Method and apparatus for on-demand stencil chemical etch direct parts marking automation and carrier for chemical etch stencil mesh

Abstract

A unit for on-demand chemical etch. Stencil media is unwound from a stencil unwind hub and passed underneath the thermal print head and printed. The stencil media is a sandwich that is comprised of a porous material married to a pressure-sensitive adhesive coated carrier to supply stiffness and support to the mesh. After the stencil is printed, the carrier is peeled away and is rewound onto a carrier rewind hub, leaving only the printed stencil. This printed stencil is transported underneath the etching electrode, at which time, the electrode actuates downward, sandwiching the printed stencil between the electrode and the target object so that the chemical etching process may be performed. The spent stencil rewinds onto a stencil rewind hub. The stencil printing and etch functions can be provided in a handheld unit. The handheld unit is comprised of an actuating etching head, a print head, a ribbon support system and media support system.

1 . An apparatus for on-demand chemical etch comprising: 
 a stencil web;    a media support system; and    an etching head mechanism    wherein said stencil web transported under said etching head mechanism by said media support system.    
     
     
         2 . The apparatus of  claim 1  wherein said media support system comprises a stencil unwind hub and a stencil rewind hub.  
     
     
         3 . The apparatus of  claim 1  further comprising: 
 a printing mechanism, said printing mechanism comprising a print head, a thermal transfer ribbon and a ribbon support system; and  
 a spent carrier rewind;  
 wherein said printing mechanism is located before the etching head mechanism.  
 
     
     
         4 . The apparatus of  claim 1  wherein said etching head mechanism extends and sandwiches said stencil web between said etching head mechanism and a target object.  
     
     
         5 . The apparatus of  claim 4  further comprising a grounding electrode on said etching head mechanism.  
     
     
         6 . The apparatus of  claim 4  wherein said target object is on a conveyor and said conveyor is adapted to be actuated upwards to push the target object against the etching head.  
     
     
         7 . The apparatus of  claim 1  wherein said stencil web is preprinted.  
     
     
         8 . The apparatus of  claim 1  further comprising a part surface wiper.  
     
     
         9 . The apparatus of  claim 1  further comprising a handheld unit wherein said stencil web, media support system and said etching head mechanism are adapted to be housed in said handheld unit.  
     
     
         10 . The apparatus of  claim 2  further comprising a handheld unit wherein said stencil web, media support system and said etching head mechanism are adapted to be housed in said handheld unit.  
     
     
         11 . The apparatus of  claim 3  further comprising a handheld unit wherein said stencil web, media support system and said etching head mechanism are adapted to be housed in said handheld unit.  
     
     
         12 . The apparatus of  claim 4  further comprising a handheld unit wherein said stencil web, media support system and said etching head mechanism are adapted to be housed in said handheld unit.  
     
     
         13 . The apparatus of  claim 12  further comprising a grounding electrode on said etching head mechanism.  
     
     
         14 . The apparatus of  claim 9  wherein said media support system comprises a cartridge and the stencil web is loaded in the cartridge as a stack of preprinted stencils.  
     
     
         15 . The apparatus of  claim 14  wherein the media support system further comprises a collection bin adapted to hold used stencils.  
     
     
         16 . The apparatus of  claim 9  wherein the etching head is spherical and comprises with a plurality of stencils.  
     
     
         17 . The apparatus of  claim 10  wherein the etching head is replaceable.  
     
     
         18 . A method for on-demand chemical etch comprising the steps of: 
 obtaining a stencil web; said stencil web on a media support system comprising a media unwind hub and a stencil rewind hub;    transporting said stencil web under a print head;    printing in reverse on said stencil web to create a stencil;    peeling away a carrier from said stencil;    transporting said stencil under an etching head;    sandwiching said stencil between said etching head and an object;    applying a wetting solution;    actuating an electrode;    rewinding a spent stencil on the stencil rewind hub.