The DOLIUM 20- and 30litre kegs incorporate valve systems injection molded in glass reinforced polyamide, and protective, stability-adding external keg rings for handling and storage. Both elements were designed and developed in co-operation between injection molded polymer components manufacturer, Quadrant CMS and Dispack Projects.
A cost-effective and more environmental friendly option for a beer keg has to meet t product integrity, food safety regulations and performance requirements set by beverage producers, distributors and end-users. Priority was also given to limiting the operational impact versus the traditional keg, by achieving compatibility with existing filling lines and draught equipment.
The partners chose the market's four most popular metal valves and their corresponding couplers as the main reference points for the development.
"Converting applications from metal to plastics is something we're very familiar with at Quadrant however close collaboration with the customer is needed," comments Jan Claeys, account manager at Quadrant. "For this project we had to follow both a conservative and innovative approach …We had to take into consideration the need to match the new plastic valves with the existing couplers in the market, and Dispack's desire to preserve the handling and safety requirements especially by integration of a pioneering internal pressure relief safety feature."
For the final kegs, four versions of valves were produced. All can be used with the most common couplers on the market for connecting kegs to draft dispensing systems. Particular attention was given to accommodating the plastic valves to the variations in tolerance of the metal couplers from different manufacturers. The system uses glass reinforced polyamide.
The development of the new one-way beer kegs involved CAD and engineering, as well as production of rapid prototypes. Final testing of the accompanying top and bottom handling rings as well as the valve system and the safety pressure relief valve have been carried out on parts made on single-cavity prototype moulds before final multi-cavity moulds were built.
The four variants of the plastic valve systems mean that customers have no need to invest in modifications for the filling of the kegs or for connecting them to the draft systems.
The keg, with its special top and bottom rings has been designed so that it can be handled in vertical and horizontal way without the need for a supplementary protective cover. The rings make the keg stackable and ensure that it is protected during handling.
The shelf-life is equal to stainless steel kegs, and by avoiding long distance return transport, important transport costs are reduced, as well as the excessive energy consumption of empty stainless steel kegs. The kegs are 100% recyclable.