CONSTRUCTION BOARD

Abstract: The invention relates to a longitudinal laminate board (1) of binder fixed mineral wool, which is suitable as a core of a sandwich element having surface layers of e.g. thin sheet metal. The laminate board consists of adjacently disposed longitudinally oriented rods (2), whose fibre plane forms a right angle to the plane of the laminate board. The rods are shorter than the laminate board and jointed to each other. The joints are distributed over the laminate board so as to eliminate their weakening effect on the resistance of the board. The total joint surfaces of the laminates form, within an interval (a) of the board, in which (a) depends on the length of the board and the number of laminates in the width, maximally one third of the cross-section of the board. As to areas of the length (a) next to the end faces and next to the support lines of multi-field boards, higher requirements of absence of joints are then posed on interposed areas.

Description: Construction board The invention relates to a construction board, in. particular to a longitudinal laminate board of binder fixed mineral wool, which is suitable as a core of a sandwich element having a surface layer, e.g. of sheet metal, on each side, consisting of adjacently disposed rods, the longitudinal di¬ rection of which coincide with the one of the laminate board and whose fibre plane form a right angle to the plane of the laminate board. Laminate boards of this type are prior known, having been used for instance in shipbuilding industry as insulating walls of variouβ spaces. The sandwich element of mineral wool has been used to some extent within the shipbuilding industry. So far, however, longitudinal elements have not been available, neither aβ roof or floor elements, nor as wall elements. o The idea of rotating cut laminates 90 and of reassembling them in the turned position, thus obtaining a laminate board having fibres oriented perpendicularly to the plane of the board, is prior known. Such a laminate board has excellent resistance properties and is able to transfer shearing forces between its surface planes. Finished sandwich elements of mineral wool with the fibres oriented perpendicularly to the surface plane of the element would be usable aβ supporting roof, floor and wall elements, thus simplifying construction operations noticeably. The object of this invention iβ to provide long sandwich ele¬ ments having a core consisting of fire, noise and heat insu¬ lating laminate boards for roof, floor and wall constructions . According to the invention, this object has been achieved by composing the laminate board of rods that are βhorter than the laminate board and by letting aligned rods coincide with¬ out intervale so as to form a joint, whereby the total joint surfaces of the laminates within one interval of the length a βomwehere along the length of the laminate board form maxi¬ mally one third of the cross-sectional surface of the board, in which a = L : l,90n and L = the length of the laminate board, when the board is used as a one-field construction with support points at the ends, and L = the span, when the board is used as a multi-field-constuction with one or more supporting points between the ends, and n = the number of la¬ minates in the width of the laminate board. The facts mentioned about the joint surface of the laminates are pertinent regardless of the joint surface being vertical to the surface layer of the laminate board or its being til¬ ted, the joint surface being greater in the latter case than in the former. The total surface of the joint surfaces must not exceed one third of the cross—sectional surface. As an example one can mention a laminate board with 9 laminates, whereby the length a of the board may comprise three vertical joint surfaces, none of which iβ an inclined joint surface, which would result in a total joint surface that is greater than one third of the total cross-sectional surface. According to the invention, a long construction board can be provided, of the size order of 9-10 m, by means of laminates o rotated 90 and reassembled, without handling mineral wool mats and cut laminates of the corresponding length. By distri¬ buting the joints between the variouβ aligned rode appro- priately over the surface of the laminate board, a board is obtained, which used as a core of a sandwich element has the same reβiβtance properties aβ a board without joints, i.e. in which the weakening influence of the joints has been elimina¬ ted. According to a preferred embodiment 'of the laminate board of the invention, none of the joints is closer to an end of the laminate board than a. According to another preferred embodiment of the board, maxi¬ mally one joint is disposed within the range 2a from any end of the board. According to a further development of the invention, maximally two joints are disposed within the dis¬ tance 3a from any end of the board. The facts mentioned above about the existence of joints at the ends of the laminate board, iβ also true about the areas on each side of intermediate supports of a multi-field construction. A force concentration namely arises at interme¬ diate supports like at the end supports. These critical areas must not contain as many joints aβ interposed areas. The con¬ clusion is valid for elements in a horizontal position as well as for elements in a vertical position. As a general rule, the distance a indicating the length of the critical area, equals L : 2n. Since the support points, among others, have a certain extension, the length a has to be made somewhat longer, and thus the length L is appro¬ priately divided by 1 , " 9n. Further, the distance between joints of two adjacent rows of rods' preferably equals at least the thickness of the rods in the laminate board, i.e. the thickness of the laminate board. According to a preferred embodiment of the process, the rods are connected with a glue joint by applying glue to the end surfaces before connecting and fixing e.g. by drying subsequent to the forming of the laminate board. The glue application is appropria¬ tely performed before the phase displacement of the rod flow. According to another preferred embodiment of the process, the end surfaceβ of the rode are face milled or prepared so as to match the surfaces well, before a possible glue application. According to another preferred embodiment, the future lateral surfaceβ of the rods are face milled or prepared so that the rods will fit tightly to each other. According to another embodiment, traces are made in the end faceβ of the rode, parallel to the plane of the laminate board or perpendicular to these, so as to provide a finger joint between the rods . According to a further embodiment, the rods are pressed together during the connecting moment at a pressure exceeding 100 Pa, pre ferably 500 Pa. The mineral wool mat used as βtarting material consists of a bin der fixed mineral wool, which may be a rock wool or a glass wool forming essentially plane parallel layers conβiβting of vitreouβ fibreβ more or less in disorder. By rotating the rods cut from t mat, rods having vertically oriented fibreβ are obtained, which valuable for the reβistance requirements of the laminate board when used aβ a construction element. This fibre orientation, al¬ lowing shearing forces to be transferred between the surface pla nes of the board, enables the uβe of very long boards, of the si order of 9-10 m, for constuction purposes. the joints is eliminated. This relation is obtained by ful¬ filling the conditions defined in the claims with regard to the parametreβ a, L and n. The parametreβ a, L and n are used for determining the exact position for cutting off a long rod into a laminate of the la¬ minate board and for phase displacing the long rod with re¬ gard to the preceding long rod in the board. The parametres are used for programming a computer for automatic control of the cutting of the long rods. A preferred embodiment of the laminate board according to the invention is described below with reference to the enclosed figure. The laminate board iβ indicated by 1, the rode by 2 and the joint between the rods forming the laminates of the laminate board by 3. In the rode 2 forming the outmoβt laminate, the vertical orientation of the fibre planeβ iβ indicated. It can be noted that the the joints 3 are relatively equally diβtributed over the laminate board and a comparison between the above parametreβ βhows that all the criteria are being fulfilled. Aβ deβcribed in our parallel application mentioned above, the manufacture of the laminate board is carried out by assemb¬ ling laterally rods cut from a mineral wool mat and rotated in order to form the laminate board. The assembling of the rods that have been cut off and rotated can be accomplished in various manners. In a preferred manner, the rode are aββembled consecutively into a long rod, in which rode having the desired length <=the length of the laminate board) are cut and assembled into a laminate board. In another preferred manner, several rods are cut from the mineral wool sheet and rotated and subsequently phase displa¬ ced axially. The phase displaced rods are subsequently as¬ sembled with end faces against each other with the preceding flow of correspondingly cut and phaβe displaced rode into a flow of long rods, in which a length equalling the one of the laminate board is cut off. After that, the two surface layers are applied onto the laminate board. Provided with surface layers, which can be of thin sheet me¬ tal, a concrete layer, minerite or similar, the construction board of the invention is usable as βupporting wall, floor or roof elements. The board has good fire and heat insulating properties owing to its construction, and it iβ easy to in¬ stall.

