Length-reduction method for man-made mineral fibers for biological experiments

A simple fiber length-reduction method was developed to obtain a large amount of fiber samples with different length distributions for use in various biological experiments. This press method is only to press a raw fiber sample charged in a stainless cylinder at an adequate pressure, and is effective for man-made mineral fibers (MMMF) such as glass wool, rock wool and wool and refractory fibers (ceramic fibers, mullite fibers) and some brittle natural mineral fibers such as fibrous brucite and wollastonite. The mean fiber-length of man-made mineral fibers became shorter with the increase in the pressure applied without diameter change. We could obtain a length-reduced fiber sample with a suitable length distribution by this method. This press method is therefore a size-selective method able to produce a large amount of pulverized fiber sample depending on the press cylinder size for biological experiments. A very small amount of non-fibrous particles with aspect ratios (length vs. diameter) of under 3 was seen in the pulverized fiber samples. To eliminate such non-fibrous particles as well as too long fibers from the sample, separation by sedimentation in water was somewhat effective.