Patent attributes
Earplugs (22, 24) and a combination (20) of a pair earplugs and a cord (26) that joins them, each can be detected by metal and/or magnetic detectors even if the parts of the combination becomes separated and fall into a batch of food, etc. Each earplug includes an earplug core (32) formed of a first elastomer with a multiplicity of metal-mag detectable particles (36) (particles detectable by electrical or magnetic detectors) embedded in the first elastomer, and an earplug covering (32) of a second elastomer (that may be the same as the first one) that is devoid of such particles. The cord includes a cord core (50) formed of a first flexible polymer with metal-mag detectable particles embedded therein, and a cord covering (54) formed of a second polymer that is devoid of such particles. The particles are preferably of iron, which is magnetically detectable but that can mark skin or clothing that it contacts, but which is isolated from the skin and clothing by the earplug and cord coverings. The earplug covering can be molded and then filed with the earplug core. The cord core can be extruded and the covering extruded around the core.