Claims: Claims 1. A longitudinal laminate board (1) of binder fixed mineral wool, suitable as a core of a sandwich element having a sur¬ face layer, e.g. of sheet metal, on each side, consisting of adjacently disposed rods <2> the longitudinal direction of which coincide with the one of the laminate board and in which the fibre plane forms a right 'angle to the plane of the laminate board, characterized in that the laminate board <1) iβ composed of rods (2) that are shorter than the laminate board and in that the aligned rods are in contact with each other without intervals, thus forming a joint <3>, whereby the toal joint surfaceβ of the laminates within one interval of the length a somewhere along the length of the laminate board form maximally one third of the crosβ-sectional surfa¬ ce of the board, in which a = L : l,90n and L = the length of the laminate board, when the board is being used as a one- field board, and L = the span, when the board is being used aβ a multi-field board, and n = the number of laminates in the width of the laminate board. 2. A laminate board according to claim 1, characterized in that no joint <3) is disposed closer to an end of the laminate board (1) or a support line of a multi-field board than a. 3. A laminate board according to claim 1 or 2, characterized in that maximally one joint <3) is diposed within the distance 2a from the end of the laminate board (1) or a support line of a multi-field board. 4. A laminate board according to any of claims 1-3, characterized in that maximally two joints <3> are within the distance 3a from the end of the laminate board <1> or a support line of a multi-field board. 5. A laminate board according to any of jclaims 1-4, characterized in that the distance between the joints (3) of two adjacent longitudinal rods is at least equal to the thicknesβ of the laminate board <1). 6. A laminate board according to any of claimβ 1-5, characterized in that the end faceβ of each joint <3) are pressed against each other forming a border layer, in which fibreβ from both the rode C2) are included. 7. A laminate board according to any of claimβ 1-6, characterized in that the end faces are glued against each other. 8. A laminate board according to any of claims 1-7, characterized in that the fibres planes are essentially pa¬ rallel to the axes of the rode <2>.

Inventors: BRUNILA ESKO, HESELIUS LARS, BRUNILA, ESKO, HESELIUS, LARS
Applicants: PARTEK AB, OY PARTEK AB
Application year: 1989
Main classification: E04B1
IPC codes: E04C2