Hardboard fibrous cake prepn. - from unclassified material dispensed from two bunkers with classification effected by spreading during levelling of cake

摘要

Hardboard cake is prepd. by passing an endless belt past two fibrous material storing and dispensing bunkers between which is disposed a compactor and depositing the unclassified fibrous material from the bunkers such that at least during the levelling of the fibrous material in the cake the material is spread by casting so that in the end result the fine and finest particles form the upper and lower layers and the coarse and coarsest particle form the intermediate central layer. Unclassified particulate material impregnated in known manner is used to obtain hardboards which previously required classified particulate material which also required impregnation in the classified state.