Plastics manufacturer British Polythene Industries now expects to report a strong set of first-half results thanks to strong agricultural demand and lower raw material costs.The maker of plastics for agricultural, manufacturing, waste management and construction industries said it expected results would be "comfortably ahead" of the comparative period in 2012 and left it confident of beating full-year expectations.BPI's raw material input costs eased in April and May, and while it reported that it was currently seeing cost increases in June, management argued that "it seems unlikely that overall market demand will support this reversal".Despite lower volumes and continued down-gauging seen in some of its markets and a slow start to the year resulting from the unseasonally cold spring weather, the overall results were held up by agricultural films markets proved resilient enough to compensating for the other shortfalls. Consequently, management said it currently anticipated interim results would show similar overall volumes to the first half of 2012.2012's interim results showed sales down 7.0% to £273.1m reflecting volumes down 5.0%.OH