Lightweight high-strength water-soluble core mold material and preparation method thereof

Abstract

The invention provides a light high-strength water-soluble core mold material and a preparation method thereof, and the water-soluble core mold material is prepared by mixing the following components in parts by weight: 10-30 parts of a water-soluble adhesive, 100-120 parts of a light filler and 2-10 parts of reinforced fibers. The water-soluble adhesive, the light filler and the reinforced fibers are mixed to prepare the core mold material, the light filler and the reinforced fibers can be bonded together through the water-soluble adhesive in the preparation process, and the specific type of light filler can effectively reduce the weight of the large-size core mold material, reduce the operation difficulty and improve the forming precision of a composite material product. A certain content of reinforcing fibers are added, so that the compression strength of the core mold material can be obviously enhanced; therefore, the core mold material disclosed by the invention has the advantages of light weight, high compression strength and good high-temperature-resistant mechanical property, the compression strength can reach 10-25MPa, the density is 0.45-1.2 g / cm < 3 >, and the core mold material can be suitable for molding processes of various resin-based composite materials.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material preparation, and in particular to a light-weight, high-strength, water-soluble core mold material and a preparation method thereof. Background Art

[0002] Due to their high stiffness, thermal conductivity, and good surface roughness, metal materials are often selected as mold materials for composite molding during the preparation of resin-based composite structural parts. These advantages of metal molds are primarily reflected when used as outer molds. However, using metal materials as core molds has the following disadvantages: the heavy weight of metal core molds increases the operational difficulty during the composite molding process; and for some composite parts with complex internal structures, metal core molds are difficult to process, making it impossible to demold the composite part after it has been integrally formed.

[0003] Using water-soluble core mold materials instead of metal materials to make core molds can solve the above problems. Traditional water-soluble core molds mainly use quartz sand as the core mold filler, but quartz sand has a high density. For some large composite parts, using quartz sand to make core molds has a limited weight reduction effect. In addition, the core mold is easily damaged during the molding process, and the core mold strength is low, which affects the molding accuracy of the composite material.

[0004] Based on this, there is an urgent need to provide a lightweight, high-strength water-soluble core mold material and a preparation method thereof. Summary of the Invention

[0005] The embodiments of the present invention provide a lightweight and high-strength water-soluble core mold material and a preparation method thereof, which can solve the problem that traditional water-soluble core mold materials are heavy and have poor strength.

[0006] In a first aspect, the present invention provides a lightweight, high-strength water-soluble core mold material, which is made by mixing the following components in parts by weight: 10-30 parts of a water-soluble adhesive, 100-150 parts of a lightweight filler, and 2-10 parts of reinforcing fibers.

[0007] Preferably, the water-soluble adhesive is a polyvinyl alcohol aqueous solution; wherein the mass concentration of the polyvinyl alcohol aqueous solution is 10-40%.

[0008] Preferably, the lightweight filler is a mixture of fly ash beads and quartz sand; wherein the particle size of the fly ash beads is 0.05-0.3 mm.

[0009] Preferably, in the lightweight filler, the content of the fly ash beads is 35-90%, and the content of the quartz sand is 10-65%.

[0010] Preferably, the reinforcing fiber is at least one of carbon fiber, glass fiber, quartz fiber or aramid fiber.

[0011] Preferably, the length of the reinforcing fibers is 10-50 mm.

[0012] Preferably, the mass ratio of the lightweight filler to the water-soluble adhesive and the reinforcing fiber is 100:(10-30):(2-10).

[0013] Preferably, the density of the water-soluble core mold material is 0.45 to 1.2 g / cm 3 , the compression strength is 10~25MPa.

[0014] In a second aspect, the present invention further provides a method for preparing the lightweight, high-strength, water-soluble core mold material according to any one of the first aspects above, the preparation method comprising the following steps:

[0015] (1) adding polyvinyl alcohol into water and stirring to obtain the water-soluble adhesive;

[0016] (2) mixing fly ash beads and quartz sand in proportion to obtain the lightweight filler;

[0017] (3) adding a lightweight filler and a reinforcing fiber to the water-soluble adhesive in sequence, stirring and mixing to obtain a core mold slurry;

[0018] (4) adding the core mold slurry into a mold, and then curing and demoulding the mold to obtain the light-weight, high-strength, water-soluble core mold material.

