Aerated fiber cement building products and methods of making the same
AssigneeJames Hardie Technology Limited
InventorsSarah Grundy, Kelvin Lau, Xiangyuan Liu, Thomas Patrick Mueller, Joe Zhou Peng, Steven Terzian
Life of this patent
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Abstract
Disclosed herein are low density fiber cement articles, such as fiber cement building panels and sheets, comprised of multiple overlaying fiber cement substrate layers having small and uniform entrained air pockets and low density fillers distributed throughout. The combination of entrained air pockets and low density fillers provide a low density fiber cement matrix with physical and mechanical properties similar to comparable low density fiber cement matrix without entrained air pockets.
Claims15
A fiber cement formulation, comprising:
- less than 50% by weight of a siliceous aggregate;
- about 25%-38% by weight a hydraulic binding agent;
- about 5%-15% by weight of cellulose fibers;
- about 1.5%-3.5% by weight of microspheres;
- about 3%-8% by weight of expanded perlite;
- and
- about 0.1%-0.5% by weight of an air entrainment agent.
A building article comprising:
- a plurality of thin overlaying fiber cement substrate layers, each of said overlaying fiber cement substrate layer is bonded to an adjacent overlaying substrate layer thereby forming a fiber cement matrix;
- a first plurality of filler particles having a first density and incorporated in the fiber cement matrix, wherein the first plurality of filler particles comprises about 0.1%-5% by volume of the fiber cement matrix;
- a second plurality of filler particles having a second density and incorporated in the fiber cement matrix, wherein the second plurality of filler particles have an average density less than the average density of the first plurality of filler particles;
- a plurality of air voids defined by air pockets entrained in the fiber cement matrix such that the air voids are formed directly in the fiber cement matrix with no material separating the air voids from the fiber cement matrix, wherein the air voids comprise about 3%-20% by volume of the fiber cement matrix, wherein the air voids are closed cell.
A fiber cement formulation, comprising:
- a binding agent comprising 5-80% by weight of the total weight of the formulation;
- cellulose fibers comprising 5-15% by weight of the total weight of the formulation;
- a first filler comprising 1-15% by weight of the total weight of the formulation;
- a second filler comprising 1-10% by weight of the total weight of the formulation, said second filler having a density less that the first filler;
- and
- wherein an air entrainment agent comprises 0.6%-5.0% by weight of the total weight of the formulation.
Dependencies are inferred from the claim text.