Model wax for machining, method and application

Abstract

The invention discloses model wax for machining, a method and application, the model wax comprises the following raw materials in parts by weight: 30-60 parts of polyethylene wax, 20-50 parts of EVA, 1-30 parts of resin, 0-5 parts of a reinforcing compatibilizer, 0-3 parts of a plasticizer and 0-1 part of a defoaming agent, the softening point of the polyethylene wax is not lower than 110 DEG C, and the softening point of the resin is not lower than 80 DEG C. According to the invention, the composition of the model wax is optimized, so that the model wax does not need to be melted and molded by mold pressing in the procedure, the wax model with the required shape and size precision can be quickly processed on the existing basic surface of the machining wax by utilizing machining equipment, the size is accurate, the processing efficiency is high, and the wax model is not stuck to a knife.

Description

Technical Field

[0001] The invention belongs to the technical field of precision machining and manufacturing, and particularly relates to a model wax for machining, a method and an application thereof. Background Art

[0002] Machining, or machining, is a widely used manufacturing technology. It involves removing excess material from raw materials through machining methods such as cutting, grinding, or drilling to achieve the desired shape, size, and surface quality. Machining is widely used in various fields of modern industry, including automotive, aerospace, electronic equipment, and medical devices. These parts require precise machining to achieve the required shape and dimensional accuracy to ensure the reliability and safety of automobiles, electronic equipment, etc. Investment casting blanks require subsequent machining to meet the requirements of commercial precision castings or precision castings in the aerospace field.

[0003] Investment casting requires mold development, wax melting, wax evaporation, paste preparation, wax injection molding, wax model assembly with a sprue system, and cleaning. This process is time-consuming and costly, and complex shapes are difficult to form. Machining wax models do not require melting or mold pressing. Instead, machining equipment creates a wax model with the desired shape and dimensional accuracy on the existing surface of the machined wax. This allows for rapid molding without the need for a mold. Machining wax models simplify the investment casting process and significantly shorten the production time of investment castings.

[0004] The medium-temperature mold material with the highest bending strength is far from meeting the requirements of machining and cannot be directly used to machine into a wax model with the required shape and dimensional accuracy. Therefore, in response to the above technical problems, it is necessary to provide a model wax for machining, a method and an application.

[0005] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0006] The object of the present invention is to provide a model wax for machining, a method and an application thereof.

[0007] In order to achieve the above object, a specific embodiment of the present invention provides the following technical solutions:

[0008] The model wax used for machining comprises the following raw materials, calculated by weight: 30 to 60 parts of polyethylene wax, 20 to 50 parts of EVA, 1 to 30 parts of resin, 0 to 5 parts of reinforcing and compatibilizing agent, 0 to 3 parts of plasticizer, and 0 to 1 part of defoaming agent, wherein the softening point of the polyethylene wax is not lower than 110°C, and the softening point of the resin is not lower than 80°C.

[0009] In one or more embodiments of the present invention, the molecular weight of the polyethylene wax is 2,000-10,000.

[0010] In one or more embodiments of the present invention, the molecular weight of the polyethylene wax satisfies: the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 1.5 to 3.5.

[0011] In one or more embodiments of the present invention, the VA content in EVA is 20%-30%, and the melt index is ≤150.

[0012] In one or more embodiments of the present invention, the resin is selected from the group consisting of: C5 hydrogenated petroleum resin, C5 / C9 copolymerized hydrogenated petroleum resin, terpene resin, polymerized rosin, and rosin glycerol ester.

[0013] In one or more embodiments of the present invention, the reinforcing compatibilizer is refined rice bran wax.

[0014] In one or more embodiments of the present invention, the plasticizer is selected from the group consisting of: UN399, polystyrene, and phthalates.

[0015] In one or more embodiments of the present invention, the defoaming agent is selected from: organic silicon defoaming agents, such as silicone oil defoaming agents, etc.

[0016] In one or more embodiments of the present invention, a method for processing model wax for machining comprises the following steps: placing polyethylene wax, EVA, and a reinforcing compatibilizer in a reactor and heating and stirring at a low speed; when the substances in the reactor are heated to a molten state and uniformly mixed, adding a resin, a plasticizer, and a defoaming agent into the reactor and stirring until they are evenly distributed; after the temperature rises to 130-140°C, the temperature is kept for no more than 30 minutes; finally, stirring is continued until there are no particles in the reactor, the slurry in the reactor is poured into a mold for molding, cooled to room temperature, demoulded to obtain a blank, and then the blank is subjected to high-precision machining. Preferably, the low-speed stirring speed is 10-30RPM, and the stirring time is 10-25 minutes.

