Abstract:

A series of nonwovens with various mechanical and thermal properties was prepared by a textile technique based on melt-spun continuous PP fibres modified with paraffin as a phase change material (PCM). The PCM is not encapsulated; it forms a structure like “islands in sea” in the PP fibres. This permits the addition of a larger amount of the active substance to the fibre than in the encapsulated version. The nonwovens made of such fibres retained high thermal resistance. Paraffin was added to the PP fibre in amounts of 10 - 30 wt%; 20 wt% appeared to be best in terms of thermal properties and processability. To prevent fibre to fibre sticking at elevated temperatures, the nonwovens were made of a blend of paraffin-modified and standard PP fibres in variable proportions. The thermal activity determined by the kind of paraffin used was estimated to be in the range of 30 - 60 °C. The fibre heat accumulation capacity stemming from the phase transition in the PCM was in the range of 3.6 - 19.4 kJ/m2, at a thermal regulation factor (TRF) from 0.8 to 0.4.