Controlling set times during gypsum board production
From: Author: Publish time:2015-08-28 15:18 Clicks:259
Gypsum boards are produced in a highly automated continuous process. Quick setting and hardening is of crucial importance to run the production at high speed for maximum capacity utilization. The use of calcined gypsum in combination with highly effective accelerator, especially fine ground gypsum, is currently state of the art. Consequently, the setting starts immediately after binder contact with water. On the other hand, beginning of setting needs to be delayed to enable an efficient mixing process and a homogeneous distribution ofplaster slurry at the forming table.In our study, various commercially available retarders were tested for their efficiency and compatibility with numerous mix-designcomponents. A new high-performance gypsum retarder, DH series of set retarders, was found to set a new standard in retarding efficiency without demonstrating the known negative characteristics of existing technologies.