WO1999046460A1

WO1999046460A1 - An elongate building element, sheet material for forming same and method of manufacture thereof

Info

Publication number: WO1999046460A1
Application number: PCT/AU1999/000154
Authority: WO
Inventors: K. Brennan
Original assignee: Boral Limited
Priority date: 1998-03-12
Filing date: 1999-03-12
Publication date: 1999-09-16
Also published as: AUPP230298A0

Abstract

An elongate building element, such as a batten, track, rail stud or the like formed from a sheet material, wherein the elongate building element comprises a plurality of elongate formations which extend longitudinally along the elongate building element, the elongate formations having an overall height of up to about 2.6 times the thickness of the sheet material.

Description

AN ELONGATE BUILDING ELEMENT, SHEET MATERIAL FOR

FORMING SAME AND METHOD OF

MANUFACTURE THEREOF

The present invention relates to an elongate building element having a plurality of elongate formations thereon, a sheet material for forming same, and a method of manufacturing the sheet material. More particularly, the invention relates to elongate building elements formed from a preformed sheet material having a plurality of elongate formations thereon, whereby the sheet material is strengthened by the formations with the result that less material can be used to form the elongate building elements without substantially affecting the structural performance thereof.

Sheet materials having various formations thereon to improve strength are known, as are methods of making such sheet materials. For example, Australian Patent No. 682311 describes a method of cold rolling sheet material to form a number of projections on surfaces of the sheet, with a corresponding depression underlying each of the projections on the other surface of the sheet. The projections and depressions are formed in a plurality of rows and provide a material which is more rigid than the sheet material from which it is formed. As such, the mass of the material required for a particular purpose can be reduced.

It is also known to produce corrugated metal materials, for example corrugated iron. These materials are typically used with broad corrugations which provide stability and strength in the longitudinal direction of the corrugations. Again, the inclusion of corrugations along the length of the material provide a stronger material than the corresponding sheet metal without corrugations. Therefore, less mass of material may be suitable for particular purposes.

The invention aims to provide elongate elements for building purposes having improved strength in the longitudinal direction. The present invention also aims to provide an alternate sheet material and method for making same having increased strength in a - 2 -

longitudinal direction which may be used to form such elongate elements.

According to a first aspect of the invention there is provided an elongate building element, such as a batten, track, rail stud or the like formed from a sheet material, wherein the elongate building element comprises a plurality of elongate formations which extend longitudinally along the elongate building element, the elongate formations having an overall height of up to about 2.6 times the thickness of the sheet material.

The elongate formations may comprise a plurality of interrupted formations, each of which extends partially along the length of the elongate building element, provided that the interruptions in the formations do not collectively form a substantially continuous line across the length of the elongate building element. Alternatively, each of the elongate formations extends along the entire length of the elongate building element.

The overall height of each of the elongate formations is up to about 2.6 times the thickness of the material from which the elongate building element is made. More preferably about 2.0 times the thickness, and most preferably about 1.7 times the thickness of the material from which the elongate building element is made. Furthermore, the pitching of the formation, that is the distance between a point on one formation to the same point on the following formation, is preferably about 10 times the thickness of the material from the which the elongate building element is made.

The elongate formations may take any suitable form. For example, the elongate formations may comprise a plurality of ribs which extend along one side of the sheet material from which the elongate building element is formed. In this case the overall height of the formations would be the total height of the rib and sheet material. It is preferred that the elongate formations comprise a plurality of corrugations extending along the elongate building element. - 3 -

The corrugations are preferably such that half pitches are substantially identical but inverted. That is, a corrugation trough on the elongate building element has the same dimensions as a corrugation peak on the elongate building element.

The corrugations may take any suitable form. For example the corrugations may be round or square corrugations. In a preferred embodiment the corrugations are substantially trapezoidal in cross section. That is, each trough has a flat base portion connected with flat top portions of adjacent peaks by diagonally extending portions. The diagonally extending portions of material connecting the base portions of the troughs and top portions of the peaks preferably extend at an angle of from about 30° to about 60° to the plane of the sheet material, more preferably about 45° to the plane of the sheet material.

The sheet material from which the elongate building elements are made is preferably a preformed sheet material, the plurality of elongate formations having been mechanically worked into the sheet material prior to roll forming of the elongate building elements.

The elongate building element may be any element to which structural stability in the longitudinal direction is advantageous. For example, the building element may comprise a ceiling batten, cross-rail, wall track, wall stud or the like.

According to a second aspect of the invention there is provided a method of cold rolling a sheet material which is to be used to form an elongate building element according to the first aspect of the invention, the method comprising passing a sheet material between a pair of rollers to form a preformed sheet material having a plurality of longitudinally extending elongate formations, the elongate formations having an overall height of up to about 2.6 times the thickness of the sheet material.

