CEILING CORNER ELEMENT

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Application No. 102024137575.2, filed Dec. 13, 2024, and German Application No. 102025139722.8, filed Sep. 30, 2025, the entire contents of each of which is hereby incorporated by reference

FIELD OF INVENTION

The present disclosure relates to ceiling seam strips for incorporating in building material surfaces and reinforcement strips for drywall installation.

BACKGROUND

An important part of installing drywall involves the joining of drywall sheets, e.g. sheetrock sheets. The seam cover strips are used to reinforce the seams between drywall sheets to prevent crack formation in the finished surface, and to obtain smooth seams. Ideally, these seam cover strips contribute to the strength, airtightness, noise reduction and durability with regard to humidity where the sheets are joined together. The quality of the strips covering the seams is a substantial factor in appearance of the finished drywall surface.

The following are some of the decisive criteria for the quality of the seam cover strips: highest tensile forces the cover strips can withstand, stretching of the cover strips when pulled on, thickness of the cover strips, stiffness of the cover strips, (air) permeability of the cover strips, and surface texture of the cover strips. The highest tensile forces the cover strips can withstand and the stretching thereof when pulled on are important factors with regard to their reinforcement capacity, particularly with regard to preventing crack formation in the finished drywall surfaces. The thickness of these cover strips affects how they can be incorporated in the finished surface and the appearance thereof. Permeability to air determines how quickly the plastering compound applied thereto will dry.

Building surfaces have been reinforced in the prior art with seam cover strips made of nonwovens containing cellulose, which are incorporated in the surface by embedding them directly in the plastering compound (e.g. in the seams between drywall sheets in the form of 5 cm wide strips, or covering entire plastering compound surfaces with 1 meter wide sheets). The nonwovens currently in use, made of cellulose fibers or mixtures of cellulose and synthetic polymer fibers, frequently do not adhere adequately to the plastering compounds. For this reason, are roughened, pricked, or punctured mechanically, which thickens them, making more difficult to obtain a smooth surface, and makes them more difficult to plaster over. Plastering these nonwovens results in a poor adherence between the embedded nonwovens and the plastering compound, as has been shown in peeling tests. Consequently, it is difficult to obtain an optimal reinforcement to prevent crack formation in the finished surfaces.

Drywall construction is quick, adaptable, and reduces building moisture. The sheets are attached to substructures made of metal or wood, and subsequently plastered over to obtain a smooth surface. The individual sheets are attached to the substructure with screws or adhesive, and the seams and corners are formed with suitable materials and technologies. For the inner and outer corners, transitions are of particular interest with regard to their appearance in terms of modern architectural design and acoustics. The corner joint is a special aspect of drywall construction, formed where two walls and the ceiling meet. This inner corner joint between the drywall sheets should be sealed properly to prevent cracks and uneven surfaces. Professional ceiling corner elements are important for the visual and functional quality of the ceiling. The formation of such corners is particularly difficult, because the seams must be precise and designed to last. Typical steps for this include the application of tape, plastering over the seam, and subsequent smoothing of the surface. Special brackets or corner elements are used to obtain optimal strength and appearance. These are made of a special paper that is thin and will not tear when wet, which also remains smooth when wet, and can withstand substantial tension.

Conventional corner pieces, which are commercially available, are cut manually from stamped sheets, and then folded to fit the specific corner. This folding is such that there is overlap on one of the surfaces, where it is glued together to obtain the preformed corner. This overlap affects the fitting to the specific shapes of the drywall surface, but is necessary for gluing the preformed corner together. This causes problems when plastering over the structure due to the difference in thickness. The overlap may also result in irregular joints or visible wrinkles, having a negative impact on the appearance. This can require more time to smooth over, and involve additional plastering. This also may be less precise, particularly in corners that are not at perfect right angles.

SUMMARY

An object of the present invention is to create a seam cover strip for incorporating in building material surfaces with which the embedded nonwoven strips adhere well to the plastering compound. This is achieved with seam cover strips for incorporating in building material surfaces that have the features as claimed in the independent claims. Advantageous embodiments are the subject matter of the associated dependent claims.

A further object of the present invention is to create a method for producing a drywall corner structure that overcomes the disadvantages of the prior art, and results in a smooth drywall surface. It is also the object of the invention to create a preformed ceiling corner element for use in the method for producing a drywall corner structure that overcomes the disadvantages of the prior art and can be easily attached to a drywall surface to obtain a smooth surface.

