Abstract: A stream of molten material free falls through a drop tube and impinges on a chill surface adjacent the bottom of the drop tube to form rapidly solidified particulate. The chill surface is so inclined and moved relative to the stream of molten material as to have an upward component of motion counter to the downward direction of fall of the stream to significantly enhance shearing and rapid quenching of molten material striking the chill surface. The resulting solidified particulate is discharged from the chill surface for collection in a particulate collection chamber beneath the chill surface. Production quantities of rapidly solidified particulate can be continuously made.

Abstract: Polyamide substrates are pre-conditioned for electroless plating by contact with an aqueous alkaline solution having a pH of at least about 10 and etched with an aqueous acid etch solution of an organic acid containing at least two carbon atoms, in combination with from 1 to 10 percent by weight of an inorganic acid which is nondeleteriously reactive with the organic acid. Trichloroacetic acid is the preferred organic acid and sulfuric, hydrochloric and/or nitric the preferred inorganic acids. Contact with the aqueous alkaline solution can be eliminated where the polyamide is caprolactam.

Abstract: Filled polyester substrates are conditioned for electroless plating by contact with an alkaline conditioner having a pH of at least 8, followed by contact with an aqueous acid fluoride etch solution having a pH less than about 5 and a fluoride concentration of at least 1 mole per liter of solution.

Abstract: Filled polycarbonate resin substrates are conditioned for electroless plating by contact with an alkaline conditioner having a pH of at least 8, followed by contact with an aqueous acid fluoride etch solution having a pH less than about 5 and a fluoride concentration of at least 1 mole per liter of solution.

Abstract: Polyamide substrates are pre-conditioned for electroless plating by contact with an alkaline aqueous solution having a pH of at least about 10 and etched with an aqueous acid etch solution. The aqueous acid etch solution is preferably an aqueous solution of an organic acid containing at least two carbon atoms, particularly an acetic acid compound, such as trichloroacetic acid.

Abstract: Caprolactam polymeric substrates are conditioned for electroless plating by etching with an aqueous solution of organic acid containing from 2 to 4 carbon atoms, preferably an acetic acid compound, such as trichloroacetic acid.