Twin shaft mixers with weightless mixing zone were designed and developed by the Norwegian inventor Halvor Forberg. They are an excellent solution wherever fast and precise industrial mixing is required.
The twin shaft mixer has two parallel drums that overlap and are fitted with angled paddles. The shafts rotate at speeds that vary and are calculated to give optimum mixing effect for each of the various sizes of mixers that are made.
Due to the very short batch cycle time, (a few minutes only - dependant on product and batch size) the same production can be achieved with a smaller mixer, which means less capital expenditure and lower electricity bills.
In South Africa, these mixers are manufactured by GRAMEC (Pty) Ltd of Johannesburg, and are available in 14 sizes ranging from nominal 7 litres up to 7,000 litres. Each size mixer can process batches from 30% to 100% of nominal size (ie. a one-ton mixer can be used for batches down to 300kg.)