The invention forms a seam cover strip for incorporating in building material surfaces comprising a nonwoven containing cellulose fibers with a polymer coating on at least one side. The polymer coating substantially improves the adhesive properties between the smooth reinforcing nonwoven and the plastering compound on the building material surface.

This nonwoven can also contain synthetic polymer fibers. As a result, the nonwoven textile can be produced inexpensively.

The polymer coating can also be applied to both sides of the nonwoven. This allows for an optimal incorporation in the surface for preventing crack formation.

The polymer coating is ideally multilayered. This chemical finish results in a stiffer fiber-reinforced nonwoven.

The polymer material ideally contains an adhesive that is activated by water. After drying, the adhesion between the embedded nonwoven and the plastering compound on the building material surface is strengthened.

The polymer material is ideally composed of modified starch polymers, methylcellulose polymers, activated polyvinyl alcohol polymers, or a mixture thereof. A significantly improved surface and seam reinforcement is obtained on the building material for preventing crack formation with the resulting adhesion between the embedded nonwoven and the plastering compound on the building material surface.

A polymer material composed of mixture of modified methylcellulose and starch, in particular potato starch, has proven to be advantageous. This results in a stiffer textile structure with a minimal “chemical component.”

The starch advantageously contains an amylopectin content of 10-40% by weight, preferably 15-30% by weight, ideally 20% by weight.

The nonwoven ideally has a surface area weight of 40-250 g/m², preferably 70-200 g/m², ideally 80-150 g/m². This allows the cover strips to be easily incorporated in the plastering compound surface.

The dry surface area weight of the polymer material on the nonwoven is 5-40 g/m², preferably 8-30 g/m², ideally 8-15 g/m². This results in seam cover strips that can be easily plastered over.

The width of the nonwoven is preferably 2-150 cm, more preferably 3-120 cm, ideally 5-100 cm. This increases the mechanical strength of the seam cover strip.

The seam cover strips are advantageously produced in a process comprising the following steps: providing a nonwoven containing cellulose fibers; coating the nonwoven with a polymer material using a squeegee, by spraying it on, in a reverse coating process, and/or in a rotary printing process; and drying the nonwoven coated with the polymer material.

This results in the desired properties, e.g. improved tear-resistance, elasticity, thickness, and texture.

The coating applied in step b. is ideally applied to one side of the nonwoven. This makes it easier to cut the strips to size on site.

The coating can also be applied to both sides of the nonwoven. This results in seam coating strips that maintain their shape, which can be inexpensively produced.

The seam coating strips are preferably applied to the building material surfaces in a plastering compound.

The invention shall be explained in greater detail below in reference to the drawing.

In some embodiments, the invention relates to a method for producing a drywall corner structure and a preformed ceiling corner element. The invention relates to the technical field of methods for creating and working on corner joints, in particular corner joint structures formed when installing drywall sheets in which a special corner element is used to precisely and robustly join drywall sheets or similar structures at the corners of walls and ceilings. Drywall is a construction method involving the production of walls, ceilings and panels made of prefabricated elements such as drywall sheets. Drywall is used in modern buildings as well as for renovation and restoration, forming an efficient means for installing electrical and plumbing components.

This is achieved by a method for producing a drywall corner structure that has the features of the independent claims. Advantageous embodiments form the subject matter of the associated dependent claims.

The invention results a method for producing a drywall corner structure comprising the steps: providing a preformed ceiling corner element that can be incorporated in a drywall surface composed of a first section with a first folding edge and second folding edge, a second section on the first folding edge that has a third folding edge, a third section on the third folding edge that has a first outer edge, and a fourth section on the second folding edge that has a second outer edge, in which the first folding edge is perpendicular to the second folding edge, third folding edge, first outer edge, and second outer edge; providing a drywall corner structure comprising a first drywall surface, and second and third drywall surfaces that extend in a first vertical direction; placing the first section on the second drywall surface, the second section on the third drywall surface, and the third and fourth sections on the first drywall surface; adjusting the angle β between the first outer edge of the third section and the second outer edge of the fourth section, such that the third and fourth sections are adjacent to one another on the first drywall surface, without overlapping; and attaching the preformed ceiling corner element. This results in a precise drywall corner with a very smooth surface.

