A process method for scratch resistance on the surface of gold

Abstract

The present invention provides a process method for anti-scratch on the surface of gold, which relates to the technical field of gold jewelry processing. This process method for anti-scratch on the surface of gold includes the following specific steps: Step 1, casting blank: According to the design drawing of the gold jewelry, use a special casting mold to cast the blank. After the blank is cooled and formed, take it out and soak it in cold water for cleaning and reserve; Step 2, rough grinding: Use a rough grinding machine to grind off the stock head and obvious burrs on the gold blank; Step 3, fine grinding: Use a fine grinding machine to carry out fine grinding on the gold blank. By physically grinding, chemically soaking and electrostatic spraying the gold jewelry, a protective film layer can be formed on the surface of the gold jewelry, which can not only enhance the wear resistance, scratch resistance and corrosion resistance of the gold jewelry, but also the transparent epoxy resin coating will not affect the luster of the gold, and it will not turn yellow after long-term wearing, so that the gold jewelry can maintain a high luster and beauty.

Description

Technical Field

[0001] The present invention relates to the technical field of gold jewelry processing, and specifically relates to a process method for anti-scratching on the surface of gold. Background Art

[0002] Gold is the elemental form of the chemical element gold (Au). It is a soft, golden-yellow, corrosion-resistant precious metal. Gold is one of the rarer, more precious, and very important metals. Internationally, gold is generally measured in ounces. Gold is not only a special currency for reserve and investment, but also an important material in sectors such as the jewelry industry, electronics industry, modern communication, and aerospace industry.

[0003] Gold is a very common precious metal material and is often processed into various gold jewelry, such as gold rings, gold bracelets, gold pendants, and gold necklaces. Currently, most gold jewelry is processed by casting combined with later manual processing. To show the most original texture of gold, after the gold jewelry is processed, generally no post-treatment is done. However, due to the soft texture of gold itself, during long-term wearing, it is very easy to be scratched, resulting in scratches and a small amount of wear, thus losing its own luster. The worn gold jewelry will seriously affect its aesthetics and also bring a poor user experience to users.

[0004] Therefore, we have developed a new process method for anti-scratching on the surface of gold. Summary of the Invention

[0005] (I) Technical Problems to be Solved

[0006] Aiming at the deficiencies of the prior art, the present invention provides a process method for anti-scratching on the surface of gold, which solves the problem that in order to show the most original texture of gold, after the gold jewelry is processed, generally no post-treatment is done. However, due to the soft texture of gold itself, during long-term wearing, it is very easy to be scratched, resulting in scratches and a small amount of wear, thus losing its own luster. The worn gold jewelry will seriously affect its aesthetics and also bring a poor user experience to users.

[0007] (II) Technical Solutions

[0008] To achieve the above objectives, the present invention is realized through the following technical solutions: A process method for anti-scratching on the surface of gold, including the following specific steps:

[0009] Step 1. Casting blank: According to the design drawing of the gold jewelry, use a special casting mold to cast the blank. After the blank cools and forms, take it out, soak it in cold water for cleaning, and reserve it for use;

[0010] Step 2. Rough grinding: Use a rough grinding machine to grind off the stock head and obvious burrs on the gold blank.

[0011] Step 3. Fine grinding: Use a fine grinding machine to perform fine grinding on the gold blank, removing the unevenness and a small amount of protruding parts on the surface of the blank, making the surface of the blank flat and smooth as a whole.

[0012] Step 4. Chemical cleaning: Prepare a decontamination solution and put the finely ground gold blank into the decontamination solution for cleaning to remove the oxide layer, oil stain, and dirt on the surface of the gold blank.

[0013] Step 5. Primary polishing: Immerse the pickled gold blank in water for cleaning, take it out and use a polishing machine for polishing to make the surface of the gold blank lubricated and shiny.

[0014] Step 6. Water washing and drying: Wash the polished gold blank with pure water, take it out after washing and dry it for standby.

[0015] Step 7. Electrostatic spraying: Use an electrostatic spray gun to spray a layer of epoxy resin on the surface of the gold blank to form an epoxy resin coating on the surface of the gold blank.

