Watertight fuse compressed core of fine brisant explosive particles - is wrapped in several layers of overlapping plastics film tape

摘要

Watertight fuse has a uniformly compressed explosive core and overlapped film tape wrapped around the core. The core contains a brisant explosive in fine form, such that over 50% of the particles are under 0.074 mm. It is wrapped in at least 2 plastics film tapes, which are bonded at the overlap points or held fast by synthetic monofilament(s). The overlaps of the second and subsequent tapes do not coincide with those of the earlier tapes and consecutive tapes are of increasing width. The explosive is pentaerythrityl tetranitrate. The synthetic monofilaments are flat. The core can have an outer mantle of extruded plastics. The fuse can be kept in water for several hrs. without detriment to its ignitability, even if the open end is in water. It is useful in blasting.