The pair of rollers may comprise a pair of driven rollers. However, equally good results may be obtained using undriven rollers with a roll former drive which pulls the sheet material through the pair of rollers. Preferably the pair of rollers are set to a clearance which - 4 -

is equal to the thickness of the material so that the thickness of the material is not diminished during the rolling operation.

The dimensions of the rollers are preferably selected to provide the desired characteristics to the preformed sheet material. Furthermore, the settings required to achieve the desired results will generally be a function of the mechanical properties of the sheet material being rolled. That is, on rolling, different materials have different "spring back" properties. As a result, preformed sheet material formed from different materials may be of different dimensions after being passed through the pair of rollers even though the parameters and settings of the rollers were identical during rolling. For example, when the elongate formations comprise a plurality of longitudinally extending corrugations as described above, in order to achieve an overall corrugation height of about 1.7 times the material thickness, the pair of rollers may have to be set to define a height which is greater than this due to spring back in the material. Similarly, to achieve the preferred angle of 45° for the diagonally extending portions of each corrugation relative to the plane of the sheet material, it is generally necessary for the pair of rollers to have teeth having diagonally extending side faces which are set at an angle which is greater than 45° to the plane of the sheet material passing through the rollers. A more detailed description of the rollers which may be used in accordance with the method of the invention will be discussed hereafter with reference to the accompanying drawings.

According to a third aspect of the invention there is provided a preformed sheet material for use in forming an elongate building element according to the first aspect of the invention and/or produced by a method according to the second aspect of the invention.

Preferred embodiments of the present invention will now be described in more detail with reference to the accompanying drawings in which:

Figure 1 illustrates a cross-section of a preformed sheet material having a plurality of longitudinally extending corrugations; Figure 2 illustrates preforming rolls suitable for use in preforming a sheet material - 5 -

before form rolling into an elongate building element;

Figure 3 A illustrates an exploded view of a top roll;

Figure 3B illustrates an exploded view of a bottom roll;

Figure 4A illustrates a cross-section of a ceiling batten; Figure 4B illustrates a cross-section of an alternate ceiling batten;

Figure 4C illustrates a cross-section of a top cross-rail;

Figure 4D illustrates a cross-section of a wall track;

Figures 4E and 4F illustrate a cross-section of a wall stud and a boxed stud respectively.

Referring to Figure 1, a preformed sheet material 10 comprises a plurality of corrugations 11 made up of a plurality of peaks 12 and troughs 13. Each of the peaks 12 and troughs 13 comprise a substantially flat portion 14 which is joined to adjacent troughs and peaks respectively by diagonally extending portions 15. The thickness of the material "t" is generally between 0.45 mm and 0.75 mm. This corresponds to the gauge of the sheet material prior to preforming.

The overall height of the preformed material "h" is about 1.7 times the thickness "t" of the sheet material. The pitch "p" of the corrugations 11 is about 10 times the thickness "t" of the sheet material.

As can be seen in Figures 2, 3 A and 3B, the rollers 20 comprise a plurality of teeth 21, 22 and troughs 23, 24 which extend continuously around the roller. The teeth 21, 22 of the rollers 20 are arranged such that the teeth 21 of the top roll extend into the troughs 24 of the bottom roll and, similarly, the teeth 22 of the bottom roll extend into the troughs 23 between teeth 21 on the top roll. The clearance between the top roll and the bottom roll is equal to the thickness "t" of the sheet material. Thus, the thickness "t" of the sheet material is not affected during rolling of the sheet material into the preformed sheet material 10. Furthermore, the form of the teeth 21, 22 and troughs 23, 25 on the top and bottom rolls corresponds substantially to the form of the corrugations 11 of the preformed sheet material - 6 -

10. It will however be recognized that the final dimensions of the preformed sheet material depends not only on the dimensions of the rollers, but also on the characteristics of the sheet material being preformed.

The dimensions of the teeth 21, 22 and troughs 23, 24 formed between the teeth may be selected based on the characteristics of the material to be preformed. The particular figures provided in Figures 3A and 3B exemplify dimensions which are suitable in at least some circumstances.

As previously discussed, the diagonal faces of each of the teeth and the plane of the sheet material passing through the rollers define an angle, "angle α", which is greater than 45 ° . This advantageously provides a corresponding angle in the preformed sheet material which is around 45°. Again, the reduction in the angle in the preformed sheet material as compared with that defined by the teeth of the rollers will be a function of the spring back of the sheet material being preformed. As such, the angle α defined by the teeth of the rollers should be determined in each specific case taking into consideration the spring back of the material being preformed.

