Dry putty powder based on waste powder from cutting and processing of fiber cement sheets and its putty with a fast drying time

Abstract

A dry putty powder comprises a waste powder obtained from cutting and processing of fiber cement sheets, silica aerogel nanoparticles, metakaolin, vinyl-ethylene acetate copolymers, and white cement. In the dry putty powder, one weight percent of the waste powder in a range of 45 to 50, one weight percent of silica aerogel nanoparticles in a range of 5 to 10 weight percent, one weight percent of metakaolin in a range of 5 to 10 weight percent, one weight percent of vinyl-ethylene acetate in a range of 4 to 10 weight percent, and one weight percent of white cement in a range of 10 to 40 weight percent are used. The waste powder obtained from cutting and processing fiber cement sheets contains 40 to 45% by weight of silica, 10 to 15% by weight of cellulose fibers, and 40 to 60% by weight of Portland cement. A putty is obtained by adding water to the dry powder of the putty, and the ratio of adding water to the dry powder of the putty (water: dry powder of the putty) can be 1:1, 1:2, or 1:3 depending on the type of application. After applying the said putty once on a surface, the said putty dries in a period of time between 10 and 15 minutes, which is due to the fast drying time of the ingredients and their weight percentage in the dry powder of the said putty, and greatly reduces the application time. The said putty also has an adhesion strength of about 3 MPa and a hardness of 145 seconds based on the damping of the Perzoz pendulum.

Description

Description of the invention Title of the invention Dry putty powder based on waste powder from cutting and processing of fiber cement sheets and its putty with a fast drying time Technical background of the relevant invention The present invention discloses a dry putty powder with a very fast drying time, in particular a dry putty powder based on waste powder obtained from cutting and processing of fiber cement sheets with a putty drying time in a time range of between 10 and 15 minutes after a single application to a surface. The present invention also discloses a putty obtained from the dry putty powder which has high adhesion properties. Technical problem and stating the objectives of the invention Putty powder is one of the most widely used materials in the construction and building repair industry, used to fill and smooth various surfaces. One of the main uses of putty powder is to fill cracks, seams, and imperfections in the surfaces of walls and ceilings. By filling empty spaces and smoothing the surface, this material provides a suitable base for painting, wallpapering, and other decorative works. Putty powder is also used to repair wooden, metal, and plastic surfaces. Putty powder is usually prepared from a combination of mineral powders, special adhesives, and various additives, and after mixing with water, it becomes a paste that has high ductility and adhesion. In common putties, cement and polymers are used as binding agents. Although cement is a good and durable binder and is durable and low-cost, it has poor tensile strength and crack resistance. On the other hand, using a polymer in addition to cement can enhance the toughness of the produced putty and improve the performance of the putty. In common putty powders, calcium oxide mixed with a small amount of calcium carbonate is also used as a filler. When mixing putty powder with water, lime is produced due to the reaction between water and calcium carbonate, which is a very toxic substance. On the other hand, calcium oxide reacts with water to release calcium hydroxide, which is a severe irritant to the respiratory tract and can cause chemical pneumonia. It is also very harmful to the eyes and skin of the user due to its corrosive nature.Therefore, the presence of these two substances in common traditional putties is one of the main problems of these putties, both in terms of the environment and the health of users. Another problem with traditional common putty powders is that the coating created by these types of putty powders is rough and uneven on the one hand, and has low resistance and high moisture absorption on the other. Also, when preparing the putty, the resulting putty is in two phases and it is necessary to mix the putty prepared from traditional putty powders with adhesive when using the putty, which is not only time-consuming but also costly. Therefore, in the present invention, an environmentally and user-friendly dry putty powder is disclosed, which, due to the ingredients used in it, not only does it not cause the above-mentioned problems for the user during use, but it is also economical and can be prepared in a short time, and its drying time is also very short due to these ingredients and the weight percentage of the ingredients. A description of the state of the prior