A 3DP sand mold for casting instead of a wooden mold, and a manufacturing method and application thereof

Abstract

The application discloses a 3DP sand mold for casting instead of a wooden mold and a manufacturing method and application thereof, and belongs to the technical field of 3DP inkjet printing. The manufacturing method comprises the following steps: printing sand mold semi-finished products by using a 3DP sand mold printing device according to a file in a CLI format; preparing an impregnation liquid; immersing the sand mold semi-finished products into the impregnation liquid, taking out and controlling drying after impregnation is completed; placing the sand mold semi-finished products after controlling drying into an oven for solidification; and coating the surface of the sand mold semi-finished products with a layer of a release agent, so as to obtain the 3DP sand mold for casting instead of the wooden mold. Compared with the existing wooden mold technology, the application can form sand mold molds with any structure, breaks through all structure limitations, has a fast mold forming speed, reduces a design and manufacturing period, has low sand mold mold price and manufacturing cost, and saves a large amount of cost and resource consumption.

Description

Technical Field

[0001] This invention relates to the field of 3DP inkjet printing technology, and more specifically to a 3DP sand mold for casting that replaces a wooden mold, its manufacturing method, and its application. Background Technology

[0002] In traditional casting, wooden molds are a commonly used method for molding and core making. They are low-cost, have a short production cycle, and are mainly used for casting large-diameter parts with lower precision requirements, suitable for single-piece or small-batch production. However, when temperature and humidity change, wooden molds can deform, crack, and corrode, and their low surface hardness makes them susceptible to damage from impacts. Existing wooden molds are typically designed for 50-100 uses and cost anywhere from several hundred to tens of thousands of yuan.

[0003] With the continuous development of 3DP (3D printing technology), many techniques in traditional casting processes will be gradually replaced. Finding cheaper and more efficient modeling methods has become a top priority. For wooden molds used in casting, choosing better methods to upgrade the casting process can promote the development of casting technology.

[0004] Therefore, how to develop a low-cost alternative to wooden molds for casting using 3DP sand molds, as well as its manufacturing method and application, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a low-cost alternative to wooden molds for casting, a 3DP sand mold, its manufacturing method, and its application.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for manufacturing a 3DP sand mold for casting that replaces a wooden mold, comprising the following steps:

[0008] (1) The shape of the wooden mold used for casting sand molding is designed into a three-dimensional model using three-dimensional modeling, and then cut into CLI format files using slicing software and imported into the 3DP printing equipment. The silica sand is printed into a semi-finished sand mold using the 3DP sand mold printing equipment according to the CLI format file.

[0009] (2) Preparation of impregnation solution, wherein the impregnation solution is prepared by mixing the following raw materials in parts by weight: 100-150 parts of bisphenol A diglycidyl ether, 160-200 parts of bisphenol A dicyanate, 40-50 parts of 4,4'-diaminodicyclohexylmethane, 5-8 parts of triethylamine, 3-5 parts of acetone, 3-5 parts of dimethylformamide, 3-5 parts of hydrogen bromide acetic acid solution, 2-5 parts of polysorbate-20, and 20-30 parts of sodium silicate;

[0010] (3) Immerse the sand mold semi-finished product into the impregnation solution, and remove it after impregnation and drain it;

[0011] (4) Place the dried sand mold semi-finished product into an oven for curing;

[0012] (5) Coat the surface of the sand mold semi-finished product with a layer of release agent to obtain a low-cost 3DP sand mold for casting that can replace the wooden mold.

[0013] Furthermore, in step (1), the particle size of the silica sand is 100-200 mesh.

[0014] The beneficial effects of adopting the above-mentioned further technical solution are: this particle size is a commonly used and relatively fine particle size, the surface of the molding sand mold is relatively smooth and flat, and the surface is smooth and flat after impregnation.

[0015] Further, in step (2), the preparation method of the above impregnation solution includes the following steps: adding bisphenol A diglycidyl ether and bisphenol A dicyanate to a container, stirring for 10 min, adding 4,4'-diaminodicyclohexylmethane, stirring for 10 min, adding triethylamine, stirring for 5 min, adding acetone, stirring for 5 min, adding dimethylformamide, stirring for 5 min, adding hydrogen bromide acetic acid solution, stirring for 5 min, heating the mixture to 180°C, stirring for 30 min, cooling to room temperature, adding polysorbate-20, stirring for 10 min, adding sodium silicate, stirring for 10 min, the stirring speeds of the above are 220-260 r / min, and using the impregnation solution within 30 min after preparation.

[0016] Furthermore, in step (3), the soaking time is 3-5 minutes.

[0017] Furthermore, in step (4), the curing temperature is 160°C and the curing time is 2 hours.

