A high-strength instant-dissolving mold core material and mold core prepared therefrom

Abstract

The present invention belongs to the technical field of core material preparation, discloses a high-strength instant-dissolving core material and a core prepared therefrom, wherein the high-strength instant-dissolving core material includes a high-strength part material and an instant-dissolving part material, and the material of the high-strength part includes, by number, 20-30 parts of PVA3588, 20-30 parts of PVA2499, 20-30 parts of PVA2488, 20-40 parts of polyglycerol-10, 15-35 parts of sodium carbonate, and 2-5 parts of antioxidant. The material of the instant-dissolving part includes 40-60 parts of PVA0588, 15-30 parts of polyglycerol-10, 20-40 parts of sodium carbonate, and 1-3 parts of antioxidant. The core material of the present invention has a fast dissolution rate and high production efficiency, can effectively avoid the problem of cracking of the ceramic body, and can be used for high-density injection molding.

Description

Technical Field

[0001] The invention belongs to the technical field of mold core material preparation, and in particular relates to a PVA mold core material for ceramic injection molding. Background Art

[0002] Ceramic injection molding (CIM) is a new process for producing ceramic parts, developed by combining polymer injection molding with ceramic manufacturing techniques. Ceramic powder molding is particularly advantageous for the mass production of ceramic products with high dimensional precision and complex shapes. Modified PVA (polyvinyl alcohol resin) is commonly used as the core material in CIM production. However, modified PVA cores dissolve slowly during processing, resulting in low production efficiency and long lead times. This is particularly true for large-sized products, where core dissolution is even slower. Modified PVA cores also lack mechanical strength, making them unsuitable for producing high-density ceramic products. High injection pressures are required for producing high-density ceramic products, necessitating high core strength and rigidity. Conventional modified PVA cores lack sufficient mechanical strength, making them unsuitable for high-density ceramic injection-molded products. Furthermore, modified PVA cores tend to swell when dissolved in water, significantly increasing their size. This can cause cracking in the ceramic body, hindering production.

[0003] Therefore it is very necessary to develop a high-strength quick-dissolving mold core material to overcome the above-mentioned defects. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a mold core material with high mechanical strength and fast dissolution rate and a mold core prepared therefrom.

[0005] In order to achieve the above objectives, one of the technical solutions of the present invention is: a high-strength instant-dissolving mold core material, comprising a high-strength part material and an instant-dissolving part material, the high-strength part material comprising, in parts: PVA 358820-30 parts, PVA 249920-30 parts, PVA 248820-30 parts, polyglycerol-1020-40 parts, sodium carbonate 15-35 parts, and antioxidant 2-5 parts; the instant-dissolving part material comprising: PVA 058840-60 parts, polyglycerol-1015-30 parts, sodium carbonate 20-40 parts, and antioxidant 1-3 parts.

[0006] In a preferred embodiment of the present invention, the high-strength component comprises, by parts: PVA 3588 (22-28 parts), PVA 2499 (22-28 parts), PVA 2488 (22-28 parts), polyglycerol 10 (22-38 parts), sodium carbonate (17-33 parts), and an antioxidant (3-4 parts). Among the high-strength components, PVA 3588 offers high strength and a certain degree of water solubility, but its workability is relatively poor. While PVA 2488 offers slightly weaker strength, it offers better workability. PVA 2499 offers a compromise between these three properties; the resulting blend of the three creates a material that combines workability, strength, and water solubility. Polyglycerol 10 is an essential plasticizer, enhancing the material's fluidity and significantly improving its workability. Sodium carbonate, as an inorganic filler, is both water-soluble and, as an inorganic substance, has a certain reinforcing effect on organic materials. Calcium carbonate, while reinforcing, offers a reinforcing effect, but is not water-soluble. The sodium carbonate in the quick-dissolving part of the mold core is water-soluble, so the water dissolution speed of the mold core is greatly increased.

[0007] Furthermore, the materials of the high-strength part include, by parts: PVA 358824-26 parts, PVA 249924-26 parts, PVA 248824-26 parts, polyglycerol-1024-36 parts, sodium carbonate 20-30 parts, and antioxidant 3-4 parts.

[0008] Furthermore, the materials of the high-strength part include, by parts: 358,825 parts of PVA, 249,925 parts of PVA, 248,825 parts of PVA, 30 parts of polyglycerol-10, 25 parts of sodium carbonate, and 3.5 parts of antioxidant.

