TECHNICAL FIELD

The invention relates to a corner bead for mounting on an internal or external corner of a building construction, said corner bead comprising a first flange and a second flange which are configured with a longitudinal extension and a generally L-shaped cross- section.

The invention also relates to a method for manufacturing a corner bead configured for mounting on an internal or external corner of a building construction. The method comprises providing a first flange and a second flange and arranging the first flange and the second flange in a configuration having a longitudinal extension and with a generally L-shaped cross-section. BACKGROUND OF THE INVENTION

In the field of building constructions, it it is previously known to arrange interior walls by fastening sheets of gypsum wallboards to a support structure. Such interior walls are sometimes arranged so that they define outside corners. These outside corners are in an exposed position and can be easily damaged, which is a disadvantage.

In order to protect such an outside corner from potential damage, it is previously known to use so-called corner beads. A corner bead is a relatively thin and longitudinally extending reinforcement structure having two flanges forming an L-shaped cross-section and being configured for mounting along such an outside corner. A corner bead can be

manufactured from a suitable plastics material and will act as a reinforcement of the outside corner. In this manner, any potential damage to the outside corner can be minimized or even eliminated. Also, the corner bead contributes to a clean and even surface of the building construction including the corner. According to known technology, a corner bead is mounted on an outer corner before any further surface treatment, such as painting, is carried out. A conventional way of attaching a corner bead is by gluing it to the outside corner and then applying compound on the wall element including the corner bead.

Furthermore, a previously known corner bead of the above-mentioned type is known from the patent document US 2006/283115. Even though the article disclosed in US

2006/283115 fulfills the basic requirements regarding a corner bead for mounting on a building construction, there is a need for further improvements of such devices. Firstly, there is a requirement for a simple way of attaching the corner bead to the building construction and a need for a secure attachment of the corner bead on different types of surfaces of the building construction. Also, there is a desire to provide a cost-efficient process for manufacturing such corner beads.

Consequently, there is a need for further improvements within the relevant field of technology.

SUMMARY OF THE INVENTION

In accordance with the present disclosure, there is provided an improved corner bead having the purpose of solving the above-mentioned problems related to prior art within this field. A particular purpose of the disclosure is to provide an improved process for manufacturing corner beads.

In accordance with the disclosure, these objects are obtained by means of a corner bead for mounting on an internal or external corner of a building construction, said corner bead comprising a first flange and a second flange which are configured with a longitudinal extension and a generally L-shaped cross-section. Furthermore, the first flange has a first surface intended for facing said building construction and said second flange has a second surface also intended for facing said building construction, wherein at least one of said first surface and said second surface is at least partially coated with an adhesive element.

According to the disclosure, certain advantages are obtained. Firstly, an efficient process for manufacturing corner beads at a low production cost is obtained. Also, the corner bead according to the disclosure can be securely attached to building constructions having different types of surfaces, even surfaces being coated with dust and dirt. Furthermore, the corner bead according to the disclosure can be handled by a person in an easier and quicker way during mounting on a corner. Also, the choice of adhesive element can be adapted to different temperatures, which simplifies the mounting of the corner bead.

According to an embodiment, said adhesive element is in the form of an adhesive which is applied on a protective layer, which in turn is applied on said at least one of said first surface and said second surface which is thereby coated with said hot melt adhesive. This means that the corner bead can be easily mounted by first removing the protective layer and then pressing the corner bead against the corner. After this step, compound can be applied on the wall elements and the corner in a quick and efficient manner. Also, the step of applying compound can be made without any waiting time, i.e. without first having to wait for any particular glue or similar material to dry.

According to an embodiment, the protective layer is constituted by a siliconized paper strip.

According to an embodiment, the surface or surfaces which are coated with said hot melt adhesive are positioned so as to define a further surface which is free from said hot melt adhesive, and said protective layer extends generally across the combined width of the hot melt adhesive and said further surface.

According to an embodiment, said hot melt adhesive comprises ethylene-vinyl acetate (EVA), resin and wax.

According to an embodiment, the first flange and the second flange are arranged with an angle in relation to each other which is between 85° and 95°.

