Glass Beads
Reflective glass beads for road markings can improve the reflective performance of all road marking paint. The properties of the glass beads will reflect the car lights back to the driver and improve the safety of traffic while driving at night. This allows for painted lines, caution images and warning striping to become noticeable when lighting shines upon it. With street lighting it will help pedestrians and cyclist who may need additional help in detecting street markings.
Road reflective glass beads are fine glass sphere formed by melting glass sand (waste glass) at high temperatures. Glass beads for road marking are spherical under the microscope, colorless, and transparent.
REFRACTIVE INDEX
The beads have a minimum refractive index of 1.5 when tested by the oil immersion method.
SPECIFIC GRAVITY
Beads shall have a specific gravity between 2.40 and 2.60 at 25 deg. C per ASTM D-153, Method A.
MOISTURE CONTENT
Does not exceed 0.01%
CHEMICAL STABILITY
Refluxing of a 50g sample of beads in a Soxhlet extraction apparatus for 8 hours with distilled watershall not produce more than a very slight reduction in luster or reflecting power of the beads.
FLOW
Beads shall be free flowing. A 23kg sample of beads, when emptied into a service box screen havingsieve openings of 1.18mm (U.S. Standard Sieve #16) shall pass completely through the screen withoutshaking or any excessive hand manipulation.
