In a statement published this morning (21 March), the Chesterfield-based business said that revenue decreased by 2% to £21.2m (2011: £21.5m) but underlying volumes increased by 2%.
Robinson said the revenue reduction stemmed from a 9% drop in the price of plastic resin, which was passed back to its customers.
Chairman Richard Clothier said: “It is pleasing to report continued improvement in profits despite a subdued market environment.
“Sales volumes increased by 2% year on year but, despite this, revenue declined by 2% due to our contractual arrangements with customers to pass on raw material price reductions.
“The full year effect of the new business gained during 2012 should ensure revenue growth in 2013.”
However, it said in an effort to grow the business it would need further additions to its management team which will increase costs and “temporarily limit the full effect of this growth in earnings”.
Elsewhere, it said: “Volatility in plastic resin prices can affect margins in the short term and management are anticipating some pressure on selling prices in the current market that may, to some extent, counter the impact of higher volumes. Nevertheless, progress so far in 2013 is positive and in line with our expectations.”