[0018] Furthermore, in step (5), the coating thickness is 0.3-0.5 mm.

[0019] The present invention also provides a low-cost 3DP sand mold for casting that can replace a wooden mold, produced by the above method.

[0020] The present invention also provides an application of the above-mentioned low-cost 3DP sand mold for casting, which is used to replace wooden molds, for sand molding.

[0021] The beneficial effects of this invention are:

[0022] This invention innovatively develops a low-cost 3DP sand mold forming process to replace wooden molds for casting, applicable, but not limited to, printed sand mold products. This method uses inkjet printing to form the sand mold, followed by post-processing reinforcement to achieve or even exceed the strength of wooden molds, thus replacing wooden molds as casting molds. The low-cost 3DP sand mold forming process for casting involves sand mold inkjet printing, impregnation solution preparation, impregnation treatment, curing reinforcement, and surface treatment. After impregnation and subsequent curing reinforcement, the sand mold achieves a strength greater than 20 MPa; further surface treatment increases surface gloss and facilitates demolding. Once completed, the sand mold can replace wooden molds for sand molding.

[0023] Compared with existing wooden mold technology, the present invention provides a low-cost 3DP sand mold forming process for casting that replaces wooden molds, which has the following advantages and breakthroughs:

[0024] Sand molds that can form any structure break through all structural limitations;

[0025] The mold forming speed is fast, which reduces the design and manufacturing cycle;

[0026] Sand molds have low prices and low production costs, saving a lot of costs and resources. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1

[0029] A method for manufacturing a 3DP sand mold for casting that replaces a wooden mold includes the following steps:

[0030] (1) The shape of the wooden mold used for casting sand molding, namely the wooden mold used for pump valve molding, is designed into a three-dimensional model using three-dimensional modeling, and then cut into CLI format files using slicing software and imported into the 3DP printing equipment. The silica sand with a particle size of 100-200 mesh is printed into a semi-finished sand mold using the 3DP sand mold printing equipment according to the CLI format file.

[0031] (2) Preparation of impregnation solution, the impregnation solution is prepared by mixing the following raw materials in parts by weight: 120 parts of bisphenol A diglycidyl ether, 160 parts of bisphenol A dicyanate, 40 parts of 4,4'-diaminodicyclohexylmethane, 5 parts of triethylamine, 5 parts of acetone, 3 parts of dimethylformamide, 3 parts of hydrogen bromide acetic acid solution, and polysorbate-20 5 parts of sodium silicate and 20 parts of sodium silicate; the preparation method of the impregnation solution includes the following steps: add bisphenol A diglycidyl ether and bisphenol A dicyanate to a container, stir for 10 min, add 4,4'-diaminodicyclohexylmethane, stir for 10 min, add triethylamine, stir for 5 min, add acetone, stir for 5 min, add dimethylformamide, stir for 5 min, add hydrogen bromide acetic acid solution, stir for 5 min, heat the mixture to 180℃, stir for 30 min, cool to room temperature, add polysorbate-20, stir for 10 min, add sodium silicate, stir for 10 min, the stirring speed is 260 r / min, and the impregnation solution is used within 30 min after preparation.

[0032] (3) Immerse the sand mold semi-finished product in the impregnation solution, and remove it after immersion for 5 minutes to drain;

[0033] (4) Place the dried sand mold semi-finished product into an oven for curing. The curing temperature is 160℃ and the curing time is 2h.

[0034] (5) Coat the surface of the sand mold semi-finished product with a layer of release agent. The release agent is the commercially available cold core box resin sand release agent. The coating thickness is 0.5mm, thus obtaining a low-cost 3DP sand mold for casting that can replace the wooden mold.

[0035] After completion, it is used for sand molding of pumps and valves. After molding, it is cleaned for easy use next time.

[0036] Example 2

[0037] A method for manufacturing a 3DP sand mold for casting that replaces a wooden mold includes the following steps:

[0038] (1) The shape of the wooden mold used for casting sand molding, i.e. the wooden mold used for cylinder molding, is designed into a three-dimensional model using three-dimensional modeling, and then cut into CLI format files using slicing software and imported into the 3DP printing equipment. The silica sand with a particle size of 100-200 mesh is printed into a semi-finished sand mold using the 3DP sand mold printing equipment according to the CLI format file.

