Paperbead for protecting drywall corners

Abstract

The present invention relates to drywall paperbeads, particularly drywall paperbeads for use in protecting exposed drywall surfaces having non-planar surface contours in an edge region adjacent the drywall edges. The paperbead includes an elongated core having an inner surface and an outer surface, an elongated paper strip having an inner surface and an outer surface, a thickness of between 6 and 7 mils, a weight of between 110 and 125 grams/square meter (gsm) and a porosity of 30 to 130 Gurley sec. The inner surface of the paper strip is roughened and bonded to the outer surface of the core. The outer portion of the thickness of the paper strip is impregnated with a strengthening compound, preferably a polymer strengthening compound, more preferably a latex strengthening compound in an amount of between 3.5% and 13% of the total weight of the paper strip. The width of the paper strip is greater than the width of the core such that at least one edge of the paper strip extends laterally beyond the edge of the core to form a wing on at least one edge of the paperbead. The wing of the paper strip of the paperbead follows the non-planar surface contour of the drywall in the edge region adjacent the drywall edge.

Claims

1. An improved paperbead for use in protecting exposed drywall surface having a non-planar surface contour in an edge region adjacent drywall edges of the drywall surface, the paperbead comprising an elongated core having an inner and an outer surface, an elongated paper strip having an inner surface and an outer surface, a thickness of between 6 and 7 mils, a weight of between 110 and 125 grams/square meter (gsm) and a porosity of 30 to 130 Gurley sec., the inner surface of the paper strip being roughened and being bonded to the outer surface of the core, the paper strip being of a width greater than the width of the core such that at least one edge of the paper strip extends laterally beyond the edge of the core to form a wing on at least one edge of the paperbead, the outer portion of the thickness of the paper strip being impregnated with a strengthening compound in an amount of between 3.5% and 13% of the total weight of the paper strip.

2. The improved paperbead for use as claimed in claim 1, wherein the strengthening compound penetrates only up to about half the thickness of the paper strip.

3. The improved paperbead for use as claimed in claim 2 wherein the strengthening compound is a latex strengthening compound.

4. The Improved paperbead for use as claimed in claim 3 wherein, the latex strengthening compound is cross-linked.

5. The improved paperbead for use as claimed in claim 4 wherein the inner surface of the paper strip is roughened by mechanical means.

6. The improved paperbead for use as claimed in claim 5 wherein of the outer surface the paper strip in a border region of the wing is lightly roughened or buffed.

7. The improved paperbead for use as claimed in claim 6 wherein the border region extends about 0.5 to about 1 inch from the edge of the paper strip.

8. The improved paperbead for use as claimed in claim 7, wherein the border region extends about 0.625 inch from the edge of the paper strip.

9. The improved paperbead for use as claimed in claim 7 wherein the paper strip is about 6.5 mils in thickness, having a weight of about 117 grams/square meter (gsm) and a porosity of about 80 Gurley sec. the outer portion of the thickness of the paper strip being impregnated with about 8.3% of the total weight of the paper strip of a polymer strengthening compound.

10. The improved paperbead for use as claimed in claim 9 wherein the core has a pair of flanges, the paper strip extending beyond the flanges to form a pair of wings to provide a border region, the border region being roughened.

11. The improved paperbead for use as claimed in claim 9 wherein the core is selected from the group consisting of: a) a center rib and two shoulders interposed between said flanges, said shoulders connecting said center rib and said flanges; b) a bullnose and a pair of shoulders interposed between said flanges, said shoulders connecting said bullnose to said flanges; c) a shoulder and an offset rib, said flanges comprising a long flange and a short flange, said short flange having an inner surface, said shoulder connecting said long flange and said offset rib, said wing extending beyond said short flange bonded to said inner surface of said short flange; d) a center portion, an offset rib, a first flange and a second flange, said center portion positioned between said offset rib and said second flange, said second flange extending from said center portion, said first flange extending from said offset rib in a direction opposite said second flange; e) a center portion, a short flange and a long flange, said center portion positioned between said long flange and said short flange to form a J-shape; and f) one of two strips, said strips positioned so as to form a space between them and two strips being joined by a living hinge.

12. The improved paperbead for use as claimed in claim 11 wherein a formulated synthetic emulsion adhesive bonds the paper strip to the core.

