| 摘要 |
<p>Articles are moulded from particles agglomerated by a thermosetting binder in a deep draw oblique mould by fluidising the moulding material in the female mould portion by means of fluid under pressure admitted at the bottom of the female mould portion by means of a diffuser, while the male mould portion descends. The method prevents thickening and densification of the mouldings at the base. Fluidisation is controlled so that the flow is insufficient to cause the powder to fly off and is gradually reduced to zero as the compression increases until the material does not flow. High pressure fluid may be admitted after moulding to assist ejection. Moulding may employ two separate male mould portions for preforming and for moulding, the latter being enlarged. The valve controlling the admission of fluid may be geared to the closure of the press.</p> |