[0016] Step 8. Drying and shaping: Place the sprayed gold blank in a static drying room for static drying.

[0017] Step 9. Secondary polishing: Take out the dried gold blank and use a polishing machine to polish its surface. After polishing, wash it with water to obtain the finished gold jewelry.

[0018] Step 10. Quality inspection: Use a sharp object to gently scratch the surface of the gold jewelry and observe whether scratches are generated on its surface. If no obvious scratches are generated and the surface has a lubricating luster, the product is qualified.

[0019] Preferably, after rough grinding in Step 2, the processing personnel can manually weld ornaments on the gold blank according to the design requirements and perform detail decoration. Since the design shapes of different jewelry are diverse, some complex and special structural designs cannot be integrally cast by means of die casting. Therefore, after the basic part is cast and formed, ornaments can be welded on the basis of the basic blank according to the actual design drawings and schemes, and detail decoration can also be performed, including drilling, filling, and grinding, etc.

[0020] Preferably, the decontamination solution uses dilute sulfuric acid, and the ratio of sulfuric acid to water in the preparation process is 1:7 - 9. Using dilute sulfuric acid prepared with a ratio of sulfuric acid to water of 1:7 - 9 as the chemical cleaning reagent can effectively remove the oxide layer, oil stain, and various other dirt on the surface of the gold blank, and the cleaning efficiency is higher.

[0021] Preferably, the electrostatic spraying is carried out by a mechanical spraying device, and the mechanical arm and the 360-degree spray gun are used for dust-free electrostatic spraying processing in a dust-free room. Using automated equipment for electrostatic spraying can not only ensure higher spraying quality, but also ensure spraying efficiency and production progress.

[0022] Preferably, in step seven, the raw material for electrostatic spraying is liquid epoxy resin, and the thickness of the epoxy resin coating is 8-10 μm. By spraying an 8-10 μm thick epoxy resin on the surface of the gold jewelry, an epoxy resin coating can be formed on the surface of the gold jewelry. It has strong adhesion, can enhance the wear resistance, scratch resistance and corrosion resistance of the gold jewelry. At the same time, the transparent epoxy resin coating will not affect the gloss of the gold, and it will not turn yellow after long-term wearing, enabling the gold jewelry to maintain a high gloss and beauty. In addition, the daily maintenance of the epoxy resin coating is very convenient, and it can be wiped with wet wipes, towels and lens cloths in daily life.

[0023] Preferably, in the drying and forming step, the drying temperature is controlled at 65-80 °C and the drying time is 1.5-2 h, which can accelerate the solidification and forming speed of the epoxy resin coating, thereby improving production efficiency.

[0024] Preferably, in the secondary polishing process of step nine, an appropriate amount of polishing paste needs to be applied. By applying an appropriate amount of polishing paste, the polishing quality can be improved and the gloss of the surface of the gold jewelry can be enhanced.

[0025] Preferably, in step ten, the sharp object for detection is selected from metal or non-metal sharp objects. By using a hard metal or non-metal sharp object to scratch and detect the epoxy resin coating, the scratch resistance of the gold jewelry can be quickly and intuitively detected.

[0026] (III) Beneficial effects

[0027] The present invention provides a process method for anti-scratch on the surface of gold. It has the following beneficial effects:

[0028] 1. For this process method for anti-scratch on the surface of gold, by physically polishing, chemically soaking and electrostatic spraying the gold jewelry, a protective film layer can be formed on the surface of the gold jewelry, which can enhance the wear resistance, scratch resistance and corrosion resistance of the gold jewelry. At the same time, the transparent epoxy resin coating will not affect the gloss of the gold, and it will not turn yellow after long-term wearing, enabling the gold jewelry to maintain a high gloss and beauty.