[0017] In one or more embodiments of the present invention, the pattern wax for machining is used in precision casting, medical devices, art reproduction, or jewelry design.

[0018] Compared with the prior art, the model wax, method, and application for machining of the present invention optimize the composition of the model wax so that it does not require melting and mold pressing during the process, and can be used to quickly process a wax model of the desired shape and dimensional accuracy on the existing base surface of the machining wax using machining equipment. The wax product of the present invention also has the following advantages: high hardness, easy processing, easy cleaning of wax scraps or wax powder during machining without residue; high softening point. Since mechanical energy is converted into thermal energy, the temperature of the model wax rises during machining. The high softening point can avoid the risk of sticking to the knife due to melting of the wax material and the risk of reduced strength; it has a certain toughness and does not stick to the knife, and has moderate rigidity, which reduces the wear on the blades on the machining equipment and facilitates the maintenance and care of the machining equipment; and has a high surface finish. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0020] The model wax for machining of the present invention comprises, by weight, 30 to 60 parts of polyethylene wax, 20 to 50 parts of EVA, 1 to 30 parts of resin, 0 to 5 parts of reinforcing compatibilizer, 0 to 3 parts of plasticizer, and 0 to 1 part of defoaming agent.

[0021] The polyethylene wax has a molecular weight of 2000-10000, a softening point greater than or equal to 110°C, preferably a softening point of 115-120°C, a ratio of weight average molecular weight Mw to number average molecular weight Mn (Mw / Mn) of 1.5-3.5 as measured by gel permeation chromatography, and a surface hardness of less than 1 dmm at 25°C;

[0022] EVA, ethylene-vinyl acetate copolymer, VA content 20%-30%, melt index: ≤150;

[0023] The resin is one or a mixture of C5 hydrogenated petroleum resin, C5 / C9 copolymerized hydrogenated petroleum resin, terpene resin, polymerized rosin, rosin glycerol ester, etc., and has a softening point greater than or equal to 80°C, preferably 100-120°C. Preferably, the C5 / C9 copolymerized petroleum resin obtained by copolymerization and modification of C5 into C9 has improved compatibility with EVA due to its properties as both an aliphatic resin and an aromatic resin. By using this specific product, the present invention further achieves the goal of adding rice bran wax to build a bridge between the paraffin wax and EVA system, improving compatibility and further optimizing the product's machinability.

[0024] The reinforcing compatibilizer is refined rice bran wax, which has high hardness and its main components are lipids formed by long-chain fatty acids and fatty alcohols. During the mixing process, under the thermal motion of molecules, the long-chain alkane part of the rice bran wax molecule is arranged together with the paraffin molecules, and the ester bond part of the molecule is arranged together with the vinyl acetate of EVA. The rice bran wax acts as a bridge to improve the compatibility between the components.

[0025] The solution of the present invention not only improves the strength and hardness of the model wax by adding refined rice bran wax, but also builds a bridge between paraffin wax and EVA, improves the compatibility between components, makes the formula system more stable, and improves the strength and toughness of the model wax.

[0026] Group 1

[0027] The polyethylene wax in this example has a molecular weight of 3000, and the ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn) (Mw / Mn) measured by gel permeation chromatography is 1.5. The ethylene-vinyl acetate copolymer has a VA content of 20% and a melt index of ≤150. Melt index testing conditions are as follows: discharge port diameter: Φ2.095±0.005 mm; discharge port length: 8.000±0.025 mm; charging cylinder diameter: Φ9.550±0.025 mm; charging cylinder length: 152±0.1 mm; piston rod tip diameter: 9.475±0.015 mm; piston rod tip length: 6.350±0.100 mm; standard test load, level 2, 11.77 N.

[0028] Example 1

[0029] The model wax for machining of this embodiment comprises the following raw materials in parts by weight: 60 parts of polyethylene wax, 23 parts of ethylene vinyl acetate, 15 parts of C5 hydrogenated petroleum resin, 1 part of rice bran wax, 1 part of phthalate, and 0.3 part of silicone oil defoamer.

