A comparative analysis on properties of retroreflective materials for road traffic warning clothing
In this study, the properties of retroreflective material samples are comparatively examined for the development of an ISO-compliant warning clothing with an enhanced visibility of motion and comfort for road traffic workers in Korea. The samples consisted of a plain and beads type material manufactured by 3M (US)(S1), a rectangular-patterned (S2) and plain sample (S3) that are both prism-type and manufactured by a Korean ‘R’ company, and another plain and beads type sample (S4) that was also made in Korea but without a specified manufacturer. ISO 150-J01 (1997) and ISO 20471 (2013) methods were used to measure the chromaticity/luminance and retroreflective properties respectively. The general retroreflective property and under 5 conditions: after abrasion (1), bending (2), bending at low temperature (3), temperature change (4), and washing 5 times (5) retroreflective properties were measured at 12′(~0.2°) observation angle and 5° incidence. 12′ and 20′ represent the angle of reflected headlight observed by the driver of a standard vehicle (sedan), whereas 1° 30’ represent the angle of reflection affecting the driver in a larger vehicle(truck). ε = 0° and 90° represent frontal and lateral reflection. As a result, chromaticity/luminance ranked in the order of R4 > R2 ≥ R1 > R3. The measured retroreflective factors (cd/lx・m2) of all four samples exhibited levels that surpass the ISO 20471 standard, suggesting all samples’ suitability for the development of ISO-compliant warning clothing.