Patent Application
20250237070
The present invention relates generally to interior wall construction products, and more specifically to composite corner finishing strips for finishing corners created by adjacent edges of wallboard sheets.
In conventional interior construction, wallboard or drywall panels are secured to a framework of vertically and horizontally arranged frame members, typically wood or metal. Abutting edges of adjacent wallboard panels are finished using a combination of wallboard joint tape and wallboard joint compound as is well known in the art. When adjacent wallboard panels are configured to form corners, corner bead products are often installed for both aesthetics and utility. They finish a rough corner into a pleasing symmetrical transition with the respective adjoining walls, and also provide some resistance to abuse and impact on the corner. To accomplish these tasks, a suitable corner bead product should fit snugly on the wall, be easy to attach, and have material and design properties that allow it to resist at least minor impacts without severe damage or detachment from the wall.
An important feature of prior art metal corner bead is a slightly rounded corner that protrudes from the actual corner of the part. This feature is also known as the “bead”, but for purposes of describing the invention, it will be referred to as the “corner rib”. In metal corner bead, the rib aids in the finishing of the corner by allowing the finisher to easily apply some significant “fill” of joint compound all the way up to the corner. The rib typically has a radius of just 0.03-1.10 inch (0.08-2.79 cm) and a preferred maximum height above the corner bead flanges of 0.015-0.04 inch (0.04-0.10 cm), so the surface of the rib itself that is not covered by joint compound is easily painted over for a pleasing finish. If the corner bead simply has a sharp 90° angle at the corner, it is much more difficult to apply a thin layer of joint compound that covers the bead in close proximity to the actual corner and in a way that is able to be sanded to a smooth, paintable finish.
Conventional corner bead strips are made of either metal or various types of plastic, and are provided in relatively rigid lengths or in flexible rolls. Flexible corner bead strips are typically two types. In the first type, two metal strips approximately 0.010-0.015 inches (0.025-0.038 cm) thick are disposed parallel to each other, are laminated to a web of paper with a slight separation gap between the strips so that the strip may be flexed as desired to match the corner profile. The flex bead strips are then applied to the wall corner and secured using wallboard joint compound. Disadvantages of conventional flexible metal corner bead strips include that the metal is relatively heavy, expensive, is easily bent or kinked, and is often difficult to straighten completely when provided in rolled form. Metal corner beads also lack durability, in part because the core metal typically corrodes if the metal corner bead is stored or left on a jobsite in wet or humid conditions, and the metal is prone to bending if not handled carefully upon installation.
In addition, due to the gap between the adjacent strips, it is sometimes difficult to obtain a straight or plumb corner edge, and the actual corner of the wall is only protected by paper, and as such is prone to impact damage.
Conventional flexible plastic corner bead strips suffer from the same susceptibility to impact damage at the wall corner. Plastic corner bead strips can be made from a single strip of flexible plastic that is laminated to a paper web. Compared to the above-described metal strips, plastic corner strips are thicker, about 0.025-0.050 inches (0.64-1.4 cm), to provide comparable rigidity to metal.
One design criteria of flexible plastic corner bead strips is that a compromise is usually needed between a plastic that is sufficiently rigid for protecting the corner, which may include gaps between the wallboard edges, but sufficiently flexible for conforming to the wall without pulling away from the wall due to inherent bias of the strip to remain generally planar.
Known plastic corner bead products typically possess a sharp angle or corner on the spine and are more flexible and less easily dented, but they tend to crack at the corner when held in place by rigid fasteners, or often pull away from the wall when held in place by adhesive or joint compound. Specifically, most plastics do not adhere well with joint compounds. The water-based adhesive in joint compound is not compatible with the plastic surface of the plastic corner bead, making the corner bead difficult to secure in place using joint compound. Other products have attempted to address this problem by coating the plastic with fibrous material, such as non-woven paper, which is an expensive process that is often unsuccessful.
Accordingly, there is the need for a composite corner finishing strip which addresses the above-listed drawbacks.
The above-listed need is met or exceeded by the present composite corner finishing strips, including an extruded strip of plastic laminated to porous paper, and the composite corner finishing strips are attached to a drywall corner using joint compound. In a first embodiment of the present composite corner finishing strips, the laminated strips are extrusions which have a fixed profile, such as a 90 degree or rounded “bull-nose” profile. The fixed profile composite corner finishing strips are preferably produced in elongated strips or “sticks” of various lengths to accommodate various wall heights.
In a second embodiment of the present composite corner finishing strips, the laminated strips are produced in flat, flexible form which are easily rolled for convenient storage. The rolls are then cut to the proper length to fit the wall height. In this second embodiment, the flexible rolls include an axially extending recess along their center for folding the composite corner finishing strips to form a corner. Preferably, the recess defines a folding axis for the composite corner finishing strips.
