US Patent 7618676 Fibre coating method and apparatus

A fiber unit coating apparatus includes a chamber into which an uncured resin coated fiber unit is passed. Microspheres mixed with air are fed into the chamber via ducts and apertures. As a result rapid and even application of the microspheres can be achieved, and the system allows controllable application of the microspheres by varying the rate of flow of the air/microsphere mixture. Positive pressure chambers are provided to prevent the microspheres from blocking the inlet and outlet points where the fiber unit enters and leaves the chamber.