art and the history of developments related to the claimed invention. Given the wide application of putty in the construction industry and the problems with common putties mentioned above, changing the type of ingredients and the percentage composition of these ingredients can lead to changes in the physical and mechanical properties of the final putty. Therefore, obtaining a suitable composition for dry putty powder that provides the desired properties for the user according to the application is of great importance in the construction industry. Many studies and researches have been conducted on providing dry putty powder with different compositions and different percentage compositions, some of which are discussed below and the similarities and differences between these documents and the present invention. In a patent registered in China under the number CN112431434A in 2020, a putty powder containing 36 to 44 weight percent cement, 54 to 62 weight percent calcium carbonate powder, 0.8 to 1.6 weight percent rubber powder, and 0.2 to 1.2 weight percent methyl cellulose was disclosed, which was used to repair cracks and fill pores in fiber cement sheets. In this patent, after applying the putty to the surface and drying it, a sanding process was used to achieve a smooth and uniform surface. Also, in this patent, the putty can be applied in two stages, with the drying time in the first stage of applying the putty to the surface being between 6 and 8 hours and the drying time of the putty in the second stage of applying the putty being between 8 and 12 hours. This is while the putty disclosed in the present invention includes waste powder from cutting and processing fiber cement sheets, silica aerogel nanoparticles, metakaolin, vinyl-ethylene acetate copolymer, and white cement, and the putty does not require sanding after application to the surface because the putty creates a smooth and uniform surface after application and drying.Also, putty is applied to the surface at least once and its drying time is between 10 and 15 minutes. Therefore, the present invention is completely different from the above patent in terms of the ingredients used in the dry putty powder, as well as the drying time and minimum number of applications. In another application filed in China under number CN112638841A in 2019, a dry putty powder comprises 4 to 20 wt% of cement selected from a group consisting of Portland cement (4 to 10 wt%), sulfate aluminate cement (10 to 20 wt%), and aluminous cement (4 to 15 wt%), 4 to 12 wt% of gypsum (sulfur-free gypsum, CaSO4.2H2O, CaSO4.½ H2O), 1.5 to 4 wt% of polymer particles for adhesion (vinyl-ethylene acetate copolymers), 0.02 to 0.04 wt% of retarder (including tartaric acid, citric acid, sucrose, and lignosulfonate), 0.02 to 0.05 wt% of density modifier, 0.15 to 0.35 wt% of cellulose ether, and 65 to 85 weight percent filler with a particle size distribution in the range of 12 to 300 micrometers has been disclosed.Meanwhile, the dry putty powder disclosed in the present invention includes 40 to 50 weight percent of waste powder from cutting and processing cement fiber sheets (including 40 to 45 weight percent silica, 10 to 15 weight percent cellulose fibers, and 40 to 60 weight percent Portland cement), 5 to 10 weight percent silica aerogel nanoparticles, 5 to 10 weight percent metakaolin, 4 to 10 weight percent vinyl-ethylene acetate copolymer, and 10 to 40 weight percent white cement. Although some of the ingredients used in the above application overlap with the ingredients used in the dry putty powder disclosed in the present invention (such as Portland cement and vinyl-ethylene acetate copolymer), in other ingredients, these two powders are completely different from each other. Also, the weight percentage of Portland cement and vinyl-ethylene acetate copolymer in the application are not only not within the weight percentage range of these two compounds in the dry putty powder disclosed in the present invention, but they are used in lower weight percentages in the above application. Therefore, the above application is completely different from each other in terms of the overall composition used and also the composition of the percentages.On the other hand, the drying time of the putty obtained from the putty powder of the above application is between 3 and 4 hours, while in the present invention, this time is between 10 and 15 minutes, which is much less than in the above application. This lower drying time of the putty in the present invention is due to the type of compounds used in the dry putty powder and also the percentage composition of these compounds. Providing a solution to an existing technical problem along with an accurate, sufficient, and integrated description of the invention The present invention describes a dry putty powder for application to a surface, such that the putty prepared from this dry