According to an embodiment, the corner bead is provided with a slightly rounded corner nose located where the first flange and the second flange meet, and extending generally along the entire length of the corner bead. Such a corner nose will simplify the

subsequent process of applying compound.

According to an embodiment, the first flange has a third surface which is not facing said building construction and said second flange has a fourth surface which is not facing said building construction, wherein at least one of said third surface and said fourth surface is covered with an absorbing surface layer which is configured for absorbing compound during attachment of the corner bead to the building construction.

According to an embodiment, at least one of said first flange and said second flange is provided with a pattern of perforations extending generally along the longitudinal direction of said flange or flanges.

According to an embodiment, the corner bead is manufactured at least partly from a biodegradable plastic material.

According to an embodiment, the adhesive is a hot melt adhesive.

Furthermore, the above-mentioned objects of the disclosure are obtained by means of a method for manufacturing a corner bead configured for mounting on an internal or external corner of a building construction. The method comprises: providing a first flange and a second flange; and arranging the first flange and the second flange in a

configuration having a longitudinal extension and with a generally L-shaped cross-section. Furthermore, the method comprises: forming said first flange with a first surface which is configured for facing said building construction; forming said second flange with a second surface which is also configured for facing said building construction; and coating at least one of said first surface and said second surface at least partially with an adhesive element.

Furthermore, the above-mentioned objects are obtained by means of a system for manufacturing a corner bead which is configured for mounting on an internal or external corner of a building construction, comprising an extruder unit for providing a corner bead material with a first flange and a second flange and being configured for arranging the first flange and the second flange in a configuration having a longitudinal extension and with a generally L-shaped cross-section. Furthermore, the extruder unit is configured for forming said first flange with a first surface which is configured for facing said building

construction, and forming said second flange with a second surface which is also configured for facing said building construction; and that the system further comprises a unit for coating at least one of said first surface and said second surface at least partially with an adhesive element. Further advantages and advantageous features of the invention are disclosed in the following description and in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in greater detail below with reference to the figures shown in the appended drawings.

Figure 1 shows a perspective view of a building construction on which a corner bead according to the disclosure is mounted;

Figure 2 shows a perspective view of a part of the corner bead;

Figure 3 shows a further perspective view of a part of the corner bead according to Figure 2;

Figure 4 is a cross-sectional view of the corner bead according to Figures 2 and

3; and

Figure 5 is a view of the corner bead showing in particular a pattern of

perforations of the corner bead; and

Figure 6 is a schematic view of a manufacturing process for the corner bead.

DESCRIPTION OF EMBODIMENTS

Different aspects of the present disclosure will now be described more fully with reference to the enclosed drawings. The embodiments disclosed herein can, however, be realized in many different forms and should not be construed as being limited to the aspects described below. With initial reference to Fig. 1 , there is shown a perspective view from above of a building construction 1 comprising a number of wall elements 2, suitably in the form of gypsum or plasterboard wallboard elements which are attached to a support structure 3. The building construction 1 as such is well-known and is for this reason not described in further detail here. The building construction 1 is designed with an outwardly facing corner 4, i.e. extending along a corner where two wall elements 2 meet. As mentioned initially, it is known that such an outside corner 4 may be exposed to damage. In order to provide reinforcement of the outside corner 4, and to make the outside corner 4 look tidy and of high quality, a corner bead 5 is mounted on the outside corner 4. This is done prior to further surface treatment such as painting or attaching wall-paper.

According to an embodiment of the disclosure, the corner bead 5 is formed as a longitudinally extending element having a first flange 6 and a second flange 7 which are configured generally with an L-shaped cross-section. As further disclosed in Fig. 2, which is a perspective view of an end section of the corner bead 5 according to the embodiment, the first flange 6 has a first inner surface 8 and the second flange 7 has a second inner surface 9. The first and second inner surfaces 8, 9 are intended to face the building construction 1 when the corner bead 5 is mounted by attaching it as intended on the corner 4, and as shown in Fig. 1.

