Pre-processed workpiece having a surface deposition of absorber dye rendering the workpiece weld-enabled
AssigneeGentex Corporation
InventorsScott Hartley, Robert Sallavanti
Life of this patent
Estimating the term…
Abstract
A weldable workpiece having a surface deposition including an absorber dye possessing strong absorption and a high extinction coefficient. The dye is deposited at a uniform density and thereby has the capacity to convert inbound radiant energy over about 0.1 J per square millimeter into thermal energy via vibronic relaxation and exothermic decomposition. In optical applications, the workpiece forms welds of high photopic and optical transmission. The improved transmission results from the solvent residues, additives, dyes and by-products being mutually miscible with the workpiece surface. A method for preprocessing the workpiece describes steps for selecting polymers, dyes and vehicles.
Claims17
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 mm2 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/mm2 and 11.4 J/mm2 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.
Dependencies are inferred from the claim text.