US Patent 8424728 Plastic closure for thixotropic dispensing bottles

A plastic closure including a bottom part and a lid that has an annular retaining bead in the bottom part. A disk having a support surface is held positively or non-positively in the bead. The disk includes one or more through-passages, which open into a chamber. A thixotropic fluid present in a flexible container reaches the chamber through the through-passages, where the fluid performs a directional change from axial to radial and after a second directional change from radial to axial flows out through the spout opening, wherein a constriction between the two directional changes accelerates the flow.