Seal for shafts and valve stems

摘要

A packing material having a resilient core and a uniform non-seamed exterior surface comprising a plurality of discrete compressible particles attached to the flexible core and to each other, the particles being compressed after attachment. The method comprises surrounding the flexible elongate core with a plurality of powder-like particles which together feed through a plurality of aligned pairs of feed groove rollers. The core, with the attached particles, wraps under tension around an arcuate sector of a cylinder or wheel passing between a pair of spaced-apart walls. A roller pushes against the core to compress the powder particles together and to bias the length of packing material into a spiral coil.