13. The use of an improved paperbead for protecting exposed drywall surface having a non-planar surface contour in an edge region adjacent drywall edges of the drywall surface, the improved paperbead comprising an elongated core having an inner and an outer surface, an elongated paper strip having on inner surface and an outer surface, a thickness of between 6 and 7 mils, a weight of between 110 and 125 grams/square meter (gsm) and a porosity of 30 to 130 Gurley sec., the inner surface of the paper strip being roughened and being bonded to the outer surface of the core, the paper strip being of a width greater than the width of the core such that at least one edge of the paper strip extends laterally beyond an edge of the core to form a wing on at least one edge of the paperbead, an outer portion of the thickness of the paper strip being impregnated with a strengthening compound in an amount of between 3.5% and 13% of the total weight of the paper strip.

14. The use of the improved paperbead as claimed in claim 13, wherein the strengthening compound penetrates only up to about half the thickness of the paper strip.

15. The use of the improved paperbead as claimed in claim 14 wherein the strengthening compound is a latex strengthening compound.

16. The use of the improved paperbead as claimed in claim 15 wherein, the latex strengthening compound is cross-linked.

17. The use of the improved paperbead as claimed in claim 16 wherein the inner surface of the paper strip is roughened by mechanical means.

18. The use of the improved paperbead as claimed in claim 17 wherein the outer surface the paper strip in a border region of the wing is lightly roughened or buffed.

19. The use of the improved paperbead as claimed in claim 18 wherein the border region extends about 0.5 to about 1 inch from the edge of the paper strip.

20. The use of the improved paperbead as claimed in claim 19, wherein the border region extends about 0.625 inch from the edge of the paper strip.

21. The use of the improved paperbead as claimed in claim 19 wherein the paper strip is about 6.5 mils in thickness, having a weight of about 117 grams/square meter (gsm) and a porosity of about 80 Gurley sec., an outer portion of the thickness of the paper strip being Impregnated with about 8.3% of the total weight of the paper strip of a polymer strengthening compound.

22. The use of the improved paperbead as claimed in claim 21 wherein the core has a pair of flanges, the paper strip extending beyond the flanges to form a pair of wings to provide a border region, the border region being roughened.

23. The use of the improved paperbead as claimed in claim 21 wherein the core is selected from the group consisting of: a) a center rib and two shoulders interposed between said flanges, said shoulders connecting said center rib and said flanges; b) a bullnose and a pair of shoulders interposed between said flanges, said shoulders connecting said bullnose to said flanges; c) a shoulder and an offset rib, said flanges comprising a long flange and a short flange, said short flange having an inner surface, said shoulder connecting said long flange and said offset rib, said wing extending beyond said short flange bonded to said inner surface of said short flange; d) a center portion, an offset rib, a first flange and a second flange, said center portion positioned between said offset rib and said second flange, said second flange extending from said center portion, said first flange extending from said offset rib in a direction opposite said second flange; e) a center portion, a short flange and a long flange, said center portion positioned between said long flange and said short flange to form a J-shape; f) one of two strips, said strips positioned so as to form a space between them and g) two strips, said strips being joined by a living hinge.

24. The use of the improved paperbead as claimed in claim 23 wherein a formulated synthetic emulsion adhesive bonds the paper strip to the core.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) Preferred embodiments of the present invention are illustrated in the attached drawings in which:

(2) FIG. 1 is a perspective view of an exterior drywall corner with a preferred embodiment of the paperbead for use in the present invention applied thereto and with portions broken away and in section.

(3) FIG. 2 is a preferred embodiment of the invention showing a horizontal cross section through an exterior corner of FIG. 1.

(4) FIG. 3 is a preferred embodiment of the invention showing a vertical cross section through an exterior corner along the line 3-3 of FIG. 1.

(5) FIG. 4 is a preferred embodiment of the invention showing a cross section through an exterior corner with a Bullnose shape of paperbead applied thereto.

(6) FIG. 5 is a preferred embodiment of the invention showing a cross section through a corner with a L-shape paperbead applied thereto.

(7) FIG. 6 is a preferred embodiment of the invention showing a cross section through an interior corner with a bullnose shape of corner bead applied thereto.

(8) FIG. 7 is a perspective of a preferred embodiment of the invention showing a J-shape type of paperbead.

(9) FIG. 8 is a perspective of a preferred embodiment of the invention showing a splays-bead shape of paperbead.

(10) FIG. 9 is a perspective of a preferred embodiment of the invention showing a shadow-mold shape of paperbead.

(11) FIG. 10 is cut away view of the paper strip utilized in the paperbead of the present invention.