[0019] Preferably, in step (4), the curing temperature is 100-150° C. and the curing time is 5-50 h.

[0020] In a third aspect, the present invention further provides a use of the lightweight, high-strength, water-soluble core mold material described in any one of the first aspects in a resin-based composite material.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects:

[0022] In the present invention, a core mold material is prepared by mixing a water-soluble adhesive, a lightweight filler, and a reinforcing fiber. During the preparation process, the lightweight filler and the reinforcing fiber can be bonded together by the water-soluble adhesive. The specific type of lightweight filler can effectively reduce the weight of the large-sized core mold material, reduce the difficulty of operation, and improve the molding accuracy of the composite material product. In addition, a certain amount of reinforcing fiber can significantly enhance the compressive strength of the core mold material. In this way, the core mold material of the present invention has the advantages of light weight, high compressive strength, and good high-temperature resistant mechanical properties. The compressive strength can reach 10-25 MPa and the density is 0.45-1.0 g / cm 3 , which can be applied to a variety of resin-based composite material molding processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is a flow chart of a method for preparing a lightweight, high-strength, water-soluble core mold material provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] An embodiment of the present invention provides a lightweight, high-strength water-soluble core mold material. The water-soluble core mold material is made by mixing the following components, in parts by weight: 10-30 parts of a water-soluble adhesive (for example, 10 parts, 15 parts, 20 parts, 25 parts, or 30 parts), 100-150 parts of a lightweight filler (for example, 100 parts, 110 parts, 120 parts, 130 parts, 140 parts, or 150 parts), and 2-10 parts of reinforcing fiber (for example, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, or 10 parts).

[0027] In an embodiment of the present invention, a core mold material is prepared by mixing a water-soluble adhesive, a lightweight filler, and a reinforcing fiber. During the preparation process, the lightweight filler and the reinforcing fiber can be bonded together by the water-soluble adhesive, and a specific type of lightweight filler can effectively reduce the weight of the large-size core mold material, reduce the difficulty of operation, and improve the molding accuracy of the composite material product. In addition, a certain amount of reinforcing fiber can significantly enhance the compressive strength of the core mold material. In this way, the core mold material of the present invention has the advantages of light weight, high compressive strength, and good high-temperature resistant mechanical properties. The compressive strength can reach 10-25 MPa and the density is 0.45-1.0 g / cm 3 , which can be applied to a variety of resin-based composite material molding processes.

[0028] According to some preferred embodiments, the water-soluble adhesive is a polyvinyl alcohol aqueous solution; wherein the mass concentration of the polyvinyl alcohol aqueous solution is 10-40% (for example, 10%, 20%, 30% or 40%).

[0029] In the embodiment of the present invention, the polyvinyl alcohol aqueous solution with the above-mentioned mass concentration is used as the water-soluble adhesive, which is beneficial to making the water-soluble adhesive have better bonding strength and solubility. If the mass concentration of the polyvinyl alcohol aqueous solution is too low, the bonding strength of the water-soluble adhesive will be poor, which is not conducive to ensuring the good mechanical strength of the core mold material. If the mass concentration of the polyvinyl alcohol aqueous solution is too high, the solubility of the obtained core mold material will be poor.

[0030] According to some preferred embodiments, the lightweight filler is a mixture of fly ash beads and quartz sand; wherein the particle size of the fly ash beads is 0.05-0.3 mm (for example, it can be 0.05 mm, 0.1 mm, 0.2 mm or 0.3 mm); in the lightweight filler, the content of the fly ash beads is 35-90% (for example, it can be 35%, 40%, 50%, 60%, 70%, 80% or 90%), and the content of the quartz sand is 10-65% (for example, it can be 10%, 20%, 30%, 40%, 50%, 60% or 65%).

[0031] In an embodiment of the present invention, fly ash beads and quartz sand (particle size of 50-120 mesh) are mixed together as lightweight fillers, and the mass ratio of fly ash beads and quartz sand is reasonably controlled, which is not only beneficial to further ensure the lightness of the core mold material on the basis of ensuring a certain strength of the core mold material, but also beneficial to further enhance the solubility of the core mold material; for example, if the content of fly ash beads is too low, it is not conducive to maximizing the lightness of the core mold material, and if the content of quartz sand is too low, the lightweight filler will have poor dispersion during the mixing process with the water-soluble adhesive and reinforcing fiber, which is not only not conducive to ensuring the lightness of the core mold material, but also not conducive to better ensuring the strength of the core mold material.

