Method of manufacturing semi-matt decorative component and semi-matt decorative component

Abstract

To provide frosting of different appearance which is less likely to become dirty and is easier to wash than conventional frosting.SOLUTION: The current invention relates to a method of manufacturing a semi-matt decorative component. This method includes the following steps of: arranging decorative components with hardness -800HV or more; arranging the decorative components in a drum housing at least one material abrasive powders of a diamond, boron nitride, silicon carbide, alumina, and boron carbide; and operating the drum for at least 3 hours and moving decorative parts at an average speed between 0.5 m / minute and 1.5 m / minute. A semi-matt decorative part (1) has a silky appearance or velour appearance, and may have a pale color, such as white. It is less likely to be stained and easier to wash than a known matt part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for producing a semi-matt decorative part and to a semi-matt decorative part. The semi-matt decorative part according to the invention is not limited to the field of watches and jewellery, but can also find application in the general field of micromachining technology, in the field of mobile or portable devices, in the field of vehicles or in any other field in which the semi-matt part is used to decorate an object and is visible during the use of the object. [Background technology]

[0002] Matte decorative parts, i.e. parts that do not shine, glitter and / or reflect light, are widely known and used in various objects, in particular in the field of watches and jewellery.

[0003] Non-limiting examples of these matte decorative components include watch cases and bracelet links.

[0004] The matte appearance is achieved by the presence of scratches with a depth of a few microns. Such scratches tend to collect dirt and are difficult to clean. Moreover, such dirt is especially noticeable if the decorative part is a light color, e.g. white.

[0005] Thus, a need exists for decorative parts that are less prone to collecting dirt than known decorative parts.

[0006] A need also exists for decorative parts that are more easily cleanable than known decorative parts.

[0007] There is also a need for decorative parts that have a different appearance than known decorative parts. Summary of the Invention [Problem to be solved by the invention]

[0008] One task of the present invention is to propose a decorative part which is free from the limitations of known decorative parts.

[0009] Another object of the invention is to propose a decorative part which collects dirt less than known decorative parts.

[0010] Another object of the invention is to propose a decorative part which can be cleaned more easily than known decorative parts.

[0011] Another object of the invention is to propose a decorative part which has a different appearance than known decorative parts. [Means for solving the problem]

[0012] According to the invention, these objectives are achieved in particular by a method for producing a semi-matt decorative part according to claim 1 and by a decorative part according to claim 8.

[0013] The method for producing a semi-matt decorative part according to the present invention comprises the following steps: - sourcing a decorative component having a hardness of 800HV or greater; - placing said decorative part in a drum containing an abrasive powder of at least one material selected from the group consisting of diamond, boron nitride, silicon carbide, alumina and boron carbide; - operating the drum for at least 3 hours, moving the decorative part at between 0.5 m / min and 1.5 m / min, preferably between 0.7 m / min and 0.9 m / min, for example 0.8 m / min, thereby making it possible to obtain a semi-matt surface and a surface profile with an asymmetry in the range of -1 μm to -0.3 μm, a profile height in the range of 0.1 μm to 1.5 μm and a roughness in the range of 0.1 μm to 0.2 μm; Equipped with.

[0014] In one embodiment, the movement of the part is in more than one direction at a time, for example a vibrational movement.

[0015] In this context, the expression "semi-matt part" refers to a part that is only partially reflective, specular (reflects light in the same plane at an angle equal to the angle of incidence to the normal, like a mirror), mostly diffuse (i.e. reflects light at multiple angles), partially shiny, and partially shimmering, and whose visual appearance is silky, velvety, or velour-like.

[0016] In one embodiment, specular reflection from a part according to the invention is reduced by up to 69% compared to a polished part (i.e. a part with a smooth surface) made of the same material, and diffuse reflection from a part according to the invention is increased by more than 100%, e.g. up to 113%, compared to a polished part made of the same material.

