Faucet member and method for manufacturing the same

Abstract

To provide a faucet member capable of making adhered dirt on a surface less noticeable.SOLUTION: A faucet member 1 comprises: a base material body 2; and a decorative layer 3 formed on a predetermined surface of the base material body 2. The base material body 2 is configured such that a base material rough surface 2A having myriad fine unevennesses is formed over an entire predetermined surface. The decorative layer 3 is configured such that a decorative rough surface 3A, which comprises myriad fine unevennesses dependent on an uneven shape of the base material rough surface 2A, is formed on the base material rough surface 2A.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a faucet member and a manufacturing method thereof, and more particularly to a faucet member having a base material body and a decorative layer formed on the surface of the base material body, and a manufacturing method thereof. [Background technology]

[0002] Patent Document 1 discloses a technology for improving the stain resistance of wet area components used in indoor wet environments. Specifically, a DLC coating layer with excellent chemical non-reactivity is formed on the surface of the substrate, making it possible to easily remove limescale even if it adheres to the surface of the wet area component. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-172923 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology described in Patent Document 1 cannot prevent the adhesion of dirt such as water stains and fingerprints, so dirt that adheres to the surface is easily noticeable. Therefore, the present invention provides a faucet component that can make dirt that adheres to the surface less noticeable. [Means for solving the problem]

[0005] In order to solve the above problems, the present invention provides a faucet member and a method for manufacturing the same, as follows: That is, the first aspect of the present invention is a faucet member comprising a base material body and a decorative layer formed on a predetermined surface of the base material body, wherein a roughened base material surface having countless minute irregularities is formed over the entire predetermined surface of the base material body, and the decorative layer is configured such that a roughened base material surface has countless minute irregularities that depend on the irregular shape of the roughened base material surface.

[0006] According to the first aspect of the present invention, the decorative rough surface formed on the surface of the decorative layer depending on the uneven shape of the rough surface of the base material makes stains such as water stains and fingerprints adhering to the surface of the decorative layer less noticeable.

[0007] The second invention of the present invention is a water faucet component according to the first invention, wherein the decorative layer is a DLC coating layer formed by laminating a DLC coating classified as ta-C on the surface of a metal intermediate coating, or a nickel-chromium plating coating layer formed by laminating a chromium plating on the surface of a nickel plating.

[0008] According to the second aspect of the present invention, by forming the decorative layer using a DLC coating layer containing a DLC coating classified as ta-C, the decorative layer can be formed as a high-density, hard coating layer that has excellent appearance-maintaining properties such as abrasion resistance, insulation, heat resistance, and chemical non-reactivity. Furthermore, by forming the decorative layer using a nickel-chromium plating coating layer, the decorative layer can be formed as a coating layer that has excellent appearance-maintaining properties such as corrosion resistance, discoloration resistance, and weather resistance.

[0009] The third invention of the present invention is the first or second invention, wherein the decorative rough surface has a maximum height of 5 to 100 μm, an average interval between irregularities of 10 to 500 μm, and an average number of irregularities of 10 to 100 / mm 2 It is a water faucet component having an uneven shape.

[0010] According to the third aspect of the present invention, the decorative rough surface has the above-described uneven shape, so that stains such as water stains and fingerprints adhering to the surface of the decorative layer can be made less noticeable more effectively.

[0011] The fourth invention of the present invention is a faucet component according to any one of the first to third inventions, wherein the base material body contains 50% or more copper, with the remainder being a copper alloy consisting of lead, zinc, tin, iron, nickel, and antimony.

[0012] According to the fourth invention, stains such as water stains and fingerprints adhering to the surface of the base material body made of the copper alloy having the above-mentioned composition can be appropriately made less noticeable.

[0013] The fifth invention of the present invention is a method for manufacturing a faucet member, which includes a blasting process in which a blasting process is applied to the entire area of ​​a specified surface of a base material body to form a rough base material surface with countless fine irregularities; a mirror finishing process in which another blasting process is applied to the rough base material surface to give a mirror finish; and a decorative layer forming process in which a decorative layer is formed on the specified surface of the base material body to form a decorative layer on the rough base material surface with a decorative rough surface with countless fine irregularities that depend on the uneven shape of the rough base material surface.

