Arch drywall trim product

Abstract

A notched drywall trim piece that can take the form of a bead, hinged trim piece or bullnose piece that generally is constructed from a semi-rigid core that forms two flanges. At least one of the flanges is notched allowing the piece to follow the shape of an arch or arbitrarily curved corner. The product can generally be installed without any mechanical fasteners since the inner or wall-facing surface of the product is prepared or treated to bond directly with drywall mud or other mastic. In this manner, the piece can be installed using only wet mud or other mastic. The installation process can be aided by the used of a corner roller common in the industry to help set and align the material with the corner being trimmed. The outer or room-facing surface can optionally be treated or prepared to bond with the mud or can be prepared to directly receive paint or texture. The preparation of the flange surface can take the form of a paper or other fibrous layer, scoring, frocking (bonding a powered fibrous material), roughing, protrusions, or a water-activated adhesive or pressure sensitive (or any other) adhesive may be used.

1 . An arch drywall corner trim product comprising:
 an elongated rigid or semi-rigid core with a centerline and two flanges, the flanges having wall-facing surfaces and room-facing surfaces, at least one of said flanges containing a plurality of notches, whereby said product can bend along the centerline to match a corner curvature; and   wherein the wall-facing surface of at least one flange is prepared to bond with drywall mastic such that no mechanical attachments are necessary.   
   
   
       2 . The arch drywall corner trim product of  claim 1  wherein in the wall-facing surface of said flange is prepared by being bonded to a layer of fibrous material. 
   
   
       3 . The arch drywall corner trim product of  claim 1  wherein the wall-facing surface of said flange is prepared by roughening. 
   
   
       4 . The arch drywall corner trim product of  claim 1  wherein the wall-facing surface of said flange is prepared by scoring or protrusions. 
   
   
       5 . The arch drywall corner trim product of  claim 1  wherein the wall-facing surface of said flange is prepared by coating with a mastic compound. 
   
   
       6 . The arch drywall corner trim product of  claim 5  wherein said mastic compound is an adhesive. 
   
   
       7 . The arch drywall corner trim product of  claim 6  wherein said adhesive is water-activated or pressure sensitive. 
   
   
       8 . The arch drywall corner trim product of  claim 1  wherein the wall-facing surface of said flange is prepared by frocking. 
   
   
       9 . The arch drywall corner trim product of  claim 1  wherein both of said flanges are notched. 
   
   
       10 . The arch drywall corner trim product of  claim 1  further comprising a bead along said centerline. 
   
   
       11 . The arch drywall corner trim product of  claim 1  further comprising a flexible hinge along said centerline. 
   
   
       12 . The arch drywall corner trim product of  claim 1  further comprising a bullnose crown along said centerline. 
   
   
       13 . A method for making an arch drywall trim product that needs no mechanical attachments comprising the steps of:
 extruding a rigid or semi-rigid core with a centerline and two flanges, each of said flanges having a length and a wall-facing surface and a room-facing surface;   notching at least one of said flanges at a plurality of positions along the length of the flange;   preparing the wall-facing surface of at least one of said flanges to bond with drywall mastic.   
   
   
       14 . The method of  claim 13  wherein said wall-facing surface is prepared by extruding a layer of fibrous material on said wall-facing surface as said core is extruded. 
   
   
       15 . The method of  claim 13  wherein said wall-facing surface is prepared by scoring, frocking, roughing or by containing protrusions. 
   
   
       16 . The method of  claim 13  wherein said wall-facing surface is prepared by applying adhesive. 
   
   
       17 . The method of  claim 13  further comprising along said centerline a structure chosen from the group consisting of a bead, a flexible hinge and a bullnose crown. 
   
   
       18 . An apparatus for finishing an arched corner comprising:
 a rigid or semi-rigid core with two flanges;   a wall-facing surface of at least one of said flanges prepared to bond with drywall mastic.   
   
   
       19 . The apparatus of  claim 18  wherein said wall-facing surface is prepared by scoring, frocking, roughing or by containing protrusions. 
   
   
       20 . The apparatus of  claim 18  wherein said wall-facing surface is prepared by being bonded to a layer of fibrous material. 
   
   
       21 . The apparatus of  claim 18  wherein said semi-rigid core has a centerline with a structure running along said centerline chosen from the group containing a bead, a flexible hinge and a bullnose crown.