[0017] In the present context, the variable "asymmetry" (Rsk) refers to the asymmetry of the distribution of surface elements (especially peaks and valleys) defined over an evaluation or reference length (e.g. 250 μm). This variable provides information about the morphology of the surface state. Positive values ​​of Rsk correspond to surfaces with prominent peaks on the surface and thus a distribution shifted towards the lowest points, while negative values ​​correspond to flat surfaces with deep valleys (or valleys) and a distribution shifted towards the highest points.

[0018] In the present context, the variable "profile height" (Rt) means the height between the deepest valley and the highest peak over an evaluation length (e.g. 250 μm). This variable allows a local evaluation of the profile.

[0019] In the context of this application, the variable "roughness" (Ra) refers to the arithmetic mean roughness of the contour of the surface of a decorative part. It is defined over a reference length. This variable allows the amplitude of the roughness of the contour to be evaluated globally.

[0020] The present solution therefore provides for tumbling (repeated uncontrolled falling) with abrasive powder of at least one material among certain types of abrasives: diamond, boron nitride, silicon carbide, alumina, and boron carbide.

[0021] This abrasive powder has the special property that its particles hardly break down or do not break down at all during tumbling, which prevents the tumbling from becoming an abrasive process during tumbling. The parts actually produced are semi-matt parts, not polished parts.

[0022] In a preferred embodiment, diamond abrasive powder is used.

[0023] The use of abrasive powders, especially diamond abrasive powders, according to the invention is not obvious, firstly because of the cost of the (diamond abrasive) powders. Moreover, the powders, especially diamond powders, can cause deterioration of the drum. Also, the powders are often suspended in a liquid, for example oil, which makes cleaning of the drum complicated.

[0024] Tests carried out by the Applicant have demonstrated that the use of this abrasive powder according to the invention is not only possible, but also results in semi-matt parts which are less soiled than known decorative parts and easier to clean than known matt decorative parts. Indeed, due to its structure defined by the variables Rsk, Rt and Ra, the semi-matt parts according to the invention are less soiled than known matt parts and, even if they are soiled, are easier to clean. As a result, the semi-matt decorative parts according to the invention can also be produced in light colors, for example white.

[0025] This solution has the advantage over the prior art in particular of proposing an upholstery element with a silky or velour-like appearance, different from the (matt or thin) appearance of known upholstery elements.

[0026] In one embodiment, the method includes unloading the semi-matte decorative piece from the drum.

[0027] In one embodiment, the method essentially comprises the step of washing the drum subsequent to the step of unloading the drum.

[0028] In one embodiment, the method essentially comprises the step of washing the semi-matte decorative piece subsequent to the step of unloading the drum.

[0029] In one embodiment, the method comprises a step of inspecting, e.g., an inspection step, the semi-matt decorative piece essentially subsequent to (but generally not immediately after) the step of unloading the drum.

[0030] In one embodiment, the method comprises a step of polishing the decorative part, which essentially precedes the step of mounting the drum. In other words, in this embodiment, the method according to the invention allows for a "dulling" of the previously polished part, resulting in a semi-matt state.

[0031] In one embodiment, the particle size of the abrasive power, powder (i.e. its largest dimension) is in the range of 5 μm to 50 μm, preferably in the range of 10 μm to 30 μm, for example in the range of 15 μm to 25 μm.

[0032] In one embodiment, the particles of the abrasive powder are not all the same shape.

[0033] In one embodiment, the particles of the abrasive powder are not all the same size.

[0034] In one embodiment, the abrasive powder used on the drum is in suspension in a liquid.

[0035] In one embodiment, the liquid contains a surfactant, such as an oil and / or a soap, to improve suspension of the abrasive powder in the liquid.

[0036] In one embodiment, the method comprises placing a plurality of decorative parts, for example tens, hundreds or thousands of decorative parts, into a drum.

[0037] In one embodiment, the method also includes placing media or "chips" having a maximum dimension in the range of 0.3 mm to 15 mm into the drum along with the decorative parts. The media may be cylindrical or other suitable shape. In one embodiment, the volume of the media in the drum is about four times the total volume of the decorative parts in the drum.