With particular reference to Fig. 2, the first inner surface 8 and the second inner surface 9 are both covered with an adhesive element, suitably in the form of a hot melt adhesive 10. According to alternative embodiments, the adhesive element 10 can be applied on either one of the first inner surface 8 or the second inner surface 9. Also, the hot melt adhesive 10 can be of a type which comprises ethylene-vinyl acetate (EVA), resin and wax.

It should be noted that although the embodiment in Figs. 1 and 2 is directed to a corner bead 5 which is configured for mounting on an outside corner 4, the disclosure also includes embodiments involving a corner bead 5 which can be mounted on an inner, or internal, corner 4 ^' as indicated in Fig. 1. In such case, an adhesive element is applied on the reverse side of each flange.

Furthermore, with reference to Fig. 3, which is a perspective view of the corner bead 5 from a different angle as compared with Fig. 2, there is shown an embodiment in which a protective layer 11 is used for applying and supporting the adhesive element 10. More precisely, an adhesive element such as a layer of hot melt adhesive 10 is first applied on the protective layer 11. The protective layer 11 is subsequently applied on the second inner surface 9. In this manner, the second inner surface 9 will be coated with the hot melt adhesive 10. Also, the protective layer 11 should be peeled away and removed before attaching the corner bead 5 to a corner 4 of a building construction 1.

Fig. 3 is a simplified drawing which shows only one protective layer 11 , i.e. which is positioned along the second flange 7. It should be noted that a further protective layer with an adhesive element can be applied on the first inner surface 8 in a similar manner as described above.

As will be described below, the corner bead 5 can be attached to an outside corner 4 of a building construction 1 (see Fig. 1) by means of the adhesive element. After attaching the corner bead 5 to the building construction 1 , compound will be applied in one of more layers so as to produce an even surface of the building construction 1 including the corner 4. After applying compound, the wall elements in question can then be painted or be provided with wallpaper, in a manner which is well-known as such.

According to an embodiment, the protective layer 11 is in the form of a paper strip which is coated with a thin surface layer of silicone. According to an alternative embodiment, the protective layer can be in the form of a thin sheet of plastic material.

Furthermore, according to the embodiment shown in Fig. 3, the second inner surface 9 is configured in a manner so that the hot melt adhesive 10 covers generally the entire second inner surface 9 with the exception of a further surface 12. This further surface 12 is formed as a relatively narrow and longitudinally extending strip which is free from adhesive and which suitable extends along the inner corner of the corner bead 5, i.e. where the first flange 6 and the second flange 7 meet. The width of the further surface 12 is suitably a few millimetres, as compared with the width of the entire second inner surface 9, which is suitably within the interval 30-50 mm. It should be noted that the protective layer 11 extends across the entire second inner surface 9, i.e. generally across the combined width of the hot melt adhesive 10 and the above-mentioned further surface 12. The part of the protective layer 11 which is located on top of the further surface 12 will define a“finger grip” part of the layer 11. In this manner, a process of peeling off and removing the protective layer 11 before attaching the corner bead 5 to the building construction 1 can be further simplified. The further surface 12, i.e. without any adhesive, is provided due to the fact that the protective layer 11 is prepared separately and is coated only partly with an adhesive. According to an embodiment, only a certain width of the protective layer 11 is provided with the adhesive.

According to an embodiment, the corner bead 5 is configured so that the first flange 6 and the second flange 7 are arranged with an angle in relation to each other which is within an interval between 85° and 95°. In the event that the corner bead 5 is used in an internal corner 4 ^' , the angle between the first and second flanges is preferably within an interval of 93° and 95°.

Also, the corner bead 5 is also suitably provided with a slightly rounded corner strip 13, i.e. a so-called“nose”, which extends generally along the entire length of the corner bead 5. The provision of such a corner strip 13 simplifies the process of applying compound on the corner bead 5 after attaching it to the building construction 1.

Furthermore, the first flange 6 is formed with a third surface 14 which is not facing said building construction and the second flange 7 is formed with a fourth surface 15 which is not facing said building construction. At least one of the third surface 14 and the fourth surface 15 is covered with an absorbing surface layer 16 which is configured for absorbing compound during the process of preparing an even wall element after attaching the corner bead 5. According to an embodiment, the absorbing surface layer 16 covers generally the entire third surface 14 and fourth surface 15, i.e. it extends over the corner strip 13. An advantage of using the absorbing surface layer 16 is that the corner bead 5 will be tightly attached to the building construction in question after applying compound.

