solutions were produced each in parts by weight or percent by weight the test bodies that are produced are cuboid test bars having the dimensions 220 mm u00d7 22 36 mm u00d7 22 36 mm referred to as georg fischer test bars so as to determine the flexural strength the test bars were inserted into a georg fischer strength testing system equipped with a three point bending device simpson technologies gmbh and the force that resulted in breakage of the test bars was measured cogas method the cogas system is used to simulate the casting of a foundry core while measuring the resulting amount of condensate and gas during the casting process with liquid aluminum during the casting process of sand cores bound with organic binders the binder is thermally loaded with liquid aluminum temperature range approximately 720 u00b0 c wherein the ingredients thereof evaporate for example highly volatile solvents or crack for example low volatility solvents and resin constituents the cogas system is used to simulate such an aluminum casting process under standardized conditions and the resulting condensates are collected during the first 5 minutes after immersion into a cold trap the tables below list the flexural strengths and condensate amounts according to the cogas process examples 1 to 3 show the strength curves of cores that were produced with one part 2 consisting exclusively of mdi as the added amount of.