Stork Brabant B.v.

Cornelis Blaak

Gerardus H Van Mondfrans

A foam generator conventionally consisting of a hollow stator (1) with a coaxial internal rotor (2) together forming an annular mixing chamber. Both stator and rotor are being provided with alternative rings of polygonal pins (4, 3) reaching within the mixing chamber, each pin having at least two ribs 11 creating a vortex trail during generation. The rate of occupancy of the pins (4, 3) is such that within a cross-sectional range for the mixing chamber between 40-90 cm.sup.2, the quotient: ##EQU1## amounts at least to 1.5 and is preferably between 2.4 and 3.0.

Foam generator

An apparatus to be used in the screen-printing art distributes viscous printing substance and comprises first and second distribution passages extending lengthwise along an elongated common passage. The distribution passages have first ends in proximity to each other and second ends in proximity to each other. Feed means supply the viscous substance to each distribution passage, each distribution passage having, along its length, a tapered outflow opening. The tapered outflow opening of the first distribution passage increases from the first end to the second end thereof and the tapered outflow opening of the second distribution passage increases from the second end to the first end thereof. The two distribution passages work together to evenly distribute the viscous substance to the elongated common passage.

System adapted to distribute a viscous substance

Coating a porous substratum with a viscous substance is performed by means of a rotatable cylindrical sieve (plain-mesh screen), comprising an internal squeegee for pressing said substance through the perforations of the screen. The substratum are passed in contact with the screen and is supported at the contact zone by a roller. Although the peripheral speeds of the screen and the substratum is substantially equal, the rotational speed of the support roller is such, that its peripheral speed is either smaller or greater than that of the substratum to an extent of at least 5%. This avoids the occurrence of the phenomenon of pinhole formation in the coated substratum.

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Boxmeer, Netherlands

Cornelis Blaak