Method for projecting a bubble-free coating film or curtain

Abstract

Abstract APPARATUS AND METHOD FOR CURTAIN COATING AND ALSO AN ARTICLE COATED WITH A COMPOSITION FREE OF CONTAMINATING PARTICLES AND/OR BUBBLES. THE APPARATUS INCLUDES MENAS FOR REMOVING CONTAMINANTS AND MEANS, SUCH AS A NOZZLE, FOR PROJECTING A FALLING CURTAIN OF A VISCOUS LIQUID COATING COMPOSITION AND MAY INCLUDE AS ADDITIONAL ELEMENTS A CONVEYING MEANS FOR AN ARTICLE TO BE COATED, A CATCH BASIN FOR THAT PORTION OF THE FALLING CURTAIN NOT USED FOR COATING A RESERVOIR, AND A PUMP. CONTAMINATING PARTICLES AND/OR BUBBLES ARE REMOVED FROM THE COATING COMPOSITION WHILE IT IS IN THE FORM OF A VISCOUS LIQUID BY PROPELLING THE CONTAMINATED LIQUID IN LAMINAR FLOW THROUGH AN OUTER CONDUIT IN WHICH A SMALLER CONCENTRIC INNER CONDUIT IS LOCATED HAVING AN OPEN END FACING THE FLOW OF LIQUID WHEREBY CONTAMINATING PARTICLES IN THE CONTAMINATED LIQUID MOVE AS A RESULT OF VELOCITY GRRADIENT SEPARATION TOWARD THE CENTER OF THE FLOWING LIQUID AND ARE REMOVED THROUGH THE INNER CONDUIT. PREFERABLY, THE CAPACITY OF THE INNER CONDUIT IS IN THE RANGE OF FROM 1/36 TO 9/16 THE CAPACITY OF THE OUTER CONDUIT AND EXTRENDS THROUGH THE WALL OF THE OUTER CONDUIT AT A POINT DOWNSTREAM FROM THE INNER OPEINING OF THE INNER CONDUIT, THE CAPACITY OF THE DOWNSTREAM PORTION OF THE OUTER CONDUIT TOGETHER WITH THE CAPACITY OF THE INNER CONDUIT BEING SUBSTANTIALLY EQUAL.

Inventors

• 👤 Dean B Chenoweth
• 👤 Richard L Barnard

Bibliographic Details