. in addition to prices and volumes , major factors affecting the profitability of industrial pack- aging are raw material and energy costs , manufacturing efficiency and product mix . industrial packaging net sales for 2006 increased 6% ( 6 % ) compared with 2005 and 8% ( 8 % ) compared with 2004 . operating profits in 2006 were 82% ( 82 % ) higher than in 2005 and 7% ( 7 % ) higher than in 2004