Abstract: The fiber boxes (60) each contain fiber (62) and are removably mounted to a fiber injector (9) for injecting the fiber (62) into a material flow stream. The fiber boxes (60) each have an enclosure (61) for containing the fiber (62), preferably a single fiber (62). An aperture 70 provides a feed hole (70) for passing the fiber (62) from an interior of the enclosure (61) to an exterior of the enclosure (61). Contacts (64) having ends disposed on an exterior of the enclosure (61), spaced apart for registering with mating contacts (54) on a fiber distribution ring (40). A frangible element (68) extends between the contacts (64) and provides electrical continuity between the two contacts (64), such that when the fiber (62) is fully withdrawn from within the enclosure (61) the frangible element (68) separates and breaks electrical continuity between the two contacts (64).

Abstract: A fiber injector (8) has a fixed attachment (10) rigidly secured to the end of a material delivery boom. The fixed attachment (10) has a control handle (20) for controlling the location of the boom and distribution of fibers (62) into the material flowing through the boom. A rotary attachment (30) is rotatably secured to the fixed attachment (10) and is selectively rotated by an electric motor (12). A fiber distribution ring (40) is removably secured to the rotary attachment (30) and has a number of box holders (50) for receiving fiber boxes (60). The fiber boxes (60) contain the fiber (62) being injected into a material flow stream. A fiber brake (24) is mounted for selectively moving to cover fiber delivery apertures (52) in the fiber distribution ring (40) to selectively stop injection of the fiber (62) into the material flow stream.