A two-component water-soluble binder for warm core box casting and its use method

Abstract

The present invention discloses a two-component water-soluble binder for use in a warm core box method for casting and a method for using the binder. The binder comprises component A and component B, and during use, the mass ratio of component A to component B is 1:0.4-0.7. The two-component water-soluble binder for use in a warm core box method for casting provided by the present invention comprises two components, wherein component B is an auxiliary agent used to improve the bonding and application properties of component A. The combined use of the two components has good moisture absorption resistance, can improve the fluidity of the mixture, enhance the strength of the sand core, and reduce the residual strength of the waste sand, thus having a positive effect on the casting production and product quality of the castings, and will be widely used in the field of casting technology.

Description

Technical Field

[0001] The invention belongs to the technical field of casting molding materials, and particularly relates to a two-component water-soluble binder for casting using a warm core box method and a method for using the same. Background Art

[0002] Foundry binders include inorganic and organic binders. Clay is the most widely used inorganic binder for foundry applications, but castings produced using clay sand suffer from poor quality and high pollution levels. Castings produced using organic resin sand have significantly improved quality, but the generation of harmful gases such as phenols, aldehydes, and amines during the various steps of the organic resin sand process poses a greater risk to the human body. With increasingly stringent requirements for environmental protection and clean production, especially with the competitive development and widespread use of various organic binders, the development of new environmentally friendly binders has garnered significant attention from foundry professionals worldwide.

[0003] Water-soluble binders are mostly inorganic binders or organic binders. The amount of gas emitted by water-soluble binders during use is only 1 / 10 of that of organic resins. They are environmentally friendly and are the only iterative product among casting binders that can reduce waste gas and harmful gases from the source and has a wide range of applications. They are the development trend and leading product of the future binder market.

[0004] Waterglass is a commonly used water-soluble inorganic binder. Using CO2 to harden waterglass sand for sand core production has the disadvantage of low core strength. To achieve high-strength sand molds, the waterglass dosage must be increased, typically to 8.0-10.0% or even higher. After pouring, the waste sand has a high residual strength, making it difficult to separate the casting from the core and molding sand. Ester-hardened waterglass has poor disintegration properties, resulting in low strength when reused. Two-component inorganic binders used in the warm core box method have poor moisture absorption resistance and are prone to sticking to the sand, clogging the nozzle.

[0005] Chinese invention patent publication number CN104942220A discloses a core-making process using an inorganic binder thermal curing method. This process uses specialized pearl sand instead of traditional foundry silica sand, significantly reducing the amount of inorganic binder added. However, the prior art lacks a technical solution for reducing the amount of inorganic binder added to conventional foundry silica sand while simultaneously improving sand core strength and reducing the residual strength of waste sand. Summary of the Invention

[0006] In view of the above-mentioned deficiencies in the prior art, the present invention provides a two-component water-soluble binder for warm core box casting and a method for using the same.

[0007] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0008] On the one hand, a two-component water-soluble binder for casting using a warm core box method is provided, comprising component A and component B, wherein the mass ratio of component A to component B is 1:0.4-0.7;

[0009] Wherein: Component A comprises the following ingredients in percentage by mass: 50% to 60% deionized water, 0.05% to 0.5% sodium polymethacrylate, 0.05% to 0.4% sodium lauryl sulfate, 0.05% to 0.5% polyacrylamide, 25% to 35% silicate, 10% to 15% polyvinyl alcohol, and 0.05% to 2% sodium tripolyphosphate;

[0010] Component B includes the following ingredients in percentage by mass: 30% to 40% of silica fume, 5% to 10% of zircon powder, 5% to 10% of corundum powder, 0.1% to 2% of graphite powder, 30% to 40% of propyl methyl cellulose, and 5% to 10% of ethylene / vinyl acetate copolymer.

[0011] Furthermore, component A includes the following ingredients in percentage by mass: 55% deionized water, 0.3% sodium polymethacrylate, 0.2% sodium lauryl sulfate, 0.3% polyacrylamide, 30% silicate, 15% polyvinyl alcohol, and 1% sodium tripolyphosphate.

[0012] Furthermore, component B includes the following ingredients in percentage by mass: 35% silica fume, 5% zircon powder, 10% corundum powder, 1% graphite powder, 40% propyl methyl cellulose, and 10% ethylene / vinyl acetate copolymer.

[0013] Furthermore, the silicate in component A is at least one of sodium silicate, potassium silicate and lithium silicate.