putty powder, after application to a surface, creates a very smooth surface free of any roughness or unevenness. In one embodiment of the present invention, a dry putty powder comprises a waste powder obtained from cutting and processing fiber cement sheets, silica aerogel nanoparticles, metakaolin, vinyl-ethylene acetate copolymer, and white cement. The use of said waste powder in the preparation of said dry putty powder in addition to reducing production costs also leads to better management of industrial waste. In one or more embodiments of the present invention, said waste powder can be used in a weight percent in a range of 45 to 50 weight percent relative to the total weight of said dry putty powder in said dry putty powder. In one or more embodiments of the present invention, said waste powder can have an average particle size of less than 75 microns, preferably an average particle size in a range of 50 to 75 microns. In one embodiment of the present invention, said waste powder can include silica, cellulose fibers, and Portland cement. In one or more embodiments of the present invention, the weight percent of silica, the weight percent of cellulose fibers, and the weight percent of Portland cement in said waste powder may be 40 to 45 weight percent, 10 to 15 weight percent, and 40 to 60 weight percent, respectively, where the weight percents are based on the total weight of said waste powder. In one or more embodiments of the present invention, said cellulose fibers may have a length in a range of 0.5 mm to 4 mm.In one or more embodiments of the present invention, said silica may have an average particle size in the range of 50 to 75 micrometers. In one or more embodiments of the present invention, the Portland cement has an average particle size in the range of 53 to 75 micrometers. The silica aerogel nanoparticles are a very light, porous material with properties such as high thermal and moisture insulation, low density, high specific surface area, and transparency. The use of silica aerogel in the dry powder of the said putty leads to a reduction in the weight of the putty, an increase in the resistance to cracking, a decrease in the permeability of the putty applied to the surface to water, and an increase in the resistance to fire. In one or more embodiments of the present invention, silica aerogel nanoparticles can be added to the said dry powder putty in a weight percentage within a range of 5 to 10 weight percent relative to the total weight of the dry powder of the putty. In one or more embodiments of the present invention, silica nanoparticles can also be used as a substitute for silica aerogel nanoparticles or in combination with silica nanoparticles in the said dry powder of the putty. Metakaolin, which is obtained by thermal processing of kaolinite, a type of clay mineral, acts as a filler and mechanical property enhancer in the dry powder of the said putty. The use of metakaolin in the dry powder of the said putty leads to increased strength, increased adhesion strength, increased stability, as well as reduced shrinkage and permeability of the putty. In one or more embodiments of the present invention, metakaolin can be used in a weight percent in a range of 5 to 10 weight percent relative to the total weight of the dry powder of the said putty. In one or more embodiments of the present invention, kaolinite (kaolin), calcium chloride, silica (in the form of nanoparticles or microparticles), and / or a combination thereof can be used as a substitute for metakaolin or in combination with metakaolin in the dry powder of the said putty. In one or more embodiments of the present invention, said vinyl-ethylene acetate copolymer is used as a binder in said dry putty powder. In one or more embodiments of the present invention, a weight percent of said vinyl-ethylene acetate copolymer can vary in a range of 4 to 10 weight percent based on the total weight of said dry putty powder. In one or more embodiments of the present invention, said white cement may be used in a weight percentage in a range of 10 to 40 weight percent relative to the total weight of said dry putty powder. In one or more embodiments of the present invention, the dry putty powder according to any of the embodiments of the present invention may also include a pigment. In one or more embodiments of the present invention, said pigment may be used at a weight percent in a range of 3 to 5 weight percent relative to the total weight of said dry putty powder, according to the desired degree of lightness or darkness of the desired color. In one or more embodiments of the present invention, a water absorption capacity of said dry putty powder is equal to 3% and a density of said dry putty powder is in a range of 1.13 to 1.4 grams per cubic centimeter. In one or more embodiments of the present invention, a putty for application to a surface may comprise a dry