Back to results
US 4,297,311 AGranted
Method of manufacturing improved mineral board
AssigneeConwed Corporation
InventorsNorman Sherman, John H. Cameron
Life of this patent
Estimating the term…
Abstract
A method of producing an improved mineral board and the resulting product are disclosed. According to the present invention, the board is predominantly composed of perlite and a binder therefor, preferably urea-formaldehyde resin. The perlite is crushed after the composition is in its final shape but before the binder is set whereby its strength is substantially increased. The composition and process of making the board substantially reduce energy costs as compared to known methods for making wet-process mineral boards. The product composition may include up to 95% perlite by weight.
Claims33
A method of manufacturing a mineral product comprising the sequential steps of:
- (a) forming an admixture comprising perlite and a resin binder therefor, at least 75% by weight of the solids content of said admixture being composed of the perlite/resin binder combination, the perlite being in the expanded form and having an initial average bulk density no greater than about 10 pounds per cubic foot, the said perlite/resin binder combination containing by weight from about 50% to about 95% perlite and from about 5% to about 50% resin binder where the expanded perlite is derived from an active perlite, and the said perlite/resin binder combination containing by weight from about 60% to about 95% perlite and from about 5% to about 40% resin binder where the expanded perlite is derived from an inactive perlite;
- (b) mixing said admixture;
- (c) forming a shaped product from said admixture;
- (d) subjecting said shaped product to pressure to form it into its final shape, said pressure being sufficient to reduce the bulk volume of the perlite by a crushing factor of at least about;
- (i) where the expanded perlite has been derived from an active perlite:
- (1) y=6.5-0.26x where x is from about 5 to about 15
- (2) y=3.1-0.035x where x is from about 15 to about 50
- (ii) where the expanded perlite has been derived from an inactive perlite:
- (3) y=2.3-0.03x where x is from about 5 to about 40
- wherein in each of formulas (1), (2) and (3):
- y is the crushing factor and x is the percent by weight of binder in the perlite/resin binder combination;
- and, thereafter,
- (e) curing the resin binder.
10 more elements
A method of manufacturing a mineral product comprising the sequential steps of:
- (a) forming an admixture comprising perlite and a urea-formaldehyde binder therefor, at least 75% by weight of the solids content of said admixture being composed of the perlite/urea-formaldehyde binder combination, the perlite being in the expanded form and having an initial average bulk density no greater than about 10 pounds per cubic foot, the said perlite/urea-formaldehyde binder combination containing by weight from about 50% to about 95% perlite and from about 5% to about 50% urea-formaldehyde binder where the expanded perlite is derived from an active perlite, and the said perlite/urea-formaldehyde binder combination containing by weight from about 60% to about 95% perlite and from about 5% to about 40% urea-formaldehyde binder where the expanded perlite is derived from an inactive perlite;
- (b) mixing said admixture;
- (c) forming a shaped product from said admixture;
- (d) subjecting said shaped product to pressure to form it into its final shape, said pressure being sufficient to reduce the bulk volume of the perlite by a crushing factor of at least about:
- (i) where the expanded perlite has been derived from an active perlite:
- (1) y=6.5-0.26x where x is from about 5 to about 15
- (2) y=3.1-0.035x where x is from about 15 to about 50
- (ii) where the expanded perlite has been derived from an inactive perlite:
- (3) y=2.3-0.03x where x is from about 5 to about 40
- wherein in each of formulas (1), (2) and (3):
- y is the crushing factor and x is the percent by weight of urea-formaldehyde binder in the perlite/urea-formaldehyde binder combination;
- and thereafter,
- (e) curing the urea-formaldehyde binder.
10 more elements
A method of manufacturing a mineral product comprising the sequential steps of:
- (a) forming an admixture comprising perlite and a urea-formaldehyde binder therefor, at least about 95% by weight of the solids content of said admixture being composed of the perlite/urea-formaldehyde binder combination, the said combination containing by weight from about 60% to about 90% perlite and from about 10% to about 40% resin binder, and the perlite being derived from active perlite and the perlite being in the expanded form and having an initial average bulk density of from about 2 to about 4 pounds per cubic foot, said admixture further including from about 25% to about 40% water by weight of the perlite/urea-formaldehyde combination;
- (b) mixing said admixture without substantial reduction in bulk volume of the perlite;
- (c) forming a shaped product from said admixture;
- (d) subjecting said shaped product to pressure to form it into its final shape, said pressure being sufficient to reduce the bulk volume of the perlite by a crushing factor of at least about 4;
- and
- (e) curing the urea-formaldehyde binder.
3 more elements
Dependencies are inferred from the claim text.