KR102034573B1 - Method of fabricating hollow jewelry - Google Patents

Abstract

The present invention relates to a hollow jewelry manufacturing method. According to the present invention, the inside of a model, which is three-dimensionally printed as a hollow jewelry product, is manufactured to be kept hollow, and the model is heated and burned to be removed through a gradual temperature rising process after electrolytic casting, so even if resin which is the model is expanded by heat, a crack on a final product can be prevented. In order to achieve the purpose, the method includes the following steps of: (S1) designing a model of jewelry by hollowing the model at 25-70%; (S2) outputting the model of jewelry designed in the step (S1) through a three-dimensional printer; (S3) plating the surface of the model of jewelry outputted in the step (S2) with a conductive metal layer; (S4) forming an electrodeposition layer on the surface of the conductive metal layer plated in the step (S3); and (S5) removing the model outputted in the step (S2) through a gradual temperature rising process making a temperature rise for one hour in a room temperature-200°C section, making a temperature rise for one hour in a 200-300°C section after maintaining 200°C for 30 minutes to one hour making a temperature rise for two hours in a 300-400°C section after maintaining 300°C for 30 minutes to one hour, making a temperature rise for one hour in a 400-650°C section after maintaining 400°C for 30 minutes to one hour, and maintaining 650°C for 30 minutes to one hour from the model of jewelry with the electrodeposition layer formed in the step (S4) to the model outputted in the step (S2).

Description

Hollow jewelry manufacturing method {Method of fabricating hollow jewelry}

The present invention relates to a method of manufacturing a hollow jewelry, more specifically, to give a conductivity on the surface of the model manufactured by the 3D printer and remove the model only after forming the electrodeposition layer to empty the interior to reduce the weight and save material It relates to a jewelry manufacturing method.

Jewelry made of precious metals or natural gemstones to suit a variety of fashion styles is divided into fine jewelry and custom jewelry. Fine jewelry is made of expensive natural gemstones such as diamonds and rubies and precious metals such as gold and platinum. Custom jewelry, also called fashion jewelry, is produced by plating precious metals such as gold, silver, rhodium, and palladium on metals made of imitation and synthetic gemstones or zinc, iron and brass.

Here, the lost wax casting method, which is a method of manufacturing custom jewelry, is divided into a whole process → a main process → a finishing process. Specifically, ① 2D design and styling → ② original production (working or 3D) Printing) → ③ Manufacture of rubber molds → ④ Mass replication of wax wax for mass production → ⑤ Casting of plaster and metal replicas → ⑥ Fine work and polishing → ⑦ Plating and surface treatment → ⑧ Post-treatment such as jewelry setting → ⑨ Quality inspection and packaging This complicated, time-consuming and skilled technician is required.

Moreover, even in the above ⑦ plating and surface treatment process, it is composed of complex processes such as polishing → ultrasonic degreasing → electrolytic degreasing → under plating → precious metal plating → coating.In addition to the plating and surface treatment process, waste water, gypsum sludge, Dust is generated and workers are exposed to hazardous environment, there was a problem that environmental pollution caused by waste water.

In addition, when manufactured by the electroforming method (electroforming method), unlike the above-described vanishing model casting method, it is possible to impart a light fit by hollowing the inside, the wax model (mandrel, mandrel produced in step ④ of the vanishing model casting method) ) An electrically conductive solution is applied to the surface, and the model is immersed in an electrolytic bath to prepare a thick electrode.

In such an electrolytic casting method, conductive metal paints such as silver and copper are sprayed onto the wax model, and the metal layer such as gold and silver is electrodeposited to a thickness of about 0.2 to 0.7 mm by an electroplating method, and then the wax model is appropriately applied. In addition to the disadvantage that the price of conductive metal paint is expensive, the sprayed paint may not be applied to a uniform thickness and aggregate or flow at one point, resulting in rough or defective product surface. There were disadvantages that could occur.

From this, a method of manufacturing a model by using a different conductive material has been proposed. For example, Patent Publication No. 2004-0046608 discloses a hollow jewelry forming method using electroforming technology.

The above method uses a low melting point alloy as a model, and deposits a hollow pendant, medal, earring on the surface of the low melting point alloy model produced by using a silicon mold through copper plating, etc. Crafts ornaments and clothing ornaments and accessories.

However, in the case of lead, tin, bismuth, etc., which are low melting point alloys proposed by the above-mentioned patents for manufacturing by the above method, they are recently applied to actual product manufacturing as metals that are not allowed in the manufacturing process as well as in finished products due to human hazards. It is difficult to do, and the use of metal as a model has the disadvantage that the manufacturing process is more complicated.