Furthermore, as indicated in Figs. 2 and 3, the first flange 6 and the second flange 7 are provided with a pattern of perforations 17. This pattern extends generally along the entire length of the corner bead 5. By providing this pattern of perforations 17, the corner bead 5 can be attached more securely to the surface of the building construction 1 since compound will more easily penetrate through the corner bead 5 and reach the surface of the corner 4, while also covering the corner bead 5.

With reference to Fig. 3, the protective layer 11 is shown as a non-perforated strip of material. This is the case in an embodiment in which the manufacturing process of the corner bead 5 involves perforating the corner bead 5 before the protective layer 11 is applied onto the corner bead 5. However, according to a further embodiment, the protective layer 11 can be applied before the perforations 17 are made. In such a manufacturing process, the protective layer 11 will also have perforations of the same pattern as the actual corner bead 5.

With regard to the absorbent surface layer 16, it should be noted that, according to different embodiments, the perforations 17 can be made before or after applying said absorbent surface layer 16.

According to an embodiment, the corner bead 5 is manufactured from a plastics material such as ABS plastics. According to a further embodiment, the corner bead 5 is manufactured from a biodegradable plastic material, which is an advantage from an environmental point of view. Such a material can be based on a composition comprising biodegradable polyester, starch, a filler material and a binding agent, in suitable proportions. As regards the filler material, such material can according to an embodiment comprise dolomite in the form of particles with a polished surface. A further advantage of using a biodegradable material for the corner bead 5 is that it can be manufactured slightly thinner than the embodiment involving an ABS plastics material. This will simplify the process of applying compound and also means that less compound material has to be used, which is a further advantage.

Fig. 4 shows a cross-sectional view of the corner bead 5 according to an embodiment of the disclosure. As indicated, the corner bead 5 comprises a first flange 6 and a second flange 7 on which a layer of adhesive material 10 is applied. A protective layer 11 is provided on top of the adhesive material 10. It should be noted that Fig. 4 shows an embodiment in which both the first flange 6 and the second flange 7 supports a layer of adhesive material 10 and a protective layer 11.

Furthermore, a thin strip corresponding to the above-mentioned further surface 12 is provided, wherein the further surface 12 is free from adhesive material. Also, a corner strip 13, or“nose”, is provided where the first flange 6 and second flange 7 meet. The first flange 6 has a third surface 14 facing away from the building construction in question (not shown in Fig. 4) and the second flange 7 has a fourth surface 15 facing away from the building structure. An absorbing surface layer 16 is provided along the third surface 14 and the fourth surface 15. Finally, a pattern of perforations 17 is arranged on the first flange 6 and the second flange 7.

Fig. 5 shows a view of the corner bead 5 in which the pattern of perforations 17 is shown in detail. According to an embodiment, the perforations 17 are provided in the form of a number of columns 18, for examples three columns 18 as shown in Fig. 5, which columns 18 are sligthly offset in relation to each other. Also, the columns 18 of perforations 17 are concentrated to the outer section of the second flange 7. In this manner, the corner bead 5 can be securely fitted to a building construction while covering it by means of compound.

Fig. 5 shows a view which only discloses perforations 17 in the second flange 7. It should be noted, however, that according to an embodiment, a similar pattern of flanges is provided in the first flange 6 too.

According to the disclosure, there is also provided a process for manufacturing a corner bead 5 as described above. Such a manufacturing process is initiated by providing the first flange 6 and the second flange 7, and also arranging the first flange 6 and the second flange 7 in a configuration having a longitudinal extension and with a generally L-shaped cross-section. Such a process step is carried out by extrusion of a suitable material, for example an ABS plastic material.

Furthermore, the adhesive element 10 is provided on the surfaces 8, 9 of the first flange 6 and the second flange 7 which face the corner 4 of the building construction 1. This is achieved by first attaching the adhesive material 10 to the protective layer 11 and then attaching the protective layer 11 on the above-mentioned surfaces 8, 9. This means that a certain amount of the adhesive material will adhere to said surfaces 8, 9.

