Boards and panels
First Claim
1. A process for the manufacture of a non-asbestos corrugated sheet for external use from a mixture comprising, on a dry weight basis, 40-60% cement, 30-40% silica and 5-15% cellulose fibers, comprising the following steps:
- (1) processing the cellulose fibers to a freeness of 18°
-35°
S.R.;
(2) mixing the cellulose fibers with the cement and silica in a flocculating agent to produce an aqueous slurry;
(3) taking up the slurry on the moving permeable belt of a Hatschek machine to form a film of damp composition thereon and transferring said film to a rotating drum on which the mixture builds up;
(4) removing a desired thickness of mixture from the drum in the form of a flat sheet;
(5) forming said flat sheet into a corrugated shape;
(6) placing said corrugated sheet in the press and reducing its thickness therein; and
(7) subjecting the pressed corrugated sheet to an autoclaving reaction to cause reaction to occur between said cement and said silica to form a binder matrix.
2 Assignments
0 Petitions
Accused Products
Abstract
A process for the manufacture of a non-asbestos corrugated sheet comprising forming into corrugated form an aqueous slurry of a mixture comprising, on a dry weight basis, 40-60% cement, 30-40% silica and 5-15% cellulose fibres, compressing said corrugated form so produced in a press to reduce its thickness and increase its density, removing said form from said press and submitting said form to autoclaving to cause reaction to occur between said cement and said silica to form a binder matrix. The aqueous slurry may include a moldability aid such as finely divided silica, and the corrugated forms are suitably compressed individually and then passed through a steam tunnel partially to harden them before autoclaving. In corrugated sheets formed are suitable for external cladding and roofing.
155 Citations
17 Claims
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1. A process for the manufacture of a non-asbestos corrugated sheet for external use from a mixture comprising, on a dry weight basis, 40-60% cement, 30-40% silica and 5-15% cellulose fibers, comprising the following steps:
-
(1) processing the cellulose fibers to a freeness of 18°
-35°
S.R.;(2) mixing the cellulose fibers with the cement and silica in a flocculating agent to produce an aqueous slurry; (3) taking up the slurry on the moving permeable belt of a Hatschek machine to form a film of damp composition thereon and transferring said film to a rotating drum on which the mixture builds up; (4) removing a desired thickness of mixture from the drum in the form of a flat sheet; (5) forming said flat sheet into a corrugated shape; (6) placing said corrugated sheet in the press and reducing its thickness therein; and (7) subjecting the pressed corrugated sheet to an autoclaving reaction to cause reaction to occur between said cement and said silica to form a binder matrix. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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Specification