[0014] According to the fifth aspect of the present invention, the decorative rough surface formed on the surface of the decorative layer depending on the uneven shape of the rough surface of the base material makes stains such as water stains and fingerprints adhering to the surface of the decorative layer less noticeable. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a plan view schematically showing a water faucet member according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view schematically showing the cross-sectional structure of the water faucet member. [Figure 3] FIG. 4 is a process diagram showing a method of manufacturing a faucet member. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0017] (Faucet component 1) First, a faucet member 1 according to an embodiment of the present invention and a method for manufacturing the same will be described. As shown in Figure 1, the faucet member 1 according to this embodiment is configured as a main body member of a faucet fitting used in indoor plumbing environments. The faucet member 1 may also be the piping of a faucet fitting. As shown in Figure 2, the faucet member 1 comprises a base material body 2 made of a copper alloy and a decorative layer 3 formed on the surface of the base material body 2.

[0018] The decorative layer 3 is configured to selectively apply either a DLC coating layer or a nickel-chrome plating coating layer depending on the application of the faucet member 1. The DLC coating layer is a coating layer formed by laminating a DLC coating classified as ta-C on the surface of a metallic intermediate coating. The nickel-chrome plating layer is a coating layer formed by laminating a chrome plating on the surface of a nickel plating.

[0019] The base material body 2 is made of a copper alloy containing copper as a main component. Specifically, the base material body 2 is made of a copper alloy containing 50% or more copper, with the remainder being lead, zinc, tin, iron, nickel, and antimony. The base material body 2 may be made of pure copper, brass, bronze, cupronickel, or nickel silver. The specific shape of the base material body 2 is not particularly limited, and may be a tubular shape such as a circular pipe or a square pipe, a columnar shape such as a cylindrical or rectangular column, a spherical shape, a box shape, or a plate shape.

[0020] As shown in Fig. 3, the base material body 2 is machined after casting to form a predetermined shape, and then the surface is buffed and finished to a predetermined surface roughness (pre-process S1). The base material body 2 then undergoes a lead removal process S2 and a blasting process S3 to form a base material rough surface 2A with countless fine irregularities on its entire surface (see Fig. 2). Depending on the type of decorative layer 3 formed on its surface, the base material body 2 may then undergo a mirror-finishing process S4 to finish the entire base material rough surface 2A to a mirror-polished state while retaining the irregularities.

[0021] Specifically, when the decorative layer 3 is formed of a DLC coating layer, the base material body 2 is subjected to a mirror-finishing treatment step S4, and the entire base material rough surface 2A is mirror-finished. However, when the decorative layer 3 is formed of a nickel-chromium plating coating layer, the mirror-finishing treatment step S4 of the base material body 2 is omitted. This is because, when nickel-chromium plating is applied to the base material body 2, the base material body 2 is subjected to alkaline cleaning during the nickel plating process, and the surface is finished to remove any work-affected layers.

[0022] Thereafter, depending on the type of decorative layer 3, the base material body 2 is subjected to a cleaning treatment step S5 to remove dirt adhering to its surface and clean it. Specifically, when the decorative layer 3 is formed of a DLC coating layer, the base material body 2 is subjected to a cleaning treatment step S5 to remove dirt adhering to the entire base material rough surface 2A. However, when the decorative layer 3 is formed of a nickel-chromium plating coating layer, the cleaning treatment step S5 for the base material body 2 is omitted. The reason for this is the same as the reason for omitting the mirror-finishing treatment step S4 described above.

[0023] The base material body 2 is then subjected to a decorative layer forming process S6, in which a decorative layer 3 consisting of a DLC coating layer or a nickel-chromium plating coating layer is integrally formed on the rough surface 2A of the base material. This results in a decorative layer 3 having a decorative rough surface 3A on the rough surface 2A of the base material, which is a rough surface with countless fine irregularities depending on the uneven shape of the rough surface 2A of the base material. As a result, the surface of the faucet member 1 consisting of the decorative rough surface 3A can be configured so that even if dirt such as water stains or fingerprints adheres to the surface, this dirt is less noticeable. Each process is described in detail below.

