(Sharecast News) - Plastic and paperboard packaging manufacturer Robinson reported year-on-year sales growth of 15% in the first four months of its financial year on Thursday, as investors gathered for the annual general meeting.The AIM-traded firm said underlying volumes were 12% higher in the period, with the balance of the increase being put down to increased prices being offset by movements in foreign exchange rates.Chairman Alan Raleigh said margins and operating costs were at a similar level as last year, with a subsequent increase in operating profits.Net borrowings were at a similar level to the end of 2018, after capital expenditure of £1m."We expect lower sales in the second quarter from reversal of the stock builds relating to new product launch pipelines, Brexit contingency planning in the UK and from re-phasing of new projects across the group," Raleigh told shareholders."The outlook for the year remains in line with previously communicated sales growth - double digit percentage - and market profit expectations."