Determination of the Polyurethane Parameters for Riding Comfort Evaluation in Automobile Seating Application

Riding comfort for automobile seating can be classified into two categories, long time riding comfort and short term riding comfort. The attributes that govern the riding comfort includes static spring constant and energy lost due to hysteresis. The emerging trend towards long term riding comfort could be governed by the above mentioned factors. The hysteresis loss characteristic is related to Poly-Urethane (PU) properties used extensively in automotive seating application. The nature with which the energy is released considering the same material and varying the hardness directly contributes to the comfort analysis for automobile seating and vice versa. Two curves can define the same area but the loading and unloading trend for the two cases could be different and so be the riding comfort. A conclusion would be drawn by obtaining hysteresis loss rate by changing the different parameters (hardness, density). One parameter would be varied by keeping the others constant. The data presented will show the difference in comfort by variation of hardness and density of an automobile seat. Hysteresis loss rate graph would be obtained for all the seating combination via the physical testing of the seats.