METHOD AND DEVICE FOR PREHEATING A PRESSED MATERIAL MAT DURING MANUFACTURE OF WOOD MATERIAL BOARDS

摘要

The invention relates to a method for preheating a pressed material mat (14) spread on an endlessly and continuously circulating molding band (6) during manufacture of wood material boards, wherein microwaves from one or both press surface sides are beamed into the pressed material mat (14) to preheat the pressed material mat (14) and the pressed material mat (14) is compacted and hardened by application of pressure and heat after transfer to a continuously operating press (1). The invention consists of microwaves in a frequency range of 2400-2500 MHz being used to heat the pressed material mat (14), wherein the microwaves for each press surface side are generated from 20 to 300 microwave generators (26) with magnetrons (20) of a respective output of 3 to 50 kW. A device for preheating pressed material mats (14) is also provided, in which 20 to 300 microwave generators (26) with magnetrons (20) with an output of 3 to 50 kW and with a frequency range of 2400-2500 MHz are arranged in a conveyor furnace (4) per area side.