[0014] Furthermore, the molecular weight of the polyacrylamide in component A is 2 million to 14 million.

[0015] On the other hand, a method for using a two-component water-soluble binder for a warm core box method for casting is provided, the method comprising the following steps:

[0016] (1) Preparation of component A:

[0017] ①Heat and boil deionized water for 5 to 20 minutes;

[0018] ② Add sodium polymethacrylate, sodium lauryl sulfonate and polyacrylamide in proportion and stir until completely dissolved;

[0019] ③ Add one or more of sodium silicate, potassium silicate, and lithium silicate, stir until completely dissolved, heat to 200℃~250℃, and keep warm for 4~7 hours;

[0020] ④ After the temperature drops below 100°C, sodium tripolyphosphate and polyvinyl alcohol are added and stirred to dissolve to complete the reaction to obtain component A;

[0021] (2) Preparing component B: stirring and mixing silica fume, zircon powder, corundum powder, graphite powder, propyl methyl cellulose, and ethylene / vinyl acetate copolymer in proportion to obtain component B;

[0022] (3) Preparation of sand core: Mix component B with sand for 30 seconds to 1 minute, the amount of component B added is 0.4 to 0.7 of component A, then add component A and mix for 1 minute, the amount of component A added is 2% to 3% of the sand mass, put it into the core making mold of the warm core box, shoot the core, and blow in a mixture of hot carbon dioxide and air to make a sand core.

[0023] Furthermore, in step (3), the volume ratio of carbon dioxide to air is 50-60:10.

[0024] Furthermore, in step (3), the heating temperature of the core-making mold is 120-160° C., and the core-shooting pressure is 0.5-0.6 MPa.

[0025] The beneficial effects of the present invention are:

[0026] 1. The two-component water-soluble binder for the warm core box method for casting provided by the present invention consists of two components, wherein component B is an auxiliary agent used to improve the bonding performance and application performance of component A. The combined use of the two components has good anti-hygroscopicity, can improve the fluidity of the mixture, increase the sand core strength, and reduce the residual strength of waste sand, which plays a positive role in the casting production and product quality of castings and will be widely used in the field of casting technology.

[0027] 2. The method of use provided by the present invention improves the components and preparation of the water-soluble binder, as well as the key reaction parameters in the core making process. The castings produced can solve the problem of difficulty in cleaning the core sand after casting of castings with complex internal cavity structures. The sand core has both high strength and excellent collapse performance, and does not damage the castings or pollute the environment. It can achieve green casting and has broad application prospects. DETAILED DESCRIPTION

[0028] The specific embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0029] Example 1

[0030] A two-component water-soluble binder for casting using a warm core box method comprises a component A and a component B.

[0031] Component A comprises the following ingredients in percentage by mass: 50% deionized water, 0.05% sodium polymethacrylate, 0.05% sodium lauryl sulfonate, 0.05% polyacrylamide, 25% sodium silicate, 10% polyvinyl alcohol, and 0.05% sodium tripolyphosphate.

[0032] Component B includes the following ingredients in percentage by mass: 30% silica fume, 5% zircon powder, 5% corundum powder, 0.1% graphite powder, 30% propyl methyl cellulose, and 5% ethylene / vinyl acetate copolymer.

[0033] (1) Preparation of component A

[0034] ①Heat and boil deionized water for 10 minutes;

[0035] ② Add sodium polymethacrylate, sodium lauryl sulfonate and polyacrylamide in proportion and stir until completely dissolved;

[0036] ③ Add sodium silicate, stir until completely dissolved, heat to 200℃, and keep warm for 7 hours;

[0037] ④ After the temperature drops below 100°C, sodium tripolyphosphate and polyvinyl alcohol are added and stirred to dissolve to complete the reaction to obtain component A.

[0038] (2) Preparation of component B: Silica fume, zircon powder, corundum powder, graphite powder, propyl methyl cellulose, and ethylene / vinyl acetate copolymer are stirred and mixed uniformly in proportion to obtain component B.

[0039] Example 2

[0040] A two-component water-soluble binder for casting using a warm core box method comprises a component A and a component B.

[0041] Component A comprises the following ingredients in percentage by mass: 55% deionized water, 0.3% sodium polymethacrylate, 0.2% sodium lauryl sulfonate, 0.3% polyacrylamide, 30% silicate, 15% polyvinyl alcohol, and 1% sodium tripolyphosphate.