[0039] (2) Preparation of impregnation solution, the impregnation solution is prepared by mixing the following raw materials in parts by weight: 150 parts of bisphenol A diglycidyl ether, 180 parts of bisphenol A dicyanate, 50 parts of 4,4'-diaminodicyclohexylmethane, 5 parts of triethylamine, 5 parts of acetone, 3 parts of dimethylformamide, 3 parts of hydrogen bromide acetic acid solution, and polysorbate-20 5 parts of sodium silicate and 30 parts of sodium silicate; the preparation method of the impregnation solution includes the following steps: add bisphenol A diglycidyl ether and bisphenol A dicyanate to a container, stir for 10 min, add 4,4'-diaminodicyclohexylmethane, stir for 10 min, add triethylamine, stir for 5 min, add acetone, stir for 5 min, add dimethylformamide, stir for 5 min, add hydrogen bromide acetic acid solution, stir for 5 min, heat the mixture to 180℃, stir for 30 min, cool to room temperature, add polysorbate-20, stir for 10 min, add sodium silicate, stir for 10 min, the stirring speed is 220 r / min, and the impregnation solution is used within 30 min after preparation.

[0040] (3) Immerse the sand mold semi-finished product in the impregnation solution, and remove it after immersion for 5 minutes to drain;

[0041] (4) Place the dried sand mold semi-finished product into an oven for curing. The curing temperature is 160℃ and the curing time is 2h.

[0042] (5) Coat the surface of the sand mold semi-finished product with a layer of release agent with a coating thickness of 0.5 mm to obtain a low-cost 3DP sand mold for casting that can replace the wooden mold.

[0043] Table 1 Comparison of parameters between wooden mold and sand mold of Examples 1-2 of this invention

[0044] Wooden mold >20 ±0.5~±1 Ra25 50 5~20 Hundreds to tens of thousands Example 1: Sand mold >20 ±0.3 Ra25 >100 times 1~2 tens to hundreds Example 2 Sand mold >20 ±0.3 Ra25 >100 times 1~2 tens to hundreds

[0045] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for manufacturing a 3DP sand mold for casting that replaces a wooden mold, characterized in that, Includes the following steps: (1) The shape of the wooden mold used for casting sand molding is designed into a three-dimensional model using three-dimensional modeling, and then cut into CLI format files using slicing software and imported into the 3DP printing equipment. The silica sand is printed into a semi-finished sand mold using the 3DP sand mold printing equipment according to the CLI format file. (2) Preparation of impregnation solution, wherein the impregnation solution is prepared by mixing the following raw materials in parts by weight: 100-150 parts of bisphenol A diglycidyl ether, 160-200 parts of bisphenol A dicyanate, 40-50 parts of 4,4'-diaminodicyclohexylmethane, 5-8 parts of triethylamine, 3-5 parts of acetone, 3-5 parts of dimethylformamide, 3-5 parts of hydrogen bromide acetic acid solution, 2-5 parts of polysorbate-20, and 20-30 parts of sodium silicate; (3) Immerse the sand mold semi-finished product into the impregnation solution, and remove it after impregnation and drain it; (4) Place the dried sand mold semi-finished product into an oven for curing; (5) Coat the surface of the sand mold semi-finished product with a layer of release agent to obtain a low-cost 3DP sand mold for casting that can replace the wooden mold.

2. The method for manufacturing a 3DP sand mold for casting that replaces a wooden mold according to claim 1, characterized in that, In step (1), the particle size of the silica sand is 100-200 mesh.

3. The method for manufacturing a 3DP sand mold for casting that replaces a wooden mold according to claim 1, characterized in that, In step (2), the preparation method of the impregnation solution includes the following steps: adding bisphenol A diglycidyl ether and bisphenol A dicyanate to a container, stirring for 10 min, adding 4,4'-diaminodicyclohexylmethane, stirring for 10 min, adding triethylamine, stirring for 5 min, adding acetone, stirring for 5 min, adding dimethylformamide, stirring for 5 min, adding hydrogen bromide acetic acid solution, stirring for 5 min, heating the mixture to 180°C, stirring for 30 min, cooling to room temperature, adding polysorbate-20, stirring for 10 min, adding sodium silicate, stirring for 10 min, the stirring speeds are 220-260 r / min respectively, and using the impregnation solution within 30 min after preparation.

4. The method for manufacturing a 3DP sand mold for casting that replaces a wooden mold according to claim 1, characterized in that, In step (3), the soaking time is 3-5 minutes.

5. The method for manufacturing a 3DP sand mold for casting that replaces a wooden mold according to claim 1, characterized in that, In step (4), the curing temperature is 160℃ and the curing time is 2h.

6. The method for manufacturing a 3DP sand mold for casting that replaces a wooden mold according to claim 1, characterized in that, In step (5), the coating thickness is 0.3-0.5 mm.

7. A 3DP sand mold for casting, produced by the method of any one of claims 1 to 6, as an alternative to a wooden mold.

8. An application of the 3DP sand mold for casting as described in claim 7, replacing the wooden mold, characterized in that, Used for sand molding.