Method of making a gypsum slurry with modifiers and dispersants

一种石膏浆液、分散剂的技术,应用在用改性剂和分散剂制造石膏浆液领域,能够解决生产等问题

Inactive Publication Date: 2008-06-04
USG CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

If high doses of dispersant are used to provide unpredictable dispersant efficacy, setting may be delayed to some extent where certain products such as gypsum panels cannot be produced on current high speed equipment

Method used

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  • Method of making a gypsum slurry with modifiers and dispersants
  • Method of making a gypsum slurry with modifiers and dispersants
  • Method of making a gypsum slurry with modifiers and dispersants

Examples

Experimental program
Comparison scheme
Effect test

example I

[0069] This example illustrates the importance of the order in which modifiers and dispersants are added. 400 grams of stucco from Southard, OK, 220 grams of water, 0.7 grams of HRA set accelerator and 0.89 grams of MELFLUX 2500L dispersant comprising 45% solids were used in each of the following tests. Additionally, 0.6 grams of baking soda was added to both samples as described below. Water and dispersant are added to the water, followed by the stucco and modifier (if present) in each case. After adding the stucco, the mixture was allowed to soak for 15 seconds, followed by mixing for 30 seconds to form a slurry. Add modifiers as described below.

[0070] Condition 1 is a control sample in which no soda ash modifier was added. In condition 2, the baking soda was added to the mixing water followed by the addition of the stucco to the water. In condition 3, the baking soda was added after the stucco was added to the mixing water, and the mixer was turned on immediately aft...

example 2

[0076] In this comparative example, lime was added to the gypsum slurry used to make gypsum panels and resulted in little improvement in fluidity. The amounts of all components are per 1000 square feet (104m 2 ) expressed in pounds (“lbs / MSF”) of gypsum panels. 1285 pounds of stucco was combined with other dry ingredients including 3 pounds of starch, 3 pounds of industrial dextrose, and 0.32 pounds (145 grams) of retarder. Ivory lime was premixed with water and added directly to the mixer through one of several water injection holes adjacent to the stucco inlet. The dispersant Melflux 2500L was added directly to the metered water and blended until homogeneous, and then the mixture was added to the mixer through the remaining water injection holes adjacent to the stucco inlet. The dry ingredients are blended with the stucco, which is then added to the mixer through the stucco spout.

[0077] Table II

[0078] sample

[0079] As shown in Table II, the use of 0.18%...

example 3

[0081] A plant trial was carried out whereby both the dispersant and the modifier were dissolved in measured quantities of water. The modifier soda ash was dissolved in water to make a 10% by weight solution. 3.9 lbs / msf of Melflux 2500L diluted to 32% solids was added to the measure of water followed by the 11.3 lb / msf slurry of soda ash into the measure of water and all components mixed to form a homogeneous solution. 1257 pounds of stucco was added to the mixer to form a gypsum slurry.

[0082] Table III

[0083] sample

[0084] As shown in Table III, the use of 0.1% baking soda significantly reduced the amount of water in this process.

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Abstract

In the method of making a gypsum slurry, a polycarboxylate-based dispersant, a modifier, and a hydraulic material including stucco are selected for use in the slurry. These components are then combined with water to form a slurry, wherein the modifier is added to the slurry before the slurry phase is formed from the water, the stucco, and the dispersant. It has been shown that the modifier will have less efficacy when added after the dispersant and the stucco have been contacted in the aqueous slurry. In a preferred embodiment, a quantity of stucco is obtained and the modifier and the dispersant are selected. A pre-dissolved solution of dispersant and modifier is prepared in water to form a solution prior to addition to the stucco. After mixing the solutions, the stucco is added to form the slurry. Optionally, the slurry is then shaped into a product and allowed to set.

Description

[0001] Cross References to Related Applications [0002] This application is a continuation-in-part of US Serial No. 11 / 152,323, entitled "Method of Making a Gypsum Slurry with Modifiers and Dispersants," filed June 14, 2005, which is incorporated herein by reference. [0003] This application is related to co-pending U.S. Patent Application No. 11 / 152,661, entitled "Fast Drying Wallboard"; U.S. Patent Application No. 11, entitled "Gypsum Products Utilizing a Two-Repeating Unit Dispersant and Process for Making Them" / 152,418; U.S. Patent Application No. 11 / 152,317, entitled "Modifiers for Gypsum Products and Methods of Using Them"; and U.S. Patent Application No. 11 / 152,404, entitled "Effective Use of Dispersants in Wallboard Containing Foam" ; All patents were filed on June 14, 2005 and are incorporated herein by reference. [0004] This application is related to co-pending U.S. Patent Application No. 11 / xxx,xxx (Attorney Reference Docket No. 2033.75332), entitled "Gypsum Pr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B28/14
CPCC04B28/145C04B28/26C04B2111/0062C04B2111/60Y10T428/232C04B12/04C04B20/0048C04B22/064C04B22/10C04B22/16C04B24/2647C04B24/38C04B40/0028C04B2103/12C04B2103/22C04B2103/67C04B14/06C04B22/143
Inventor 刘清霞戴维·R·布莱克本迈克尔·P·谢克布赖恩·兰德尔约翰·W·威尔逊丹尼斯·M·莱特克曼
Owner USG CORP
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