| 摘要 |
A process, with the associated apparatus, forms molded articles from binder-containing organic fibres. The process uses pressure to achieve temperatures of more than 100 DEG C. The material is preferably in the form of fibrous mats containing up to 50% heat-hardening binder and having a processing moisture content of more than 5% and preferably 10 to 25%. The compression of the material structure takes place in a single mold stroke, optionally accompanied by additional shaping. With the mold closed, steam pressure is produced during the minimum curing time of the binder in a closed, material-containing volume. The mold is maintained at a superatmospheric pressure. Additional steam can be introduced before or during this time. Following the minimum curing time, the steam pressure and moisture in the molded material are reduced without any significant change to the mold temperature and during steam pressure release the molding pressure is not reduced below a value required for keeping the mold steam tight and for maintaining a surface pressure. This molding pressure is at least equivalent to the steam pressure in the material. At the end of steam pressure release, the molding pressure is released and the mold is opened for removing the workpiece. |