[0029] , This process method for scratch resistance on the surface of gold sprays an epoxy resin coating on the surface of gold jewelry. During daily wear, even if it is slightly scratched, no scratches will be generated. This not only greatly improves the scratch resistance of gold jewelry, but also makes its daily maintenance very convenient and easy to clean. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is the process flow chart of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0032] Embodiment 1:

[0033] As Figure 1 shown, the embodiment of the present invention provides a process method for scratch resistance on the surface of gold, including the following specific steps:

[0034] Step 1, casting blank: According to the design drawing of the gold jewelry, use a special casting mold to cast the blank. After the blank is cooled and formed, take it out and wash it with cold water for standby;

[0035] Step 2, rough grinding: Use a rough grinding machine to grind off the material head and obvious burrs on the gold blank. After rough grinding, the processing personnel can manually weld decorations on the gold blank according to the design requirements and perform detail modification;

[0036] Step 3, fine grinding: Use a fine grinding machine to perform fine grinding on the gold blank to remove the uneven and slightly protruding parts on the surface of the blank, making the surface of the blank flat and smooth as a whole;

[0037] Step 4, chemical cleaning: Prepare a decontamination solution. The decontamination solution uses dilute sulfuric acid. The ratio of sulfuric acid to water during the preparation process is 1:7 - 9, and put the finely ground gold blank into the decontamination solution for cleaning to remove the oxide layer, oil stain and dirt on the surface of the gold blank;

[0038] Step 5, primary polishing: Immerse the pickled gold blank in water for cleaning, take it out and use a polishing machine for polishing treatment to make the surface of the gold blank lubricated and shiny;

[0039] Step 6, water washing and drying: Wash the polished gold blank with pure water, take it out after washing and dry it for standby;

[0040] Step 7. Electrostatic spraying: Use an electrostatic spray gun to spray a layer of epoxy resin on the surface of the gold blank to form an epoxy resin coating on the surface of the gold blank. The electrostatic spraying is carried out using mechanical spraying equipment, and the dust-free electrostatic spraying process is carried out in a dust-free room by a robotic arm and a 360-degree spray gun; The raw material is liquid epoxy resin, and the thickness of the epoxy resin coating is 8-10 μm;

[0041] Step 8. Drying and forming: Place the sprayed gold blank into a static drying room for static drying. The drying temperature is controlled at 65-80 °C, and the drying time is 1.5-2 h;

[0042] Step 9. Secondary polishing: Take out the dried gold blank and polish its surface using a polishing machine. Apply an appropriate amount of polishing paste during the polishing process, and then wash it with water after polishing to obtain the finished gold jewelry;

[0043] Step 10. Quality inspection: Gently scratch the surface of the gold jewelry with a sharp object and observe whether scratches are generated on its surface. If no obvious scratches are generated and the surface has a lubricating luster, the product is qualified.

[0044] Example 2:

[0045] The difference between this example and Example 1 is as follows: It includes the following specific steps:

[0046] Step 1. Blanking: According to the design drawing of the gold jewelry, use a special casting mold to cast the blank. After the blank cools and forms, take it out, soak it in cold water for cleaning and set aside;

[0047] Step 2. Rough grinding: Use a rough grinder to grind off the sprue and obvious burrs on the gold blank. After rough grinding, the processing personnel can manually weld decorations to the gold blank according to the design requirements and perform detailed decoration;

[0048] Step 3. Fine grinding: Use a fine grinder to perform fine grinding on the gold blank to remove the uneven and slightly protruding parts on the surface of the blank, making the surface of the blank flat and smooth as a whole;

[0049] Step 4. Chemical cleaning: Prepare a decontamination solution. The decontamination solution uses dilute hydrochloric acid, and the ratio of hydrochloric acid to water during the preparation process is 1:8. Then put the finely ground gold blank into the decontamination solution for cleaning to remove the oxide layer, oil stain and dirt on the surface of the gold blank;

[0050] Step 5. Primary polishing: Immerse the pickled gold blank in water for cleaning, take it out and polish it using a polishing machine to make the surface of the gold blank lubricated and shiny;

[0051] Step 6. Washing and drying: Wash the polished gold blank with pure water, take it out after washing and dry it for standby;

