Mineral deposits originally consist of calcium and magnesium carbonates. Carbonates, which are generally insoluble, are precipitated by heating water containing soluble calcium and magnesium bicarbonates. Bicarbonates are thermally unstable and break down to form carbonates and thus scale when heated.
Factors affecting scale deposition:
- The higher the (temporary) hardness of the water, the more scale will precipitate.
- The higher the pH (alkaline pH) of the water, the greater the tendency to scaling
- The higher the temperature to which the water is heated, the more scale will precipitate.
Scale precipitation and deposition on sewer walls increases dramatically when water temperatures exceed 60 degrees Celsius. It also depends on the hardness of the water, so in some areas the problems caused by scale are greater than others. To counter scale problems, most injection molding plants use some form of water treatment to minimize the risk of deposits based on minerals such as calcium or magnesium.w
For descaling of calcium and magnesium deposits, it is advisable to use DS2 cleaner.
Another type of deposits is formed during the corrosion process. These can be solid, water-insoluble deposits (such as encrustations during the microbial corrosion process) or scale - a layer of solid corrosion products or hard iron oxides. Like other deposits, they are dangerous to the ducts, restricting flow and reducing the efficiency of heat extraction.
Scale in water-cooled mold ducts will usually have a high concentration of iron oxides/corrosion by-products. This is mainly because companies use "closed loop" water supply systems where the concentration of iron oxide is up to seven times higher than in ordinary tap water. Another reason for the formation of deposits as a result of the corrosion process may be water left in the sewers after the cleaning process. Oxygen dissolved in the water reacts with the steel, causing corrosion.
To remove scale with a high concentration of iron oxides, it is advisable to use DS1 cleaner.