[0024] (Blast treatment process S3) In the blasting process S3, the surface of the base material body 2 is subjected to blasting, and the entire surface of the base material body 2 is provided with a maximum height of 5 to 100 μm, an average spacing between irregularities of 10 to 500 μm, and an irregularity count of 10 to 100 / mm. 2 In this way, a rough base material surface 2A consisting of an uneven shape is formed. If it is desired to form the rough base material surface 2A only in a partial area of ​​the surface of the base material body 2, a masking material made of a resin or rubber sheet (not shown) can be attached to the other areas and then blasted. This allows the rough base material surface 2A to be formed only in the surface area of ​​the base material body 2 other than the area where the masking material is attached.

[0025] The blasting process described above makes it possible to form a rough base material surface 2A with countless fine irregularities arranged all over the surface, even if the base material body 2 has a surface with a complex shape. Examples of blasting devices used in the blasting process include air blasting devices (compressor type, blower type, etc.) that use air to project media (abrasive material), and shot blasting devices that throw media by rotating a motor.

[0026] The depth and surface roughness of the roughened base material surface 2A formed by blasting can be appropriately controlled by adjusting the particle size, shape, material of the media, blasting pressure, blasting density, blasting time, etc. Examples of media materials include zirconium, alumina (white and brown), silicon carbide (green and black), silica sand, iron, copper, stainless steel, zinc, aluminum, garnet, resin, and glass. The media may also be made of an elastic base material coated with fine abrasive grains.

[0027] Examples of the shape of the media include spherical and acute-angled shapes. Examples of the particle size of the media include those of 5 μm to 2 mm. The projection pressure of the media is preferably 0.1 to 0.5 MPa. In order to finish the base material rough surface 2A to an appropriate surface roughness, it is particularly preferable to perform the blasting treatment using media made of zirconium with a particle size of 600 μm, projecting the media onto the base material rough surface 2A at a projection pressure of 0.3 MPa for 15 seconds.

[0028] (Mirror finish processing step S4) In the mirror-finishing process S4, another blasting process (mirror-finishing process) using media with even smaller particle sizes is performed on the entire rough surface 2A of the base material body 2, and the entire surface (rough surface 2A) of the base material body 2 is polished to a mirror-like finish. This mirror-finishing process removes fine scratches that have been left on the surface of the base material body 2 by the previous buffing and blasting processes.

[0029] In the mirror-finishing process step S4, the entire rough base material surface 2A of the base material body 2 is ground to a uniform depth of 2 μm or less. Therefore, even if the entire rough base material surface 2A is mirror-finished after the rough base material surface 2A is formed on the base material body 2 in the previous blasting process step S3, the uneven pattern of the rough base material surface 2A will not disappear.

[0030] The surface roughness of the base material body 2 finished by the mirror finish treatment can be appropriately controlled by adjusting the particle size, shape, material of the media, blasting pressure, blasting density, blasting time, etc. In order to finish the base material rough surface 2A to an appropriate surface roughness, it is particularly preferable to perform the mirror finish treatment using media in which abrasive grains of SDC (metal-coated synthetic diamond) with a particle size of 1 μm are carried around a base material with a particle size of 0.5 mm, and blasting the base material rough surface 2A at a blasting pressure of 0.2 MPa for 5 to 15 minutes.

[0031] Specifically, if the base material body 2 is made of bronze, the media should be projected for 5 to 15 minutes, and if the base material body 2 is made of brass, the media should be projected for 8 to 15 minutes. By performing the mirror finish treatment step S4 in the above manner, it is possible to achieve a mirror finish while suppressing a temperature rise in the base material body 2, and this is suitable as a treatment step to be performed before forming the decorative layer 3.