[0032] According to some preferred embodiments, the reinforcing fiber is at least one of carbon fiber, glass fiber, quartz fiber or aramid fiber, and the length of the reinforcing fiber is 10-50 mm (for example, 10 mm, 20 mm, 30 mm, 40 mm or 50 mm).

[0033] In the embodiment of the present invention, the above-mentioned types of fibers are used as reinforcing fibers, and the length of the reinforcing fibers is reasonably controlled, which is conducive to ensuring that the reinforcing fibers have good dispersion in the core mold material, thereby ensuring that the core mold material as a whole has high strength.

[0034] According to some preferred embodiments, the mass ratio of the lightweight filler to the water-soluble adhesive and the reinforcing fiber is 100:(10-30):(2-10) (for example, it can be 100:10:2, 100:20:2, 100:30:2, 100:10:5, 100:10:10, 100:20:5, 100:20:10, 100:30:2, 100:30:5 or 100:30:10).

[0035] In the embodiment of the present invention, a certain content of reinforcing fiber is beneficial to enhancing the strength and high-temperature mechanical properties of the core mold material on the basis of ensuring the lightness of the core mold material. If the content of the reinforcing fiber is too high, it is not only not conducive to significantly improving the strength of the core mold material, but also increases the process cost and the weight of the material; and, by adding lightweight fillers of appropriate types and contents to cooperate with the reinforcing fibers, it is not only beneficial to further enhance the strength of the core mold material while ensuring the good lightness of the core mold material, but also beneficial to further ensure the good solubility of the core mold material. If the content of the lightweight filler is too high, it is not only unable to further reduce the weight of the core mold material, but also can effectively reduce the weight of the core mold material. weight, and will reduce the strength of the core mold material; further, if the content of the water-soluble adhesive is too low, it is not conducive to ensuring strong bonding performance between the components in the core mold material. Although increasing the content of the water-soluble adhesive is conducive to further enhancing the bonding performance between the components, when its content is too high, it is not only not conducive to ensuring the lightness of the core mold material, but also will reduce the solubility of the core mold material; therefore, by reasonably controlling the mass ratio of lightweight fillers, water-soluble adhesives and reinforcing fibers, it is conducive to ensuring that the core mold material has the advantages of light weight, high strength, high temperature mechanical properties and good solubility.

[0036] According to some preferred embodiments, the density of the water-soluble core mold material is 0.45 to 1.2 g / cm 3 , the compression strength is 10~25MPa.

[0037] An embodiment of the present invention further provides a method for preparing the lightweight, high-strength, water-soluble core mold material described in any one of the above items, the method comprising the following steps:

[0038] (1) adding polyvinyl alcohol into water and stirring to obtain the water-soluble adhesive;

[0039] (2) mixing fly ash beads and quartz sand in proportion to obtain the lightweight filler;

[0040] (3) adding a lightweight filler and a reinforcing fiber to the water-soluble adhesive in sequence, stirring and mixing to obtain a core mold slurry;

[0041] (4) adding the core mold slurry into a mold, and then curing and demoulding the mold to obtain the light-weight, high-strength, water-soluble core mold material.

[0042] In the embodiment of the present invention, after a core mold slurry is prepared by mixing a water-soluble adhesive, a lightweight filler and a reinforcing fiber in a certain proportion, the core mold slurry can be poured into a corresponding mold. In order to ensure the good strength of the core mold material, the core mold slurry can be compacted with the help of a tool or a press during the molding process. The core mold slurry loaded into the mold is then heated and dehydrated to solidify. During the heating process, the fastening screws of the mold can be removed to accelerate the dissipation of water vapor. After the mold is removed, a lightweight and high-strength water-soluble core mold material can be obtained. It can be seen that the raw materials used in the embodiment of the invention are low in cost and environmentally friendly, the process for preparing the core mold is simple to operate, and has good promotion and application value.

[0043] According to some preferred embodiments, in step (4), the curing temperature is 100-150°C (for example, 100°C, 110°C, 120°C, 130°C, 140°C or 150°C), and the curing time is 5-50h (for example, 5h, 10h, 20h, 30h, 40h or 50h).

