(Waste)water saving
Due to a combination of pollution and overconsumption, droughts and water scarcity are no longer considered rare or extreme in Europe. About 20% of Europe’s land and 30% of its population are affected by water scarcity every year. Water scarcity can be expected to be an even greater challenge in the coming years as the climate changes. Regions across Europe are seeing an increase in the frequency of droughts. Southern European areas in particular are expected to experience more water shortages over the next decade, with potentially disastrous consequences for industry (Source: EIT Food, 2023). This underlines the vital importance of water conservation.
In traditional pre-treatment lines, the cleaning and pickling zones often cause negative effects, such as carry-over of chemicals to subsequent process steps and sludge formation in the baths. This leads to unnecessarily large wastewater volumes. AD’s chemical process has an optimised pickling process that significantly reduces (waste)water flows. At the Aliplast line in Belgium, which is Qualicoat Seaside certified, the cleaning and pickling steps are both acidic in nature, reducing the negative effects of carry-over. Moreover, the entire (waste)water flow is more efficient, leading to additional savings on wastewater and fresh water. In Portugal, the pickling process has been optimised in line with the Qualimarine standard.
The challenge is to find the right balance between sufficient water flushing and minimal water consumption. A key element in this ‘sustainable water system’ is the recirculation of water streams in the process, a unique feature of the AD Chemicals process. An added advantage is that this process also reduces chemical consumption and enables energy and maintenance savings.
How much water can be saved? As a benchmark, a cascade line with an output of 11,000 m² of aluminium per day can switch from an average water consumption of 4,000–5,000 litres per hour to 500–900 litres per hour. This results in an 87% reduction in water consumption, in turn reducing the ecological footprint and contributing to water availability in arid areas.
Quality
These optimisations represent important steps in making the pre-treatment process more sustainable for vertical powder-coating lines. The chemical pre-treatment process has proven to be stable through years of experience. The improved cleaning and pickling process, followed by a chromium-free conversion layer, results in an aluminium surface ready for coating, with excellent paint adhesion and anti-corrosion properties. These properties exceed the standards of Qualicoat, GSB and Qualimarine. These labels require 1,008 hours of AASS, while AD and Corialis have shown that quality standards are still met even after 3,024 hours of AASS.
