Method for surface treating plastic products

Abstract

A method for surface treating plastic products is provided. The method includes the steps of providing a plastic substrate, the plastic substrate being made of electroplatable material; forming at least one electroconductive coating on the plastic substrate surface by electro-less plating; forming a copper layer on the electroconductive coating by electroplating; partially etching the surface of the copper layer using a laser to form a rough area; and forming a top coating on the copper layer by electroplating. Both shiny appearance and dusky appearance of the plastic substrate can be present by this method.

1 . A method for surface treating plastic products comprising:
 providing a plastic substrate, the plastic substrate being made of electroplatable material;   forming at least one electroconductive coating on a surface of the plastic substrate by electro-less plating;   forming a copper layer on the electroconductive coating by electroplating;   
       partially etching the copper layer using a laser to form a rough area; and forming a top coating on the copper layer by electroplating. 
     
     
         2 . The method for surface treating plastic products as claimed in  claim 1 , further comprising dipping the plastic substrate with the copper layer in a protecting solution before etching the copper layer. 
     
     
         3 . The method for surface treating plastic products as claimed in  claim 2 , wherein the protecting solution contains about 20 to 120 g/l potassium dichromate. 
     
     
         4 . The method for surface treating plastic products as claimed in  claim 2 , wherein the plastic substrate with the copper layer is immersed in the protecting solution for about 1 to 5 minutes. 
     
     
         5 . The method for surface treating plastic products as claimed in  claim 2 , further comprising employing an electrolysis process to treat the copper layer using the plastic substrate as a cathode, the protecting solution as the electrolyte while the plastic substrate with the copper layer is immerged in the protecting solution. 
     
     
         6 . The method for surface treating plastic products as claimed in  claim 5 , wherein the electrolysis process is carried out at a current density in an approximate range from 0.5 to 2 A/dm2. 
     
     
         7 . The method for surface treating plastic products as claimed in  claim 2 , further comprising a step of degreasing the plastic substrate after etching the copper layer. 
     
     
         8 . The method for surface treating plastic products as claimed in  claim 1 , wherein the at least one electroconductive coating includes a copper coating. 
     
     
         9 . The method for surface treating plastic products as claimed in  claim 8 , wherein the at least one electroconductive coating further includes a nickel coating formed on the copper coating. 
     
     
         10 . The method for surface treating plastic products as claimed in  claim 1 , wherein the top coating is selected from a group consisting of chrome, copper-zinc alloy, nickel, zinc, and tin. 
     
     
         11 . The method for surface treating plastic products as claimed in  claim 1 , further comprising degreasing, etching, and activating the plastic substrate surface before the electro-less plating.