Process for the patterned deposition of powdered thermoplastic adhesive materials on the outer surface of a surface form

Claim 1

A process for the patterned deposition of powdered thermoplastic adhesive materials on the outer surface of a substrate, the process comprising the steps of providing an engraved component having a pattern of depressions in its outer engraved face thereof, providing separate sources of supply for adhesive powders, providing said sources of supply with adhesive powders having different melting characteristics, heating the outer engraved face to be coated, causing relative movement between the outer engraved face and the sources of supply and coating a preselected area of the outer engraved face first with one of the adhesive powders to cause the powder to be deposited in the depressions, raking the preselected area of the outer engraved face with a first rake to free the outer face of the coated material except in the area of the depressions, the first rake having a setting angle extending from the outer engraved face of the engraved component which is greater than a similar angle for a second rake, then coating the preselected area of the outer face with the second of the adhesive powders having a different melting characteristic as compared to the first powder, positioning the second rake at a setting angle relative to the outer-engraved surface which is at the most, at an angle of 90 degrees, raking the preselected area of the outer face with the second rake to remove the second coat of material from the outer face except at the area of the depressions and leaving the depressions provided with separate powder layers superimposed on one another which layers have different melting characteristics, then pressing the engraved surface containing the powdered materials into contact with the substrate to cause the powder material to become adhered to the substrate, and then separating the substrate from the engraved surface to draw the powder from the depression of the engraved surface.