[0042] Component B includes the following ingredients in percentage by mass: 35% silica fume, 5% zircon powder, 10% corundum powder, 1% graphite powder, 40% propyl methyl cellulose, and 10% ethylene / vinyl acetate copolymer.

[0043] (1) Preparation of component A

[0044] ①Heat and boil deionized water for 15 minutes;

[0045] ② Add sodium polymethacrylate, sodium lauryl sulfonate and polyacrylamide in proportion and stir until completely dissolved;

[0046] ③ Add potassium silicate and sodium silicate, stir until completely dissolved, heat to 220℃, and keep warm for 6 hours;

[0047] ④ After the temperature drops below 100°C, sodium tripolyphosphate and polyvinyl alcohol are added and stirred to dissolve to complete the reaction, thereby obtaining component A.

[0048] (2) Preparation of component B: Silica fume, zircon powder, corundum powder, graphite powder, propyl methyl cellulose, and ethylene / vinyl acetate copolymer are stirred and mixed uniformly in proportion to obtain component B.

[0049] Example 3

[0050] A two-component water-soluble binder for casting using a warm core box method comprises a component A and a component B.

[0051] Component A comprises the following ingredients in percentage by mass: 52% deionized water, 0.5% sodium polymethacrylate, 0.4% sodium lauryl sulfonate, 0.5% polyacrylamide, 10% lithium silicate, 14% sodium silicate, 10% potassium silicate, 14% polyvinyl alcohol, and 1.6% sodium tripolyphosphate.

[0052] Component B includes the following ingredients in percentage by mass: 32% silica fume, 10% zircon powder, 10% corundum powder, 2% graphite powder, 40% propyl methyl cellulose, and 8% ethylene / vinyl acetate copolymer.

[0053] (1) Preparation of component A

[0054] ①Heat and boil deionized water for 20 minutes;

[0055] ② Add sodium polymethacrylate, sodium lauryl sulfonate and polyacrylamide in proportion and stir until completely dissolved;

[0056] ③ Add lithium silicate, sodium silicate and potassium silicate, stir until all dissolved, heat to 250℃ and keep warm for 5 hours;

[0057] ④ After the temperature drops below 100°C, sodium tripolyphosphate and polyvinyl alcohol are added and stirred to dissolve to complete the reaction, thereby obtaining component A.

[0058] (2) Preparation of component B: Silica fume, zircon powder, corundum powder, graphite powder, propyl methyl cellulose, and ethylene / vinyl acetate copolymer are stirred and mixed uniformly in proportion to obtain component B.

[0059] Example 4

[0060] Preparation of sand cores:

[0061] Mix component B with sand for 1 minute, with the added amount of component B being 50% of component A. Then add component A and mix for 1 minute, with component A being 2% of the sand mass. Place the sand into the core-making mold in the core-making box. Heat the mold to 120-160°C and shoot the core at a pressure of 0.5-0.6 MPa. Blow in a mixture of hot carbon dioxide and air (the volume ratio of carbon dioxide to air is 55:10) to produce the sand core.

[0062] Comparative Example 1

[0063] An inorganic binder sold on the market.

[0064] Comparative Example 2

[0065] A two-component water-soluble binder for casting using a warm core box method comprises only component A. Component A comprises the following ingredients in percentage by mass: 55% deionized water, 0.3% sodium polymethacrylate, 0.2% sodium lauryl sulfonate, 0.5% polyacrylamide, 43% sodium silicate, and 1% sodium tripolyphosphate.

[0066] Comparative Example 3

[0067] Chinese invention patent publication number CN104942220A discloses a core-making process using an inorganic binder heat-curing method. To demonstrate the core-making effect of this method on ordinary foundry sand, the pearl sand was replaced with ordinary foundry sand. Water glass, an inorganic additive, was added to the sand at a ratio of 2.5% by weight and mixed thoroughly. The mixed water glass sand was then passed through a hot core box core shooter at a pressure of 0.5 MPa for 10 seconds to form a corresponding sand core. The sand mold was then heated and cured at 250°C for 100 seconds to obtain a complete sand core.

[0068] Sand cores were prepared using the warm core box two-component water-soluble binder for casting prepared in Examples 1-3 and the inorganic binder of Comparative Examples 1-2 using the method provided in Example 4. These cores are designated as Sand Core Samples 1-5. The sand core prepared in Comparative Example 3 is designated as Sand Core Sample 6. Sand Core Samples 1-6 were subjected to performance testing. The performance test results are shown in the following table.

[0069]

[0070] Note: The number of “*” represents the quality of disintegration. The more “*”, the better the disintegration.