[0009] In a preferred embodiment of the present invention, the material of the fast-dissolving portion includes: 45-55 parts of PVA 0588, 17-28 parts of polyglycerol-10, 25-35 parts of sodium carbonate, and 1-3 parts of antioxidant. The formulation of the fast-dissolving portion material is designed to have two characteristics: one is fast solubility; the other is good fluidity. This allows it to be well filled into the pores of the high-strength portion, forming a good cross-linked structure with the high-strength portion. There are two advantages to forming a cross-linked structure between the high-strength portion and the fast-dissolving portion: one is that the fast-dissolving portion dissolves first, and after dissolution, the surface area of ​​the high-strength portion in contact with water is greatly increased, thereby accelerating the dissolution rate of the high-strength portion; the other advantage is that although the high-strength portion has relatively high strength, it has poor toughness and is relatively brittle. If only the high-strength part is used as the entire mold core, there will be a problem of the mold core breaking or cracking due to the impact of the material during injection molding. However, when the high-strength part is used in combination with the quick-dissolving part, the quick-dissolving part has better toughness. In this way, the quick-dissolving part toughens the entire mold core, avoiding the problem of the mold core being cracked or broken due to the impact of the injection molding material during injection molding.

[0010] When the core is water-soluble, the quick-dissolving portion dissolves rapidly under the action of water. Water enters the core, forming channels within the core. This significantly increases the area of ​​the high-strength portion exposed to water, greatly accelerating the core's dissolution rate. Furthermore, due to the rapid dissolution of the quick-dissolving portion, the dimensional changes caused by the swelling of the high-strength portion are largely absorbed and absorbed by the internal channels. This also solves the problem of ceramic body cracking caused by the swelling of the modified PVA core during water dissolution.

[0011] Furthermore, the materials of the instant part include: 45-60 parts of PVA 0588, 20-25 parts of polyglycerol-10, 27-33 parts of sodium carbonate, and 1-3 parts of antioxidant.

[0012] Furthermore, the materials of the instant part include: PVA 058846-48 parts, polyglycerol-1022-24 parts, sodium carbonate 29-31 parts, and antioxidant 1.5-2.5 parts.

[0013] In order to achieve the above purpose, the second technical solution of the present invention is: the mold core is prepared with high-strength instant-dissolving mold core material, and its preparation process is to first injection mold the high-strength part and then embed the injection-molded instant-dissolving part.

[0014] Furthermore, during the core preparation process, the high-strength portion covers the quick-dissolving portion, or the high-strength portion and the quick-dissolving portion are interlaced with each other.

[0015] Furthermore, during the core preparation process, the high-strength portion and the quick-dissolving portion are granulated before injection molding.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The high-strength part of the high-strength instant mold core prepared by the present invention has good processing performance, and its mechanical strength and rigidity are suitable for producing high-density ceramic injection molded products.

[0018] 2. The instant-dissolving portion of the high-strength instant mold core prepared by the present invention dissolves quickly and helps accelerate the dissolution of the high-strength portion, thereby accelerating the overall water dissolution rate of the mold core and improving production efficiency.

[0019] 3. The high-strength instant mold core prepared by the present invention has a combined structure of a high-strength part and an instant part, and has improved overall toughness, and can resist cracking or breaking caused by the impact of the injection molded material. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the physical structure of a mold core with a hole prepared in an embodiment of the present invention;

[0021] Figure 2Schematic diagram of the structure of the instant part injected into the mold core in an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is described in more detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited to these embodiments.

[0023] The high-strength, instant-dissolving core material comprises a high-strength portion and an instant-dissolving portion. The high-strength portion comprises, in parts: 20-30 parts PVA 3588, 20-30 parts PVA 2499, 20-30 parts PVA 2488, 20-40 parts polyglycerol-10, 15-35 parts sodium carbonate, and 2-5 parts antioxidant. The instant-dissolving portion comprises 40-60 parts PVA 0588, 15-30 parts polyglycerol-10, 20-40 parts sodium carbonate, and 1-3 parts antioxidant. During the production process, the core made from this high-strength, instant-dissolving core material is injection-molded first, followed by the embedded, injection-molded instant-dissolving portion. Furthermore, both the high-strength and instant-dissolving portions are granulated prior to injection molding.