The second embodiment of the present composite corner finishing strips preferably has a tapered profile which helps facilitate adhering the laminated strips to the wall with joint compound. Specifically, the present composite corner finishing strips preferably include flanges which extend away from either the recess, such that the thickness of the flanges is greatest at an edge closest to the recess, which allows joint compound to fill in and cover the composite corner finishing strip.
Preferably, the flanges of the composite corner finishing strips are provided with perforations which extend through the flanges forming openings. The perforations allow the joint compound to penetrate beyond the surface of the plastic to improve adhesion between the composite corner finishing strips and the surrounding wallboard panels. Preferably, before the plastic core of the composite corner finishing strips is laminated to the porous paper, the plastic core is perforated with visible holes in a pattern that includes between 6 and 25 holes per square inch. While other shapes are contemplated, the perforations preferably are circular and have a diameter in a range of approximately 0.05-0.20 inches (0.127-0.508 cm). Preferably still, at least a portion of the perforations are proximate to the recess of the plastic core.
The increased surface area of contact between the joint compound and the plastic core of the present composite corner finishing strips provided by the perforations, as well as the keying effect caused by the dried joint compound in the perforations, help improve bonding of the joint compound and the composite corner finishing strips.
When adhered to a drywall corner, the present composite corner finishing strips form a crisp, monolithic surface. Additionally, the present composite corner finishing strips are more durable than metal corner beads and provide improved adhesion with drywall surfaces than existing products.
More specifically, the present disclosure includes a composite corner finishing strip for finishing a wallboard corner joint having a plastic body with a first flange and a second flange, each flange having a rib edge and an opposite free edge, such that the respective rib edges are joined to form a corner rib defining an angle. At least one of the first flange and the second flange have a plurality of perforations, the corner rib extends beyond a corner defined by the first and second flanges, and defines an interior space, and a web of face paper at least partially covers the body.
In preferred embodiments, at least one of the flanges tapers in thickness from the rib edge to the free edge, and the face paper has a free end extending past the free edge of each of the flanges, such that a length ratio of the free edge to the face paper end is approximately 0.5 to 0.9. Preferably, the defined angle is in the range of 75°-105°.
In additional preferred embodiments, the perforations are circular in shape and extend through the flange, the perforations have a diameter between around 0.05 inches and around 0.20 inches, the perforations are provided in a pattern that includes between 6 and 25 holes per square inch, and the perforations are staggered along a length of the corner bead. Preferably, at least a portion of the perforations are proximate to the corner rib.
A second embodiment of the present disclosure includes a composite corner finishing strip for finishing a wallboard corner joint having a plastic body with a first flange and a second flange, each flange extending away from a recess of the plastic body. The first flange and the second flange have a free edge, a recess edge, and a plurality of perforations. The composite corner finishing strip includes a web of face paper at least partially covering the body.
In a preferred embodiment, the recess defines a folding axis of the plastic body, the plastic body being configured for being bendable about the longitudinal axis to a 90-degree angle without relaxing back to an initial flat position.
In a preferred embodiment, the recess has a curved shape, such that a thickness of the plastic body is smallest at a bottom of the curved shape. In an embodiment, the recess is V-shaped, such that a thickness of the plastic body is smallest at a bottom of the V-shape. In another embodiment, the recess has an elliptical shape, such that a thickness of the plastic body is smallest at a bottom of the elliptical shape. In another embodiment, the recess has an obround shape, such that a thickness of the plastic body is smallest at a bottom surface the obround shape. Preferably, plastic is selected for impact resistance, and is reversibly deformable.
In another preferred embodiment, at least one of the flanges tapers in thickness from the recess to the free edge, such that the flanges have a thickness in the range of 0.040-0.055 inch near the recess and a thickness in the range of 0.025-0.035 inch near the free edge. Preferably, the face paper has a free end extending past the free edge of each of the flanges and the plastic body is provided in sheet form.
Referring now to
Included on the composite corner finishing strip 10 is a body 18 having a first, preferably planar flange or wing 20 and a second, preferably planar flange or wing 22, both flanges being panel-like in configuration. Each flange 20, 22 has a rib edge 24 and an opposite free edge 26. The respective rib edges 24 of each of the flanges 20, 22 are joined to form a corner rib 28 defining an angle α. In a preferred embodiment, the angle α is approximately 85° and more preferably is less than 90° to exert a clamping force on the corner 16 upon assembly. However, it is contemplated that the exact dimension of the angle α may vary to suit the situation.
A feature of the present composite corner finishing strip 10 is that the corner rib 28 extends beyond an intersection ‘X’ (
In the preferred embodiment, the body 18 is integrally formed and is made of plastic, preferably of a type which is injection moldable or extrudable, including but not limited to polystyrene, polyvinylchloride (PVC), polyethylene (PET), polyethylene terephthalate glycol (PETG) and polycarbonate. In the present application, “plastic” will be understood to refer to any polymeric material, whether or not filled with fibers, minerals or other additives known in the art, including, but not limited to those materials identified above. In addition, the plastic is selected for impact resistance, and is reversibly deformable.
