Patent EA-000493-B1 (EA)
Title: Process and apparatus for the production of a mineral fiberboard
Inventor: WYSS PETER
IPC: D04H1/736
Filed: 1997-03-24
Abstract: 1. A continuous process for the production of bonded mineral fiberboard having a thickness t from a fleece having a thickness greater than 2 t comprising compressing the fleece depthwise, substantially without simultaneous longitudinal compression to a first thickness and to a weight w per unit area, subsequently longitudinally compressing the fleece while the fleece is constrained to a second thickness and thereby producing a longitudinaily compressed fleece, transporting the longitudinally compressed fleece to a bonding station (25) and bonding the fleece in the bonding station (25) to form a bonded mineral fiberboard, characterized in that the first thickness is in the range 0.8 to 1.5 t, preferably between 0.9 and 1.3 t, the second thickness is in the range between 1 to 1.3 t, preferably 1 to 1.1 t, the longitudinal compression is conducted continuously or in one or more stages substantially without pleating of the fleece and produces a longitudinally compressed fleece with a weight per unit area of 2 to 10 w, and the fleece is constrained against break-out as it is transported between the longitudinal compression and the bonding station. 2. A process according to Claim 1, characterized in that the longitudinal compression of the fleece is effected in one stage. 3. A process according to Claim 1 or Claim 2 in which the longitudinally compressed fleece and the bonded board have a weight per unit area of 2 to 6 w, preferably 2.5 to 4 w. 4. A process according to any of Claims 1 to 3, in which the longitudinal compression is effected by feeding the fleece by means of a first conveyor device (30) to a second conveyor device (32), the second conveyor device (32) being driven at a lower speed than the first conveyor device and in which each conveyor device (30, 32) comprises two opposite roller groups (30', 30") each comprising at least two spaced-apart rollers (39). 5. A process according to Claim 4 in which the opposite roller groups of at least one conveyor device (30, 32; 31, 33, 35, 37) are driven at different speeds. 6. A process according to any preceding Claim in which the fleece is longitudinally stretched after the longitudinal compression. 7. A process according to any preceding Claim in which the fleece is formed of man-made vitreous fibers, preferably Rockwool fibers, and contains uncured binder and the binder is cured by heating at the bonding station. 8. A process according to any preceding Claim in which the fleece is formed by cross-lapping. 9. A process according to any preceding Claim in which the longitudinally compressed fleece is, before the bonding station, divided parallel to the major surfaces into two or more sub-webs and each sub-web is constrained against break-out as it travels towards the bonding station and at least one of webs is compressed in the thickness direction and/or length direction and the sub-webs are then combined and bonded at the bonding station. 10. A process according to Claim 9 in which the contact surfaces are provided with binder before being combined. 11. A process according to Claim 9 or Claim 10 characterized in that the combined webs are longitudinally compressed before the bonding station. 12. A process for the continuous production of a bonded mineral fiber board in which a fiber felt is precompressed in the direction of thickness to a thickness of 1 to 3 times the end product and is then subjected to longitudinally compression by means of at least two conveyor pairs driven at different speeds to produce a longitudinally compressed felt and is then bonded at a bonding station (25) to give a bonded mineral fiberboard, characterized in that the thickness of the felt in the longitudinal compression stage and before the bonding station respectively is between approximately 0.9 and 1.3 times the thickness of the end product, the longitudinal compression is effected substantially without thickness compression, the longitudinal compression is effected to approximately 0.5 to 0.1 times the original length, the compression is effected in a continuous compression zone, and the felt is held in order to prevent break-out between the longitudinal compression unit (19, 19-) and the bonding station (25). 13. A process according to Claim 12, characterized in that the thickness of the felt in the longitudinal compression zone is substantially the same as the nominal thickness of the end product. 14. A product comprising fiberboard made by a process according to any preceding Claim. 