The preformed sheet material, and therefore the elongate building members, is preferably formed from a material selected from zincalume G300 AZ100, galvanised steel, zinc sheet, alumabond and colourbond.

Reference will now be made to Figures 4A to 4F, although the description will not go into substantial detail in the description of these figures.

The elongate elements, including sealing battens, cross-rail, wall track and wall stud, illustrated in Figures 4A to 4F are formed by roll forming sheet material which has previously been mechanically treated into a preform as discussed above. During roll forming into the elongate building elements, it is advantageous if the corrugations in the preformed material be unaffected. However, during roll forming of the elongate building elements at 7 -

least some flattening may occur along the form lines in the elongate building elements.

The elongate building elements are preferably formed from a sheet material, for example zincalume G300 AZ100, having a gauge varying from 0.45 mm to 0.75 mm depending on the particular element. For example, the sealing batten illustrated in Figure 4A is typically formed from a material having a gauge of 0.45 mm or 0.55 mm, the sealing batten illustrated in Figure 4B is typically formed from a material having a gauge of 0.45 mm. The top cross-rail illustrated in Figure 4C typically has a gauge of 0.55 or 0.75 mm, and the wall track and wall stud illustrated in Figures 4D and 4E respectively typically have a gauge of 0.45, 0.55 or 0.75 mm.

Reference will now be made to tensile tests which have been conducted by a laboratory registered by the National Association of Testing Authorities, Australia. The tests were carried out in accordance with Australian Standard Testing Method 1391-1991.

The tests were carried out on samples of 0.45 mm flat sheet and 0.45 mm corrugated C-section sheet steel. The sheet steel had a surface coating of aluminium and zinc alloy. The test piece was a flat, reduced section having a 20 mm parallel width. The nominal gauge length was 80 mm.

Test results: TABLE 1

Sample Yield Stress Tensile Strength Percentage Identification (MPa) (MPa) Elongation

0.45 mm Flat 408 461 19 (Z) 0.45 mm corrugated 483 536 14

0.45 mm Flat 338 * 382 * 0.45 mm corrugated 396 * 440 *

Notes: * Calculations based on full product thickness

(Z) Test piece broke outside middle third of gauge length - 8 -

The test results illustrate an increase in tensile strength of the corrugated sample as compared with that of the flat sample of 16.3%, and 15.2% for calculations based on the full product thickness. This increase in tensile strength represents a substantial improvement in the sample when corrugations as herein described are present as compared with when they are not.

Advantageously the improved tensile strength of the sheet material makes it possible to form elongate building elements which have less mass without substantially affecting the structural performance of the building elements. In use, it is envisaged that this will be advantageous for both economic and environmental reasons.

While the present invention has been described with particular reference to preferred embodiments, the present invention is susceptible of being embodied with various alterations and modifications that may differ particularly from those described in the preceding specification. These variations and alterations are possible without departing from the scope of the invention.

Claims

- 9 -THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. An elongated building element formed from a sheet material, said elongate building element comprising a plurality of elongate formations which extend longitudinally along the elongate building element, said elongate formations having an overall height of up to about 2.6 times the thickness of said sheet material.

2. An elongate building element according to claim 1, wherein each of said elongate formations extends along the entire length of said elongate building element.

3. An elongate building element according to claim 1 , wherein said overall height of said elongate formations is about 1.7 times the thickness of said sheet material.

4. An elongate building element according to claim 1, wherein the pitching of said elongate formations is about 10 times the thickness of said sheet material.

5. An elongate building element according to claim 1, wherein said elongate formations comprise a plurality of ribs which extend along one or both sides of said sheet material, or a plurality of corrugations extending along said sheet material.

6. An elongate building element according to claim 5, wherein said elongate formations comprise a plurality of corrugations, said corrugations being substantially trapezoidal in cross section.

7. An elongate building element according to claim 1, wherein said building element comprises a sealing baton, cross rail, wall track, wall stud or the like.

8. A method of cold rolling a sheet material which is to be used to form an elongate building element according to claim 1, said method comprising passing a sheet material between a pair of rollers to form a pre-formed sheet material having a plurality of - 10 -

longitudinally extending elongate formations, said elongate formations having an overall height of up to about 2.6 times the thickness of said sheet material.

9. A method according to claim 8, wherein said pair of rollers are set to a clearance which is equal to the thickness of said sheet material during the rolling operation.

10. A pre-formed sheet material for use in forming an elongate building element according to claim 1 , said sheet material comprising a plurality of elongate formations which extend longitudinally along said sheet material, said elongate formations having an overall height of up to about 2.6 times the thickness of said sheet material.