Improved resin performance in MDF through development of blowline blending process

Abstract

This paper discusses the development of a design approach for the blowline in a medium density fibreboard plant to optimise resin performance. Mass and energy flows in the refiner determine the flow in the blowline and it is necessary to determine these if the blowline is to be optimised to minimise the resin required. Once the flow in the blowline is established then the blowline sizes can be selected. These depend on the length of the blowline that is largely determined by the location of the refiner and the dryer and the number and location of bends. The other significant factor that determines the resin requirement is the initial size of the droplets sprayed into the blowline. A steam atomised nozzle has proved to be effective in the limited space and conditions in the blowline, providing a uniform droplet size over a wide flow range. The design of this nozzle has been developed to provide a further improvement in performance. Optimisation of both the blowline velocities and the resin injection nozzles is necessary to achieve the best resin result.