Fiber for fiber cement and resulting product
View Patent ↗A fiber-cement product which includes a treated cellulose wood pulp fiber. The fiber is treated with fibrillated carboxymethyl cellulose or a carboxyethyl cellulose and poly(diallyldimethylammonium chloride). The fiber can be bleached or partially bleached, refined or unrefined or a mixture of refined and unrefined fiber.
1. A naturally cured fiber-cement product comprising:
cement;
a synthetic polymer fiber; and
a treated cellulose wood pulp fiber, said pulp fiber being treated with a fibrillated carboxyalkyl cellulose having a degree of substitution lower than about 0.45 and with a quaternary ammonium polymer.
2. The fiber-cement product of claim 1 , wherein the quaternary ammonium polymer is poly(diallyldimethylammonium chloride).
3. The fiber-cement product of claim 1 , wherein the synthetic polymer fiber is one or more of a polypropylene fiber and a polyvinyl alcohol fiber.
4. The fiber-cement product of claim 1 , wherein the synthetic polymer fiber is present in an amount of about 1.5-3.0% by weight.
5. The fiber-cement product of claim 1 , wherein the wood pulp fiber is present in an amount of about 1.0-5.0% by weight.
6. A naturally cured fiber-cement product comprising cement and a treated cellulose wood pulp fiber, said fiber being treated with a fibrillated carboxyalkyl cellulose having a degree of substitution lower than about 0.45 and with a quaternary ammonium polymer.
7. The fiber-cement product of claim 6 , wherein the fibrillated carboxyalkyl cellulose is present in the treated cellulose wood pulp fiber in an amount of about 1.0-4.0% by weight.
8. The fiber-cement product of claim 6 , wherein the treated cellulose fiber has at least 2 meq/100 g of fiber of the quaternary ammonium polymer retained thereon.
9. The fiber-cement product of claim 6 , wherein the quaternary ammonium polymer is poly(diallyldimethylammonium chloride).
10. The fiber-cement product of claim 9 , wherein the treated cellulose fiber has about 0.5-2.0% by weight of poly(diallyldimethylammonium chloride) retained thereon.
11. The fiber-cement product of claim 6 , wherein the fibrillated carboxyalkyl cellulose is fibrillated carboxymethyl cellulose.
12. The fiber-cement product of claim 6 , further comprising one or more of a synthetic polymer fiber and an untreated cellulose wood pulp fiber.
13. A method of preparing a fiber-cement product, the method comprising:
adding fibrillated carboxyalkyl cellulose having a degree of substitution lower than about 0.45 and a quaternary ammonium polymer to cellulose wood pulp fibers to produce a treated cellulose fiber having quaternary ammonium polymer retained thereon;
forming a fiber-cement product from the treated cellulose fiber and cement; and
naturally curing the formed fiber-cement product.
14. The method of claim 13 , further including, prior to adding fibrillated carboxyalkyl cellulose, fibrillating said carboxyalkyl cellulose.
15. The method of claim 14 , wherein fibrillating is performed using high shear mixing of carboxyalkyl cellulose in water.
16. The method of claim 13 , wherein the fibrillated carboxyalkyl cellulose is added in an amount of about 0.1-10% by weight of the cellulose wood pulp fibers.
17. The method of claim 13 , wherein the quaternary ammonium polymer is added in an amount of at least 2 meq/100 g of the cellulose wood pulp fibers.
18. The method of claim 13 , wherein the quaternary ammonium polymer is poly(diallyldimethylammonium chloride).
19. The method of claim 18 , wherein the poly(diallyldimethylammonium chloride) is added in an amount of about 0.1-10% by weight of the cellulose wood pulp fibers.
20. The method of claim 18 , wherein the treated cellulose fiber has about 0.5-2.0% by weight of poly(diallyldimethylammonium chloride) retained thereon.