigid frames. |
| |
D. |
Distorted artwork. |
D. |
Obtain new corrected artwork. |
| |
E. |
Too much off-contact. |
E. |
Reduce off-contact, replace screen. |
| Drying in |
A. |
Coating dries too fast. |
A. |
Use slower drying coating - consult supplier. Use flood coat immediately after printing. |
| |
B. |
Operation is too slow. |
B. |
Speed up the process. |
| |
C. |
Too much air flow over the screen. |
C. |
Redirect air flow from fans or other sources. |
| Fading |
A. |
Too much heat in the drying/curing operation. |
A. |
Reduce temperature or increase speed through dryer/oven. |
| |
B. |
Exposure. |
B. |
(1) Apply protective overcoat. |
| (2) Check baking/curing cycle. |
| (3) Consult supplier for more stable coating material. |
| |
C. |
Excessive thinning. |
C. |
Reduce thinner. |
| Film cured, but is easily marred. |
A. |
High surface resistance. |
A. |
(1) Add mar and slip agent. |
| (2) Consult supplier. |
| |
B. |
Poor abrasion resistance. |
B. |
(1) Add mar and slip agent. |
| (2) Consult supplier. |
| Fish eyes |
A. |
Dirty or contaminated substrate. |
A. |
Clean substrate. |
| Also: |
| Crawl |
| |
B. |
Silicone additives. |
B. |
Reduce or change additives. |
| |
C. |
Poor wetting of substrate. |
C. |
Add wetting agent. |
| |
D. |
Contaminated coating material. |
D. |
Discard. |
| |
E. |
Solvent in screen. |
E. |
Dry the screen. |
| |
F. |
Incompatible solvent used in clean-up. |
F. |
Change solvent. |
| |
G. |
Contaminated screen. |
G. |
Remove coating material, clean screen, reprint. |
| Flaking |
A. |
Coating film too thick. |
A. |
Reduce film thickness with finer screen, thinner screen emulsion, thinner coating viscosity, or harder squeegee. |
| |
B. |
Damage to coating film from impact, handling or stacking. |
B. |
Handle with care. |
| Foam |
|
See Bubbles. |
|
|
| Gelling |
A. |
Moisture absorption. |
A. |
(1) Keep containers sealed. |
| (2) Add Anti-Gel additive - consult supplier. |
| |
B. |
Use acidic additives with basic pigments. |
B. |
Reduce or change wetting agents. |
| |
C. |
Excessive storage of coating materials in warm areas. |
C. |
Discard. |
| |
D. |
Storage beyond shelf life. |
D. |
Discard. |
| |
E. |
Incompatible additives. |
E. |
Discard. |
| Ghost |
|
See Halo. |
|
|
| Halo |
A. |
Movement of screen during print. |
A. |
(1) Tighten frame in holder. |
| Also: |
(2) Replace screen due to overstretched fabric. |
| Ghost, Shadow, Blur |
|
| |
B. |
Too much off-contact. |
B. |
Reduce off-contact. |
| |
C. |
Too little off-contact. |
C. |
Increase off-contact. |
| |
D. |
Coating material too thick or too thin. |
D. |
(1) Reduce with thinner. |
| (2) Add fumed silica. |
| Heavy edges or incomplete print. |
A. |
Screen frame too small for image size. |
A. |
Use larger frames or smaller images. |
| |
B. |
Too much off-contact. |
B. |
Reduce off-contact gap. |
| |
C. |
Squeegee too short. |
C. |
Use longer squeegee (squeegee should extend 1 inch beyond image on both sides). |
| |
D. |
Variation in thickness of substrate. |
D. |
Use softer squeegee. |
| |
E. |
Improper alignment of printing head and printing table. |
E. |
Align printing head and table. |
| |
F. |
Clogged screen. |
F. |
Clean or replace screen. |
| |
G. |
Insufficient squeegee. |
G. |
Lengthen distance of squeegee travel beyond image area. |
| |
H. |
Uneven squeegee blade. |
H. |
Sharpen squeegee. |
| Hickey |
A. |
Airborne contamination, dirty substrate, foreign particles in coating, poor haousekeeping. |
A. |
Enclose screen room. Clean substrate immediately before using. Do not put used coating material back into container with fresh coating. Keep non-essential personnel out of screening area. |
| Lifting |
A. |
First layer not adequately cured. |
A. |
Increase cur time/temperature. |
| |
B. |
Solvent in second layer is too aggresive. |
B. |
Consult supplier. |
| |
C. |
Contaminated substrate. |
C. |
Clean substrate. |
| Livering |
|
See Gelling. |
|
|
| Loss of gloss |
A. |
Flocculation |
A. |
(1) Add wetting agent - consult supplier. |