[0044] In the embodiment of the present invention, by reasonably controlling the temperature and time during the curing process, the core mold slurry can have a better dehydration efficiency, thereby ensuring better mechanical strength of the core mold material as a whole.

[0045] An embodiment of the present invention further provides a use of the lightweight, high-strength, water-soluble core mold material described in any one of the above items in a resin-based composite material.

[0046] The water-soluble core mold material prepared in the embodiment of the present invention can dissolve quickly in water, has an applicable temperature of room temperature to 200°C, a compressive strength of 10 to 25 MPa, and good high-temperature mechanical properties. It can be applied to a variety of resin-based composite material molding processes, thereby solving the technical problem that complex composite materials with special shapes and deep cavities, as well as composite materials with small openings, cannot be demolded after being integrally molded using a metal rigid core mold.

[0047] In order to more clearly illustrate the technical solutions and advantages of the present invention, a lightweight, high-strength, water-soluble core mold material and a preparation method thereof are described in detail below through several embodiments.

[0048] Example 1:

[0049] (1) Add 20 g of polyvinyl alcohol powder to water and stir thoroughly until completely dissolved to obtain a water-soluble adhesive with a mass concentration of 20%;

[0050] (2) Mix 400g of fly ash beads and 100g of quartz sand evenly to obtain a lightweight filler;

[0051] (3) 20 g of the water-soluble adhesive in step (1) was added to 100 g of the lightweight filler in step (2) and mixed thoroughly, and then 10 g of reinforcing fiber (carbon fiber with a length of 30-50 mm) was added and mixed thoroughly to obtain a core mold slurry;

[0052] (4) The core mold slurry is poured into the mold, the core mold slurry is compacted by a press, and the mold is placed in an oven at 120°C and heated and cured for 20 hours. After demolding, a lightweight, high-strength, water-soluble core mold material is obtained.

[0053] Example 2:

[0054] (1) Add 50 g of polyvinyl alcohol powder to water and stir thoroughly until completely dissolved to obtain a water-soluble adhesive with a mass concentration of 16%;

[0055] (2) Mix 1000g of fly ash beads and 500g of quartz sand evenly to obtain a lightweight filler;

[0056] (3) 30 g of the water-soluble adhesive in step (1) was added to 100 g of the lightweight filler in step (2) and mixed thoroughly, and then 2 g of reinforcing fiber (quartz fiber with a length of 30-50 mm) was added and mixed thoroughly to obtain a core mold slurry;

[0057] (4) The core mold slurry is poured into the mold, the core mold slurry is compacted by a press, and the mold is placed in an oven at 130°C and heated and cured for 10 hours. After demolding, a lightweight, high-strength, water-soluble core mold material is obtained.

[0058] Example 3:

[0059] (1) Add 50 g of polyvinyl alcohol powder to water and stir thoroughly until completely dissolved to obtain a water-soluble adhesive with a mass concentration of 40%;

[0060] (2) Mix 500g of fly ash beads and 300g of quartz sand evenly to obtain a lightweight filler;

[0061] (3) 10 g of the water-soluble adhesive in step (1) was added to 100 g of the lightweight filler in step (2) and mixed thoroughly, and then 8 g of reinforcing fiber (glass fiber with a length of 30-50 mm) was added and mixed thoroughly to obtain a core mold slurry;

[0062] (4) The core mold slurry is poured into the mold, the core mold slurry is compacted by a press, and the mold is placed in an oven at 150°C and heated and cured for 5 hours. After demolding, a lightweight, high-strength, water-soluble core mold material is obtained.

[0063] Example 4:

[0064] Example 4 is basically the same as Example 1, except that in step (3), the content of the water-soluble adhesive is 40 parts.

[0065] Example 5:

[0066] Example 5 is basically the same as Example 1, except that in step (3), the content of the lightweight filler is 130 parts.

[0067] Example 6:

[0068] Example 6 is basically the same as Example 1, except that in step (3), the content of the lightweight filler is 90 parts.

[0069] Example 7:

[0070] Example 7 is basically the same as Example 1, except that in step (3), the content of quartz sand in the lightweight filler is 200g, and the content of fly ash beads is 85g.

[0071] Example 8:

[0072] Example 8 is basically the same as Example 1, except that in step (3), the content of the reinforcing fiber is 12 parts.

