Method for embedding reflective beads in thermoplastic pavement marking lines

Abstract

A method and apparatus for applying or re-applying retro-reflective glass beads to in-place thermoplastic pavement marking lines. A heated container warms the beads to a temperature below their melting point but above the melting point of the line. The heated beads are then uniformly dispersed onto the surface of the line. Heat from each bead is thereby transferred into the surrounding thermoplastic material, causing the material to melt and the bead to adhere. The beads are then embedded into the thermoplastic by suitable means such as a roller. By adjusting the temperature of the beads and/or the downward force of the rollers, the depth of the embedded beads can be controlled for optimum reflectivity and adhesion, and variations in ambient operating conditions can be accommodated. The line is usable by traffic essentially immediately after bead application. The same apparatus can be used to apply beads of varying sizes. Associated mechanical support equipment and procedures are consistent with exiting techniques, making the invention amenable to small scale manual operation as well as extensive automatic highway operation.

Dependencies are inferred from the claim text.