[0038] In one embodiment, the decorative component is made of at least one of ceramic, cermet, sapphire, and sintered glass.

[0039] In one embodiment, the drum, once used for the method according to the invention, can no longer be used for other different processes (such as polishing) and remains dedicated to the method according to the invention. In fact, the required polishing powder causes deterioration of the walls of the drum and affects the surface condition of the parts to be polished in it. On the other hand, it can be reused for the method according to the invention.

[0040] In one embodiment, the drum is operated for a period of time greater than 3 hours, for example 5 hours or 10 hours.

[0041] The invention also relates to a decorative part having a hardness of 800 HV or more, a flawed surface, a surface profile with an asymmetry in the range of -1 μm to -0.3 μm, a profile height in the range of 0.1 μm to 1.5 μm, a roughness in the range of 0.1 μm to 0.2 μm, and a semi-matt surface.

[0042] In one embodiment, the decorative component is made of ceramic, cermet, sapphire, and / or sintered glass.

[0043] In one embodiment, the distribution of the scratch orientations on the surface is random, i.e. the scratches are not all in the same direction, rather each scratch has a direction that does not necessarily coincide with the direction of another scratch, and these scratches are caused by abrasion, impact or erosion.

[0044] In one embodiment, the density of scratches per unit surface area is uniform across the surface, hi one embodiment, the density is in the range of 100 to 400 scratches for a 100 μm square surface, preferably 180 to 220 scratches for a 100 μm square surface.

[0045] In one embodiment, the flaw defines a valley and a peak.

[0046] In this context, the term "apex" refers to a protrusion, i.e., a protrusion defined between two ends, one end (the proximal end) being larger than the other end (the free or distal end). The apex may be in the shape of a pyramid, a cone, a truncated pyramid, a truncated cone, etc.

[0047] The apexes may be separated by a surface, in particular a valley, i.e. a depression or an opening, defined by at least two surfaces. In a variant, these surfaces are the lateral surfaces of two successive apexes.

[0048] The vertices do not necessarily have to be periodically, i.e. regularly spaced, but may have different cross sections, such as, but not limited to, an inverted V-shape, an inverted U-shape, etc. The semi-matt decorative part according to the invention may comprise vertices of different shapes.

[0049] In one embodiment, the bottom of the valley is located at a substantially constant depth in the semi-matt decorative part according to the invention, however, valleys of various depths can also be envisaged.

[0050] In one embodiment, the average height between the valley depth and the peak height is in the range of 0.1 μm to 1 μm. This average height of the profile elements is defined over the evaluation length. This variable is close to the variable R of the International Organization for Standardization standard ISO 12085 and can be considered as a pattern variable (see ISO 25178).

[0051] In one embodiment, at least one of the height of the peaks and the depth of the valleys is irregular.

[0052] In a preferred embodiment, the scratches are all substantially straight or rectangular, hi another embodiment, at least some of the scratches are not straight, for example they are curvilinear.

[0053] In one embodiment, the length of the scratches on the surface ranges from 1 μm to 70 μm.

[0054] In one embodiment, the width of the scratches on the surface ranges from 1 μm to 5 μm.

[0055] In one embodiment, specular reflection from a part according to the invention is reduced by up to 70% compared to a polished part made of the same material, and diffuse reflection from a part according to the invention is increased by more than 100% compared to a polished part made of the same material.

[0056] In one embodiment, the semi-matt decorative piece is a one-piece piece, ie a piece made in one piece.

[0057] In one embodiment, the semi-matte decorative piece is a link of a bracelet (eg, a watch) or a case of a watch (eg, a watch).

[0058] The invention also relates to timepieces (for example clocks or watches) and to articles of jewellery comprising semi-matt decorative parts according to the invention.