In addition to the body 18, described above, the present composite corner finishing strip 10 also preferably includes chemical adhesives 38 or other known fastening technology which are used to secure a web of face paper 40 to the body 18, such that the face paper covers at least a portion of the body. In the preferred embodiment, the face paper 40 covers the exterior surface 34 of the entire body 18. The face paper 40 preferably envelops the body 18 and provides a substrate to which wallboard joint compound 36 readily adheres for facilitating finishing of the corner joint. Preferably, the face paper 40 is also coated with a thin, wax-like nose coating 42 to facilitate sliding of the taping knife or trowel used to apply the wallboard joint compound 36.
As is seen in
As illustrated in
Referring now to
Once the perforations 48 are formed in the body 18, the face paper 40 is laminated to body using the chemical adhesive 38, such as a pressure sensitive adhesive based on styrene block copolymer chemistry or a polyurethane reactive adhesive. Preferably, the perforations 48 are formed as visible holes in a pattern that includes between 6 and 25 holes per square inch. The perforations 48 preferably are circular and have a diameter a range of approximately 0.05-0.20 inches (1.27-5.08 cm). Preferably still, at least a portion of the perforations 48 are proximate to the corner rib 28.
Referring now to
The composite corner finishing strip 100 is preferably provided in flat, flexible form which is optionally rolled for convenient use and storage. Then, the composite corner finishing strip 100 is cut to the proper length to fit a height of the wall and folded along a recess 102 located in approximately the center of the composite corner finishing strip to the correct angle to fit over the drywall panels 12, 14.
Another feature of the present composite corner finishing strip 100 is that at least one, and preferably both of the flanges 20, 22 taper in thickness between an edge of the recess 102 and the free edge 26, so that the free edge is relatively pointed compared to a thickness of the flanges next to the recess. Thus, the flanges 20, 22 are preferably mirror images of each other. This tapered configuration facilitates the user blending the composite corner finishing strip 100 into the wall through the use of wallboard joint compound 36 and a taping knife, as is well known in the art.
In addition, the taper provides gradually increasing strength to the composite corner finishing strip 100 closer to the recess 102, where shock impacts are more likely to occur. The gradually tapering cross-section towards the free edge 26 facilitates more efficient use of material. While other thicknesses are contemplated depending on the application and material used, in the preferred embodiment, the thickness of the flanges 20, 22 near the recess 102 is in the range of 0.03-0.06 inches (0.08-0.15 cm), and near the free edge 26 is in the range of 0.01-0.025 inches (0.03-0.06 cm).
The recess 102 of the composite corner finishing strip 100 replaces the corner rib 28 of the composite corner finishing strip 10. In a preferred embodiment, a longitudinal axis 104 within the recess 102 defines a fold line of the composite corner finishing strip 100. The plastic body 18 of the composite corner finishing strip 100 is configured to be bendable about the longitudinal axis 104 to a 90-degree angle without relaxing back to an initial flat position of the plastic body.
Preferably, the thinnest point of the composite corner finishing strip 100 is at the longitudinal axis 104. In preferred embodiments, the thickness of the composite corner finishing strip 100 at the longitudinal axis 104 is in a range of approximately 0.01-0.02 inches (0.025-0.051 cm). Additionally, a width of the recess 102 is sufficiently large to accommodate the thickness of the body 18 when the porous paper 40 is folded 180 degrees. Preferably, the width of the recess 102 is a range of approximately 0.08-0.15 inches (0.203-0.381 cm).
Referring now to
Referring to
Angled edges 108 defining the V-shaped recess 106 preferably are symmetrical on opposite sides of the longitudinal axis 104, and preferably define an angle β between the angled edges 108. Preferably, the angle β between the angled edges 108 is between 90 and 140 degrees, though alternative angles are contemplated. It is also contemplated that intersections between the angled edges 108 and a top surface 110 of the composite corner finishing strip 100 are rounded.
As depicted in
In a preferred embodiment, the radius of curvature R of the curved edges 114 is in a range of approximately 0.10-0.30 inches (0.25-0.75 cm). Preferably still, the radius of curvature R is around 0.15 inches (0.38 cm). The curved edges 114 are preferably either parabolic or circular in shape. However, other geometries of the curved edges 114 are contemplated, as is known in the art.
Referring now to
As with the V-shaped recess 106, it is contemplated that intersections 120 between the elliptical recess 116 and the top surface 110 of the composite corner finishing strip 100 are rounded.
Referring now to
As with the elliptical recess 116, it is contemplated that intersections 126 between the obround recess 122 and the top surface 110 of the composite corner finishing strip 100 are rounded.
Referring now to
As noted above, the body 18 is preferably extruded. However, when the body 18 is cooling after leaving the extruder, the plastic inevitably shrinks to an extent. Thus, the dimensions of the recesses 102 will reduce as the body 18 leaves the extruder.
While a particular embodiment of the present composite corner finishing strips has been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.
| Number | Date | Country | |
|---|---|---|---|
| 63624555 | Jan 2024 | US |