[0032] (Cleaning process step S5) In the cleaning process step S5, a cleaning method using a hydrocarbon-based cleaning liquid is used to remove and clean the dirt adhering to the surface of the base material body 2. Note that the cleaning process step S5 may be a step of cleaning the surface of the base material body 2 by a cleaning method using an aqueous cleaning liquid, a semi-aqueous cleaning liquid, or a chlorine-, bromine-, or fluorine-based solvent-based cleaning liquid.

[0033] In the cleaning process S5, first, a rough cleaning is performed by water cleaning to remove abrasives adhering to the surface of the base material body 2. Next, a main cleaning is performed by emulsion cleaning to clean the surface of the base material body 2. This emulsion cleaning combines an ultrasonic cleaning method in which water is vibrated by ultrasonic waves with a vacuum cleaning method in which the inside of the cleaning tank is repeatedly depressurized and then abdominally pressurized to a near-vacuum state.

[0034] Combining emulsion cleaning with ultrasonic cleaning makes it possible to effectively clean dirt adhering to the base material body 2. Furthermore, combining emulsion cleaning with vacuum cleaning makes it possible to spread the cleaning liquid to the inside of blind holes and blind holes that cannot be cleaned under atmospheric pressure, thereby effectively cleaning even the small gaps in the base material body 2. In particular, combining vacuum cleaning with ultrasonic cleaning makes the ultrasonic effect stronger than under atmospheric pressure, allowing for more effective cleaning. Note that in addition to or instead of the above cleaning methods, emulsion cleaning may be combined with degassing cleaning, rotational cleaning, swing cleaning, or shower cleaning.

[0035] Combining the degassing cleaning method can further enhance the effectiveness of ultrasound when using ultrasonic cleaning. Combining the rotational cleaning method and the oscillating cleaning method can physically create a flow of cleaning liquid, further enhancing the cleaning effect. It also makes it easier for the ultrasound to hit the surface of the base material body 2 evenly. Other methods for physically creating a flow of cleaning liquid include circulating or bubbling water. Furthermore, by combining the shower cleaning method, it is possible to spray the cleaning liquid on the base material body 2 not only from above, but also from the sides and below, allowing for proper cleaning. Other cleaning methods include high-pressure jet cleaning, spray cleaning, and brush cleaning.

[0036] By the above cleaning, oil and other contaminants adhering to the surface of the base material body 2 are dissolved in the cleaning liquid and dispersed throughout the cleaning liquid. Furthermore, the contaminants adhering to the base material body 2 are dissolved in the cleaning liquid and replaced by the cleaning liquid. Next, in the cleaning process step S5, a process of vapor cleaning is performed on the surface of the base material body 2 as a rinse. In vapor cleaning, the cleaning liquid is boiled and steam is used to clean the contaminants remaining on the surface of the base material body 2 with even greater precision.

[0037] Next, in the cleaning process step S5, a drying process is performed to dry the cleaning liquid remaining on the surface of the base material body 2. This drying process is performed by so-called vacuum drying. Vacuum drying is a well-known method in which the pressure inside the cleaning tank is reduced to near vacuum, rapidly lowering the boiling point of the cleaning liquid and causing the cleaning liquid to dry by bumping. By using vacuum drying, the pressure inside the cleaning tank, which has been heated by the previous vapor cleaning, is reduced, effectively promoting the bumping drying of the cleaning liquid, and the drying process can be performed appropriately so as not to leave stains or the like on the base material body 2.

[0038] The drying process may be performed by hot air drying or suction drying. Hot air drying is a known method of drying the surface of the base material body 2 by sending hot air into the inside of the cleaning tank. Suction drying is a known method of drying the surface of the base material body 2 by sending compressed hot air into the inside of the cleaning tank and simultaneously drawing it out from the opposite side with a suction blower. Hot air drying and suction drying can also be applied to cleaning tanks that use aqueous cleaning liquids and cannot be vacuum dried.

[0039] (Decoration layer film formation process S6) In the decorative layer forming step S6, a decorative layer 3 made of a DLC coating layer or a nickel-chromium plating coating layer is integrally formed on the rough base material surface 2A of the base material body 2. First, the DLC coating layer forming step of forming a DLC coating layer on the rough base material surface 2A will be described below.

