POLYISOCYANATE FOAM HAVING ISOTROPIC CELLS AND METHOD AND APPARATUS THEREFOR

摘要

A polyisocyanate foam having isotropic cells is manufactured by foaming operation in an apparatus comprising a mould composed of side walls capable of extending and retrenching or folding and unfolding perpendicularly to free rising direction, a detecting means, if desired, and a mould extending means provided on the respective side wall which operates to spread out the mould perpendicularly to free rising direction. Foaming in the free rising direction proceeds in a creamy state up to the position of the means in the unopened mould and then, foaming perpendicularly to free rising direction continues during a period of time from a creamy state to a tack-free state while the mould is spreading out, whereby isotropic cells are formed. The so-manufactured foam has high dimensional stability and is suitably for insulating materials, especially low temperature insulating materials.