[0030] Polyethylene wax, EVA, and rice bran wax are placed in a reactor and heated, and stirred at a low speed of 25 rpm for 20 minutes; when the substances in the reactor are heated to a molten state and evenly mixed, the resin, plasticizer, and defoamer are added to the reactor and stirred until they are evenly distributed; the temperature rises to 130°C and then kept warm for 23 minutes; finally, stirring is continued until there are no particles in the reactor, the slurry in the reactor is poured into a mold for molding, cooled to room temperature, and demolded to obtain a cylindrical blank, which is then turned on a high-precision lathe for sample testing.

[0031] Example 2

[0032] The model wax for machining of this embodiment contains the following raw materials in parts by weight: 40 parts of polyethylene wax, 30 parts of ethylene vinyl acetate, 28 parts of terpene resin, 2 parts of rice bran wax, 0.5 parts of phthalate, and 0.03 parts of silicone oil defoamer.

[0033] Place polyethylene wax, EVA, and rice bran wax in a reactor and heat them, stirring at a low speed of 30 rpm for 25 minutes. When the substances in the reactor are heated to a molten state and evenly mixed, add the resin, plasticizer, and defoamer into the reactor and stir until they are evenly distributed. After the temperature rises to 130°C, keep warm for 30 minutes. Finally, continue stirring until there are no particles in the reactor. Pour the slurry in the reactor into a mold for molding, cool to room temperature, and demold to obtain a cylindrical blank. The blank is then turned on a high-precision lathe for sample testing.

[0034] Example 3

[0035] The model wax for machining of this embodiment contains the following raw materials in parts by weight: 48 parts of polyethylene wax, 22 parts of ethylene vinyl acetate, 25 parts of polymerized rosin, 5 parts of rice bran wax, 0.3 parts of phthalate, and 0.02 parts of silicone oil defoamer.

[0036] Place polyethylene wax, EVA, and rice bran wax in a reactor and heat them, stirring at a low speed of 10 rpm for 10 minutes; when the substances in the reactor are heated to a molten state and mixed evenly, add the resin, plasticizer, and defoamer into the reactor and stir until they are evenly distributed; after the temperature rises to 130°C, keep warm for 5 minutes; finally, continue stirring until there are no particles in the reactor, pour the slurry in the reactor into a mold for molding, cool to room temperature, demold, and obtain a cylindrical blank, which is then turned on a high-precision lathe for sample testing.

[0037] Example 4

[0038] The model wax for machining of this embodiment contains the following raw materials in parts by weight: 30 parts of polyethylene wax, 39 parts of ethylene vinyl acetate, 28 parts of C5 / C9 copolymerized hydrogenated petroleum resin HH2-1103 (Henghe Petroleum Resin, Henghe Materials Technology Co., Ltd.), 3 parts of rice bran wax, 0.1 parts of phthalate, and 0.01 parts of silicone oil defoamer.

[0039] Place polyethylene wax, EVA, and rice bran wax in a reactor and heat them, stirring them at a low speed of 18 rpm for 15 minutes. When the substances in the reactor are heated to a molten state and evenly mixed, add the resin, plasticizer, and defoamer into the reactor and stir until they are evenly distributed. After the temperature rises to 130°C, keep it warm for 13 minutes. Finally, continue stirring until there are no particles in the reactor. Pour the slurry in the reactor into a mold for molding, cool it to room temperature, and demold it to obtain a cylindrical blank. The blank is then turned on a high-precision lathe for sample testing.

[0040] Example 5

[0041] The model wax for machining of this embodiment contains the following raw materials in parts by weight: 30 parts of polyethylene wax, 39 parts of ethylene vinyl acetate, 28 parts of C5 / C9 copolymerized hydrogenated petroleum resin HH2-1003 (Henghe Petroleum Resin, Henghe Materials Technology Co., Ltd.), 3 parts of rice bran wax, 0.1 parts of phthalate, and 0.01 parts of silicone oil defoamer.

[0042] Place polyethylene wax, EVA, and rice bran wax in a reactor and heat them, stirring them at a low speed of 18 rpm for 15 minutes. When the substances in the reactor are heated to a molten state and evenly mixed, add the resin, plasticizer, and defoamer into the reactor and stir until they are evenly distributed. After the temperature rises to 130°C, keep it warm for 13 minutes. Finally, continue stirring until there are no particles in the reactor. Pour the slurry in the reactor into a mold for molding, cool it to room temperature, and demold it to obtain a cylindrical blank. The blank is then turned on a high-precision lathe for sample testing.