Meanwhile, the jewelry industry is an important industry that accounts for about 12% of the 3D printing market. The jewelry industry is rapidly replacing 3D printing technology by applying 3D printing technology faster than any other industry in the design, manufacture and production of jewelry.

In particular, the 3D printing technology using photocurable resins, waxes, thermosets or thermoplastics in the jewelry industry is capable of simultaneously printing a variety of patterns in a short time without limiting the implementation of highly complex, creative and sophisticated designs. This is very advantageous in terms of design value and time and cost of producing the product, compared with conventional wax fabrication and pattern making techniques such as aluminum casting for casting.

Therefore, as a model for electrolytic casting for the production of hollow jewelry, it is eco-friendly and does not use a low melting point alloy containing lead, bismuth, etc., and has a hollow design of limited design using a wax injection model by a conventional simple rubber mold as a model. Breaking away from the jewelry production method, the resin printed by 3D printing can be directly used as a model for electroforming, thus saving material and light ornaments, and developing products with free, creative and sophisticated designs, and reducing prototype development costs. And it is possible to shorten the development period of the product, and to quickly respond to the multi-product and small-quantity small-volume production products at low cost, there is an advantage to meet the various needs of consumers.

1 is a process diagram briefly showing a conventional hollow jewelry manufacturing process.

Patent No. 10-1871350 (name of the invention: jewelry manufacturing method), as shown in Figure 1, a design step of designing jewelry products; A mandrel manufacturing step of inputting data of the design product and processing a mandrel by a 3D printer based on the input data; Imparting conductivity to the surface of the mandrel, but imparting conductivity to attach copper or silver; Electrolytic casting step of plating a mandrel to which conductivity is given, to smoothly surface the curved part or the corner part by periodically applying a pulse and a reverse pulse; The mandrel removal step of removing the mandrel to complete the jewelry product; including, the jewelry outer surface as well as the edge portion of the jewelry according to the periodic application of the pulse-reverse pulse is disclosed.

FIG. 2 is a view illustrating a 3D printed mandrel and an incision cross section of the manufacturing process of FIG. 1, the inside of which is designed to be filled with resin, and FIGS. 3 and 4 illustrate a mandrel after electroforming during the manufacturing process of FIG. 1. This figure shows the final product damaged by cracks as the model resin receives heat and expands when heated and removed.

As shown in Figure 2, the 3D printed mandrel of the jewelry product is designed to be filled with resin inside, and in the process of removing heat by applying heat to the mandrel after electroforming, the mandrel resin receives heat and expands As a result, as shown in Figs. 3 and 4, there is a problem that a crack occurs in the final product, resulting in breakage.

Patent Publication No. 2004-0046608 (Invention name: Hollow jewelry forming method using electroforming technology) Patent No. 10-1871350 (Invention name: jewelry manufacturing method)

The present invention is to solve the above problems, to make the interior of the 3D printed model of the jewelry product to maintain the hollow state, and after removing the burning by heating the model in a step-up temperature increase process after conveying, the resin model The object of the present invention is to provide a hollow jewelry manufacturing method that does not cause cracks in the final product even when heated and expanded.

In order to solve the above problems, the present invention, the step of hollowing out the model of jewelry to 25 to 70% (S1) and design; Outputting a model of the jewelry designed in the step S1 to a 3D printer (S2); Plating (S3) a conductive metal layer on the surface of the model of the jewelry output in the step (S2); Forming an electrodeposition layer on the surface of the conductive metal layer plated in the step S3; And, in the step (S4) from the model of the jewelry with the electrodeposition layer is formed, the model output in the step (S2) is heated to a room temperature ~ 200 ℃ section for 1 hour, and maintained at 200 ℃ 30 minutes to 1 hour 200 After heating the ~ 300 ℃ section for 1 hour, and maintained at 300 ℃ 30 minutes to 1 hour, and then heated the 300 ~ 400 ℃ section for 2 hours, and maintained at 400 ℃ 30 minutes to 1 hour after 400 ~ 650 The step of raising the temperature section for 1 hour, and maintaining at 650 ° C for 30 minutes to 1 hour, step of removing the model output in the step (S2) by stepwise heating (S5); comprising a hollow It provides a jewelry manufacturing method.

