resolves end user complaints about traditional arc lamps.
The science behind creating UV-curable materials has grown
into a billion-dollar-plus industry, enabling new applications for curing
across many markets. UV curing offers its users savings in both time and money,
as well as relief from increasingly restrictive environmental regulations. As
materials have progressed, so too must UV light-source technology. Creating UV
light with the desired properties has evolved with recent significant
improvements, demonstrating that there is a new light on the horizon. Phoseon’s
Semiconductor Light Matrix (SLM) Technology solves the following problems that
UV light source users have expressed.
- Operating Cost: Ever-increasing energy
costs have focused attention on not only electrical efficiency but also overall
- Productivity: Frequent bulb replacement
is disruptive to manufacturing, thus decreasing productivity.
- Yield: Reliability associated with a
drop in UV output over time causes yield issues.
- Heat: Excessive heat distorts
- Regulatory Compliance: Increasing
regulatory constraints have made end users more aware of what new technologies
are being integrated into their production lines.
1. Comparison of Operating Cost between Arc Lamp and SLM Technology
The savings realized from using SLM technology cover both
reduced down time and actual operating costs.
Electricity prices for industrial uses in the United States have more than
tripled over the last 20 years. Therefore, end users are paying closer
attention to electrical requirements of their production equipment. Electrical
consumption (kW/hr) is reduced up to seven times when using SLM Technology vs.
traditional arc lamps.
Traditional arc lamps operate at a very high temperature (850-950°C), requiring
air extraction and an additional burden on the factory HVAC system. When using
SLM technology, which operates at 60°C, there is no requirement for air
Traditional arc lamps create light from mercury vapor, which means that
discarded lamps cannot simply be thrown away. Therefore, there is a cost
associated with waste removal.
Labor costs associated with lamp replacement and maintenance are virtually
eliminated when using SLM Technology.
Figure 1 compares relative operating costs to SLM technology using traditional
arc lamp technology as the baseline at a factor of 1.
When the curing process stops working due to insufficient UV
output, the output is typically replenished by replacing the UV source. The UV
source replacement frequency, as well as general maintenance, will impact
productivity. The expected lifetime for arc lamps is 500-1000 hours, compared
to >10,000 hours for SLM technology. (Arc lamps will continue to generate
output, but when the output drops below the process window for a given
application the lamp must be replaced.)
Replacement of UV lamps involves the time it takes to physically change the
bulb, in addition to cooldown and warmup time. Many arc lamps also use special
reflectors to filter unwanted wavelengths of light. These reflectors must be
inspected, cleaned and replaced when necessary, which can take up to five hours
Since SLM technology has a significantly longer lifetime, downtime associated
with changing UV sources is reduced from perhaps once a month to once a year or
less. The improvement in system uptime associated with UV light source
replacement alone is reported to be from 97% with arc lamps to greater than 99%
when using SLM Technology.
2. Comparison of Lifetime between Arc Lamp and SLM Technology
SLM technology makes monitoring UV light source operating
parameters easier to ensure higher yield. Since SLM technology does not drop
over time like arc lamps, the process is more reliable, reducing down time
while increasing yield (see Figure 2).
Feedback from end users who have replaced arc lamps with SLM technology indicates
that yield improvements have gone from 95% to 99%. This is particularly true
for UV curing of pressure-sensitive adhesives, wherein too much or not enough
UV dose will require that the product be scrapped.
Many applications are sensitive to heat, e.g., printing onto
plastics or styrene. Since SLM technology operates at less than 60°C - while
lamps operate at more than a factor of 10 higher temperatures - the risk
associated with excess heat is correspondingly less.
3. Comparison of Output Intensity and Wavelength between Arc Lamp and SLM Technology
The need for restricting the use of hazardous substances and
solvents is becoming more of a deciding factor for moving to UV-cured materials
to address restrictions on solvents. However, considerations must also be made
for the UV light source itself. Traditional arc lamps use an electric discharge
from mercury vapor to produce light. At the moment, arc lamps are exempt from
the reduction of hazardous substances (RoHS) directive, but concerns related to
having such a toxic substance in the workplace remain.
Traditional arc lamps emit light over the full spectral range. When oxygen
molecules (O2) are exposed to light in the 180-220nm wavelength range, they
split into (O) atoms and recombine with oxygen molecules (O2) to form triatomic
oxygen (O3) or ozone. Ozone is a hazardous material that must be extracted.
Conversely, SLM technology produces only the targeted UV light, which does not
produce ozone (see Figure 3).
technology works to solve many of the problems resulting from the use of
traditional arc lamps, and also helps to simplify the UV curing process. SLM
technology is available to answer the call for a better UV light source.
For more information on SLM technology, contact Phoseon Technology,
7425 NW Evergreen Parkway, Hillsboro OR 97124; phone (503) 439-6446; fax (503)
439-6408; e-mail firstname.lastname@example.org; or visit www.phoseon.com.