INTRODUCTION
"NIKKALITE"
Retroreflective Sheet is a product of Nippon Carbide Industries Co., Inc. used
in traffic signs and is expected to sustain hard weather both in cold district
experiencing subzero temperatures and hot district like a buring desert. It should
not fade a certain lengthy time and it should secure vivid visibility both in day
time and night time.
STRUCTURE OF RETROREFLECTIVE SHEET
Retroreflection is an optical mechanism that the incident light is reflected always
to a direction of the light source. Reflective sheet is made to increase the visibility
from a direction of the light source by an effect of retroreflection unlike luminous
paint which initiates the light by itself nor fluorescent substance which emits
fluorescent light by excitation. High reflective small glass beads of 40-90 micron dia.
are distributed evenly inside the resin composit to make a thin and flexible film with
the overall thickness of 100-300 micron. Each glass bead is a perfect sphere which acts
as a convex lens and the incident light is refracted through the glass and focused into
a point. There is a reflective layer at the bottom of the sphere and, thus, the incident
light is reflexted direct to the light source. This mechanism makes the reflective film
quite visible as if itself were a light source.
IMAGE DRAWINGS OF RETROREFLECTIVE SHEET
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TYPES OF RETROREFLECTIVE FILM
● MG (ECONOMY GRADE)
WEATHER DURABILITY: 3 YEARS
● CG (COMMERCIAL GRADE)
WEATHER DURABILITY: 5 YEARS (RED/YELLOW 3 YEARS)
● EG (ENGINEERING GRADE)
WEATHER DURABILITY: 7 YEARS (RED/YEELOW 3 YEARS)
● SEG (SUPER ENGINEERING GRADE)
WEATHER DURABILITY: 10 YEARS (RED/YELLOW 3 YEARS)