The angle β is preferably 0° to 20°, more preferably 0° to 10°, ideally 0° to 5°. By adjusting this angle, the preformed ceiling corner element can be optimally adapted to the adjoining drywall surfaces, such that a precise and robust corner is formed.

The method can also contain an additional step c1, in which the first outer edge on the third section and/or the second outer edge on the fourth section are cut such that the angle β is preferably 0° to 20°, more preferably 0° to 10°, ideally 0° to 5°. This ensures that the third and fourth sections do not overlap.

Putty is used in step e), and/or an adhesive on the ceiling corner element is activated by adding water. This makes it easy to work on the corner, and simplifies alignment and smoothing of wrinkles.

The sections of the preformed ceiling corner element are placed on the inner surface of the drywall sheets in step c). This results in a particularly smooth inner surface, thus simplifying further work, i.e. wallpapering or painting.

It is beneficial to place the sections of the preformed ceiling corner element on an outer surface of the drywall sheets in step c). Formation of cracks is prevented by the adhesion between the ceiling corner element and the drywall surface.

It has proven to be advantageous when the preformed ceiling corner element is placed in step c) such that the first folding edge covers the seam between the second drywall surface and the third drywall surface, the third folding edge covers the seam between the first drywall surface and the third drywall surface, and the second folding edge covers the seam between the first drywall surface and the second drywall surface, such that all the surfaces are flush. This results in a robust and durable drywall corner structure.

The sections of the preformed ceiling corner element each have at least one adhesive surface with which they are attached to the corresponding drywall surfaces in step c). This makes it possible to place the individual sections precisely on the drywall surfaces.

The invention also relates to a preformed ceiling corner element that comprises a first section with a first folding edge and second folding edge, a second section on the second folding edge with a third folding edge, a third section on the third folding edge that has a first outer edge, and a fourth section on the second folding edge that has a second outer edge, in which the first folding edge is perpendicular to the second folding edge, third folding edge, the first outer edge and second outer edge. This makes it possible to form precise and robust corners in the drywall.

It has proven to be advantageous when the preformed ceiling corner element is placed in a drywall corner structure. This drywall corner structure comprises a first drywall surface, and second and third drywall surfaces extending in a first vertical direction. The preformed ceiling corner element can be precisely placed on these drywall surfaces.

The angle β between the first outer edge of the third section and the second outer edge of the fourth section can be advantageously adjusted such that the third section and fourth section are adjacent to one another on the first drywall surface, without overlapping. Consequently, the third section and fourth section can be joined precisely, without overlapping or forming a gap between them.

The length L of the various sections is 1 cm to 10 cm, preferably 1.5 cm to 5 cm, ideally 2 cm to 3 cm. The height H of these sections is 2 cm to 8 cm, preferably 3 cm to 7 cm, ideally 4 cm to 6 cm. This ensures an optimal fit to the shape of the drywall corner.

The ceiling corner elements are preferably provided in step a) in a container in which they are stacked such that they can be removed individually.

Ideally, a preformed ceiling corner element is used in the method for producing a drywall corner structure. This results in a precise corner in the drywall structure that can be produced quickly.

In some aspects, the techniques described herein relate to a seam cover strip (101) for incorporating in building material surfaces including a nonwoven (102) containing cellulose fibers, which has a polymer coating (103) on at least one side.

In some aspects, the techniques described herein relate to a seam cover strip (101), wherein the nonwoven (102) also contains synthetic polymer fibers.

In some aspects, the techniques described herein relate to a seam cover strip (101), wherein the polymer coating (103) is applied to both sides of the nonwoven (102).

In some aspects, the techniques described herein relate to a seam cover strip (101), wherein the polymer coating (103) is multilayered.

In some aspects, the techniques described herein relate to a seam cover strip (101), wherein the polymer material (103) contains an adhesive that is activated by water.

In some aspects, the techniques described herein relate to a seam cover strip (101), wherein the polymer material (103) contains modified starch polymers, methylcellulose polymers, activated polyvinyl alcohol polymers, or a mixture thereof.

In some aspects, the techniques described herein relate to a seam cover strip (101), wherein the polymer material (103) contains a mixture of modified methylcellulose and starch, in particular potato starch.

In some aspects, the techniques described herein relate to a seam cover strip (101), wherein the starch advantageously contains an amylopectin content of 10-40% by weight, preferably 15-30% by weight, ideally 20% by weight.

