Method for making fire-resistant foam insulation panels
A continuous process for preparing insulation panels having thick (0.2 mm to 1 mm) metal facing panels and a fiber-reinforced polymer foam core is disclosed. In the process, a bottom metal facing panel ( 2 ) is continuously supplied. A mat ( 10 ) of reinforcing fibers and a foamable resin composition ( 19 ) are applied to the bottom facing panel. A flexible barrier layer ( 5 ) is applied atop the foamable resin composition, and the assembly is passed through nip rolls ( 12,13 ) to compress the assembly and force the resin composition into the fiber mat. An adhesive layer ( 4 ) and top metallic facing layer ( 1 ) are then applied on top of the flexible barrier layer, and the resulting assembly is gauged and cured by passing it through a double band laminator ( 11 ).
1. A continuous process for preparing a foam laminate having metallic facing sheets, comprising
a) continuously feeding a bottom metallic facing sheet that includes a metal layer having a thickness of 0.2 to 1.0 mm onto a moving surface;
b) continuously applying a fiber mat and a curable, foamable resin composition onto the moving bottom metallic facing sheet;
c) prior to fully expanding the foamable resin composition, continuously applying a layer of a substantially flexible barrier material on top of the fiber mat and foam-forming resin composition;
d) prior to fully expanding the foamable resin composition, continuously passing the bottom metallic facing layer, fiber mat, resin composition and flexible barrier material through a constricted region to compress the bottom metallic facing layer, fiber mat, resin composition and flexible barrier material together such that the resin composition becomes pushed into and impregnates the fiber mat, and the flexible barrier material is contacted with the resin composition;
e) then continuously applying a layer of an adhesive layer on top of the layer of the flexible barrier material;
f) then continuously applying a top metallic facing sheet that includes a metal layer having a thickness of 0.2 to 1.0 mm on top of the adhesive layer and
g) passing the resulting assembly through a double band laminator to contact the top metallic facing sheet with the adhesive layer, gauge the assembly to a predetermined thickness and if necessary to further cure the resin composition, the adhesive layer, or both the resin composition and adhesive layer, to form the foam laminate.
2. The process of claim 1 wherein the foamable resin composition is at least partially expanded and partially cured prior to applying the top metallic facing layer.
3. The process of claim 2 , wherein the foamable resin composition is isocyanate-based.
4. The process of claim 3 , wherein the fiber mat has a weight of 20 to 80 g/m 2 .
5. The process of claim 3 , wherein the fiber mat is a mat of glass fibers.
6. The process of claim 3 , wherein the flexible barrier material is a multi-layer structure including a layer of a glass or other ceramic fiber bonded on one or both sides with a non-porous layer.
7. The process of claim 3 , wherein the layer of flexible barrier material has a thickness of 20 to 100 mm.
8. The process of claim 3 , wherein the metal layer of the metallic facing sheets is steel.
9. The process of claim 3 , further comprising, prior to or during step b), depositing a layer of an adhesive between the bottom metallic layer and the foamable resin composition.
10. The process of claim 9 , wherein the layer of adhesive deposited between the bottom metallic layer and the foamable resin composition is deposited prior to or simultaneously with the fiber mat.
11. The process of claim 3 , wherein the foamable resin composition expands to a thickness of 20 to 240 mm and the insulation panel has a thickness of 25 to 250 mm.