Spasciani’s filters have plastic housing because plastic has a better mechanical and chemical resistance to agressive substances.
Spasciani manufacture plastic housing filters since more than 20 years. Before they used to manufacture them in aluminium as many manufacturers still do today.
The reason for that choice is due to the resistance of the plastic used to the chemicals with which the charcoal is impregnated. With ageing, in fact, even if one coats the aluminium surface, an electro-chemical reaction starts, which causes the corrosion of the housing. In some cases you can reach a pass through corrosion particularly with partially used filters where the reaction is enhanced by the moisture and corrosive gases absorbed by the charcoal. The picture shows the corrosive action inside a competitor’s new filter, still having three years shelf life to go.
Another reason for choosing plastic is the resistance to strokes. A metal filter with a dented thread cannot be used any more. This cannot happen with plastic ones as they cannot be deformed.
Shocks on plastic filters do not cause reduction in performances due to the perfect filling which exceeds the Rough Usage tests prescribed by EN14387.