[0052] Step 7. Electrostatic spraying: Use an electrostatic spray gun to spray a layer of epoxy resin on the surface of the gold blank to form an epoxy resin coating on the surface of the gold blank. The electrostatic spraying is carried out using mechanical spraying equipment, and the dust-free electrostatic spraying process is carried out in a dust-free room by a robotic arm and a 360-degree spray gun. The raw material used is liquid epoxy resin, and the thickness of the epoxy resin coating is 8 - 10 μm;

[0053] Step 8. Drying and forming: Place the sprayed gold blank in a static drying room for static drying. The drying temperature is controlled at 65 - 80 °C, and the drying time is 1.5 - 2 h;

[0054] Step 9. Secondary polishing: Take out the dried gold blank and polish its surface using a polishing machine. Apply an appropriate amount of polishing paste during the polishing process, and wash it clean with water after polishing to obtain the finished gold jewelry;

[0055] Step 10. Quality inspection: Gently scratch the surface of the gold jewelry with a sharp object and observe whether scratches are generated on its surface. If no obvious scratches are generated and the surface has a lubricating luster, the product is qualified.

[0056] Example 3:

[0057] The differences between this example and Example 1 and Example 2 are as follows: It includes the following specific steps:

[0058] Step 1. Blanking: According to the design drawing of the gold jewelry, use a special casting mold to cast the blank. After the blank cools and forms, take it out and soak it in cold water for cleaning and reserve;

[0059] Step 2. Rough grinding: Use a rough grinding machine to grind off the sprue and obvious burrs on the gold blank. After rough grinding, the processing personnel can manually weld ornaments to the gold blank according to the design requirements and carry out detailed decoration;

[0060] Step 3. Chemical cleaning: Prepare a decontamination solution. The decontamination solution uses dilute hydrochloric acid, and the ratio of hydrochloric acid to water during the preparation process is 1:8. Put the finely ground gold blank into the decontamination solution for cleaning to remove the oxide layer, oil stain, and dirt on the surface of the gold blank;

[0061] Step 4. Primary polishing: Immerse the pickled gold blank in water for cleaning, take it out and polish it using a polishing machine to make the surface of the gold blank smooth and shiny;

[0062] Step 5. Water washing and drying: Wash the polished gold blank with pure water and reserve it;

[0063] Step 6, Electrostatic spraying: Use an electrostatic spray gun to spray a layer of epoxy resin on the surface of the gold blank to form an epoxy resin coating on the surface of the gold blank. The electrostatic spraying uses mechanical spraying equipment, and the mechanical arm and 360-degree spray gun are used for dust-free electrostatic spraying processing in a dust-free room; the raw material is liquid epoxy resin, and the thickness of the epoxy resin coating is 8-10μm;

[0064] Step 7, Drying and forming: Place the sprayed gold blank in a static drying room for static drying. The drying temperature is controlled at 65-80°C, and the drying time is 1.5-2h;

[0065] Step 8, Quality inspection: Use a sharp object to gently scratch the surface of the gold jewelry and observe whether scratches are generated on its surface. If no obvious scratches are generated and the surface has a lubricating oil luster, the product is qualified;

[0066] Inspection Items Surface Defects Surface Gloss Surface Flatness Surface Coating Coverage Surface Color and Luster Comprehensive Evaluation Example 1 No Scratches High Smooth and Flat, Fine Touch Uniform Coverage, Same Thickness Golden Yellow, Uniform Qualified Example 2 No Scratches High Smooth and Flat, Fine Touch Uniform Coverage, Same Thickness Golden Yellow, Uniform Qualified Example 3 No Obvious Scratches High Smooth and Flat Uniform Coverage, Same Thickness Golden Yellow, Uniform Qualified

[0067] Surface defect detection standard:

[0068] Under normal light (60 lux), visually inspect the product at a distance of 20CM for appearance. Make a judgment of qualified or unqualified by comparing with the standard. It is mainly an inspection that relies on the sensory organs of personnel to evaluate or judge the product quality, and judge whether there are surface defects such as sand holes, scratching, blister points, pitting, pinholes, and fogging.

