Section 4184.� Reflectorizing Spheres for Traffic Paint
A.��� This specification covers two types of glass spheres, dual coated and uncoated, for the production of reflectorized pavement markings.
� Waterborne and VOC compliant solvent borne traffic paint: use dual coated beads (silicone and silane).
� Epoxy pavement markings: use silicone only coated beads (no silane).
B.�� The glass beads shall not exhibit a characteristic of toxicity, relative to heavy metals. Glass beads shall not contain more than 200 ppm total of lead, antimony, or arsenic. Manufacturer shall provide a certificate of analysis stating total lead, antimony, and arsenic content for each batch of glass beads supplied. Use transparent, clear, colorless glass spheres that are:
� Free from milkiness, dark particles, and excessive air inclusions.
� Essentially clear from surface scarring or scratching.
� Free of hard lumps and clusters
� Readily dispensed under any conditions suitable for paint striping.
4184.02���� SPECIFIC REQUIREMENTS.
Meet the gradation requirements of Table 4184.02-1.
|
Table 4184.02-1: Gradation Requirements (Glass Spheres) |
|
|
Sieve Size |
Percent Passing |
|
16 (1180 �m) |
100 |
|
20 (850 �m) |
90-100 |
|
30 (600 �m) |
50-75 |
|
40 (425 �m) |
15-45 |
|
50 (300 �m) |
0-15 |
Minimum of 80% true spheres.
Minimum refractive index of 1.50.
D.��� Properties of Dual Coated Spheres.
1.���� Coated with a dual coating that has both a moisture resistant silicone coating and an adhesion promoting silane coating.
2.���� Passes the moisture resistance test and the adherence coating test.
E.��� Properties of Silicone Coated Spheres.
1.���� Coated only with a silicone coating (no silane).
2.���� Passes the moisture resistance test and test negative for the adherence coating test.
Test the specific requirements according to Office of Materials Test Method No. Iowa 814.