Casting bar for use in manufacture of composite panels

An apparatus for delivering foam-producing reaction mixture to a surface comprising at least one casting bar and a distribution manifold. The casting bar having: an inlet; a bore formed along a length of the casting bar and in fluid communication with the inlet, wherein a cross-section of the bore is substantially circular near the inlet and gradually becomes substantially elliptical as it approaches an end away from the inlet; and orifices in the casting bar on a side facing the surface. If there are two casting bars they may be angled upwards relative to the surface or angled backwards relative to the direction of movement of the surface. Also described is a process of producing composite panels comprising a foam layer and two covering layers. 种用于将产生泡沫的反应混合物传送到表面的装置，包括至少个铸棒和分配歧管。所述铸棒具有：入口；沿着铸棒的长度形成并且与入口流体连通的孔，其中，孔的横截面在靠近入口处大致圆形，并且随着孔接近远离入口的端部逐渐变为大致椭圆形；以及铸棒中的在面对所述表面的侧面上的孔洞。如果存在两个铸棒，那么它们可以相对于表面向上成角或者相对于表面的移动方向向后成角。还公开了种用于制备包括泡沫层和两个覆盖层的复合板的方法。