| 摘要 |
The invention comprises a process for the manufacture of agglomerated bodies from mineral fibres including the steps of forming the fibres and depositing them on transporting means, for example a conveyer belt, wherein, for the purpose of agglomerating the fibres, a hot plaster wash is applied to the fibres (i) before they are deposited on the transporting means, or (ii) whilst they are on the transporting means, or (iii) both before they are deposited on the transporting means and whilst they are on the transporting means. The invention also comprises apparatus for carrying out the above process which comprises two or more fibre-forming devices placed successively after each other above the transporting means, a hot plaster wash spraying device being associated with each fibre-forming device for spraying hot plaster wash on to the fibres. The hot plaster wash is preferably applied to the fibres, for example by spraying, soon after they leave a device for forming the fibres. A mat formed by the fibres to which the hot wash has been applied may be rolled and cooled during the setting of the plaster. Any common plaster, for example, plaster of Paris, may be used and inert fillers, colouring matter, accelerators, setting delayers, hardeners, or organic compounds such as polyvinyl alcohol, may be added. Minerals such as barium sulphate, kaolin and mica which decompose endothermally at temperatures of 500 to 700 DEG C. may also be incorporated in the plaster. The plaster wash is generally applied at a temperature above 70 DEG C. and the quantity of mixing water is about 70 to 80% by weight of the plaster. The proportion of plaster to fibres may vary and may also vary through the depth of the product. Thus products may be formed having a high proportion of plaster in the surface regions and a low proportion in the central region, or vice versa, the latter products being useful as fire-retardent panels. An example illustrates the process using apparatus consisting of three high speed spinners placed in series above a conveyer belt, each spinner producing streamlets of material which are attenuated into fine fibres by the action of currents of gas. The attenuated fibres are then sprayed with the hot plaster wash by means of atomisers placed below the spinners, the treated fibres then falling on to a conveyer belt. Optionally, layers of plaster may be introduced by means of distributers placed above the conveyer belt and between successive spinners. |
