Despite battling rising polymer prices, plastic packaging firm RPC saw an improvement in underlying operating profit in the final three months of 2010.Sales volumes in the third quarter of the company's financial year were ahead of the same period in the previous year as growth in the personal care and coffee capsule sectors continued as anticipated. The company managed to pass on to customers the effects of rising polymer costs and this, together with the increased volumes, saw revenue in the October - December quarter advance from a year earlier.Operating profit (before restructuring and impairment charges) was ahead of the corresponding period of 2009 as the group benefited from the increase in activity levels while operating from an improved cost base. As anticipated, the adjusted profit before tax in the third quarter was ahead of the same period of the previous financial year.The financial position remains robust, the company said, with satisfactory cash flow development in the third quarter and significant head room under the group's new debt facilities. "With the RPC 2010 [restructuring] programme drawing to a close, the focus is now firmly on growing the overall business," said RPC's chief executive officer, Ron Marsh.