[0059] Embodiments of the invention are illustrated in the accompanying drawings and description. [Brief description of the drawings]

[0060] [Figure 1] FIG. 1 is a perspective view of one embodiment of a semi-matt decorative part according to the present invention. [Diagram 2] FIG. 2 is a partial cross-sectional view of the semi-matt decorative piece of FIG. [Figure 3A] FIG. 3A shows the profile of a surface with zero roughness asymmetry parameter Rsk. [Figure 3B]FIG. 3B shows the profile of a surface with a positive roughness asymmetry parameter Rsk. [Figure 3C] FIG. 3C shows the profile of a surface with a negative roughness asymmetry parameter Rsk. [Figure 4A] FIG. 4A is a perspective view of the surface of a semi-matte decorative piece according to one embodiment. [Figure 4B] FIG. 4B is a perspective view of the surface of the sandblasted decorative part. [Diagram 5] FIG. 5 is a top view of the surface of a semi-matt decorative piece according to one embodiment. [Figure 6A] FIG. 6A is another view of the surface of a semi-matte decorative piece according to one embodiment, seen from above. [Figure 6B] FIG. 6B is a top view of the sandblasted surface of the decorative part. [Figure 7A] FIG. 7A is a top view of a system for measuring the specular reflectance of a part and a polished part according to the invention, and at the bottom shows a top view of the two parts as seen by the system's video camera. [Figure 7B] FIG. 7B shows a top view of a system for measuring the diffuse reflectance of a part and a polished part according to the invention, with a top view of the two parts as seen by the system's video camera shown at the bottom. [Figure 8] FIG. 8 is a flow chart illustrating steps of a method for producing a semi-matt decorative part according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0061] Figure 1 is a perspective view of one embodiment of a semi-matt decorative part 1 according to the invention. In the depicted example, the part 1 is a bracelet link. The part 1 in Figure 1 has a first surface 10 and a second surface 12 opposite the first surface 10. In the depicted embodiment, the second surface 12 is parallel to the first surface 10. In the embodiment of Figure 1, the semi-matt decorative part 1 is a monoblock part (single part).

[0062] Although the semi-matte decorative piece of FIG. 1 is a link having a particular shape and geometry, the invention is not limited to such geometry or form and applies to any other geometry in shape, proportion, and / or size.

[0063] Furthermore, the present invention is not limited to bracelet links (links of a metal wristwatch strap).

[0064] According to the invention, the decorative part 1 has a hardness of 800 HV or more, a scratched surface, a surface profile with an asymmetry in the range of -1 μm to -0.3 μm, a profile height in the range of 0.1 μm to 1.5 μm, a roughness in the range of 0.1 μm to 0.2 μm and a semi-matt surface.

[0065] In one embodiment, the decorative part 1 is made of at least one of ceramic, cermet, sapphire and sintered glass.

[0066] FIG. 2 is a partial view of a cross section of the semi-matt decorative part 1 of FIG. 1 taken along the line AA of FIG.

[0067] The surface 10 of the decorative part 1 consists of valleys 13 and peaks 11. The peaks 11 do not necessarily have to be periodic, i.e. regularly spaced, and may have different cross sections, such as, by way of non-limiting example, an inverted V-shape, an inverted U-shape, etc. The semi-matt decorative part 1 according to the invention may comprise peaks of different shapes.

[0068] In the embodiment of Figure 2, the vertices 11 are irregularly distributed on the surface, in other words, the vertices 11 are not arranged to form rows and columns of mutually perpendicular lines and columns.

[0069] In the embodiment of Figure 2, the bottom 130 of the valley is located at a substantially constant depth in the semi-matt decorative part according to the invention, however, valleys 13 of various depths are equally conceivable.

[0070] In one embodiment, the average height between the depth of the depression and the height of the apex is in the range of 0.1 μm to 1 μm. This average height of the elements of the profile is defined over the evaluation length. This variable is close to the variable R of ISO 12085 and can be considered as a pattern variable (see ISO 25178).