powder of said putty disclosed in any of the embodiments of the present invention and water. In one or more embodiments of the present invention, the amount of water added to said dry powder (water:dry putty powder) may be a weight ratio of 1:1, 1:2, or 1:3. In one or more embodiments of the present invention, after a single application of said putty to a surface, the putty dries in a time period of between 10 and 15 minutes. In one or more embodiments of the present invention, said putty has a pH in the range of 10 to 12. In one or more embodiments of the present invention, said putty has an adhesion strength greater than 1.5 MPa, preferably in the range of 1.5 to 3 MPa. This high level of adhesion strength is due to the presence of the compounds mentioned in the above embodiments in combination with certain percentages in the dry putty powder. In one or more embodiments of the present invention, a water retention capacity of said putty is equal to 99%. Also, said putty has a compressive strength of 15 MPa.In one or more embodiments of the present invention, a hardness level of said putty after application to a surface based on the damping of a Pezoz pendulum with a number of impact oscillations equal to less than 150 equals 145 seconds. The aforementioned putty can be applied to all cement, concrete, and gypsum surfaces. The aforementioned putty can also be used for sealing, caulking, and filling connection points, as well as for leveling surfaces made with fiber cement sheets and kunaf, and prefabricated gypsum walls. Explanation of shapes, maps and diagrams Table 1 shows the physical properties of dry putty powder, in accordance with one or more embodiments of the present invention. Table 2 shows the results of a test to determine the adhesion strength of a putty prepared from the dry putty powder disclosed in the present invention after a single application to a surface, in accordance with one or more embodiments of the present invention. Table 3 shows the results of a test to determine the hardness of putty prepared from the dry putty powder disclosed in the present invention after a single application to a surface by the pendulum damping method, in accordance with one or more embodiments of the present invention. Table 4 shows the mechanical properties of putty prepared from the dry putty powder disclosed in the present invention after a single application to a surface, in accordance with one or more embodiments of the present invention. A clear and precise statement of the advantages of the claimed invention over prior inventions. The dry putty powder and putty prepared from the dry putty powder disclosed in the present invention have the following advantages: 1. Cheap and affordable; 2. Environmentally friendly and humane; 3. High execution speed; 4. Quick drying, odorless and non-allergenic; 5. Creating a smooth, rough surface, thus eliminating the need for sanding before painting; 6. Ability to accept color; 7.Good bonding strength; 8. Low water absorption after application to the surface; 9. Moisture resistant after the putty is applied and dried; 10. No scaling; 11. Resistant to cracking; 12. Creating a double coverage compared to traditional and common putties; 13. Increased adhesion strength compared to traditional and common putties; 14. Having appropriate compressive strength after application to the surface; and 15. Having appropriate hardness after application to the surface. Description of at least one implementation method for implementing the invention To prepare dry putty powder, 45-0.5% by weight of waste powder obtained from cutting and processing of fiber cement sheets is mixed with 5-10% by weight of silica aerogel, 5-10% by weight of metakaolin, 4-10% by weight of vinyl-ethylene acetate copolymer, and 10-40% by weight of white cement. All weight percentages are based on the total weight of dry putty powder. Next, water is added to the dry putty powder at a weight ratio of 2 to 1 and stirred manually for 5 minutes until a homogeneous putty with appropriate viscosity is obtained. Then, the prepared putty is applied to a desired surface and after 10-15 minutes, the applied putty dries and if necessary, the next layer of putty can be applied on it. Putty prepared from dry putty powder is stable at ambient temperature (25°C) for more than 3 hours and less than 24 hours and can be applied to surfaces. The dry putty powder has physical properties including a milky color, a density of 1.4 grams per cubic centimeter, an average particle size of 53 micrometers, and a water absorption rate of 3 percent (Table 1).Also, the putty made from this dry putty powder has a pH in the range of 10 to 12. In order to check the adhesion strength of the applied putty, the adhesion determination test was performed in accordance with ASTMD4541 using the Posi test at m-deflesko device. In this test, a part of the applied putty that