(12) FIG. 11 is a plan view of the latex impregnated side of the paperbead of the invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

(13) The present invention is directed to the use of an improved paperbead for protecting exposed drywall surfaces having a non-planar contour in an edge region adjacent the drywall edges. The improved paperbead is able to follow the non-planar contours of the drywall surface in the edge region to result in an improved installed fit and finish. The paperbead includes an elongated core having an inner surface and an outer surface. The paperbead also includes an elongated paper strip having an inner surface and an outer surface, a thickness of between 6 and 7 mils, having a weight of between 110 and 125 grams/square meter (gsm) and a porosity of 30 to 130 Gurley sec. The inner surface of the paper strip is bonded to the outer surface of the core. The inner surface of the paper strip is also roughened to improve adhesiveness to joint compounds. The paper strip has a width greater than the width of the core such that at least one edge of the paper strip extends laterally beyond an edge of the core to form at least one wing along the edge of the paperbead. The outer portion of the thickness of the paper strip is impregnated with between 3.5% and 13% of the total weight of the paper strip of a strengthening agent, preferably a polymer strengthening agent, more preferably a latex strengthening agent. Preferably a border region of the outer surface of the paper strip along the wing of the paper strip is also roughened. The combination of paper strip properties as described herein results in a paperbead which maintains sufficient strength to keep the paper strip resistant to scuffing, while at the same time, achieving good bonding to joint compounds and allowing the paper strip to follow non-planar contours of the surface of the drywall adjacent the edges. The particular advantages of the use of this paperbead will be set out hereinbelow. Preferred embodiments of the paperbead according to the present invention will now be described.

(14) Referring now to the drawings in detail, preferred embodiments of the paperbead of the present invention are illustrated. In particular, referring to FIGS. 1, 2 and 3, a rib-shape embodiment of the paperbead for use in the invention is illustrated generally indicated by the number 10. A paperbead 10 is shown covering an exposed drywall corner 12 formed by two sheets of drywall 14. The Sheets of drywall 14 are attached to underlying framing member 16 by the use of suitable fasteners such as screws 18. While the embodiments illustrated, in the drawing show metal studs as the framing member 16, it will be appreciated by those skilled in the art that other types of framing members including channels or members constructed of other materials including wood may take the place of the metal stud. Typically, screws 18 are driven through the drywall 14 and into the framing member 16 so that the head 18a is below the surface of the drywall 14 to form a depression 21. In some instances, the screws 18 may be installed too deep to result in a deeper depression 21 or may be installed at an angle. During installation of the drywall 14, there may also be other defects which may result in the drywall surface having a non-planar contour in the edge region 14a. These defects can include knife cuts 20 or other deformations 22.

(15) The paperbead 10 has an elongated core 24 and an elongated paper strip 26 bonded to the core as shown in FIGS. 1 and 2. The core 24 is preferably made out of metal, such as galvanized steel which meets or exceeds ASTM-C1047 zinc coating specifications. However, other metals or materials such as plastic can function as the core element. In an exemplary embodiment, the core 24 is made of galvanized steel having a thickness of about 0.009 to 0.0150 inches, more preferably 0.0120 to 0.0150 inches. In the rib-shape embodiment of the paperbead, the core 24 is formed into a rib shape having flanges 24a, a center rib 24c and a pair of shoulders 24b connecting the center rib 24c and the flanges 24a. The core 24 also has an outer surface 24d and an inner surface 24e. The flanges 24a are commonly positioned at an angle of no greater than about 89 degrees relative to each other, but other angular variations may be utilized to accommodate the relative positioning of the drywall sheets 14 and/or the desired shape of the corner. In the rib-shape embodiment shown in FIGS. 1, 2 and 3, the flanges 24a are about 1 inch wide. The center rib 24c is generally about 0.0625 inches high and 0.125 inches wide.

(16) The paperbead can be used to protect exterior corners, as shown in the embodiments of FIGS. 1 to 5, or to protect interior corners as shown in the FIG. 6 embodiment. For example, FIGS. 4 and 6 illustrate the use of a bullnose shape embodiment paperbead for protecting, respectively, an exterior and interior corner.

