IMPROVEMENTS IN OR RELATING TO FOAM FILLED HONEYCOMB STRUCTURES

摘要

Spherical heat foamable pellets (2) are used for reinforcing honeycomb structures (4). The pellets are preferably of average diameter from 0.5 mm to 0.9 mm and preferably at least 80% of the pellets have a diameter in this range. The pellets can form a free flowing stream which can be poured into the cells (5) of the honeycomb where they can be foamed by heating to form a reinforcing foam which can also bond the honeycomb structure to facing sheets. It is preferred that the pellets are based on a thermosetting resin and contain a curing agent that can cure the foamed resin to produce an integral rigid reinforcing foam within the cells of the honeycomb.