The present invention provides a process for the rapid and efficient production and examination of polyurethane (“PU”) foam-forming formulations in which only a small amount of material is required.
Screening of PU foam formulations is generally carried out by hand. Laboratory packets containing from 200 to 300 g of foam are produced after all of the ingredients have been manually weighed, mixed together in a bench stirrer, and the mixture has been poured into paper packets. Disadvantages of this manual screening are the low maximum throughput of 15 packets per day per technician, poor reproducibility resulting from the non-documenting of errors/deviations in weighing, stirring times, stirrer speed, etc., and a laborious determination by hand of reaction parameters such as the cream time, full rise time, fiber time and tack-free time.
A problem when conducting physical testing of PU foams is that the removal of a plurality of identical sample bodies in accordance with the DIN standard (sample size at least 125 cm3) is virtually impossible due to flow distance phenomena and fluctuations in density (up to 10%) and to the limited sample quantity from one identical batch. Additionally, destructive testing techniques frequently also mean that the sample body can be used only for a single measurement thereby necessitating the use of a plurality of packets which are as nearly identical as possible but which may frequently have properties which differ from one another (for example, differences in densities or in open cell content). Defined storage times must be observed before the samples are examined, in order to avoid or standardize ageing of the samples due to cell gas exchange.