Siam Cement Plc (SCC) will invest more than one billion baht to raise its production capacity for printing, writing paper and mortar cement, according to SCC president Kan Trakulhoon.   The SCC’s board of directors approved a 335-million-baht investment in a wholly-owned mortar plant with a capacity of 450,000t per year in Saraburi.  The new plant is expected to become operational in the second quarter of next year.   Its mortar cement is used for plastering of interior and exterior walls, and bricklaying.  Currently, SCC has a mortar capacity of 650,000t per year.