In some aspects, the techniques described herein relate to a seam cover strip (101), wherein the nonwoven (102) ideally has a surface area weight of 40-250 g/m², preferably 70-200 g/m², ideally 80-150 g/m².

In some aspects, the techniques described herein relate to a seam cover strip (101), wherein the dry surface area weight of the polymer material (103) on the nonwoven (102) is 5-40 g/m², preferably 8-30 g/m², ideally 8-15 g/m².

In some aspects, the techniques described herein relate to a seam cover strip (101), wherein the width of the nonwoven (102) is preferably 2-150 cm, more preferably 3-120 cm, ideally 5-100 cm.

In some aspects, the techniques described herein relate to a seam cover strip (101), produced in a process including the steps: a. providing a nonwoven (102) containing cellulose fibers; b. coating the nonwoven (102) with a polymer material (103) using a squeegee, by spraying it on, in a reverse coating process, and/or in a rotary printing process; c. drying the nonwoven (102) coated with the polymer material (103).

In some aspects, the techniques described herein relate to a seam cover strip (101), wherein the coating is applied to one side of the nonwoven (102) in step b.

In some aspects, the techniques described herein relate to a seam cover strip (101), wherein the coating is applied to both sides of the nonwoven (102) in step b.

In some aspects, the techniques described herein relate to a seam cover strip (101) 1 to 11, for incorporated in a plastering compound on a building material surface.

In some aspects, the techniques described herein relate to a method for producing a drywall corner structure (2) including the following steps: a. providing a preformed ceiling corner element (1) that can be incorporated in a drywall surface composed of a first section (11) with a first folding edge (21) and second folding edge (22), a second section (12) on the first folding edge (21) that has a third folding edge (23), a third section (13) on the third folding edge (23) that has a first outer edge (31), and a fourth section (14) on the second folding edge (22) that has a second outer edge (32), in which the first folding edge (21) is perpendicular to the second folding edge (22), third folding edge (23), first outer edge (31), and second outer edge (32); b. providing a drywall corner structure (2) including a first drywall surface (2a), and second and third drywall surfaces (2b, 2c) that extend in a first vertical direction; c. placing the first section (11) on the second drywall surface (2b), the second section (12) on the third drywall surface (2c), and the third section (13) and fourth section (14) on the first drywall surface (2a); d. adjusting the angle (β) between the first outer edge (31) of the third section (13) and the second outer edge (32) of the fourth section (14), such that the third section (13) and fourth section (14) are adjacent to one another on the first drywall surface (2a), without overlapping; e. attaching the preformed ceiling corner element (1).

In some aspects, the techniques described herein relate to a method, wherein the angle (β) is 0° to 20°, preferably 0° to 10°, ideally 0° to 5°.

In some aspects, the techniques described herein relate to a method, also including a step c1, in which the first outer edge (31) on the third section (13) and/or the second outer edge (32) on the fourth section (13) can be cut to adjust the angle (β).

In some aspects, the techniques described herein relate to a method, wherein a putty is used in step e), and/or an adhesive on the ceiling corner element (1) is activated by adding water.

In some aspects, the techniques described herein relate to a method, wherein the sections (11, 12, 13, 14) of the preformed ceiling corner element (1) are each placed on an inner side of the drywall surfaces (2a, 2b, 2c) in step c).

In some aspects, the techniques described herein relate to a method, wherein the sections (11, 12, 13, 14) of the preformed ceiling corner element (1) are each placed on an outer side of the drywall surfaces (2a, 2b, 2c).

In some aspects, the techniques described herein relate to a method, wherein in placing the preformed ceiling corner element (1) in step c), the first folding edge (21) covers a seam between the second drywall surface (2b) and third drywall surface (2c), the third folding edge (23) covers the seam between the first drywall surface (2a) and third drywall surface (2c), and the second folding edge (22) covers the seam between the first drywall surface (2a) and second drywall surface (2b), such that all the surfaces are flush.

In some aspects, the techniques described herein relate to a method, wherein the sections (11, 12, 13, 14) of the preformed ceiling corner element (1) each have at least one adhesive surface with which they are attached to the corresponding drywall surfaces (2a, 2b, 2c) in step c).