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According to the hollow jewelry manufacturing method of the present invention having the above-described solution, by making the interior of the 3D printed model of the jewelry product to maintain the hollow state, by removing the burned while applying heat to the model after the electroforming in a step-up process Since the resin output through the 3D printer is directly used as a model, even if the 3D printed model resin is expanded in the de-polymerization process by combustion to remove the model, the hollow jewelry product with creative and sophisticated design is affected. The effect of being able to make a hollow jewelry completely by not affecting.

1 is a process diagram briefly showing a conventional hollow jewelry manufacturing process,
FIG. 2 is a view showing a 3D printed mandrel and an incision cross section of the manufacturing process of FIG. 1, the inside of which is designed to be filled with resin;
3 and 4 is a view showing the final product during the manufacturing process of Figure 1, when the resin is applied as a model when the heat is removed after the electroforming to remove the cracks as the model resin receives heat and expands,
5 is a process diagram briefly showing a hollow jewelry manufacturing process according to an embodiment of the present invention,
FIG. 6 is a view showing a 3D printed model of a hollow jewelry product having a hollow interior and a cut section thereof during the manufacturing process of FIG. 5;
FIG. 7 is a view showing a hollow jewelry and a cut-away cross section in which the model is removed by applying heat at a stepwise temperature to a model in which the inside is hollow after electroforming in the manufacturing process of FIG. 5;
FIG. 8 is a graph illustrating a graph of measuring the degree of mass loss according to temperature when the resin, which is a model included in the jewelry product, in which the electroforming is completed, is burned and removed in the manufacturing process of FIG.
9 and 10 are examples of pure gold electroplated hollow jewelry products produced by the manufacturing method according to an embodiment of the present invention and the cut surface thereof is photographed with a scanning electron microscope.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, which are intended to be described in detail so that those skilled in the art can easily implement the present invention. It is not intended that the technical spirit and scope of this invention be limited. Terms used to define relative positions such as front, rear, left, right, top, bottom, and outside are based on the accompanying drawings.

5 is a process diagram briefly showing a hollow jewelry manufacturing process according to an embodiment of the present invention.

Hollow jewelry manufacturing method according to an embodiment of the present invention, as shown in Figure 5, the hollowed out of the model of the jewelry design (S1), and the model of the jewelry designed in the step (S1) 3D printer Outputting (S2), plating the conductive metal layer on the surface of the model of the jewelry output in the step (S2) (S3), and forming an electrodeposition layer on the surface of the conductive metal layer plated in the step (S3) Step S4 and step S5 of removing the model output in the step S2 from the model of the jewelry in which the electrodeposition layer is formed in the step S4 by stepwise temperature raising.

FIG. 6 is a view illustrating a 3D printed model of a hollow jewelry product having a hollow interior and a cut section thereof during the manufacturing process of FIG. 5.

In the step (S1), when the model of the jewelry to be used for electroforming is designed to output to a 3D printer using a photocurable resin, wax, thermosetting or thermoplastic, the conventional design is designed in a solid manner filled inside Unlike in the embodiment of the present invention, as shown in Figure 6, the interior is designed to be 25 to 70% hollow.

As described above, in the embodiment of the present invention, by hollowing the design within the predetermined range without filling the interior of the electroforming tank model, the resin expands the product in the temperature range of 250 ~ 400 ℃ especially in the desinification process by combustion after electroforming This makes it possible to prevent the failure from being broken.

Specifically, as shown in Table 1, the degree of breakage of the electroplated metal surface due to the expansion of the model used as the electroformed model is different between the size of the jewelry product, the metal thickness of the electroformed product, and the hollowing volume of the model. There is a correlation.

In the embodiment of the present invention, when manufacturing a hollow silver bracelet having a pipe outer diameter of 12 mm, when the thickness of the metal electrodeposited by electroforming is 0.3 mm or more, when the space ratio of the model used as the model is less than 50% If the surface was destroyed during the combustion process, and the thickness of the metal electrodeposited by electroforming was over 0.4 mm, the space ratio of the model used as the model was less than 40%, and the thickness of the metal electrodeposited by electroforming was 0.7 mm. In this case, the metal surface was destroyed when the space ratio of the model used as the model was less than 25%.

[Table 1] Example of the production of hollow silver bracelets with an outer diameter of 12 mm

In addition, in the case of manufacturing hollow silver bracelets having a pipe outer diameter of 4 mm, when the metal thickness electrodeposited by electroforming is 0.3 mm or more, when the space ratio of the model used as the model is less than 45%, the metal surface in the combustion process When the metal thickness electrodeposited by electroforming was more than 0.7 mm, the metal surface was destroyed when the space ratio of the model used as the model was less than 25%.