(17) A bullnose paperbead 28 has a core 30 having a pair of flanges 30a, a bullnose 30c, a pair of shoulders 30b, an outer surface 30d and an inner surface 30e. The outer surface 30d is defined as that surface facing away from the corner 12, independent of whether that outer surface forms a concave or a convex surface as shown in FIGS. 4 and 6. The flanges 30d are generally about 1 inch wide and are positioned, in this embodiment, at an angle of about ninety degrees relative to one another. Other angular variations can be implemented. The radius of the bullnose 30c is typically in the range of about 0.5 inches to 1.5 inches. In the preferred embodiment shown, each of the shoulders 30b is about 0.125 inches wide and has a drop of 0.0625 from the surface of the bullnose 30c to the surface of the flange 30a.

(18) A third embodiment of the paperbead for use in the present invention is the shaped paperbead 32 shown in FIG. 5. In this embodiment, the core 34 has a long flange 34a, a short flange 34b, an offset rib 34c, a shoulder 34d positioned between the offset rib 34c and the long flange 34a, an inner surface 34e and an outer surface 34f. In this embodiment, the long flange 34a is about 1.5 inches to 2 inches long, while the short flange 34b is about 0.75 inches long. The long flange 34a is positioned in this embodiment at no greater than about 89 degrees (per ASTM-C1047) to the short flange 34b forming an L-shape. In an exemplary embodiment, the offset rib 34c is about 0.0625 inches high and about 0.125 inches wide.

(19) A fourth embodiment of the paperbead for use in the present invention is the J-shaped paperbead 36 shown in FIG. 7. In this embodiment, the core 38 has a long flange 38a, a short flange 38b, and a center portion 38c positioned between the flanges. The core 38 also has an outer surface 38d and an inner surface 38e. The long flange 38a is typically about 1 inch long. The short flange 38b is typically about inches long. The center portion 38c is typically about inches to inches wide. An offset rib 38f is also shown in this embodiment as positioned between the center portion 38c and the long flange 38a. However, the offset rib 38f can also be positioned between the center portion 38c and the short flange 38b. Two offset ribs 38f can be provided, one positioned between the center portion 38c, and the short flange 38b, the other between the centre portion 38c and long flange 38a. Alternatively, the ribs 38f may be excluded all together. In an exemplary embodiment, the offset rib 38f is about 0.0625 inches high and about 0.125 inches wide.

(20) A fifth embodiment of the paperbead for use in the present invention is the shadow-mold paperbead 40 shown in FIG. 9. In this embodiment, the core 42 has a first flange 42a, a second flange 42d, a center portion 42b, and an offset rib 42c. The core 42 also has an outer surface 42e and an inner surface 42f. The first flange 42a extends from the offset rib 42c forming an angle of about 90 degrees to the center portion 42b. The center portion 42b is positioned between the offset rib 42c and the second flange 42d. The second flange 42d extends from the center portion 42b at an angle of about 90 degrees in a direction opposite from the first flange 42a. In an exemplary embodiment, the flanges 42a and 42d are generally about inches to 1 inch in width, but are not necessarily of equal width. The center portion 42b is about inches to 1 inch in width.

(21) A sixth embodiment of the paperbead for use in the present invention is the splay-bead paperbead 44 shown in FIG. 8. In this embodiment, the core 46 has two strips 46a each of which has an outer surface 46b and an inner surface 46c. In an exemplary embodiment, the strips 46a are about inches to inches in width.

(22) Referring again to FIGS. 1 and 2, an inner surface 26a of the paper strip 26 is bonded to the outer surface 24d of the core 24. In the rib-shape embodiment, the paper strip 26 extends laterally beyond the edge of each of the core flanges 24a about 1 inch to form a pair of wings 26c. In a preferred embodiment, a border region 26d (see FIGS. 1 and 11) of the outer surface 26b along the edge of the paper strip 26 may receive additional processing as described below.

(23) Now referring again to FIG. 5, in making the L-shaped paperbead 32, the wing 26c extending beyond the short flange 34b is wrapped around the flange and its inner surface 26a is bonded to the inner surface 34e of the short flange 34b.

(24) As shown in FIG. 8, in the splay-bead paperbead 44 embodiment of the invention, the outer surfaces 46b of the two core strips 46a are bonded to the inner surface 26a of the paper strip 26 leaving a space 48 between them. The space 48 may be, for example, 0.050 inches. This spacing allows the strips 46a to rotate relative to each other. The strips 46a, therefore, can be positioned at different angles relative to each other. Accordingly, the splay-bead paperbead 44 can accommodate a variety of wall angle combinations. In an exemplary embodiment, the paper strip 26 extends beyond the metal strips 46a about inches to 1 inches. In another embodiment of the invention, the strips 46a are polymer or plastic strips connected one to the other by a living hinge rather than being spaced apart.