Next, the absorbing surface layer 16 is attached to the outside of the corner bead 5, i.e. to the third surface 14 and fourth surface 15 which do not face the building construction. According to an optional process step, the corner bead 5 is then marked with a suitable logotype, product number etc., after which the above-mentioned perforation 17 are formed. Finally, the corner bead 5 is cut to a suitable length. Fig. 6 shows a schematic view of a system for manufacturing a corner bead 5 in accordance with the disclosure. Initially, it should be noted that a suitable plastics material is fed into an input port 19. The plastics material is fed into an extruder 20 which is configured for forming a corner bead as described above. In particular, the extruder 20 produces a continuous piece of corner bead material 21 which is subsequently cut into a suitable length at a later stage of the manufacturing process.

It should be noted that an extrusion process in which a particular object is manufactured by forcing a material through a die is known as such. For this reason, it is not described in detail here.

The extrusion process in the extruder 20 results in a corner bead material 21 which is relatively hot and soft and which needs to be cooled. For this reason, the corner bead material 21 is fed through a cooling station 22, which is shown here in a schematical manner as a water container through which the corner bead material 21 is fed.

Next, the cooled corner bead material 21 is fed into a further unit 23 which is configured for applying the absorbent surface layer 16 which is described above with reference to Fig. 2.

The next step in the manufacturing process is a further unit 24 which is configured for applying the above-mentioned protective layer 11 on the corner bead material 21. As indicated in Fig. 6, there is a separate drawing showing that the protective layer 11 is pre manufactured in a separate unit 25 for this purpose. According to an embodiment, as mentioned above with reference to Fig. 3, the protective layer 11 is manufactured with a relatively narrow surface 12 which is formed in longitudinally extending manner and which which is free from adhesive. This is obtained by arranging an adhesive applicator 26 in a manner so that an adhesive 10 is only applied on an adhesive section 27 of the protective layer 11 , i.e. by applying the adhesive on a certain width of the protective layer 11 and without applying any adhesive on the above-mentioned surface 12. According to an embodiment, the adhesive 10 is a hot melt adhesive.

As mentioned above, the width of the surface 12 can be a few millimetres, as compared with the width of the entire second inner surface 9, which is suitably within the interval 30- 50 mm. This is due to the precision which can be obtained by means of the adhesive applicator 26, which only applies adhesive on a well-defined section (i.e. the adhesive section 27) of the protective layer 11. The surface 12 defines a“finger grip” part of the layer 11 which simplifies a process of peeling off and removing the protective layer 11 before attaching the corner bead 5 to the building construction 1 in question.

The protective layer 11 is consequently fed into the manufacturing process and applied on the corner bead material 21 (as indicated with an arrow 28 in Fig. 6) by means of the unit 24. The resulting corner bead material 21 is then guided to a perforation and cutting unit 29, which is first configured for providing the perforations mentioned above and indicated with reference numeral 17 in Figs. 2-5, and which is also configured for cutting the corner bead material 21 into individual corner beads 5 having a desired length.

In summary, and according to an embodiment, there is provided an improved process of manufacturing a corner bead 5 which is based on a first step of applying an adhesive on the protective layer 11 and subsequently applying the protective layer 11 on a corner bead 5 (or corner bead material 21). This leads to a process with high accuracy and precision as regards the process of applying the adhesive. This means that the above- mentioned further surface 12 can be used as a“finger lift” area which simplifies handling of the corner bead 5.

The invention is not limited to the embodiment but can be varied within the scope of the appended claims. For example, the shape, length and thickness of the flanges 6, 7 may vary. Also, other parameters such as the pattern of perforations and the area of the adhesive element may also vary.

Furthermore, the corner bead can be attached to both outside and inner corners. In the event that the corner bead is used in an internal corner, the adhesive element (with the protective layer) and the absorbing surface layer must be positioned on the reverse sides of the flanges as compared with the disclosure above, which describes a corner bead for an outside corner.