[Table 2] Example of the production of hollow silver bracelets with an outer diameter of 4 mm

In generalization through the embodiment of the present invention, the smaller the size of the jewelry product or the thinner the thickness of the electroforming metal, the larger the hollowing space ratio of the model used as the electroforming model.

The step S2 is commonly used as a 3D printing material in the jewelry industry in order to produce the model of the jewelry designed in the step S1 in consideration of the space ratio, and burned at a high temperature after the electroforming. Removable photocurable resins, waxes, thermosets or thermoplastics can be used to select from DLP, SLA, FDM and MJP systems.

At this time, the data that is the basis of the jewelry shape is input to the program of the 3D printer, the 3D printer produces a model by laminating the material by the input data, and becomes the basis of the jewelry appearance as the final material and the core material Its role is to maintain plating and shape in the later process, and also to make hollow jewelry finished.

The step (S3), by applying an electroless plating process to the surface of the model produced in the step (S2), by plating a conductive metal layer containing a high conductive metal, such as copper, silver to enable electrolytic casting.

The electroless plating process is performed by chemical reduction without electrolytic reaction, and the catalyst is selected from Pd / Sn mixed colloidal catalyst obtained by mixing PdCl ₂ , SnCl ₂ , and hydrochloric acid, and is a commercially available DLP method for 3D printing. Since the electroless plating catalyst treatment agent for photocuring resin is not developed at present, in the present invention, the catalyst treatment agents listed in [Table 3] are prepared, processed, plated with commercially available electroless copper plating solution, and required for electroforming process. Surface electrical conductivity was obtained. At this time, the surface electrical conductivity obtained by the catalyst treatment process and electroless copper plating was measured as 2.976 ㅧ 10 ³ S / cm.

Table 3 Composition of the Ionic Palladium Catalyst Prepared by Example of the Present Invention

And the above picture is an example of a metal layer formed by the electroless copper plating process catalyzed by the Pd / Sn mixed colloid prepared in the embodiment of the present invention, the gold plating process for electroforming after electroless copper plating is well You can see the progress.

In step S4, an electrodeposition layer is formed on the outer surface of the conductive metal layer plated in step S3 by electroforming.

In the electroforming step, the metal of the thick film is electrodeposited to a thickness of 0.2 to 0.7 mm by an electroplating method in an aqueous solution in which gold, silver, or copper, such as 24K gold, 18K gold alloy, and 14K gold alloy is dissolved.

In an embodiment of the present invention, an electrodeposition layer having an electrodeposition layer thickness of 0.2 to 0.7 mm is formed through an electroforming bath, and an electrodeposition layer including any one or more metals selected from gold, silver, and copper is formed.

In expensive precious metal jewelry products, the thickness of the electrodeposition layer is preferably 0.2 to 0.25 mm in the case of pure gold (99.9%) or gold alloy (14K and 18K gold), and may be weak in hardness and strength when the thickness is less than 0.2 mm. In case of exceeding 0.25 mm, there is a problem of unnecessary waste of materials.

FIG. 7 is a view showing hollow jewelry and a cut-away cross section of the hollowed out model after removing the model by heating the model in a hollow state after the electroforming, and FIG. 8 is a manufacturing process of FIG. 5. This is a graph showing the degree of mass loss according to temperature when the resin, which is a model contained in the jewelry product, has been burned and removed.

From the model of the jewelry in which the electrodeposition layer is formed in the step S4, the model output in the step S2 is removed by stepwise heating.

The process of removing the model may be performed by selecting one of the conventional methods well known in the art to which the present invention pertains, and in the embodiment of the present invention, a method of applying heat is applied.

When the internal model is completely removed through a staged combustion process after conducting and electroconductive processing on the surface of the model manufactured by hollowing the interior by the method according to the embodiment of the present invention, as shown in FIG. Quality jewelry products can be manufactured.

Here, even though the model resin was hollowed 25 to 70% by the hollowing design method according to the embodiment of the present invention, when the resin was burned while heating up at a temperature from 650 ° C. at a time, the temperature range was 250 ° C. to 400 ° C. A significant amount of resin burns rapidly and can crack the surface of the finished product. This tendency can be further exacerbated in the case of delicate design products where the hollowing rate is lowered.

In general, small sized and delicately designed jewelry has a limit to increase the hollowing rate by 50% or more.In the case of printing the resin by 3D printing, in order to maintain the shape of the product, the wall of the hollowed product may be infinitely thin. Because there is no number. In the embodiment of the present invention, the wall thickness of the hollow resin is limited to 0.3 mm or more.

