A New Fiber Resination System ― MDF Mechanical Blending

摘要

The large quantity of resin often required for medium density fiberboard (MDF) production is one of the major concerns for MDF manufacturers, primarily because of the exorbitant resin related costs, and secondly because of the elevated formaldehyde levels in the board and releases from the dryer. IMAL has produced automatic blending systems for the wood-based panel industry for over 30 years with installations worldwide. A primary company objective has always been to seek methods to reduce the amount of resin used without altering board quality in any way. Today, after several years of trials and testing, IMAL has found a blending method for the MDF industry that can provide a suitable solution to the concerns set out above. Significant results have been achieved with this method in six plants. The evidence proves that resin quantities can be reduced by between 20 to 35 percent with improved board mechanical properties. Most installations around the world use the traditional blow-line system, with the advantage of a uniform resin-fiber distribution, due to the high turbulence of the flow created by the high velocity and the constant expansion of the steam as it travels toward blow-line outlet. The drawback to this method, however, is that the resin has to pass through the elevated temperatures of the dryer, often between 110° and 140°C, which has a devastating effect on the adhesive properties of the resin. To offset the loss in the adhesive properties, the manufacturer has to increase resin quantities to achieve the desired product quality.