| 摘要 |
Cellular retroreflective sheeting (40) comprises a first film (10) of thermoplastic material which has been formed to define arrays of minute cube-corner reflective elements (12) on one face thereof. The reflective elements are covered with a second thin thermoplastic film (36) and the two films together pass over a patterned roller where a series of sonic welding heads (50) rapidly bond the films together forming small cells (52) of retroreflective cube-corner elements (12) in the pattern of the roller. Because the heat generated in the welding process is localized to the pattern of the roller, cell walls may be formed having narrow thickness yet good bonding of the films is achieved. Further, residual heat does not appreciably transfer to adjacent retroreflective elements (12), therefore, distortion of adjacent elements is minimized and a sheeting (40) construction is achieved having superior brilliance and durability as well as maximum retroreflective capability over a wide angular range of incident light. Also disclosed is a method for forming such sheeting (40). |
