| 摘要 |
<p>Foamed flat sheet building components are produced from a reaction mixt., from phenolic resins in particular without any usual foaming agent. The resin mix is brought to the temp. of a dosing mixer and injected into the mould contg. fillers, or fibres. More material is concd. first at the part where foaming is to start, and a specific smaller quantity is subsequently injected, so producing a thermal barrier effect from the first quantity and a vertically rising foam fron until the vent is reached. This effect is also produced by heating the initial quantity while it is in the injection needle and/or feed tube or the mould wall where filling starts, or by exotherm. Controlled foaming with very short foaming distance, producing homogeneous articles without voids, suitable for very thin components giving "texture tailoring" effect.</p> |