(25) In making the J-shaped paperbead 36, the inner surface 26a of the paper strip 26 can be bonded to the outer surface 38d of the core 38 in a number of ways. For instance, in the embodiment shown in FIG. 7, one wing 26c extends beyond the long flange 38a about inches and a second wing 26c wraps around the short flange 38b about 0.125 inches. In other J-shaped paperbead 36 embodiments, the wings 26c may extend beyond or wrap around the long flange 38a and short flange 38c in any number of combinations.

(26) In the shadow-mold paperbead 40 embodiment, one wing 26c extends beyond the first flange 42a about inches to 1 inch. The second wing 26c wraps around the second flange 42d about 0.125 inches as shown in FIG. 9.

(27) FIG. 10 shows the paper strip 26 as used in the present invention. The paper strip 26 is made from a stock paper, preferably a softwood and/or hardwood fiber Kraft stock paper. However, synthetic fiber products can also be used. The paper strip is between 6 and 7 mils in thickness, has a weight of between 110 and 125 grams/square meter (gsm), a porosity of between 30 and 130 Gurley sec. and has two surfaces, an outer surface 26b and an inner surface 26a. The outer portion 26e of the thickness of the paper strip 26 is impregnated with between 3.5% and 13% of a strengthening compound 54 based on the weight of the paper strip. Outer portion 26e is preferably impregnated about half the thickness t of the paper strip. To obtain high wet and dry strength properties, the strengthening compound is preferably a polymer, more preferably a latex. Generally, a latex consists of a stable colloidal dispersion of a polymeric substance in an aqueous medium. There are a large number of commercial latexes. For example, rubber latexes, including a styrene-butadiene rubber, and resin latexes, including acrylic resins, may be used to impregnate the stock paper strip. The inner surface 26a of the paper strip 26 is roughened resulting in a rough and irregular surface pattern.

(28) In a preferred embodiment, the latex is cross-linked. As a result, the paper strip has a good internal bond and exhibits excellent Z-direction tensile strength properties. Cross-linking can be accelerated by heating or superheating the latex impregnated paper strip. The process of impregnating the paper strip and cross-linking the latex does not increase the thickness of the paper strip yet increases its strength properties and its ability to resist abrasion. The paper strip also provides an excellent outer surface 26b for paint adhesion.

(29) In a preferred embodiment, paper strip 26 is composed of 100% soft wood pulp formed on a Fourdrinier paper machine. A polyamide wet strength resin is preferably added prior to forming to impart wet strength properties to the sheet. After forming, the sheet is pressed and the dried on conventional dryer cans.

(30) The paper strip 26 is then impregnated with latex in its outer portion 26e such that the latex only penetrates about half way through the thickness t of the paper strip. The inner surface 26a of paper strip 26 is roughened to obtain a felt-like texture.

(31) Most types of metal paperbeads, exterior and interior, are produced by feeding a roll of paper and a flat metal strip into a paperbead roll former. Preferably, as the paper is being fed into the roll former, the non-impregnated inner surface 26a of the paper strip is roughened by an abrasive, granular, or metal wire surface. The metal strip is roll formed into its respective core shape, whether it be a bullnose type, a center rib type, an L-shaped type or any other type of corner bead. Metal cores can also be made by extrusion. As noted previously, plastic cores can also be utilized. In an exemplary embodiment, the paper strip 26 is covered with a hot melt glue on the non-impregnated inner surface 26a. For example, several suitable fast-setting hot melt glues are commercially available. This type of glue is typically a formulated synthetic emulsion adhesive. The paper strip is then bonded to the outer surface of the core by applying pressure to the core and the paper strip with a series of pressure rolls to ensure an even bond. The paperbead is then cut to the desired length.

(32) Referring to FIG. 11, in a preferred embodiment, outer surface 26b of the paperbead has a border region 26d on the outer edges of the paper strip 26. The edges 24f of the underlying core 24 are shown in dashed lines. The border region 26d is provided with a means for improved bonding with joint compound as is common in the art. This means may include slitting of the paper strip or skiving where the surface is slightly roughened or buffed by an abrasive, granular or metal wire surface. The width z of the border region 26d may cover a part or all of the entire wing 26c, preferably about 0.5 to about 1 inch, more preferably about 0.6 to about 0.7 inch, and most preferably about 0.625 inch. The purpose of the border region 26d is to improve bonding of the paperbead with the exterior layer compound or joint cement to prevent edge cud when the paperbead is applied to walls as described below. Although FIG. 11 shows a generic paperhead similar to that shown in FIG. 1, the border region 26d is also applicable to other configurations, such as the bullnose paperbead 28 (FIGS. 4 and 6), L-shaped paperbead 32 (FIG. 5), J-shaped paperbead 36 (FIG. 7), shadow-mold paperbead 40 (FIG. 9), and splay-bead paperbead 44 (FIG. 8).