[0040] In the DLC coating layer deposition process, first, an intermediate coating deposition process is performed in which a metallic intermediate coating is deposited over the entire area of ​​the rough base material surface 2A of the base material body 2. Next, a DLC coating deposition process is performed in which a DLC coating classified as ta-C is deposited over the entire area of ​​the deposited intermediate coating. In other words, the DLC coating layer deposition process consists of an intermediate coating deposition process in which an intermediate coating is deposited, and a DLC coating deposition process in which a DLC coating is deposited.

[0041] The intermediate coating is interposed between the base material body 2 and the DLC coating formed on its surface, and functions as an intermediate layer to improve adhesion between them. The intermediate coating is formed directly on the rough base material surface 2A of the base material body 2. The intermediate coating can be made of at least one metal selected from the group consisting of nickel, titanium, chromium, tungsten, and silicon.

[0042] The intermediate coating may have a single layer structure made of one metal selected from the above group, or may have a laminate structure made of two or more metals. It is particularly preferable that the intermediate coating be made of titanium, which has excellent adhesion to the base material body 2 and the DLC coating and excellent corrosion resistance.

[0043] In the intermediate coating deposition process, the intermediate coating is deposited in a layered form on the rough base surface 2A of the base material body 2 by a sputtering method classified as a PVD method (physical vapor deposition method). In the intermediate coating deposition process, first, an ion bombardment process using argon ions is performed to remove passivation films such as oxide films and hydroxide films that are exposed on the rough base surface 2A of the base material body 2.

[0044] Next, by sputtering, a negative voltage is applied to a cathode target (film-forming material) in a vacuum into which an inert gas (argon gas) has been introduced, generating a glow discharge, and the gas ions collide with the film-forming material, knocking out particles of the film-forming material that adhere and deposit on the surface of the base material body 2, forming a dense thin film. By forming the intermediate coating by sputtering, a dense, highly adhesive thin film of uniform thickness can be formed on the rough base material surface 2A of the base material body 2 without exposing the base material body 2 to liquid or high-temperature gas.

[0045] The intermediate coating may be formed on the rough base surface 2A of the base material body 2 by an arc ion plating method other than the sputtering method. The arc ion plating method is a known method in which a film-forming material is evaporated in a vacuum, and the positively charged film-forming material is ionized (ionized) by arc discharge, and then attracted to the surface of the base material body 2 to which a negative charge has been applied, thereby forming a film.

[0046] In the DLC coating deposition process, the DLC coating is deposited in a layered form with uniform thickness on the surface of an intermediate coating deposited on the rough base surface 2A of the base material body 2 by vacuum arc deposition, which is classified as a PVD (physical vapor deposition) method. The DLC coating is formed by the vacuum arc deposition method as a coating classified as ta-C, which has the highest proportion of SP-3 structure among DLCs (diamond-like carbons) and is characterized by its highest density and hardness. ta-C is amorphous carbon with a proportion of SP-3 structure of 50% to 90% and a hydrogen content of 5% by mass or less.

[0047] Specifically, the DLC coating is formed by the well-known FCVA (filtered cathodic vacuum arc) method, which is known as a vacuum arc deposition method that can produce films with minimal surface defects. The FCVA method is a well-known method that filters droplets (macroparticles with an SP-2 structure or a similar composition structure), which are electrically neutral evaporated particles that can be emitted from solid graphite, the evaporation source of the cathode target, from the plasma during plasma transport, making them less likely to adhere to the coating when a ta-C coating is deposited on a workpiece by vacuum arc deposition.

[0048] By making it difficult for droplets to adhere to the coating, the coating surface can be formed with minimal irregularities, ensuring geometric uniformity (flatness) and chemical uniformity. As a result, the DLC coating can be formed with a smooth surface and with mechanical properties that are less likely to deteriorate. The DLC coating is preferably formed using the above-mentioned FCVA method so that the surface defects are 20% or less. Furthermore, the DLC coating is preferably formed to a thickness of 0.5 to 5.0 μm and a Vickers hardness of 1,500 to 5,000 Hv. When the thickness of the coating is several tens of nanometers to several tens of μm, the hardness of the coating can be expressed as nanoindentation hardness.

