Method and apparatus for making high compression structural foam

A method of making a structural foam billet of predetermined thickness having high compression strength in the Y direction comprising depositing a stream of foam forming stock onto the surface of a moving conveyor in a manner in which the mass of the foam forming stock varies a plurality of times over a first length of the conveyor surface in the direction of movement of the conveyor surface, the total of the varying mass being laid over the first length being sufficient to form the structural foam billet over said first length.

A method of making a structural foam billet of predetermined thickness having high compression strength in the Y direction comprising depositing a stream of foam forming stock onto the surface of a moving conveyor so that the mass of the stream varies between high and low over a plurality of sequential time periods as it is laid on the conveyor surface, sufficient total mass being laid over the plurality of sequential time periods to form the structural foam billet.

A method of making a structural foam billet of predetermined thickness having high compression strength in the Y direction comprising depositing a stream of foam forming stock onto the surface of a moving conveyor and for intermittent periods pressing a portion of the foam forming stock toward the surface of the conveyor before the foam forming stock is expanded to the predetermined thickness.

A method of making a structural foam billet having high compression strength in the Y direction by depositing a plurality of blobs of foam forming stock having a total mass that is large enough to form the billet when expanded, spaced from one another so that they independently expand in the Y direction before joining together into the structural foam billet.