Patent ID: 7344774

Claim:
A surface deposition of absorber dye in combination with a workpiece having a reflective surface made from a first thermoplastic polymer which softens on heating comprising: a first thermoplastic workpiece having a bulk portion and a reflective surface; a surface deposition derived from an evaporated liquid solution containing: a compatible solvent; an absorber dye possessing both strong absorption and a high extinction coefficient at a welding wavelength of a radiant energy source, and being present in a concentration of between 0.01 and 0.0001 grams/ml; and additives to adjust viscosity, surface tension and drying time, so that following evaporation said surface deposition of absorber dye in combination with said first workpiece comprises a substantially laminar welding zone with a defined edge having a generally uniform density of about 5 to about 3000 nanograms of dye per mm 2 thereby rendering said reflective surface weld-enabled, and wherein the solvent residue and said additives are mutually miscible with the reflective surface thereby avoiding photopic occlusion; so that said laminar welding zone has the capacity to convert inbound radiant energy at said welding wavelength between about 0.1 J/mm 2 and 11.4 J/mm 2 into thermal energy, wherein radiant energy is adapted to weld said reflective surface to a mating thermoplastic workpiece to form an optically fused portion having a photopic transmission that is at least 1.10 times greater than the separate workpieces.