[0071] In one embodiment, at least one of the height of the peaks and the depth of the valleys is irregular.

[0072] Figure 3A shows the profile of a surface with zero arithmetic mean roughness Rsk, Figure 3B shows the profile of a surface with a positive arithmetic mean roughness Rsk, and Figure 3C shows the profile of a surface with a negative arithmetic mean roughness Rsk.

[0073] The asymmetry of the semi-matt decorative part 1 according to the invention is negative (as in FIG. 3C).

[0074] Furthermore, tests carried out by the Applicant have demonstrated that the asymmetry of the semi-matt decorative part 1 according to the invention is more pronounced than that of the sandblasted surface, ranging from -0.3 μm to -0.15 μm, which is reflected in deeper valleys and lower peaks.

[0075] Tests carried out by the Applicant have demonstrated that the overall profile height of the semi-matt decorative part 1 according to the invention is smaller than that of the sandblasted surface, being in the range of 2 μm to 3 μm.

[0076] Tests carried out by the Applicant have demonstrated that the arithmetic mean roughness of the contour of a semi-matt decorative part 1 according to the invention is smaller than that of a sandblasted surface and is in the range of 0.3 μm to 0.5 μm.

[0077] In one embodiment, the average height between the valley depth and the peak height of the semi-matt decorative part 1 according to the invention ranges from 0.1 μm to 1 μm.

[0078] Tests carried out by the Applicant have demonstrated that the average height between the valley depth and the peak height of the semi-matt decorative part 1 according to the invention is lower than that of a sandblasted surface, which is in the range of 1.3 μm to 2 μm.

[0079] Figure 4A is a perspective view of the surface of a semi-matt decorative part according to one embodiment, and Figure 4B is a perspective view of the surface of a sandblasted decorative part. Figures 4A and 4B show the difference in roughness between the surfaces according to measurements.

[0080] The sandblasted surfaces considered during the tests mentioned in connection with Figures 4B and 6B are surfaces of parts (in particular parts made of the same material as the semi-matt parts of Figures 4A and 6A) having a hardness of 800 HV or more obtained by sandblasting (with corundum powder), the sandblasting step being followed by a shot blasting step with glass beads, the sandblasted parts having a matt appearance.

[0081] 5 shows a top view of the surface of a semi-matt decorative part 1 according to one embodiment. It is possible to see the scratches resulting from the abrasive powder spread over the surface of the decorative part 1, which are characteristic of decorative parts according to the invention.

[0082] As can be seen in FIG. 5, in one embodiment, the distribution of scratch orientations across the surface is random, i.e., not all scratches are in the same direction; rather, each scratch has a direction that does not necessarily match the direction of another scratch, and these scratches are created by abrasion, impact, or erosion.

[0083] In one embodiment, the density of scratches per unit surface area is uniform across the surface, as can be seen in Figure 5. In one embodiment, the density is in the range of 100 to 400 scratches (locations, number) for a square surface with a side length of 100 μm, and preferably in the range of 180 to 220 scratches for a square surface with a side length of 100 μm, as can be seen in Figure 5.

[0084] In a preferred embodiment, the scratches are all substantially straight or rectangular, In one embodiment, at least some of the scratches are not straight, for example, curvilinear, as can be seen in Figure 5.

[0085] As can be seen in FIG. 5, in one embodiment, the length of the scratches on the surface ranges from 1 μm to 70 μm.

[0086] In one embodiment, the width of the scratches on the surface ranges from 1 μm to 5 μm.

[0087] Figure 6A shows another view from above of the surface of a semi-matt decorative part 1 according to an embodiment. In this embodiment, the semi-matt decorative part 1 has scratches characteristic of a process related to the friction of the abrasive powder on the surface of the decorative part 1. These scratches are not present in a sandblasted surface, which has a granular and uniform appearance, for example, as can be seen in Figure 6B. Figure 7A shows, at the top, a system 201 for measuring the specular reflection from a part 1 according to the invention and from an abraded part 1' made of the same material, and, at the bottom, a view from above of the two parts 1, 1' as seen by the video camera 22 of the system 201.