(33) As shown in FIGS. 1 to 4, a paperbead 10 or 28 is installed by first applying a thin bonding layer 60 of joint compound or joint cement of about 4 inches to 4 inches wide to the leading edges of two interfacing drywall sheets 14. The corner beads 10 or 28, including the core 24 or 30 and the paper strip wings 26c are then firmly embedded in the bonding layer 60. Excess joint compound is removed by wiping the paper strip surface with a finishing knife. As the bonding layer 60 of the joint compound dries, the paperbead 10 or 28 follows the contour of the surface of the drywall 14, particularly the non-planar contours from screw heads 18a, knife cuts 20 or other deformations 22. This is best illustrated in FIG. 1, where the paper strip 26 is shown following the non-planar contour 21 from an underlying screw head 18a forming a shallow depression 19, and in FIG. 3.

(34) An exterior layer 62 of joint compound is then applied to the top of the paperbead 10 or 28 extending about 8 inches inward on the drywall sheet 14, leaving only a paper covered center rib 24c or a paper covered bullnose 30c exposed. The exterior layer 62 of joint compound is allowed to dry and is then sanded and feathered to produce a smooth surface between the drywall sheet 14 and the paper covered center rib 24c or the paper covered bullnose 30c. J-shaped paperbeads 36, shadow-mold paperbeads 40 and splay-bead paperbeads 42 are installed in a similar fashion.

(35) As shown in FIG. 6, an interior paperbead is also installed by embedding a paperbead 28 and paper strip wings 26c in a bonding layer 60 of joint compound. After drying, an exterior layer 62 of joint compound is applied, sanded and feathered. Interior bullnose paperbeads 28 will have an exposed paper covered bullnose 30c.

(36) FIG. 5 shows an U-shaped paperbead 32 installed by applying a thin bonding layer 60 of joint compound to a drywall sheet 14 and the exposed end 14b of the sheet. The L-shaped paperbead 32 is embedded in the bonding layer 60. An exterior layer 62 of joint compound is then applied to cover a paper covered long flange 34a and wing 26c. This layer is sanded and feathered to provide a smooth and continuous surface between a paper covered offset rib 34c and the drywall sheet 14.

(37) In preliminary testing, a paperbead for use in accordance with the present invention was compared with the preferred embodiment of a paperbead produced in accordance with Rennich et al as described in U.S. Pat. No. 7,214,434. The paperbead for use in the present invention utilized a paper strip of about 6.5 mils in thickness, having a weight of about 117 grams/square meter (gsm) and a porosity of about 80 Gurley sec., the outer portion of the thickness of the paper strip being impregnated with about 8.3% of the total weight of the paper strip of a polymer strengthening compound. Both paperbeads were produced to include top side skiving of the border region and met QC specifications. Each of the paperbeads was installed on a test wall with 90 deg corners and tested using ASTM C474 standards and test methods and both paperbeads met the ASTM C475 standard specifications for joint Compound and Joint Tape for finishing Gypsum Board. However, in this testing, it was readily but surprisingly observed that the described paperbead of the present application was following and adhering to non-planar contours of the drywall surface noticeably better than the prior art paperbead. For example, as is illustrated in FIG. 1, when applied over screw head depressions 21, the wings 26c of the paperbead 10 adhered very closely to the underlying depressions 21, whereby a significant visible depression 19 was seen in the outer surface of the wings 26c. In contrast, no such significant visible depressions could be seen when the prior art paperbead was used. Unexpected improvements noted included more rapid adhesion to the drywall, improved ability of the paperhead to follow the contours and indentations of the drywall, and reduced edge lifting of the paperbead, resulting in a faster, more efficient installation and superior bond to the joint compound.

(38) Similar results were confirmed in blind field tests on job sites conducted with professional drywall trim applicators.

(39) Although the present invention has been described in detail by way of illustration and example, various changes and modifications may be made without departing in any way from the spirit of the invention and scope of the appended claims. In addition, many of the features and dimensions portrayed in the drawings have been exaggerated for the sake of illustration and clarity.