Fourdrinier Formers June 2017
OVERMADE has completed the delivery of a DYNAFLO-FL hydraulic headbox for PRATT PAPER (USA). With a pond width of 6200 mm and an operation output of approx. 750 tpd., the headbox is intended for the bottom layer of a machine which produces up to 1200 tpd of high quality testliner and fluting, at a speed of 1100 mpm.

The customer opted for the OVERMADE headbox for the excellent distribution of the fiber it is capable to grant, as it contributes to achieve the highest market standards of CD basis weight profile and paper properties. The target of the modification is to improve the efficiency of the forming section when basis weights, ranging from 100 gsm to 273 gsm, are produced using up to 80% of mixed waste paper and only 20% of OCC.

The performances are the result of the latest innovations applied to the “DYNAFLO CONCEPT”, the exclusive turbulence generator developed in OVER's pilot plant. The CD basis weight profile is controlled by means of a dilution system, while an additional edge flow control system is capable of locally adjusting the flow from 60% to 160% of its nominal value, designed to optimize the fiber orientation across all the paper width.
The headbox is supplied with stiff lamellas in the slice area to maintain a high level of micro-turbulence up to the jet exit, thus improving paper formation at high speeds.

DYNAFLO-FL, the headbox for high speed Fourdrinier forming section, is available also in a multilayer layout, that enables to use stocks of different characteristics or qualities to produce multilayer paper with a single forming section available.