| abstract |
PURPOSE: To obtain boards which are fire-retardant and have strength and water-resistance by compressing cellulosic or lignocellulosic materials by means of binder such as polyisocyanate. n CONSTITUTION: Cooked chips are transferred to a refiner 14 where they are separated into their constituent fibers. A binder is preferably a material consisting of monomeric isocyanates, oligomeric isocyanates, and mixtures of isocyanates having a functionality of at least 2. A nozzle assembly 18 is connected to a blowline 16 for emulsifying the binder with a diluent and applying the resulting emulsion to the fibers. After exiting the blowline 16, the fibers enter a dryer 24 where they are partially dewatered. The fibers next pass to a blender 30 wherein the isocyanate binder, sizing, release agents or the like can be mixed with the fibers, if desired. After going into a fiber storage bin 38, the fibers are sent to a forming head apparatuses 40. Forming mat 41 is deaerated by a prepress 44 and then compressed by a hot press 46 wherein the binder is cured to form a board product. n COPYRIGHT: (C)1991,JPO |