[0043] Example 6

[0044] The model wax for machining of this embodiment contains the following raw materials in parts by weight: 30 parts of polyethylene wax, 39 parts of ethylene vinyl acetate, 25 parts of C5 / C9 copolymerized hydrogenated petroleum resin HH2-1103 (Henghe Petroleum Resin, Henghe Materials Technology Co., Ltd.), 3 parts of rice bran wax, 0.1 parts of phthalate, and 0.01 parts of silicone oil defoamer.

[0045] Place polyethylene wax, EVA, and rice bran wax in a reactor and heat them, stirring them at a low speed of 18 rpm for 15 minutes. When the substances in the reactor are heated to a molten state and evenly mixed, add the resin, plasticizer, and defoamer into the reactor and stir until they are evenly distributed. After the temperature rises to 130°C, keep it warm for 13 minutes. Finally, continue stirring until there are no particles in the reactor. Pour the slurry in the reactor into a mold for molding, cool it to room temperature, and demold it to obtain a cylindrical blank. The blank is then turned on a high-precision lathe for sample testing.

[0046] Example 7

[0047] The model wax for machining of this embodiment contains the following raw materials in parts by weight: 30 parts of polyethylene wax, 39 parts of ethylene vinyl acetate, 28 parts of C5 / C9 copolymerized hydrogenated petroleum resin HH2-1103 (Henghe Petroleum Resin, Henghe Materials Technology Co., Ltd.), 5 parts of rice bran wax, 0.1 parts of phthalate, and 0.01 parts of silicone oil defoamer.

[0048] Place polyethylene wax, EVA, and rice bran wax in a reactor and heat them, stirring them at a low speed of 18 rpm for 15 minutes. When the substances in the reactor are heated to a molten state and evenly mixed, add the resin, plasticizer, and defoamer into the reactor and stir until they are evenly distributed. After the temperature rises to 130°C, keep it warm for 13 minutes. Finally, continue stirring until there are no particles in the reactor. Pour the slurry in the reactor into a mold for molding, cool it to room temperature, and demold it to obtain a cylindrical blank. The blank is then turned on a high-precision lathe for sample testing.

[0049] Example 8

[0050] The model wax for machining of this embodiment contains the following raw materials in parts by weight: 30 parts of polyethylene wax, 39 parts of ethylene vinyl acetate, 28 parts of C5 / C9 copolymerized hydrogenated petroleum resin HH2-1103 (Henghe Petroleum Resin, Henghe Materials Technology Co., Ltd.), 0.1 parts of phthalate, and 0.01 parts of silicone oil defoamer.

[0051] Place polyethylene wax, EVA, and rice bran wax in a reactor and heat them, stirring them at a low speed of 18 rpm for 15 minutes. When the substances in the reactor are heated to a molten state and evenly mixed, add the resin, plasticizer, and defoamer into the reactor and stir until they are evenly distributed. After the temperature rises to 130°C, keep it warm for 13 minutes. Finally, continue stirring until there are no particles in the reactor. Pour the slurry in the reactor into a mold for molding, cool it to room temperature, and demold it to obtain a cylindrical blank. The blank is then turned on a high-precision lathe for sample testing.

[0052] Example 9

[0053] The model wax for machining of this embodiment contains the following raw materials in parts by weight: 30 parts of polyethylene wax, 39 parts of ethylene vinyl acetate, 28 parts of C5 / C9 copolymerized hydrogenated petroleum resin HH2-1103 (Henghe Petroleum Resin, Henghe Materials Technology Co., Ltd.), 5 parts of rice bran wax, and 0.01 part of silicone oil defoamer.

[0054] Place polyethylene wax, EVA, and rice bran wax in a reactor and heat them, stirring them at a low speed of 18 rpm for 15 minutes. When the substances in the reactor are heated to a molten state and evenly mixed, add the resin, plasticizer, and defoamer into the reactor and stir until they are evenly distributed. After the temperature rises to 130°C, keep it warm for 13 minutes. Finally, continue stirring until there are no particles in the reactor. Pour the slurry in the reactor into a mold for molding, cool it to room temperature, and demold it to obtain a cylindrical blank. The blank is then turned on a high-precision lathe for sample testing.

[0055] Example 10

[0056] The model wax for machining of this embodiment contains the following raw materials in parts by weight: 30 parts of polyethylene wax, 39 parts of ethylene vinyl acetate, 28 parts of C5 / C9 copolymerized hydrogenated petroleum resin HH2-1103 (Henghe Petroleum Resin, Henghe Materials Technology Co., Ltd.), 5 parts of rice bran wax, and 0.1 part of phthalate.