[0071] As can be seen from the above table, compared with the binder using only component A (sand core sample 5), the use of component B as an auxiliary agent to improve the bonding performance and application performance of component A, and the combined use of the two components (sand core samples 1-3) can improve the sand core strength and significantly reduce the residual strength of the waste sand.

[0072] Compared to a commercially available inorganic binder (sand core sample 4), the combined use of component A and component B (sand core samples 1-3) reduced gas evolution, improved collapsibility, enhanced compressive strength, and significantly reduced the residual strength of the waste sand. Compared to sand core sample 6, sand core samples 1-3 showed improvements in all aspects of performance, demonstrating that the core-making process described in Comparative Example 3 is not suitable for ordinary foundry silica sand.

[0073] The method of use provided by the present invention improves the components and preparation of the inorganic binder, as well as the key reaction parameters in the core making process. The resulting casting can solve the problem of difficulty in cleaning the core sand of castings with complex inner cavity structures after casting. The sand core has both high strength and excellent collapse performance, and does not damage the casting or pollute the environment. It can achieve green casting and has broad application prospects.

[0074] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0075] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A two-component water-soluble binder for warm core box casting, characterized in that: Comprising component A and component B, wherein the mass ratio of component A to component B is 1:0.4-0.7; Wherein: Component A comprises the following ingredients in percentage by mass: 50% to 60% deionized water, 0.05% to 0.5% sodium polymethacrylate, 0.05% to 0.4% sodium lauryl sulfate, 0.05% to 0.5% polyacrylamide, 25% to 35% silicate, 10% to 15% polyvinyl alcohol, and 0.05% to 2% sodium tripolyphosphate; Component B includes the following ingredients in percentage by mass: 30% to 40% of silica fume, 5% to 10% of zircon powder, 5% to 10% of corundum powder, 0.1% to 2% of graphite powder, 30% to 40% of propyl methyl cellulose, and 5% to 10% of ethylene / vinyl acetate copolymer.

2. The two-component water-soluble binder for warm core box casting according to claim 1, characterized in that: The component A comprises the following ingredients in percentage by mass: 55% deionized water, 0.3% sodium polymethacrylate, 0.2% sodium lauryl sulfonate, 0.3% polyacrylamide, 30% silicate, 15% polyvinyl alcohol, and 1% sodium tripolyphosphate.

3. The two-component water-soluble binder for warm core box casting according to claim 1, characterized in that: The component B comprises the following ingredients in percentage by mass: 35% silica fume, 5% zircon powder, 10% corundum powder, 1% graphite powder, 40% propyl methyl cellulose, and 10% ethylene / vinyl acetate copolymer.

4. The two-component water-soluble binder for warm core box casting according to claim 1, characterized in that: The silicate in component A is at least one of sodium silicate, potassium silicate and lithium silicate.

5. The two-component water-soluble binder for warm core box casting according to claim 1, characterized in that: The molecular weight of the polyacrylamide in the component A is 2 million to 14 million.

6. A method for using the two-component water-soluble binder for warm core box casting according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) Preparation of component A: ①Heat and boil deionized water for 5 to 20 minutes; ② Add sodium polymethacrylate, sodium lauryl sulfonate and polyacrylamide in proportion and stir until completely dissolved; ③ Add one or more of sodium silicate, potassium silicate, and lithium silicate, stir until completely dissolved, raise the temperature to 200°C to 250°C, and keep warm for 4 to 7 hours; ④ After the temperature drops below 100°C, sodium tripolyphosphate and polyvinyl alcohol are added and stirred to dissolve to complete the reaction to obtain component A; (2) Preparing component B: stirring and mixing silica fume, zircon powder, corundum powder, graphite powder, propyl methyl cellulose, and ethylene / vinyl acetate copolymer in proportion to obtain component B; (3) Preparation of sand core: Mix component B with sand for 30 seconds to 1 minute, the amount of component B added is 0.4 to 0.7 of component A, then add component A and mix for 1 minute, the amount of component A added is 2% to 3% of the sand mass, put it into the core making mold of the warm core box, shoot the core, and blow in a mixture of hot carbon dioxide and air to make a sand core.

7. The method of use according to claim 6, characterized in that: In step (3), the volume ratio of carbon dioxide to air is 50-60:

10.

8. The method of use according to claim 6, characterized in that: In step (3), the heating temperature of the core-making mold is 120-160° C., and the core-shooting pressure is 0.5-0.6 MPa.

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