In some aspects, the techniques described herein relate to a preformed ceiling corner element (1) including a first section (11) with a first folding edge (21) and second folding edge (22), a second section (12) on the first folding edge (21) that has a third folding edge (23), a third section (13) on the third folding edge (23) that has a first outer edge (31) and a fourth section (14) on the second folding edge (22) that has a second outer edge (32), wherein the first folding edge (21) is perpendicular to the second folding edge (22), third folding edge (23), first outer edge (31) and second outer edge (32).

In some aspects, the techniques described herein relate to a preformed ceiling corner element (1), placed in a drywall corner structure (2) in the method, wherein the drywall corner structure (2) has a first drywall surface (2a) and second and third drywall surfaces (2b, 2c) extending in a first vertical direction.

In some aspects, the techniques described herein relate to a preformed ceiling corner element (1), wherein the angle (β) between the first outer edge (31) on the third section (13) and the second outer edge (32) on the fourth section (13) is adjusted such that the third section (13) and fourth section (14) are adjacent to one another on the first drywall surface (2a) without overlapping.

In some aspects, the techniques described herein relate to a preformed ceiling corner element (1), wherein the angle (β) is 0° to 20°, preferably 0° to 10°, ideally 0° to 5°.

In some aspects, the techniques described herein relate to a preformed ceiling corner element (1), wherein the length L of the sections (11, 12, 13, 14) is 1 cm to 10 cm, preferably 1.5 cm to 5 cm, ideally 2 cm to 3 cm, and the height H of the sections (11, 12, 13, 14) is 2 cm to 8 cm, preferably 3 cm to 7 cm, ideally 4 cm to 6 cm.

In some aspects, the techniques described herein relate to a ceiling corner element (1) including: a first surface section (11) having a first fold edge (21) and a second fold edge (22); a second surface section (12) connected to the first surface section (11) at the first fold edge (21), the second surface section (12) having a third fold edge (23); a third surface section (13) connected to the second surface section (12) at the third fold edge (23), the third surface section (13) having a first cut edge (31); and a fourth surface section (14) connected to the first surface section (11) at the second fold edge (22), the fourth surface section (14) having a second cut edge (32); wherein the first fold edge (21) runs perpendicular to the second fold edge (22) and the third fold edge (23), and wherein, in an installed position, the first surface section (11) is configured to be arranged on a first drywall surface (2b), the second surface section (12) is configured to be arranged on a second drywall surface (2c), and the third surface section (13) and the fourth surface section (14) are configured to be arranged on a third drywall surface (2a), such that the first cut edge (31) and the second cut edge (32) are arranged side-by-side without overlapping.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein an opening angle (β) is defined between the first cut edge (31) and the second cut edge (32) in the installed position.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein the first cut edge (31) and the second cut edge (32) are configured to be cut with a cutting tool to adjust the opening angle (β).

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein the opening angle (β) lies in a range between 0° and 20°.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein the opening angle (β) lies in a range between 0° and 10°.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein the opening angle (β) lies in a range between 0° and 5°.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein the first surface section (11), the second surface section (12), the third surface section (13), and the fourth surface section (14) each have a length (L) in a range between 1 cm and 10 cm.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein the length (L) lies in a range between 1.5 cm and 5 cm.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein the length (L) lies in a range between 2 cm and 3 cm.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein the first surface section (11), the second surface section (12), the third surface section (13), and the fourth surface section (14) each have a height (H) in a range between 2 cm and 8 cm.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein the height (H) lies in a range between 3 cm and 7 cm.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein at least one of the surface sections (11, 12, 13, 14) includes a self-adhesive surface.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein each of the surface sections (11, 12, 13, 14) includes a self-adhesive surface.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein at least one of the surface sections (11, 12, 13, 14) includes an adhesive material configured to be converted from a first non-adhesive state into a second adhesive state by means of water.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein the ceiling corner element (1) is formed from a material selected from the group consisting of paper, paper containing plastic fibers, or a fiber-reinforced laminate.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein the first, second, third, and fourth surface sections are formed of a nonwoven material containing cellulose fibers and has a polymer coating on at least one side.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein the nonwoven material contains synthetic polymer fibers, wherein the polymer coating is multilayered, and wherein the polymer coating contains modified starch polymers, methylcellulose polymers, activated polyvinyl alcohol polymers, or a mixture thereof.

