Patent attributes
A headbox apparatus for a papermaking machine is disclosed. The headbox apparatus defines a flow path for stock flowing between an upstream location and a downstream slice lip. The apparatus includes a plurality of blocks which are anchored within the flow path between the upstream location and the slice lip. Each block and an adjacent block of the plurality of blocks define therebetween a flow tube for the flow therethrough of the stock. The flow tube has an upstream portion having an upstream and a downstream end. The flow tube has a downstream portion having an upstream and a downstream extremity, the upstream extremity of the downstream portion extending from the downstream end of the upstream portion. The downstream portion of the flow tube has a volume which is greater than a further volume of the upstream portion of the flow tube such that when the stock flows from the upstream portion to the downstream portion of the flow tube, the stock is mixed within the downstream portion.