There are two parameters that must be considered to ensure a
successful light-curing process, 1) intensity at the curing location
and 2) cure time. Dymax recommends setting up and monitoring
a UV light-curing process as follows:
1. Choose a Light-Curing Material (LCM) – Select an LCM
that satisfies the performance requirements of the
application.
2. Determine available light-cure time – Determine the cure
time available so that the UV curing process is not a
“bottleneck” in the manufacturing process. For example, if
dispensing and assembly requires 12 seconds per part in a
one piece flow process, the maximum available cure time is
12 seconds. For a UV light-curing conveyor, determine the
minimum line speed required.
3. Choose a light-curing system – Choose the appropriate
light-curing system that will fully cure the LCM within the
cure time available. Dymax Applications Engineering can
help you identify the best light-curing system for a specific
application.
4. Determine the lowest acceptable intensity – The lowest
acceptable intensity is that which fully cures the LCM in the
available cure time (determined above). The lowest
acceptable intensity can be determined through quantitative
testing of parts cured at various intensities as shown in the
diagram to the right. In the case of a focused-beam lamp
on a conveyor, determine the lowest acceptable dose
‡
, not
intensity.
The following techniques may be used to artificially modify
intensity to facilitate determining the lowest acceptable
intensity.
■ Increase distance – Since light emitting from light-
curing lamps diverges, the intensity decreases as the
distance from the lamp increases. This is especially
useful for flood lamps.
■ Adjust Intensity – Some UV light-curing systems (like
the BlueWave
®
200 with intensity adjustment feature)
allow users to adjust intensity.
As with any manufacturing process, it is advisable to operate with a safety
factor. Dymax recommends a “bulb change” intensity that is 50-100%
higher than the “lowest acceptable intensity ”.
5. Monitor and maintain intensity – Using a radiometer,
monitor the UV light intensity at the bond line. If the intensity
reaches the “bulb change” intensity, install a new bulb or
conduct appropriate maintenance (see page 19 Maximizing
Lamp Performance). In the case of a conveyor, dose (not
intensity) should be monitored.
If the resulting cure process is causing heat damage, a
cooling fan or shorter cure time is recommended. If the
resulting bulb life is too short, a longer cure time or higher
intensity lamp is recommended.
‡
Both residence time and intensity varies
with lamp height on conveyors with
focused-beam lamps. For this reason, it is better to monitor dose (J/cm
2
) on
these systems rather than intensity. The most practical way to artificially lower
the dose on these systems is to adjust the line speed.
(22 strony)
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Komentarze do niniejszej Instrukcji