In some aspects, the techniques described herein relate to a ceiling corner element (1) including: a first surface section (11) having a first fold edge (21) and a second fold edge (22); a second surface section (12) connected to the first surface section (11) at the first fold edge (21), the second surface section (12) having a third fold edge (23); a third surface section (13) connected to the second surface section (12) at the third fold edge (23), the third surface section (13) having a first cut edge (31); and a fourth surface section (14) connected to the first surface section (11) at the second fold edge (22), the fourth surface section (14) having a second cut edge (32); wherein the first surface section (11) and the second surface section (12) are each substantially rectangular in shape, and wherein, in an installed position, the first surface section (11) is configured to be arranged on a first drywall surface (2b), the second surface section (12) is configured to be arranged on a second drywall surface (2c), and the third surface section (13) and the fourth surface section (14) are configured to be arranged on a third drywall surface (2a), such that the first cut edge (31) and the second cut edge (32) are arranged side-by-side without overlapping.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein at least one of the surface sections (11, 12, 13, 14) includes a self-adhesive surface.

In some aspects, the techniques described herein relate to a ceiling corner element (1), wherein an opening angle (β) is defined between the first cut edge (31) and the second cut edge (32), the opening angle (β) lying in a range between 0° and 20°.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic illustration of a seam cover strip obtained with the invention for incorporating in a building material surface.

FIG. 2 shows an enlarged schematic illustration of a preformed ceiling corner element for use in the method for producing a drywall corner structure obtained with the invention.

FIG. 3 shows an enlarged schematic illustration of a preformed ceiling corner element attached to the inner surface of the drywall surfaces after completing the method for producing a drywall corner structure obtained with the invention.

FIG. 4 shows a schematic illustration of a preformed ceiling corner element attached to an inner side of the drywall surfaces after completing the method for producing a drywall corner structure obtained with the invention, in which the angle β is greater than 0°.

FIG. 5 shows a schematic illustration of a preformed ceiling corner element attached to an outer side of the drywall surfaces after completing the method for producing a drywall corner structure obtained with the invention.

DETAILED DESCRIPTION

FIG. 1 shows a schematic drawing of a seam cover strip 101 obtained with the invention, for incorporating in building material surfaces. This cover strip 101 is a nonwoven 102 containing cellulose fibers with a polymer coating 103 on at least one side.

Cellulose is the main component of plant cell walls (approx. 50%) and therefore the most common organic compound and also the most common polysaccharide. Cellulose is also the most frequently occurring biomolecule. It is unbranched and made up of many hundreds to thousands of (-1,4-glycocidic bonded)-D-glucose or cellobiose units. These high molecular weight cellulose chains bond together to form larger structures that frequently function as tear-resistant fibers in plants.

The nonwoven 102 may also contain synthetic polymer fibers. These synthetic fibers are obtained through polymerization, addition reactions, or condensation reactions. The fibers are produced in industrial fiber spinning process.

The polymer coating 103 can be applied to both sides of the nonwoven 102. The polymer coating 103 can also be multilayered. The polymer material 103 contains an adhesive that is activated by water. The polymer material 103 forms an adhesive bond between the smooth nonwoven and the plastering compound on the building material surface. The polymer material 103 contains modified starch polymers, methylcellulose polymers, activated polyvinyl alcohol polymers, or a mixture thereof.

The polymer material 103 can also be a mixture of modified methylcellulose and starch, in particular potato starch. The starch advantageously contains an amylopectin content of 10-40% by weight, preferably 15-30% by weight, ideally 20% by weight.

The nonwoven 102 ideally has a surface area weight of 40-250 g/m², preferably 70-200 g/m², ideally 80-150 g/m². This allows the cover strips to be easily incorporated in the plastering compound surface. Surface area weight is also referred to as grammage or basis weight.

The dry surface area weight of the polymer material 103 on the nonwoven 102 is 5-40 g/m², preferably 8-30 g/m², ideally 8-15 g/m².

The width of the nonwoven 102 is preferably 2-150 cm, more preferably 3-120 cm, ideally 5-100 cm.

A seam cover strip 101 obtained with the invention can be incorporated in a plastering compound on a building material surface, e.g. on a seam between drywall sheets, in the form of a 5 cm wide strip, or covering entire plastering compound surfaces with 1 meter wide sheets.