| (2) Remill coating material. |
| |
B. |
Flooding and floating. |
B. |
(1) Reduce thinner. |
| (2) Add wetting agent - consult supplier. |
| |
C. |
Excessive amount of additives. |
C. |
Reduce amount of additives. |
| |
D. |
Improper atmosphere in dryer/curing oven. |
D. |
Consult supplier if gloss is important. |
| |
E. |
Excessive pigment. |
E. |
Add clear base. |
| |
F. |
Absorbtive substrate. |
F. |
Seal substrate. |
| |
G. |
Defective coating material. |
G. |
Consult supplier. |
| Meshmarks |
A. |
Insufficient leveling or flow of coating material. |
A. |
Increase film thickness. Add flow agent. |
| |
B. |
Improper thinner. |
B. |
Consult supplier. |
| |
C. |
Viscosity too high. |
C. |
Thin the coating material. |
| Moiré |
A. |
Electrostatic attraction of coating particles. |
A. |
Ground equipment. |
| |
B. |
Coating material too thin. |
B. |
(1) Reduce thinner. |
| (2) Reduce flow of coating material. |
| |
C. |
Improper screen mesh and/or angle. |
C. |
Match fabric with design. Halftones may require different angles. |
| |
D. |
Coating material too thixotropic. |
D. |
Consult supplier. |
| Orange peel |
A. |
Inadequate leveling. |
A. |
Add leveling agent and/or thinner. |
| |
B. |
Electrical charge on surface of film. |
B. |
(1) Add leveling agent - consult supplier. |
| (2) Ground equipment. |
| |
C. |
Surface tension. |
C. |
Add leveling agent and/or thinner. |
| |
D. |
Poor solvent combinations. |
D. |
(1) Consult supplier. |
| (2) Add leveling agent. |
| |
E. |
Coating material too viscous. |
E. |
Add thinner film. |
| Overcure |
A. |
Too much heat. |
A. |
Reduce temperature. |
| |
B. |
Too much exposure. |
B. |
Shorten cure time. |
| Pack-off |
|
See Blocking. |
|
|
| Peeling |
A. |
Coating film too heavy. |
A. |
Apply thinner film. |
| |
B. |
Contaminated substrate. |
B. |
Clean substrate. |
| Pinholes |
|
See Blocking, Boiling, Crater, Bubbles, Foam, Blisters, Fish eyes, Checking, Clogging, Cracking, Specks. |
|
|
| Popping |
|
See Bubbles, Craters. |
|
|
| Poor hiding power |
A. |
Insufficient pigment. |
A. |
Increase pigment content or consult supplier. |
| |
B. |
Coating too thin. |
B. |
(1) Too much thinner. |
| (2) Use coarser screen. |
| (3) Use more viscous coating material. |
| |
C. |
Flocculation. |
C. |
(1) Add wetting agent - consult supplier. |
| (2) Remill coating material. |
| |
D. |
Flooding and floating. |
D. |
Too much thinner. |
| Pull-back |
|
See Crawl. |
|
|
| Ragged lines or lettering |
A. |
Insufficient thickness of emulsion on screen. |
A. |
Ask screen supplier to apply heavier coat of emulsion. |
| Also: |
| Distorted image, Sawtooth |
| |
B. |
Plugged or clogged screen mesh. |
B. |
Clean or replace screen. |
| |
C. |
Coating material drying out in screen mesh. |
C. |
Clean or replace screen. Use slower drying coatings if available. Add retarder. |
| |
D. |
Failure of screen supplier to completely wash out image during manufacture of screen. |
D. |
Return to screen supplier. Wash out obstruction with water or Clorox® bleach. |
| |
E. |
Over-exposure of emulsion during manufacture of screen. |
E. |
Return screen to supplier. |
| |
F. |
Poor artwork. |
F. |
Obtain new corrected artwork. |
| Railroading |
A. |
Squeegee jumps from line to line on screen, causing screen to jerk and distort or smear the image. |
A. |
Angle the squeegee so it doesn't hit the lines straight on. Angle the image in the screen. Softer squeegee will reduce the severity of the problem. Use higher tensioned screen. |
| Rubs |
A. |
Handling damage. |
A. |
Provide instruction in handling the coated product. |
| |
B. |
Abrasion from conveyor. |
B. |
Make sure the equipment is free of any obstructions and all sections of the conveyor are running at the same speed. Provide separation material for substrate when stacked. |
| Running |
A. |
Coating material too thin. |
A. |
Use more viscous soating material. |
| Also: |
| Sagging, Weeping, Slumping |
| |
B. |
Coating film too thick. |
B. |
Apply thinner film. |
