Ultraviolet laser treating of molded surfaces

Claim 2

A process for preparing the surface of a molded plastic-containing article for subsequent bonding, painting, or other surface-modifying treatment, comprising the steps of: (a) introducing the molded article, having its surface coated with a thin layer of mold-release agent, into a preparation zone maintained under controlled conditions of temperature and pressure; (b) scanning the surface of the molded article within the preparation zone with focused pulsed ultraviolet radiation having sufficient fluence and pulse length to effect substantially complete fragmentation of the mold-release agent; (c) removing the fragments of the mold-release agent from the preparation zone; and (d) passing the thus-prepared molded plastic-containing article, now substantially free of mold-release agent, directly to a selected surface-modifying treatment zone.

Claim 3

The process of claim 1 wherein the preparation zone is maintained at substantially ambient temperature and at a reduced pressure.

Claim 4

The process of claim 1 wherein the pulse length of the ultraviolet radiation is within the range from about 15 to about 55 nanoseconds.

Claim 5

The process of claim 1 wherein the fluence of the ultraviolet radiation is at least about 0.01 joule per square centimeter.

Claim 6

The process of claim 1 wherein the fluence of the ultraviolet radiation is within the range from about 0.04 to about 0.70 joule per square centimeter.

Claim 7

The prccess of claim 1 wherein the ultraviolet radiation consists of an excimer laser beam.

Claim 8

The process of claim 6 wherein the excimer laser beam is selected from the class consisting of argon fluoride, krypton fluoride, xenon chloride, and xenon fluoride laser beams.

Claim 9

The process of claim 1 wherein the molded article comprises polyurethane and the mold-release agent comprises zinc stearate or paraffin wax.

Claim 10

The process of claim 1 wherein the molded article comprises a polyester-glass fiber composite and the mold-release agent comprises zinc stearate.

Claim 11

The process of claim 9 wherein the polyester-glass fiber composite additionally comprises calcium carbonate as a filler material.

Claim 12

A process for providing improved bonding properties in the surface layer of a molded composite article, comprising at least an organic polymer component and a fiber component, comprising the steps of: (a) introducing the molded composite article, having its surface layer coated with a thin film of a mold-release agent, into a treating zone; (b) generating ultraviolet radiation, comprising an excimer laser beam, said laser beam having a fluence of at least about 0.15 joule per square centimeter; (c) directing the ultraviolet radiation upon the entire surface layer of the molded composite article in the treating zone in a scanning pattern, to effect substantially complete decomposition of the mold-release agent coating thereon together with decomposition of at least a portion of the polymer component contained in said surface layer; (d) removing the decomposition products from the treating zone; and (e) recovering the molded composite article from the treating zone, for selected bonding processing.

Claim 13

A process for providing improved bonding properties in the surface layer of a molded composite article, comprising at least an organic polymer component and a fiber component, comprising the steps of: (a) introducing the molded composite article, having its surface layer coated with a thin film of a mold-release agent, into a treating zone; (b) generating ultraviolet radiation, comprising an excimer laser beam, said laser beam having a fluence of at least about 0.15 joule per square centimeter; (c) directing the ultraviolet radiation upon the entire surface layer of the molded composite article in the treating zone in a scanning pattern, to effect substantially complete decomposition of the mold-release agent coating thereon together with decomposition of at least a portion of the polymer component contained in said surface layer; (d) removing the decomposition products from the treating zone; and (e) recovering the molded composite article from the treating zone, for selected bonding processing.

Claim 14

The process of claim 11 wherein the mold-release agent is zinc stearate.

Claim 15

The process of claim 11 wherein the organic polymer component is a polyester material.

Claim 16

The process of claim 11 wherein the fiber component comprises glass or graphite.

Claim 17

The process of claim 11 wherein the organic polymer component is polyethylene terephthalate and the fiber component is glass fiber.

Claim 18

The process of claim 11 wherein the excimer laser is a krypton fluoride laser having a wavelength of 248 nanometers.

Claim 19

The process of claim 11 wherein the excimer laser is a xenon chloride laser having a wavelength of 308 nanometers.

Claim 20

The process of claim 11 wherein the excimer laser is a xenon fluoride laser having a wavelength of 351 nanometers.

Claim 21

The process of claim 11 wherein the excimer laser beam has a pulse length within the range from about 15 to about 55 nanoseconds.