FRACTURE ASSESSMENT OF PMMA SI KITCHEN SINKS MADE FROM ACRYLIC CASTING DISPERSION/

Acrylic casting dispersion is used to fabricate kitchen sinks made of PMMA/Si which stands for poly-methyl methacrylate mixed with a fine di spersion of silica. The composite is suited for sanitary wares that ar e subjected to severe temperatures, giving rise to high thermal stress es. This leads to failure by cracking in the region near the drain hol e. Such conditions are investigated by determining the mechanical and fracture properties for two different chemical compositions of PMMA. T hey are referred to by trade marks from ICI as Asterite and Amatis. Da ta are obtained for temperatures from 0 to 95 degrees. Extensometry da ta are also obtained to the thermal stresses around the drain hole sub jected to alternating flow of cold and hot water. Critical crack lengt hs are determined from the critical stress intensity factor and maximu m local tensile stresses based on measured data. They are estimated to be 1.5 mm and 4.0 mm, respectively, for the Asterite and Amatis compo sites. These results confirm with practice where the cracking of the f ormer was observed while the latter did not crack.