Abstract: A closing appliance used in a flexible tube comprising a communicating tube, a column-like portion, and a thin-walled portion formed between the communicating tube and column-like portion. The column-like portion has two wings facing to each other at an end opposite to the thin-walled portion. The wings have rounded surface on the side of the inner surface of the flexible tube, and a total lateral sectional area of the two wings is from 25 to 50% of a sectional area of a hollow portion of the flexible tube. Thanks to wings, damage of the flexible tube on centrifugal separation process can be avoided.

Abstract: A specific gravity indicator used for measuring the specific gravity of an aqueous liquid, which is a shaped article comprising a styrene homopolymer and a styrene-butadiene elastomer and having a specific gravity of 1.005 to 1.035. By the specific gravity indicator, the specific gravity of an aqueous liquid such as urine at a standard temperature can be measured with a high accuracy at an arbitrary temperature.

Abstract: A method of producing synthetic resin spinnerettes. Vertically extending synthetic filaments are mounted on a frame structure and placed in a mold. A thermoplastic or themosetting resin is poured into the mold and allowed to set. The molded body is removed from the mold and the filaments are removed therefrom to leave orifices.