IMAL в журнале MDF YEARBOOK Magazine, 2014-2015.
Contribution from IMAL
Imal, as experts in resinaton systems for over 40 years, has recently designed the Hi-Jet system, which sprays the resin into the blow line at over 100 bar to achieve a perfect distribution of the resin over the fibres. Early research began with microscope analysis of the resin crystals from which we discovered that a reduction in the size of the crystals used on line achieves much better resin distribution over the fibres. Consequently, a lower resin load is required to achieve the same desired board properties.
The IMAL design sprayer nozzles are the only ones of their king on the market. Our system does not mix the resin with steam, but adds the steam in small quantities into the blow line through separate nozzles, mounted opposite the glue nozzles, to help open up the fibres and hence achieve a better distribution. The glue is sprayed through special sprayers that keep the pressure constant, even if flow rate varies. This is extremely important, because if the production line is to run at a different rate due to a change in panel thickness, and the resin flow rate rises from 10-50 kg per minute, then our nozzles keep the pressure at 100 bar, or at the set pressure.
Another big benefit of injecting the steam separately is the lack of any need to constantly open and close the blow valve. In the IMAL system, the blow valve is opened completely and then the steam is dosed to maintain the counter pressure at the refiner. Basically, the amount of steam applied is inversely proportional to fibre flow rate, thus the more fibre we have, the less steam is applied and vice versa, when fibre flow rate falls, steam consumption will rise. The system is currently producing excellent result installed in over 63 panel production facilities, 40 of which produce MDF.
Another significant innovation is the Dynasteam, which injects steam into the mat before entering the press without creating damp spots. Independent steam distribution areas on each of the two sides, also vary the amount of steam across the board width. There are no thickness limits with Dynasteam, which can accommodate 2-50 mm thick panels. Recently, steam on a PB line increased line speed by over 20%. It is also possible on all MDF lines to achieve a 10-15% increase, which can be even higher when producing thick panels. On a large MDF line in Northern Europe, where for various reasons, the customer was not interested in running the line faster after putting the Dynasteam into operation, other production benefits also became evident because when steam is injected into the mat, the core reaches 100° C, much earlier than it would normally.
Thus, after applying steam on the line, the internal bond value rose by 15% and the operator began lowering the resin load to return to the IB value required for production. This drop in resin addition automatically leads to resin savings, which has to be an on-going cost-effective production benefit.