[0057] Place polyethylene wax, EVA, and rice bran wax in a reactor and heat them, stirring them at a low speed of 18 rpm for 15 minutes. When the substances in the reactor are heated to a molten state and evenly mixed, add the resin, plasticizer, and defoamer into the reactor and stir until they are evenly distributed. After the temperature rises to 130°C, keep it warm for 13 minutes. Finally, continue stirring until there are no particles in the reactor. Pour the slurry in the reactor into a mold for molding, cool it to room temperature, and demold it to obtain a cylindrical blank. The blank is then turned on a high-precision lathe for sample testing.

[0058] Comparative Example 1

[0059] The only difference between this comparative example and Example 4 is that: 25 parts of polyethylene wax.

[0060] Comparative Example 2

[0061] The only difference between this comparative example and Example 4 is that: 65 parts of polyethylene wax.

[0062] Comparative Example 3

[0063] The difference between this comparative example and Example 4 is only that: 15 parts of EVA.

[0064] Comparative Example 4

[0065] The difference between this comparative example and Example 4 is only that: 55 parts of EVA.

[0066] Group 2

[0067] The only difference between Example 11 and Example 4 is that the polyethylene wax has a molecular weight of 3000 and the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn measured by gel permeation chromatography is 2.

[0068] The only difference between Example 12 and Example 4 is that the polyethylene wax has a molecular weight of 3000 and the ratio of the weight average molecular weight Mw to the number average molecular weight Mn measured by gel permeation chromatography is 3.5.

[0069] The only difference between Example 13 and Example 4 is that the polyethylene wax has a molecular weight of 2000.

[0070] The only difference between Example 14 and Example 4 is that the polyethylene wax has a molecular weight of 10,000.

[0071] The only difference between Example 15 and Example 4 is that the VA content of the ethylene-vinyl acetate copolymer is 25%, and the melt index is ≤150.

[0072] The only difference between Example 16 and Example 4 is that the VA content of the ethylene-vinyl acetate copolymer is 30% and the melt index is ≤150.

[0073] The wax samples of the above examples and comparative examples were molded to form test samples, and then the performance tests were performed as follows:

[0074]

[0075]

[0076] 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 invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the 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.

[0077] 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 model wax for machining, comprising, by weight: 30 to 60 parts of polyethylene wax, 20 to 50 parts of EVA, 1 to 30 parts of resin, 0 to 5 parts of reinforcing and compatibilizing agent, 0 to 3 parts of plasticizer, and 0 to 1 part of defoaming agent, wherein: The softening point of polyethylene wax is not lower than 110℃, and the softening point of resin is not lower than 80℃.

2. The model wax for machining according to claim 1, characterized in that The molecular weight of the polyethylene wax is 2000-10000.

3. The model wax for machining according to claim 2, characterized in that The molecular weight of the polyethylene wax satisfies the following requirement: the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 1.5 to 3.

5.

4. The model wax for machining according to claim 1, characterized in that The VA content in the EVA is 20%-30%, and the melt index is ≤150.

5. The model wax for machining according to claim 1, characterized in that The resin is selected from the group consisting of: C5 hydrogenated petroleum resin, C5 / C9 copolymerized hydrogenated petroleum resin, terpene resin, polymerized rosin, and rosin glycerol ester.

6. The model wax for machining according to claim 1, characterized in that The reinforcing compatibilizer is refined rice bran wax.

7. The model wax for machining according to claim 1, characterized in that The plasticizer is selected from the group consisting of: UN399, polystyrene, and phthalates.

8. The model wax for machining according to claim 1, characterized in that The defoaming agent is selected from: organic silicon defoaming agent.

9. The method for processing model wax for machining according to any one of claims 1 to 9, comprising the following steps: placing polyethylene wax, EVA, and a reinforcing compatibilizer in a reactor, heating them, and stirring at a low speed; when the substances in the reactor are heated to a molten state and uniformly mixed, adding a resin, a plasticizer, and a defoaming agent into the reactor, and stirring until they are evenly distributed; raising the temperature to 130-140° C. and then maintaining the temperature for no more than 30 minutes; finally, continuing stirring until no particles are left in the reactor, pouring the slurry in the reactor into a mold, cooling it to room temperature, demolding it, and obtaining a blank, which is then subjected to high-precision machining.

10. Use of the model wax for machining according to any one of claims 1 to 9 in precision casting, medical devices, artwork reproduction or jewelry design.

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