[0073] Comparative Example 1:

[0074] Comparative Example 1 is substantially the same as Example 1, except that, in step (3), the lightweight filler comprises only 100 g of fly ash beads.

[0075] Comparative Example 2:

[0076] Comparative Example 2 is substantially the same as Example 1, except that in step (3), the lightweight filler comprises only 100 g of quartz sand.

[0077] Comparative Example 3:

[0078] Comparative Example 3 is basically the same as Example 1, except that, in step (3), no lightweight filler is added, that is, only 10g of the water-soluble adhesive in step (1) is added to 8g of reinforcing fiber (glass fiber with a length of 30-50mm) and mixed thoroughly to obtain a core mold slurry.

[0079] The core mold materials prepared in Examples 1 to 8 and Comparative Examples 1 to 3 were subjected to performance tests, and the test results are shown in Table 1.

[0080] Density test: The density of the core mold material is measured using the geometric method in GB / T 1463 Test method for density and relative density of fiber reinforced plastics.

[0081] Compression strength test: The compression strength of the core mold material is measured using the method in GB / T 1448 Test method for compression properties of fiber reinforced plastics.

[0082] Table 1

[0083] Examples <![CDATA[密度(g / m 3 )]]> Compressive strength (MPa) Example 1 0.77 22 Example 2 1.05 23 Example 3 1.16 25 Example 4 0.79 25 Example 5 0.77 24 Example 6 0.79 20 Example 7 1.60 22 Example 8 0.79 23 Comparative Example 1 0.45 18 Comparative Example 2 2.33 20 Comparative Example 3 1.60 16

[0084] As can be seen from Table 1, compared with the comparative example, the core mold material prepared by mixing a water-soluble adhesive of appropriate type and content with a lightweight filler and reinforcing fiber in the embodiment of the present invention has the advantages of light weight and high compressive strength, and can meet the use requirements of various resin-based composite material molding processes.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A lightweight, high-strength, water-soluble core mold material, characterized in that: The water-soluble core mold material is prepared by mixing the following components in parts by weight: 10-30 parts of a water-soluble adhesive, 100-120 parts of a lightweight filler, and 2-10 parts of reinforcing fibers.

2. The water-soluble core mold material according to claim 1, characterized in that The water-soluble adhesive is a polyvinyl alcohol aqueous solution; wherein the mass concentration of the polyvinyl alcohol aqueous solution is 10-40%.

3. The water-soluble core mold material according to claim 1, characterized in that The lightweight filler is made of a mixture of fly ash beads and quartz sand; wherein the particle size of the fly ash beads is 0.05-0.3 mm.

4. The water-soluble core mold material according to claim 3, characterized in that In the lightweight filler, the content of the fly ash floating beads is 35-90%, and the content of the quartz sand is 10-65%.

5. The water-soluble core mold material according to claim 1, characterized in that The reinforcing fiber is at least one of carbon fiber, glass fiber, quartz fiber or aramid fiber; and / or The length of the reinforcing fibers is 10-50 mm.

6. The water-soluble core mold material according to claim 1, characterized in that The mass ratio of the lightweight filler to the water-soluble adhesive and the reinforcing fiber is 100:(10-30):(2-10).

7. The water-soluble core mold material according to claim 1, characterized in that The density of the water-soluble core mold material is 0.45-1.2 g / cm 3 , the compression strength is 10~25MPa.

8. A method for preparing a lightweight, high-strength, water-soluble core mold material according to any one of claims 1 to 7, characterized in that: The method comprises: (1) adding polyvinyl alcohol into water and stirring to obtain the water-soluble adhesive; (2) mixing fly ash beads and quartz sand in proportion to obtain the lightweight filler; (3) adding a lightweight filler and a reinforcing fiber to the water-soluble adhesive in sequence, stirring and mixing to obtain a core mold slurry; (4) adding the core mold slurry into a mold, and then curing and demoulding the mold to obtain the light-weight, high-strength, water-soluble core mold material.

9. The preparation method according to claim 8, characterized in that In step (4), the curing temperature is 100-150° C. and the curing time is 5-50 hours.

10. Use of the lightweight, high-strength, water-soluble core mold material according to any one of claims 1 to 7 in a resin-based composite material.

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