Abstract:

Polyurethane (PU) foams are the most essential part of a car seat cushion. PU foams are durable and easily moldable according to the shape of the car seat, but they are poorly permeable to moisture. This impermeability of PU foam causes  wetness of the microclimate between the person and  car seat and makes it uncomfortable. In this research PU foams with two different thicknesses and three different hole sizes were obtained from industry by the moulding process. The foams were tested for moisture permeability by the standard cup method to determine the effect of the size of the hole on the overall moisture permeability. The foams were further tested with 11 of the most common top layer fabrics to check the effect of the top fabric layer on the overall moisture permeability of the car seat. All the top layers were first tested by means of a sweating guarded hot plate (SGHP) to measure the water vapour resistance (Ret) and then 4 materials with the minimum Ret values were tested with the most permeable foam. The results shows that the perforation of PU foam causes a significant increase in moisture permeability, whereas the top layer with the minimum Ret value decreases the overall moisture permeability and a maximum of 40g/m2 of moisture per hour is obtained with the most permeable foam with the least Ret value of the top layer. This research is an initial work on replacing the car seat with perforated PU-foams.