| |
C. |
Solvent too slow evaporating. |
C. |
Use faster evaporating solvent. |
| |
D. |
Contaminated atmosphere in dryer/curing oven. |
D. |
Improve ventilation in dryer/oven. |
| Sagging |
|
See Running. |
|
|
| Sawtooth |
|
See Ragged lines, lettering. |
|
|
| Scallop |
|
See Crawl. |
|
|
| Screen sticking to printed substrate |
A. |
Coating material too viscous or tacky. |
A. |
(1) Add thinner. |
| (2) Add extender. |
| |
B. |
Too little off-contact. |
B. |
Increase off-contact. |
| |
C. |
Coating material drying. |
C. |
Clean screen. |
| |
D. |
Insufficient screen tension. |
D. |
Use tighter screen. |
| |
E. |
Squeegee stroke too short. |
E. |
Lengthen squeegee travel beyond print area. |
| |
F. |
Squeegee. |
F. |
Sharpen squeegee, increase the durometer or increase angle of squeegee relative to screen. |
| Separation of vehicle and pigments. |
A. |
Flocculation. |
A. |
(1) Reduce wetting agent. |
| (2) Remill coating material. |
| |
B. |
Pigment particles excessively coarse. |
B. |
(1) Consult supplier. |
| (2) Continuous agitation. |
| Settling of solid materials in mixture. |
A. |
Flocculation. |
A. |
(1) Add wetting agent. Consult supplier. |
| (2) Remill coating material. |
| |
B. |
Viscosity too low. |
B. |
Use more viscous coating material. |
| |
C. |
Pigment particles excessively coarse. |
C. |
(1) Consult supplier. |
| (2) Continuous agitation. |
| (3) Add anti-setting agent - consult supplier. |
| Shadow |
|
See Halo. |
|
|
| Also: |
| Ghost |
| Shorelining |
|
See Moiré. |
|
|
| Silking |
A. |
Coating too thin. |
A. |
(1) Use more viscous coating material. |
| (2) Add thickener such as fumed silica. |
| Silting |
|
See Silking. |
|
|
| Skinning |
A. |
Absorption of oxygen. |
A. |
(1) Keep containers sealed. |
| (2) Full containers are less likely to skin. |
| (3) Add antioxidant - consult supplier. |
| (4) Add small amount of thinner to top of coating material before sealing container. |
| Slumping |
|
See Running. |
|
|
| Slur |
|
See Smear. |
|
|
| Smear |
A. |
Handling damage. |
A. |
Improve handling procedures. |
| Also: |
| Slur, Smudge, Shadow, Halo, Ghost, Blur, Rubs |
| |
B. |
Substrate sticks to screen after print stroke. |
B. |
(1) Increase off-contact. |
| (2) Add thinner. |
| |
C. |
Insufficient screen tension. |
C. |
Replace screen. |
| |
D. |
Excess squeegee pressure. |
D. |
Reduce pressure. |
| |
E. |
Movement of substrate under screen. |
E. |
Lock substrate into position either with guides or with vacuum. |
| |
F. |
Movement of screen during print. |
F. |
Tighten screen frame in holder. |
| |
G. |
Too much off-contact. |
G. |
Reduce off-contact. |
| |
H. |
Dull squeegee. |
H. |
Sharpen squeegee. |
| Smudge |
|
See Smear. |
|
|
| Soft film |
A. |
Inadequate drying/curing. |
A. |
Increase time and/or temperature for drying/curing. |
| |
B. |
Coating material deteriorating with age. |
B. |
Discard. |
| Specks in finished film |
A. |
Airborne dirt. |
A. |
Improve housekeeping skills. |
| |
B. |
Contaminated substrate. |
B. |
Clean substrate. |
| |
C. |
Contaminated substrate. |
C. |
Discard. |
| Spotting |
A. |
Water droplets from washer. |
A. |
Adjust/repair washer. Wipe substrate before coating. |
| Also: |
| Watermark |
| Static electricity |
A. |
Low humidity. |
A. |
Use humidifier. |
| |
B. |
Friction of squeegee on screen. |
B. |
(1) Ground equipment. |
| (2) Use anti-static air curtain. |
| |
C. |
Continuous flow of coating material through coating equipment. |
C. |
Ground equipment. |
| Stringing |
|
See Cobwebbing. |
|
|
| Tearing |
|
See Alligatoring, Cracking, Checking. |
|
|
| Watermark |
A. |
An accumulation of soluble salts on a glass surface. |
A. |
Inspect and repair washer. Remove any signs of water before storing or decorating glass. |
| Also: |
| Spotting |
| Weeping |
|
See Running. |
|
|
| Whiskering |
|
See Cobwebbing. |
|
|
| Wrinkle |
A. |
Coating film too thick. |
A. |
Apply thinner coat. |
| |
B. |
Overcoat to dry, undercoat still wet. |
B. |
Dry undercoat completely. |