Method of pouring polyisocyanurate foam directly onto a facer to improve cell orientation and density stratification

A method of forming a polyisocyanurate foam board comprising:

• providing a polyol;
• adding an isocyanate and a catalyst to the polyol to form a polyisocyanurate foam;
• treating an inner surface of at least one facer material with a flow of hydroxyl containing molecules;
• and
• coupling the polyisocyanurate foam to the treated inner surface of the facer material;
• wherein a density of the polyisocyanurate foam is lowest at an interface formed between the treated inner surface and the polyisocyanurate foam.

A polyisocyanurate foam board comprising:

• a polyisocyanurate foam core having a medial portion and opposing outer surfaces, the polyisocyanurate foam core produced from:
• an isocyanate;
• a polyol;
• and
• a facer material applied to at least one of the opposing outer surfaces of the polyisocyanurate foam core, wherein a density of the medial portion of the polyisocyanurate foam core is greater than a density of the at least one of the opposing outer surfaces of the polyisocyanurate foam core.