15. Apparatus for the continuous production of a bonded mineral board from a mineral fiber fleece comprising conveyor means (19, 40; 19, 23) for conveying the fleece to a bonding station (25), a device (17) for thickness compression of the fleece, a fleece longitudinal compression device (19; 19') following the thickness compression device (17), a bonding station (25) for bonding the longitudinally compressed fleece, and means (59, 61; 40, 42) to prevent break-out of the fleece between the longitudinal compression device and the bonding station (25), characterized by at least two roller conveyors (30, 32) disposed consecutively in the conveying direction, each roller conveyor (30, 32) comprising two opposite groups of at least two rollers (39) in each case, the opposite roller groups forming a conveying path (F) for the fleece, drive means to drive the rollers (39) of each group substantially at the same circumferential speed, means for controlling the circumferential speed of the rollers (39, 39') of each individual group independently of the speed of the rollers in each other group, and means for adjusting the spacing between the opposite roller groups (30', 30''; 32', 32'') of the conveyors (30, 32) independently of the spacing of the rollers in other conveyors. 16. Apparatus according to Claim 15, characterized in that two roller conveyors (30, 32) disposed consecutively in the conveying direction (F) are provided. 17. Apparatus according to Claim 15 or 16, characterized in that each roller group comprises two to eight rollers, preferably four to six consecutive rollers. 18. Apparatus according to any one of Claims 15 to 17, characterized in that at least one of the roller conveyors (30, 32) has means for inclining the opposite roller groups relatively to one another, for example in order to produce a fleece web tapering in the conveying direction. 19. Apparatus according to any one of Claims 15 to 18, characterized in that the roller diameter and the spacing between the rollers (39) in the conveying direction is such as substantially prevent any break-out or pleating of the fleece. 20. Apparatus according to any one of Claims 15 to 19, characterized in that the roller diameter is less than approximately 18 cm and is preferably between approximately 60 and 160 mm and particularly preferably between 80 and 120 mm. 21. Apparatus according to any one of Claims 15 to 19 characterized in that at least the first conveyor (30) has means for adjusting the position of the conveying path through said conveyor relatively to the position of the conveying path through the following conveyor or conveyors (32). 22. Apparatus according to any one of Claims 15 to 21, characterized in that the conveyors (30, 32) are disposed horizontally. 23. Apparatus according to any one of Claims 15 to 22, characterized in that a separating device (41) for separating the fleece into two or more sub-webs is provided between the roller conveyors (31, 33, 35, 37) and the bonding station (25), in that at least one compression stage (53, 54) is provided for the thickness and/or longitudinal compression of at least one sub-web and in that conveyors (59, 61, 63, 65) are provided for holding the compressed fleece and the sub-webs on the path to the bonding station (25) in order to prevent any deformation in the direction of the thickness or break-out. 24. Apparatus according to Claim 23, characterized in that the separating device (41) and at least the conveyor (47) are adjustable as to height so that the apparatus can be used optionally for the production of single-ply or multi-ply products. 25. Apparatus according to Claims 23 or 24, characterized in that means (57) are provided for the metered supply of a binding agent to the mutual contact surfaces of the sub-webs. 26. Apparatus according to any one of Claims 15 to 25, characterized in that means are provided to drive the conveyor means between the compression stage and the bonding station and in the bonding station independently of one another. 27. A continuous process for the production of a two ply or multi-ply bonded mineral fiberboard from a mineral fiber fleece by.precompression of the fleece, feeding the precompressed fleece to a separating device (41), separating the fleece by means of the separating device (41) into two or more sub-webs (43, 45), compressing at least one sub-web (45) in the direction of the thickness, followed by combining the sub-webs (43, 45') and transporting the same on to a bonding station (25) in which the fleece is bonded, characterized in that the mineral fiber fleece is longitudinally and/or thickness compressed, (preferably longitudinally compressed), in a compression unit (19) before the separating device (41) and break-out of the tensioned sub-webs (43, 45) between the compression unit (19) and the bonding station (25) is prevented by constraining means (49, 50, 51, 59, 61, 63, 65). 28. A process according to Claim 27, characterized in that at least the one thickness-compressed sub-web (45) is longitudinally compressed. 29. A process according to Claims 27 or 28, characterized in that the contact surfaces of the sub-webs (44, 45) are provided with binder before being combined. 30. A process according to any one of Claims 27 to 29, characterized in that the combined webs (44, 45') are longitudinally compressed before bonding. 31. A process according to any one of Claims 27 to 30, characterized in that the separating device (41) is continuou