The seam cover strips 101 obtained with the invention are produced in a process comprising the steps: providing a nonwoven 102 containing cellulose fibers; coating the nonwoven 102 with a polymer material 103 using a squeegee, by spraying it on, in a reverse coating process, and/or in a rotary printing process; and drying the nonwoven 102 coated with the polymer material 103.

By way of example, the coating is applied to one side of the nonwoven 102 in step b. The coating could also be applied to both sides of the nonwoven 102 in step b.

FIG. 2 shows a schematic illustration of a preformed ceiling corner element 1. The preformed ceiling corner element 1 obtained with the invention has a first section 11 with a first folding edge 21 and a second folding edge 22, a second section 12 on the first folding edge 21 that has a third folding edge 23, a third section 13 on the third folding edge 23 that has a first outer edge 31, and a fourth section 14 on the second folding edge 22 that has a second outer edge 32, in which the first folding edge 21 is perpendicular to the second folding edge 22, third folding edge 23, first outer edge 31, and second outer edge 32. The first surface section 11 and the second surface section 12 are each substantially rectangular in shape. The first fold edge 21 runs perpendicular to the second fold edge 22 and the third fold edge 23. This preformed ceiling corner element 1 can be used in the method obtained with the invention to produce a drywall corner structure 2 comprising the steps: providing a preformed ceiling corner element 1 that can be incorporated in a drywall surface composed of a first section 11 with a first folding edge 21 and second folding edge 22, a second section 12 on the first folding edge 21 that has a third folding edge 23, a third section 13 on the third folding edge 23 that has a first outer edge 31, and a fourth section 14 on the second folding edge 22 that has a second outer edge 32, in which the first folding edge 21 is perpendicular to the second folding edge 22, third folding edge 23, first outer edge 31, and second outer edge 32; providing a drywall corner structure 2 comprising a first drywall surface 2a, and second and third drywall surfaces 2b, 2c that extend in a first vertical direction; placing the first section 11 on the second drywall surface 2b, the second section 12 on the third drywall surface 2c, and the third section 13 and fourth section 14 on the first drywall surface 2a; adjusting the angle between the first outer edge 31 of the third section 13 and the second outer edge 32 of the fourth section 14, such that the third section 13 and fourth section 14 are adjacent to one another on the first drywall surface 2a, without overlapping; and attaching the preformed ceiling corner element 1.

The drywall corner structure 2 has a first drywall surface 2a, and second and third drywall sections 2b, 2c that extend in a first vertical direction. In the installed position, the first surface section 11 is configured to be arranged on the first drywall surface 2b, the second surface section 12 is configured to be arranged on the second drywall surface 2c, and the third surface section 13 and the fourth surface section 14 are configured to be arranged on the third drywall surface 2a, such that the first cut edge 31 and the second cut edge 32 are arranged side-by-side without overlapping.

The preformed ceiling corner elements 1 are provided in a container in step a) containing numerous stacked preformed ceiling corner elements 1 that can be removed individually. There are normally 20 to 30, preferably 22 to 28, ideally 25 preformed ceiling corner elements 1 stacked in the container. They can be stored and transported easily and efficiently in this manner without becoming misshapen or damaged.

The method can also contain an additional step c1 in which the first outer edge 31 of the third section 13 and/or the second outer edge 32 of the fourth section 13 has been cut such that the angle is 0° to 20°, preferably 0° to 10°, ideally 0° to 5°. Scissors or a knife can be used for this. An opening angle β is defined between the first cut edge 31 and the second cut edge 32 in the installed position. The first cut edge 31 and the second cut edge 32 are configured to be cut with a cutting tool to adjust the opening angle β.

In placing the preformed ceiling corner element 1 in step c), the first folding edge 21 covers a seam between the second drywall surface 2b and the third drywall surface 2c, the third folding edge 23 covers a seam between the first drywall surface 2a and the third drywall surface 2c, and the second folding edge 22 covers a seam between the first drywall surface 2a and the second drywall surface 2b, such that all the surfaces are flush.

A putty is used in step e), and/or an adhesive on the ceiling corner element 1 is activated by adding water. Other adhesives could also be used, e.g. solvent based adhesives or dispersion adhesives. At least one of the surface sections 11, 12, 13, 14 includes a self-adhesive surface. In some embodiments, each of the surface sections 11, 12, 13, 14 includes a self-adhesive surface. At least one of the surface sections 11, 12, 13, 14 includes an adhesive material configured to be converted from a first non-adhesive state into a second adhesive state by means of water.

