Binders for core sand bonding
Desmodur® is used as a binder for core sand bonding in foundries using the “cold box” technique.
In core sand bonding with lost molds, a mold box is placed on one half of the model and filled with molding material consisting of quartz sand and a binder formulation made up of Desmodur® and other additives. The molding material is compacted by shaking or pressing. The second half of the mold is produced and the half molds are assembled, with cores being added if necessary. Following the casting process, the metal workpiece is removed, while the sand core is destroyed by the heat. The outer sections of the mold (machine mold plates or a hand-made model) form the outer contours. Cavities in the casting are produced by cores that are inserted into the mold and flow out of the cavities as particles of sand after thermal destruction of the binder.
- Particularly suitable for the "cold box" technique
- Increases the productivity of core series
- Cast parts of better surface quality