PVC floorings as post-consumer products for mechanical recycling and energy recovery

Abstract

Old PVC flooring materials obtained from three apartment blocks built in 1964, 1971, and 1974, respectively, have been examined in parallel with newly manufactured PVC floorings. The focus of this study was to investigate how the important properties of PVC floorings change during their service life owing to ageing processes, and how these can influence their suitability as post-consumer products for recycling methods such as mechanical recycling and energy recovery. One important objective was to obtain general information regarding the degradation processes in PVC floorings that could influence these recycling methods. Our study has shown that PVC floorings as plastic waste can be mechanically recycled in the form in which they were recovered without upgrading, and without the addition of new plasticizer. It is also shows that the high alkalinity of moist concrete can lead to the decomposition of the plasticizer when PVC flooring is glued onto it. However, the degree of decomposition of plasticizer is very small relative to the mass loss by evaporation, and consequently should not cause any problems for mechanical recycling. Nevertheless, decomposition products such as butanol and octanol can cause indoor environmental problems sometimes designated as “sick building syndrome”. For this reason, gluing directly onto fresh concrete should be avoided. Gluing also makes mechanical recycling less favourable owing to troublesome dismantling, and the high degree of contamination from the glue. The heat content in PVC floorings is dependent on the proportions of PVC and plasticizer used. Consequently, changes in the heat content caused by long-term use of PVC floorings should be insignificant.