Proposed Preparative Techniques for Manufacture of Marine Dye Marker

An innovative search and rescue, marine dye marker has been developed. The marker contains the fluorescent dye, fluorescein, in a buoyant slow-dissolving matrix. When deployed on the sea surface, dye from the marker permeates the water, creating a highly visible signal of long duration suitable for detection by both aerial and surface rescue craft. A pelletizing process was developed which necessitated a formulation modification. It was necessary to include both bulking fumed silica and film producing glycerol agents to facilitate retention of the extruded shape. The percentage of ingredients were adjusted such that the dried pellets would have the same density as flake material. A granulating technique was also evaluated. Both pellets and granules gave visual signals comparable with the original laboratory scale flake method. Either method could be adapted for large scale manufacturing, with cost governing the final decision. Both processes can be used to produce a more structurally durable dye marker than a flake configuration.