Method of manufacturing dry-pressed molded articles
AssigneesEugen Buhler, Hutschenreuther AG
InventorsEugen Buhler, Klaus Strobel, Karl Schwarzmeier
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Abstract
In a method of manufacturing dry-pressed molded articles from essentially dry, pourable ceramic metal or carbon-containing molding compound in a mold of one or more parts, it is proposed to generate a negative pressure through the mold wall in the hollow space of the mold and, by means of the pressure difference generated as a result, to propel molding compound which is under pressure, for example, atmospheric pressure, through an injection opening into the hollow space of the mold and to precompress the molding compound in the mold while deaerating the molding compound, and that subsequently, the pneumatically precompressed molding compound is compression molded into a molded article having the desired final density.
Claims11
In a method of forming articles in a mold from a dry pourable granular molding compound, such as a ceramic, metallic or carbon containing granular molding compound, where the mold if formed of at least one part defining a hollow mold space with a central opening through which the molding compound is introduced centrally into the hollow space, and air discharge location connected to the hollow space for removing air therefrom, comprising the steps of fluidizing the molding compound adjacent the inlet opening to the hollow space, filling the fluidized molding compound into the hollow space through the inlet opening by drawing air out of the hollow space through the air discharge locations, compressing the molding compound filled into the hollow space to provide a precompressed body of the molded material, and subsequently pressing the precompressed body of the molded material into a molded article, wherein the improvement comprises drawing the air out of the hollow space at least at locations along the maximum circumferential periphery of the hollow space, limiting the inflow speed of the granular mold compound at the commencement of filling the compound into the hollow space for reducing the impact of the grains of the granular molding compound at the air discharge locations and providing a porous build-up of the molding compound at the air discharge locations so that the air discharge locations are not blocked by particles of the molding compound grains broken by impacting at too high a speed around the air discharge locations.
Dependencies are inferred from the claim text.