[0069] Surface flatness detection standard:

[0070] Detect the mirror effect on the surface of the product, mainly including black body mirror, electroplated mirror, and painted surface. Make a judgment through manual visual inspection, and can compare with samples and unqualified limit samples for reference.

[0071] Surface flatness detection standard:

[0072] According to the reflective characteristics of the surface coating of the product, it is divided into three categories: mirror gloss, semi-gloss, and matte. It is mainly based on visual comparison with color plates and limit samples, and a gloss meter is used for testing when necessary.

[0073] Surface coating coverage detection standard:

[0074] After the product is electroplated or sprayed, check whether the surface parts that should be covered are completely covered by the coating in the concave low positions, inner hole diameters, and small hole parts of the product.

[0075] Surface color detection standard:

[0076] Regarding the lightness and saturation of the color system generated, make a judgment by visually comparing with a color plate. Cover a matte transparent paper on both the product and the color plate for comparison and judgment. When necessary, use a color comparison box, visual comparison, or colorimeter for measurement.

[0077] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art will appreciate that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process method for scratch resistance on the surface of gold, characterized in that: It includes the following specific steps: Step 1, blank casting: According to the design drawings of the gold jewelry, use a special casting mold to cast the blank. After the blank cools and forms, take it out, soak it in cold water for cleaning and reserve it; Step 2, rough grinding: Use a rough grinding machine to grind off the stock head and obvious burrs on the gold blank; Step 3, fine grinding: Use a fine grinding machine to perform fine grinding on the gold blank, remove the uneven and slightly protruding parts on the surface of the blank, and make the surface of the blank smooth and flat overall; Step 4, chemical cleaning: Prepare a decontamination solution, and put the finely ground gold blank into the decontamination solution for cleaning to remove the oxide layer, oil stain and dirt on the surface of the gold blank; Step 5, primary polishing: Immerse the pickled gold blank in water for cleaning, take it out and use a polishing machine for polishing to make the surface of the gold blank lubricated and shiny; Step 6, water washing and drying: Wash the polished gold blank with pure water, take it out after washing and dry it for reserve; Step 7, electrostatic spraying: Use an electrostatic spray gun to spray a layer of epoxy resin on the surface of the gold blank to form an epoxy resin coating on the surface of the gold blank; Step 8, drying and forming: Place the sprayed gold blank in a static drying room for static drying; Step 9, secondary polishing: Take out the dried gold blank, use a polishing machine to polish its surface, and wash it with water after polishing to obtain the finished gold jewelry; Step 10, quality inspection: Use a sharp object to gently scratch the surface of the gold jewelry, observe whether scratches are generated on its surface. If no obvious scratches are generated and the surface has lubricating luster, the product is qualified.

2. The process method for scratch resistance on the surface of gold according to claim 1, characterized in that: After rough grinding in Step 2, the processing personnel can manually weld decorations on the gold blank according to the design requirements and perform detail modification.

3. A process method for scratch resistance on the surface of gold according to claim 1, characterized in that: The decontamination solution uses dilute sulfuric acid, and the ratio of sulfuric acid to water during the preparation process is 1:7 - 9.

4. A process method for anti-scratch on the surface of gold according to claim 1, characterized in that: The electrostatic spraying uses a mechanical spraying device, and the mechanical arm and 360-degree spray gun are used for dust-free electrostatic spraying processing in a dust-free room.

5. A process method for anti-scratch on the surface of gold according to claim 4, characterized in that: In Step 7, the raw material for electrostatic spraying uses liquid epoxy resin, and the thickness of the epoxy resin coating is 8 - 10μm.

6. A process method for anti-scratch on the surface of gold according to claim 1, characterized in that: In the drying and forming step, the drying temperature is controlled at 65 - 80°C, and the drying time is 1.5 - 2h.

7. A process method for anti-scratch on the surface of gold according to claim 1, characterized in that: During the secondary polishing in Step 9, an appropriate amount of polishing paste needs to be applied.

8. A process method for scratch resistance on the surface of gold according to claim 1, characterized in that: In Step 10, the sharp object for detection uses a metal or non-metal sharp object.

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