Performance of Polypropylene Dual Laminates in Waste Incineration Plants

In view of the restrictive environmental protection and shrinking landfill capacities in Western Europe, the controlled incineration of industrial and municipal waste in conceived plants points out a chance to indulge resources. Flue gases of such plants - probably catalytically oxidized - are first cooled down. While subsequently up-streaming, they face a counter current wash with caustic soda solution. The simultaneous demand of an acidic atmosphere and a circulating alkaline brine to the whole construction requires a careful material selection, which today is efficiently solved by choosing a combination of a thermoplastic material, serving as so-called chemical barrier, and a load-bearing structure made from glass-fiber reinforced plastic (FRP). Amongst thermoplastic materials, polypropylene plays a significant part due to its cost-performance ratio. This paper discusses the performance of polypropylene grades for sheet material in combination with different fabric backings to protect the FRP-structure from heavy alkaline and acidic attack downstream of the quenching step of waste incineration plants – additionally paying attention to the processing of semi-finished materials.