1996-02-01

Flexible Polyurethane Foam - A Durable Seating Medium 960512

High resiliency, polyurethane foam has been used for automotive seating since the early 1970's. In North America, HR foam seat cushioning has almost completely displaced conventional foam because it provides improved comfort and production economies.
Woodbridge Foam Corporation is a large supplier of moulded HR foam cushions, backs, headrests and armrests. In this paper we will discuss results we have obtained in fleet testing of production-line manufactured and laboratory poured HR foam parts. Cushions were made using toluene diisocyanate (TDI) or methylene diphenyl diisocyanate (MDI) and some parts contained recycled polyol from a glycolysis process. We have also evaluated cushions made from fibrous materials.
Seats assembled using these cushions have been durability tested for more than two thousand hours in a police cruiser fleet. On a regular basis seats were removed from the cruisers and tested to determine if dimensional and hardness changes had occurred. Seat failures and removal occurred when police officers found these seats too uncomfortable for further use.
Seats containing HR cushions made with both TDI and MDI-based formulations have performed well during the test period. The incorporation of up to 20 % glycolysed polyol did not adversely affect the foam performance. TDI cushioning with well over 5000 hours of fleet use still meets the original design intent with negligible loss of hardness or comfort. Cushions made with fibrous materials (natural and synthetic) had to be removed from the test fleet either because they were considered to be too hard and uncomfortable or because the fibrous material had degraded.
With more than five thousand hours of use (equivalent to two vehicle lifetimes), flexible HR polyurethane foam seating material has proven to be a very durable and comfortable seating medium in severe use vehicles.

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