[0088] The system 201 comprises a light source 20 and a video camera 22. The video camera 22 is positioned at an angle α equal to the angle of incidence α of the light from the light source 20 on the surface of the part 1 or 1' relative to a normal n to the surface of the part 1 or 1'.

[0089] FIG. 7B shows, at the top, a system 202 for measuring the diffuse reflectance of a part 1 and a polished part 1′ according to the present invention, and, at the bottom, a view from above of the two parts 1, 1′ as seen by the video camera 22 of the system 202.

[0090] System 201 also includes a light source 20 and a video camera 22, but the video camera 22 is positioned at an angle β that is not equal to (and, in the illustrated case, is less than) the angle of incidence α of light from the light source 20 on the surface of part 1 or 1' relative to a normal n to the surface of part 1 or 1'.

[0091] Measuring the grey level (grey density) of the images captured by the video cameras 22 of the two systems allows a quantitative comparison of the surfaces.

[0092] Tests carried out by the Applicant with a part 1 according to the invention (color black and white) relative to a polished part 1' (color black and white) made of the same material show that the specular reflection of the part according to the invention is reduced by up to 69% compared to the polished part, and the diffuse reflection of the part according to the invention is increased by more than 100%, for example up to 113%, compared to the polished part. In one embodiment, the semi-matt decorative part 1 is a bracelet link (for example of a watch) or a watch case (for example a watch case).

[0093] The invention also relates to a watch and / or an article of jewellery comprising a semi-matt decorative piece 1 according to the invention.

[0094] FIG. 8 is a flow chart of steps in a method for producing a semi-matt decorative part according to one embodiment of the present invention.

[0095] The method for producing a semi-matt decorative part according to the present invention comprises the following steps: - procuring a decorative part (step 100), the decorative part having a hardness of 800 HV or more; - placing said decorative part in a drum containing an abrasive powder of at least one material selected from the group consisting of diamond, boron nitride, silicon carbide, alumina and boron carbide (step 200); - operating the drum for at least 3 hours, moving the decorative part at an average speed between 0.5 m / min and 1.5 m / min, which makes it possible to obtain a semi-matt surface and a surface profile with an asymmetry ranging from -1 μm to -0.3 μm, a profile height ranging from 0.1 μm to 1.5 μm and a roughness ranging from 0.1 μm to 0.2 μm (step 300); Equipped with.

[0096] This solution therefore provides for a step of tumbling (allowing repeated uncontrolled falls) with abrasive powder of at least one material among certain types of abrasives, namely diamond, boron nitride, silicon carbide, alumina and boron carbide.

[0097] This abrasive powder has the special property that its particles do not break down much or at all during tumbling (during multiple free falls). This prevents the tumbling from becoming an abrasive process during tumbling. The parts actually produced are semi-matt parts, not polished parts.

[0098] In one embodiment, the method includes the step of unloading the semi-matte decorative part from the drum (not shown).

[0099] In one embodiment, the method essentially comprises a step of washing the drum (not shown) subsequent to the step of unloading the drum.

[0100] In one embodiment, the method essentially comprises a step of washing the semi-matt decorative piece (not shown) following the step of unloading the drum.

[0101] In one embodiment, the method essentially comprises a step (not shown) of inspecting the semi-matt decorative part 1 following the step of unloading the drum, for example an inspection step.

[0102] In one embodiment, the method comprises a step of polishing the decorative part (not shown), which essentially precedes the drum-mounting step 200. In other words, in this embodiment, the method according to the invention allows for a "dulling" of the previously polished part, resulting in a semi-matt state.

[0103] In one embodiment, the particle size of the abrasive powder (i.e. its largest dimension) is in the range of from 5 μm to 50 μm, preferably in the range of from 10 μm to 30 μm, such as in the range of from 15 μm to 25 μm.

