Zum Recycling von Span- und MDF-Platten

In part 1 of the work (Franke and Roffael 1998) investigations were carried out on the influence of thermal hydrolysis of UF-bonded particle- and medium density fibreboards (MDF). The degradation of UF-resins was followed up, the change of the pH-value in the water extractives, the yield and the pentosan content of the lignocellulosic material were also assessed. Due to thermal hydrolysis the pH-value of water extractives increases and their alkaline buffering capacity decreases? Moreover, it was shown that UF-resins have a relatively high resistance towards hydrolysis. In this part of the work investigations were conducted on the formaldehyde release at different test temperatures. Further, the influence of thermal treatment of the disintegrated baords on the ammonia release was assessed. Moreover, the change of the pH-value of the extractives was determined. For comparison particles from round pinewood were included in the investigation.