Akademik Veri Yönetim Sistemi
3. INTERNATIONAL DİCLE SCIENTIFIC RESEARCH AND INNOVATION CONGRESS, Diyarbakır, Türkiye, 26 - 27 Kasım 2022, ss.1672-1682
The lighting industry
generally uses metal or polymer-based reflectors to improve the performance of
light sources. Microcellular polymer foams are developed with an optimized
internal structure that can be more efficient than currently used reflectors to
enhance performance and save energy. Microcellular reflectors have been
utilized in many light applications such as billboards, LED display
backgrounds, LED lamps, flashlights, fluorescent lamps, etc. In this study, we
used polyethylene terephthalate (PET) based diffusive reflectors obtained from
the batch process production method of microcellular foams. Carbon dioxide (CO2)
was used as a foaming agent because it has easy-to-achieve supercritical state
values and high diffusive properties. PET was placed inside an autoclave with high-pressure
CO2 gas to achieve the desired diffusion. Afterward, PET sheets are
taken out of the autoclave and placed into a specially designed glycerin bath
used for homogeneous foaming, heating the PET sheets to above-glass transition
temperatures. As a result of this study, reflectors with cell sizes smaller
than 5 µm were manufactured, and light reflectance tests were conducted. The
reflected light was investigated with spectrophotometer analysis and lumen
meters. The spectrophotometer analysis showed a 97% reflectance value in the
visible wavelength range. Lumen meter analysis showed that approximately 20%
more light intensity was achieved from foamed plates than aluminum. Finally,
the reflectors were thermoformed using a flashlight die, and 52% more light
intensity was achieved than a standard aluminum reflector.