[0024] The following examples and comparative examples illustrate the high-strength instant core material and the core prepared therefrom, and verify its performance. Among them, the PVA 3588, PVA 2499, PVA 2488, and PVA 0588 used were all purchased from the Research Institute of Sichuan Vinylon Plant of Sinopec. Antioxidant 1010, with an effective substance content of 99.5%, was purchased from Shanghai Yutong Industrial Co., Ltd. In addition, the preparation of the core takes the preparation of the bent pipe core as an example, and the core size and preparation method are as follows: the length of the high-strength part of the bent pipe core in the X and Y directions is 150 mm, the chamfer radius is 50 mm, and the thickness is 50 mm in diameter. The instant-dissolving part of the bent pipe core is 7 thin bent pipes evenly arranged around the central axis of the high-strength part. The length of each thin pipe in the X and Y directions is 150 mm, the chamfer radius is 50 mm, and the thickness is 10 mm in diameter. Use high-strength material to injection mold first, such as Figure 1 The solid body with the hole shown is then injected with the quick-dissolving part Figure 2 The hole portion shown.

[0025] Example 1

[0026] The high-strength instant-dissolving mold core material is composed of: 30 parts of PVA 3588, 20 parts of PVA 2499, 20 parts of PVA 2488, 40 parts of polyglycerol-10, 15 parts of sodium carbonate, and 5 parts of antioxidant for the high-strength portion; and 60 parts of PVA0588, 15 parts of polyglycerol-10, 20 parts of sodium carbonate, and 3 parts of antioxidant for the instant-dissolving portion.

[0027] Example 2

[0028] The high-strength instant-dissolving mold core material is composed of: 20 parts PVA 3588, 30 parts PVA 2499, 20 parts PVA 2488, 30 parts polyglycerol-10, 25 parts sodium carbonate, and 3.5 parts antioxidant for the high-strength portion. The instant-dissolving portion includes 50 parts PVA 0588, 25 parts polyglycerol-10, 30 parts sodium carbonate, and 2 parts antioxidant.

[0029] Example 3

[0030] The high-strength instant-dissolving mold core material is composed of the following: 20 parts of PVA 3588, 20 parts of PVA 2499, 30 parts of PVA 2488, 20 parts of polyglycerol-10, 35 parts of sodium carbonate, and 1 part of antioxidant for the high-strength portion. The instant-dissolving portion includes 40 parts of PVA0588, 30 parts of polyglycerol-10, 40 parts of sodium carbonate, and 1 part of antioxidant.

[0031] Example 4

[0032] The high-strength instant-dissolving mold core material is composed of: 20 parts PVA 3588, 20 parts PVA 2499, 20 parts PVA 2488, 30 parts polyglycerol-10, 25 parts sodium carbonate, and 2 parts antioxidant for the high-strength portion; 40 parts PVA0588, 30 parts polyglycerol-10, 40 parts sodium carbonate, and 1 part antioxidant for the instant-dissolving portion.

[0033] Example 5

[0034] The high-strength instant-dissolving mold core material is composed of: 25 parts PVA 3588, 25 parts PVA 2499, 25 parts PVA 2488, 30 parts polyglycerol-10, 25 parts sodium carbonate, and 3.5 parts antioxidant for the high-strength portion. The instant-dissolving portion includes 40 parts PVA 0588, 30 parts polyglycerol-10, 40 parts sodium carbonate, and 1 part antioxidant.

[0035] Example 6

[0036] The high-strength instant-dissolving mold core material is composed of: 30 parts of PVA 3588, 30 parts of PVA 2499, 30 parts of PVA 2488, 30 parts of polyglycerol-10, 25 parts of sodium carbonate, and 5 parts of antioxidant for the high-strength portion; and 40 parts of PVA0588, 30 parts of polyglycerol-10, 40 parts of sodium carbonate, and 1 part of antioxidant for the instant-dissolving portion.

[0037] Comparative Example 1

[0038] All injection mold cores adopt the high-strength material formula in Example 1, and the specifications of the mold cores are the same as those in the example.

[0039] Comparative Example 2

[0040] All the injection mold cores were made using the instant material formula in Example 1, and the specifications of the mold cores were the same as in the example.

[0041] Injection molding tests and water solubility tests were performed on mold cores made entirely of high-strength materials, mold cores made entirely of instant materials, and mold cores made of high-strength instant-dissolving mold core materials (made of a cross-interconnected structure of high-strength materials and instant-dissolving materials). The water solubility test was performed by immersing the mold core in 50°C water until it dissolved, and the time required was evaluated.

