Thermoformable three dimensional retroreflective article and method of manufacture

摘要

A three dimensional retroreflective article having an outer surface with a reflectivity of at least about 200 lux, and method for making such an article from a thermoformable laminate is provided. The laminate includes a base layer of thermoformable plastic sheet material; and a layer of microbeads configured in a high-density arrangement and silvered on their bottom sides to enhance retroreflectivity. The microbeads are adhered to an outer surface of the base layer by a thermoformable cushion coat which may include a phosphorescent pigment to further enhance reflectivity. A protective sheet of transparent thermoformable sheet material overlies and may be in contact with the layer of microbeads. The laminate is heated and thermoformed into a self supporting three dimensional article having a pre-selected shape and an encapsulated bead retroreflective surface having a reflectivity of at least about 200 lux. The thermoforming step imparts sufficient non-planarity in the resulting retroreflective surface so that retroreflective dead spots created by contact between the microbeads and the protective sheet of transparent sheet material are effectively optically cancelled by overlapping zones of retroreflectivity generated by the microbeads.

主权项

1. A three dimensional article having a high intensity retroreflective outer surface, comprising:
a base layer of thermoformable plastic sheet material; a layer of retroreflective microbeads having a variation in diameter adhered to an outer surface of said base layer, and a protective sheet of transparent thermoformable sheet material overlying said layer of microbeads, wherein said protective sheet engages a top surface of some of the microbeads to form airspaces and create infrequent tangential point contact between at least a portion of said protective sheet and said some of the microbeads, wherein said base layer, layer of microbeads, and protective transparent sheet are formed into a self supporting three dimensional article having a pre-selected shape and an encapsulated bead retroreflective surface having a reflectivity of at least about 200 lux, wherein the protective sheet comprises glycol-modified polyethylene terephthalate (PETG); and wherein the protective sheet has a thickness of 20 mils to 30 mils.