Accordingly, when the model resin for electroforming is burned by the step-up process according to the present invention, even when outputting small-size and delicate jewelry by 3D printing, the hollowing ratio may be lowered to maintain a solid shape.

Referring to the degree of mass loss according to the combustion temperature of the DLP photocurable resin for 3D printing used in the embodiment of the present invention, as shown in FIG.

In the step-up step of the temperature, the jewelry product is completed in the electroforming bath inside the electric furnace commonly used in the field to which the present invention belongs, the temperature is raised from room temperature to 200 ℃ for 1 hour, and maintained at 200 ℃ 30 minutes to 1 hour After that, the temperature was raised at 200 to 300 ° C. for 1 hour, and then maintained at 300 ° C. for 30 minutes to 1 hour, and then at 300 ° to 400 ° C. for 2 hours, and maintained at 400 ° C. for 30 minutes to 1 hour. The temperature is raised for 400 to 650 ° C. for 1 hour, and maintained at 650 ° C. for 30 minutes to 1 hour to terminate the combustion process.

That is, the hollow jewelry manufacturing method according to an embodiment of the present invention, in the production of hollow jewelry, can significantly reduce the number of processes compared to the conventional jewelry production process, in particular to hollow the interior of the model Removal by staged temperature increases makes it possible to produce jewelry products of high quality that are not damaged by expansion of the heated resin.

9 and 10 are examples of pure gold electroplated hollow jewelry products produced by the manufacturing method according to an embodiment of the present invention and the cut surface thereof is photographed with a scanning electron microscope.

When manufacturing the pure gold electrolytic casting hollow jewelry product by the manufacturing method according to the embodiment of the present invention and photographing the cut surface of 0.25 ~ 0.30㎜ with a scanning electron microscope it can be seen that there is no damage.

9 and 10, the pure gold jewelry products manufactured according to the embodiment of the present invention reduced weight by about 74% compared to the case of the same product manufactured by the traditional casting method, diameter 65mm, thickness Despite the 99.9% pure gold barrel bracelet of 4mm, the weight is about 12g (about 3 dollars), so there is an advantage that you can not feel fatigue even after long wearing.

As described above, when the jewelry is manufactured by the manufacturing method according to the embodiment of the present invention, it does not use low melting point alloys such as lead and bismuth, which is environmentally friendly, and prevents the problem of product defects generated in the electroforming process. It is possible to manufacture hollowed out jewelry with empty space inside, so that it can realize unique design that cannot be manufactured by traditional casting method, and it can reduce the weight of product, material saving and production cost.

In addition, even large jewelry is lightweight and easy to wear, and has the advantage of manufacturing a jewelry having a creative design that can meet a variety of consumer needs.

This invention is not limited to the above embodiments, various modifications are possible within the scope of the invention described in the claims, and such modifications are also included within the scope of the invention.

S1 ~ S5: Hollow jewelry manufacturing process according to an embodiment of the present invention
S1: Jewelry Model Hollowing Design Stage
S2: 3D printer output stage of the designed jewelry
S3: conductive metal layer plating step on the surface of the printed jewelry model
S4: forming an electrodeposition layer on the surface of the plated conductive metal layer
S5: Model step temperature increase removal step output from the electrodeposition layer forming jewelry model

Claims (3)

delete delete Designing by hollowing the model of the jewelry to 25 ~ 70% (S1);
Outputting the model of the jewelry designed in the step S1 to a 3D printer (S2);
Plating a conductive metal layer on the surface of the model of the jewelry output in the step S2;
Forming an electrodeposition layer on the surface of the conductive metal layer plated in the step S3; And,
From the model of the jewelry in which the electrodeposition layer is formed in the step (S4) the temperature of the model output in the step (S2) for 1 hour to increase the temperature range from room temperature to 200 ℃ for 1 hour, 200 to 300 after maintaining for 30 minutes to 1 hour After heating the ℃ section for 1 hour, and maintained at 300 ℃ for 30 minutes to 1 hour, the temperature is raised to 300 ~ 400 ℃ section for 2 hours, and maintained at 400 ℃ for 30 minutes to 1 hour and then 400 ~ 650 ℃ section To increase the temperature for 1 hour, and to maintain for 30 minutes to 1 hour at 650 ℃, step (S5) to remove the output model in the step (S2); Hollow jewelry manufacturing comprising a Way.

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