Cost-Effective Quality Tool

A 230-litre-capacity Carbolite oven with fanned convection is being used successfully by Alutrade Ltd as part of its quality control procedures in the recycling of aluminium drinks cans.

Alutrade is a recycler of aluminium scrap with a particular expertise in recycling drinks cans, which are usually highly contaminated when received from waste management companies, local authorities and other sources. Customers for the scrap, who manufacture strip from which more drinks cans are produced, require minimal contamination including no more than 4% by weight of moisture.

Contaminants such as plastics, paper and ferrous metals are removed by various mechanised and manual processes before shredded material is compacted into bales. Moisture content is checked by randomly taking a bale from each batch, weighing it, heating it for four hours at 150°C in the oven and then weighing it again. The weight loss reveals the moisture content.

The 200-litre oven is a standard Carbolite model, so was available off the shelf and at lower cost than a bespoke unit. It is big enough to accept one or two bales, depending on the size required by Alutrade’s customers, and the fan-assisted airflow provides good temperature uniformity and fast heat-up and recovery times.

The chamber is of fully welded construction and has an exhaust port, which vents fumes through a pipe to the outside of the building. A controller with a convenient soft-touch panel on the front of the oven allows the selected time/temperature programme to be carried out automatically and without supervision.