Problem:
MEDIA NOT BEING CURED EFFECTIVELY
POSSIBLE CAUSES:
Dryer reflectors are dirty or not focused correctly
External contamination of lamp
Photoinitiator material not equally distributed as coating and ink material not correctly mixed
Lamp has overrun hours of effective usage
REMEDIES:
Clean or re-focus reflectors
Clean lamp of external contamination, such as spray powder or other contaminants
Confirm that all coating and ink material has been stirred to homogeneity before application so that all of the photoinitiator material is equally distributed
Verify the number of operating hours that the lamp has run. Different applications result in different lamp lifetimes. Lamps generally have an energy output of about 80% of their original specification after 1000 hours, provided that the lamp is operated in an appropriate environment. If the lamp has over 1000 hours of use, it may not generate enough ultraviolet energy for curing your application
Problem:
LAMP IS BOWED OR LOOKS LIKE A BANANA
POSSIBLE CAUSES:
Lamp has been overheated
REMEDIES:
The lamp must be in a cooled and controlled environment where the surface temperature of the lamp body should be at a temperature of between 600 - 800 degrees C. If the air around the lamp is not conditioned properly, this temperature will rise causing the quartz tube to soften and lose its rigidity. Adjust the cooling and airflow around the lamp to reduce the temperature of the lamp body and check condition of reflectors. However, ensure that the lamp body is not cooled below 600 degrees C, as below this temperature could lead to mercury condensing out of the plasma, which will effect lamp power and performance.
Problem:
LAMP IGNITES BUT WILL NOT ACHIEVE FULL INTENSITY
POSSIBLE CAUSES:
Too much cooling – mercury condensed behind electrodes
REMEDIES:
Check cooling system
Problem:
NEW LAMP WILL NOT IGNITE
POSSIBLE CAUSES:
Terminations loose
Power supply fault
Lamp fault
REMEDIES:
Confirm all terminations are tight
Seek advice from equipment supplier
Replace lamp
Problem:
LAMP IS DISCOLOURED
Black ends
Clouding
Mirror coated
POSSIBLE CAUSES:
There is natural “blackening” of the quartz tube at each end during the life of the lamp. This is the result of the electrode material depositing on the inside of the tube during its use.
Natural solarisation or clouding of quartz occurs as the quartz reverts to its natural crystalline structure, which is opaque to ultraviolet energy
Overcooling results in mercury being deposited on the inside of the lamp giving it a mirror-coated affect
REMEDIES:
Replace lamp
Problem:
EXTERNAL DEVITRIFICATION
“Cloudy” quartz surface
POSSIBLE CAUSES:
Ink, cleaning solution or finger mark has burnt in on a hot lamp, the arc is diverted to the polluted spot and burns a hole in the tube causing loss of vacuum.
REMEDIES:
More caution with lamp changing and/or cleaning
Problem:
LAMP IS TRIPPING-OUT (ARCING AGAINST THE REFLECTOR OR MACHINE)
POSSIBLE CAUSES:
As UV lamps usually operate at high voltages it is possible that if the tube is in close proximity to the lamp head arcing can occur. This mode of failure is also sometimes characterized by the presence of a pinhole in the tube.
REMEDIES:
Check that the lamp is correctly located and that the reflectors are not distorted.
Problem:
ORANGE DISCOLORATION INSIDE THE TUBE
POSSIBLE CAUSES:
Lamp has mechanical break (leak) whilst burning
REMEDIES:
Replace lamp