[0104] In one embodiment, the particles of the abrasive powder are not all the same shape.

[0105] In one embodiment, the particles of the abrasive powder are not all the same size.

[0106] In one embodiment, the abrasive powder used on the drum is in suspension in a liquid.

[0107] In one embodiment, the liquid contains a surfactant, such as an oil and / or a soap, to improve suspension of the abrasive powder in the liquid.

[0108] In one embodiment, the method comprises placing a plurality of decorative parts, for example tens, hundreds or thousands of decorative parts, into a drum.

[0109] In one embodiment, the method also includes placing media or "chips" having a maximum dimension in the range of 0.3 mm to 15 mm into the drum along with the decorative parts. These media may be cylindrical in shape or any other suitable shape. In one embodiment, the volume of the media in the drum is about four times the total volume of the decorative parts in the vibrating drum.

[0110] In one embodiment, the decorative component is made of at least one of ceramic, cermet, sapphire, and sintered glass.

Claims

1. 1. A method for producing a semi-matt decorative part, said method comprising: - a step (100) of procuring a decorative part, said decorative part having a hardness of at least 800 HV; - placing said decorative part in a drum containing abrasive powder of at least one material chosen from the group consisting of diamond, boron nitride, silicon carbide, alumina and boron carbide (200); - operating the drum for at least 3 hours, moving the decorative part at an average speed between 0.5 m / min and 1.5 m / min (300), thereby obtaining a semi-matt surface and a surface profile with an asymmetry (Rsk) ranging from -1 μm to -0.3 μm, a profile height (Rt) ranging from 0.1 μm to 1.5 μm and a roughness (Ra) ranging from 0.1 μm to 0.2 μm; A method for manufacturing a semi-matt decorative part, comprising:

2. The method of claim 1, wherein the particle size of the abrasive powder is in the range of 5 μm to 50 μm, preferably in the range of 10 μm to 30 μm, for example in the range of 15 μm to 25 μm.

3. The manufacturing method according to claim 1 or 2, wherein the abrasive powder is suspended in a liquid.

4. The method of claim 3 , wherein the liquid comprises a surfactant.

5. The method of claim 1 or 2, further comprising a step of polishing the decorative part before the drum mounting step (200).

6. 3. The method of claim 1 or 2, further comprising placing a medium having a maximum dimension in the range of 0.3 mm to 15 mm in the drum together with the decorative component.

7. 3. The manufacturing method according to claim 1, wherein the decorative part is made of at least one of ceramic, cermet, sapphire, and sintered glass.

8. It has a hardness of over 800HV, It has a surface with multiple scratches, a surface profile having an asymmetry (Rsk) in the range of -1 μm to -0.3 μm, a profile height (Rt) in the range of 0.1 μm to 1.5 μm, and a roughness (Ra) in the range of 0.1 μm to 0.2 μm, thereby rendering the surface semi-matt; Decorative part (1).

9. 9. A decorative element (1) according to claim 8, wherein said decorative element is made of at least one of ceramic, cermet, sapphire and sintered glass.

10. 10. Decorative part (1) according to claim 8 or 9, wherein the distribution of the directions of the scratches on the surface is irregular.

11. Decorative part (1) according to claim 8 or 9, wherein the density of the scratches per unit surface area is uniform over the surface.

12. 10. Decorative part (1) according to claim 8 or 9, wherein the scratches define valleys and peaks, and the average height between the depth of the valleys and the height of the peaks is in the range of 0.1 μm to 1 μm.

13. 10. Decorative part (1) according to claim 8 or 9, wherein at least one of the heights of the peaks and the depths of the valleys is irregular.

14. the length of the scratches on the surface is in the range of 1 μm to 70 μm; the width of the scratches on the surface is in the range of 1 μm to 5 μm; 10. Decorative part (1) according to claim 8 or 9, wherein said decorative part (1) is at least one of:

15. A watch or jewelry item equipped with a decorative component according to claim 8 or 9.

Images