The sections 11, 12, 13, 14 of the preformed ceiling corner element 1 each have at least one adhesive surface with which they are attached to the corresponding drywall surfaces 2a, 2b, 2c.

The length L of the sections 11, 12, 13, 14 is 1 cm to 10 cm, preferably 1.5 cm to 5 cam, ideally 2 cm to 3 cm. The height H of the sections 11, 12, 13, 14 is 2 cm to 8 cm, preferably 3 cm to 7 cm, ideally 4 cm to 6 cm. The first surface section 11, the second surface section 12, the third surface section 13, and the fourth surface section 14 each have a length L in a range between 1 cm and 10 cm. In preferred embodiments, the length L lies in a range between 1.5 cm and 5 cm, and more preferably the length L lies in a range between 2 cm and 3 cm. The first surface section 11, the second surface section 12, the third surface section 13, and the fourth surface section 14 each have a height H in a range between 2 cm and 8 cm. In preferred embodiments, the height H lies in a range between 3 cm and 7 cm.

These dimensions L and H of the sections 11, 12, 13, 14 are only preferred lengths and heights, which can be adjusted to the respective construction. Each section 11, 12, 13, 14 can have different dimensions, such that they are optimally fitted to the shape of the drywall surfaces 2a, 2b, 2c to obtain the desired corner.

Each section 11, 12, 13, 14 can also have different lengths L and heights H if this is necessary for a specific situation or corner. Consequently, the dimensions can be fit to the respective structural conditions, the thickness of the drywall sheets, or the desired covering of the seams.

The preformed ceiling corner elements 1 can be made of different materials, e.g. paper, paper containing plastic fibers, or a fiber-reinforced laminate. The ceiling corner element 1 is formed from a material selected from the group consisting of paper, paper containing plastic fibers, or a fiber-reinforced laminate. In some embodiments, the first, second, third, and fourth surface sections are formed of a nonwoven material containing cellulose fibers and has a polymer coating on at least one side. The nonwoven material contains synthetic polymer fibers, wherein the polymer coating is multilayered, and wherein the polymer coating contains modified starch polymers, methylcellulose polymers, activated polyvinyl alcohol polymers, or a mixture thereof.

FIG. 3 shows a schematic illustration of a preformed ceiling corner element 1 placed on an inner surface of a drywall surface 2a, 2b, 2c in an installed position in accordance with the method obtained with the invention. The sections 11, 12, 13, 14 of the preformed ceiling corner element 1 are each placed on an inner side of the drywall surfaces 2a, 2b, 2c in step c).

FIG. 4 shows a schematic illustration of a preformed ceiling corner element 1 placed on an inner surface of a drywall surface 2a, 2b, 2c in an installed position in accordance with the method obtained with the invention, in which the angle is 0° to 20°, preferably 0° to 10°, ideally 0° to 5°. Consequently, the third section 13 and fourth section 14 do not overlap on the first drywall surface 2a. This allows tolerances in the construction to be compensated for.

FIG. 5 shows a schematic illustration of a preformed ceiling corner element 1 placed on a drywall surface 2a, 2b, 2c in an installed position in accordance with the method obtained with the invention. The sections 11, 12, 13, 14 of the preformed ceiling corner element 1 are each placed on an outer side of the drywall surfaces 2a, 2b, 2c in step c).

As used herein, the term “substantially” is used to describe a condition or characteristic that may deviate from an absolute or perfect state by a small degree while still achieving the intended function or purpose. For example, “substantially rectangular” refers to a shape that is generally rectangular in form but may include minor variations, rounded corners, slight irregularities, or deviations from perfect right angles that do not materially affect the overall rectangular character or functionality of the element. Similarly, “substantially perpendicular” refers to an angular relationship that approximates 90 degrees, typically within about +10 degrees, more typically within about +5 degrees, while still achieving the intended structural or functional result. The term “substantially” accounts for manufacturing tolerances, material properties, installation variations, and other practical considerations that may result in minor deviations from theoretical ideals without departing from the scope of the described feature.

The specified features and steps are each to be regarded as optional, and can be implemented individually or collectively, depending on the requirements of the construction project. A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.