[0042] The test results are as follows:

[0043] A. Comparative Example 1: The mold core is made entirely of high-strength materials: there is a problem of the mold core cracking during injection molding, and the time required for soaking and dissolving is 72 hours.

[0044] B. Comparative Example 2: The mold core is made entirely of instant materials: During injection molding, there is a problem of severe deformation of the mold core, and the time required for soaking and dissolving is 1 hour.

[0045] C. The core molds made of a cross-linked structure of high-strength and fast-dissolving materials exhibited no cracking or deformation during injection molding. The core mold material prepared in Example 1 required 6 hours to soak and dissolve; the core mold material prepared in Example 2 required 5.7 hours to soak and dissolve; the core mold material prepared in Example 3 required 5.2 hours to soak and dissolve; the core mold material prepared in Example 4 required 5.9 hours to soak and dissolve; the core mold material prepared in Example 5 required 6.8 hours to soak and dissolve; and the core mold material prepared in Example 6 required 7.5 hours to soak and dissolve.

[0046] The above tests show that the mold cores made of the above-mentioned high-strength fast-dissolving materials have higher mechanical strength and better processing performance, so there is no cracking or deformation during injection molding; in addition, the mold cores have better solubility performance and can be dissolved within 10 hours.

[0047] The above embodiments are merely optimized implementations of the present invention, intended to illustrate the principles and effectiveness of the present invention, and are not intended to limit the present invention. It should be noted that modifications to the above embodiments by any person skilled in the art without departing from the spirit and scope of the present invention are also considered to be within the scope of protection of the present invention.

Claims

1. A high-strength instant-dissolving mold core material, characterized in that: The invention comprises a high-strength part material and a quick-dissolving part material. The high-strength part material comprises, in parts: 20-30 parts of PVA 3588, 20-30 parts of PVA 2499, 20-30 parts of PVA 2488, 20-40 parts of polyglycerol-10, 15-35 parts of sodium carbonate, and 2-5 parts of antioxidant; the quick-dissolving part material comprises: 40-60 parts of PVA 0588, 15-30 parts of polyglycerol-10, 20-40 parts of sodium carbonate, and 1-3 parts of antioxidant.

2. A high-strength instant-dissolving mold core material according to claim 1, characterized in that: The materials of the high-strength part include, by parts: 22-28 parts of PVA 3588, 22-28 parts of PVA 2499, 22-28 parts of PVA 2488, 22-38 parts of polyglycerol-10, 17-33 parts of sodium carbonate, and 3-4 parts of antioxidant.

3. A high-strength instant-dissolving mold core material according to claim 1, characterized in that: The materials of the high-strength part include, by parts: 24-26 parts of PVA 3588, 24-26 parts of PVA 2499, 24-26 parts of PVA 2488, 24-36 parts of polyglycerol-10, 20-30 parts of sodium carbonate, and 3-4 parts of antioxidant.

4. A high-strength instant-dissolving mold core material according to claim 1, characterized in that: The materials of the high-strength part include, by parts: 25 parts of PVA 3588, 25 parts of PVA 2499, 25 parts of PVA 2488, 30 parts of polyglycerol-10, 25 parts of sodium carbonate, and 3.5 parts of antioxidant.

5. The high-strength instant-dissolving mold core material according to claim 1, characterized in that: The materials of the instant part include: 45-55 parts of PVA 0588, 17-28 parts of polyglycerol-10, 25-35 parts of sodium carbonate, and 1-3 parts of antioxidant.

6. A high-strength instant-dissolving mold core material according to claim 1, characterized in that: The materials of the instant part include: 45-60 parts of PVA 0588, 20-25 parts of polyglycerol-10, 27-33 parts of sodium carbonate, and 1-3 parts of antioxidant.

7. The high-strength instant-dissolving mold core material according to claim 1, characterized in that: The materials of the instant part include: 46-48 parts of PVA 0588, 22-24 parts of polyglycerol-10, 29-31 parts of sodium carbonate, and 1.5-2.5 parts of antioxidant.

8. A mold core made of the high-strength, fast-dissolving mold core material according to any one of claims 1 to 7, characterized in that: The preparation process is to first injection mold the high-strength part and then embed the injection molded fast-dissolving part.

9. The mold core made of the high-strength instant-dissolving mold core material according to claim 8, characterized in that: The high-strength portion and the quick-dissolving portion are interspersed with each other.

10. The mold core made of the high-strength instant-dissolving mold core material according to claim 8, characterized in that: The high-strength part and the quick-dissolving part are granulated before injection molding.

Images