has a smooth surface is selected as many times as necessary and after preparing the special test adhesive, the adhesive of the loading fixture is attached to the putty applied on the surface and after a period of 24 hours, the adhesion determination test is performed continuously and at a speed of less than 1 MPa / s (1Mpa / s). The results of this test show that the adhesion strength of the putty prepared from dry putty powder is approximately 3 MPa (91.2±0.52 MPa), which is three times the adhesion strength of common putties (Table 2). In order to investigate the hardness of the putty applied to the surface, a hardness test was performed in accordance with ASTMD4366 using the Persoz pendulum hardness test method, in which the hardness is reported in terms of the time required to reduce the amplitude of the pendulum's oscillation from an angle of 12 degrees to 4 degrees. According to the results of this test, the hardness of the applied putty is approximately 145 seconds on average, during which the pendulum oscillates approximately 137 times on average (Table 3). These results indicate that the hardness of the applied putty is higher than that of conventional putties. The mechanical properties of the putty, including tensile strength, elongation at break, and compressive strength, were also investigated. The results show that the putty prepared from dry putty powder has a compressive strength of 15 MPa, tensile strength of 1.2 MPa, and elongation at break of 1.3 percent (Table 4). Explicit mention of the industrial application of the invention The dry putty powder disclosed in the present invention is used in the construction industry, especially for sealing walls made of cement fiber sheets, covering cracks on cement fiber sheet walls, for caulking, sealing and covering cracks in gypsum and cement board-based sheets, and also as a tile adhesive.

Claims

Claim What is claimed: Claim 1) A dry putty powder comprises: a waste powder resulting from cutting and processing of fiber cement sheets; silica aerogel nanoparticles; metakaolin; vinyl-ethylene acetate copolymers; and white cement, such that a putty prepared from the dry putty powder dries after a single application to a surface within a period of 10 to 15 minutes. Claim 2) The dry putty powder according to claim 1, wherein one weight percent of the waste powder is in a range of 45 to 50 weight percent relative to the total weight of the dry putty powder. Claim 3) The dry putty powder according to claim 1 or 2, wherein said waste powder comprises silica, cellulose fibers, and Portland cement. Claim 4) The dry putty powder according to claim 1 or 2, wherein said waste powder comprises 40 to 45 weight percent silica, 10 to 15 weight percent cellulose fibers, and 40 to 60 weight percent Portland cement, wherein the weight percentages are relative to the total weight of said waste powder. Claim 5) The dry putty powder according to claim 1, wherein one weight percent of silica aerogel nanoparticles is in a range of 5 to 10 weight percent relative to the total weight of said dry putty powder. Claim 6) Dry putty powder according to claim 1, wherein one weight percent of metakaolin is in a range of 5 to 10 weight percent relative to the total weight of said dry putty powder. Claim 7) The dry putty powder according to claim 1, wherein said vinyl-ethylene acetate copolymer is used as an adhesive in the formulation and a weight percent of vinyl-ethylene acetate is in a range of 4 to 10 weight percent relative to the total weight of said dry putty powder. Claim 8) Dry putty powder according to claim 1, wherein said white cement is used in an amount of one percent by weight in a range of 10 to 40 percent by weight relative to the total weight of said dry putty powder. Claim 9) The dry putty powder according to claim 1 or 4, wherein said waste powder has an average particle size of less than 75 micrometers, preferably in a range of 50 to 75 micrometers. Claim 10) The dry putty powder according to any one of claims 1 to 10, further comprising a pigment in a weight ratio of 3 to 5 weight percent relative to the total weight of said dry putty powder. Claim 11) A putty for application to a surface comprising water and a dry putty powder according to any one of claims 1 to 11, wherein the weight ratio of adding water to said dry putty powder (water:dry putty powder) is 1:1, 1:2, or 1:

3. Claim 12) The putty according to claim 11, wherein said putty has an adhesion strength greater than 1.5 MPa, preferably in a range of 1.5 to 3 MPa. Claim 13) The putty according to claim 11, wherein said putty has a hardness equal to 145 seconds based on the damping of the Perez pendulum. Claim 14) The putty according to any one of claims 11 to 13, wherein said putty has a water retention capacity of 99%. Claim 15) Putty according to any one of claims 11 to 14, wherein the putty has a pH in the range of 10 to 12.