[0049] The DLC coating is formed on the base material body 2 with good adhesion by being placed on the base material body 2 via an intermediate coating. The DLC coating is layered on the intermediate coating to form a decorative layer 3 on the surface of the faucet member 1, as shown in FIG. 2 . The decorative layer 3 has a high-density, hard, and highly abrasion-resistant decorative rough surface 3A with countless fine irregularities that depend on the irregular shape of the base material rough surface 2A of the base material body 2. The DLC coating and the intermediate coating formed below it are each formed in layers with uniform thickness on the base material rough surface 2A of the base material body 2 by the vacuum arc deposition method or sputtering method described above. Therefore, a clearly defined irregular pattern can be formed on the surface of the faucet member 1, i.e., on the decorative rough surface 3A, without having to deeply recess the base material rough surface 2A that is recessed into the base material body 2.

[0050] Next, the nickel-chrome plating layer forming process for forming a nickel-chrome plating layer on the rough surface 2A of the base material will be described. In the nickel-chrome plating layer forming process, nickel plating and chrome plating are performed in this order on the entire surface of the base material body 2, forming a nickel-chrome plating layer having nickel plating and chrome plating in a laminated state. The nickel plating is preferably formed to a thickness of approximately 7 μm. The chrome plating is preferably formed to a thickness of 0.2 to 0.4 μm.

[0051] The base material body 2 has nickel plating layered on its surface, which appropriately enhances its corrosion resistance. Furthermore, the base material body 2 has chrome plating layered on the nickel plating surface, which appropriately enhances its scratch resistance and gives it a beautiful metallic luster. The decorative layer 3 may be formed of a coating layer consisting of only nickel plating or a coating layer consisting of only chrome plating, instead of a nickel-chrome plating coating layer. Nickel plating has excellent adhesion to the copper alloy that constitutes the base material body 2, and is hard, as well as excellent corrosion resistance and heat resistance. Chromium plating serves as a protective film for the nickel plating and is excellent in scratch resistance, light reflectivity, heat reflectivity, and corrosion resistance.

[0052] By forming the nickel-chrome plating film layer, a decorative layer 3 having a decorative rough surface 3A with excellent appearance maintenance performance such as corrosion resistance, discoloration resistance, and weather resistance, which has countless fine irregularities depending on the irregular shape of the base material rough surface 2A of the base material body 2, is formed on the surface of the faucet member 1, as shown in Figure 2. The thickness of each of the nickel plating and chrome plating is not particularly limited as long as it is possible to form the decorative rough surface 3A into a shape with countless fine irregularities depending on the irregular shape of the base material rough surface 2A.

[0053] Other Embodiments Although one embodiment of the present invention has been described above, the present invention is not limited to the configuration shown in the above embodiment, and various modifications, additions, and deletions are possible within the scope of the present invention. For example, the faucet member of the present invention may be any member intended to make stains such as water stains and fingerprints less noticeable even if they adhere to the surface of the decorative layer, and may be applied to members other than the main body of a faucet or piping, such as the handle of a faucet used in indoor and outdoor wet environments. [Explanation of symbols]

[0054] 1 Faucet components 2 Base material body 2A Base material rough surface 3 Decorative layer 3A Decorative rough surface S1 Pre-process S2 Lead removal process S3 Blasting process S4 Mirror finish processing process S5 Cleaning process S6 Decorative layer deposition process

Claims

1. A water faucet member, A base material body and a decorative layer formed on a predetermined surface of the base material body, A faucet member in which a rough base material surface having countless minute irregularities is formed over the entire area of ​​the specified surface of the base material body, the decorative layer is a DLC coating layer formed by laminating a DLC coating classified as ta-C on the surface of a metallic intermediate coating, and a decorative rough base material surface having countless minute irregularities depending on the irregular shape of the rough base material surface is formed.

2. 2. The water faucet member according to claim 1, wherein the decorative rough surface has an irregular shape with a maximum height of 5 to 100 μm, an average irregularity interval of 10 to 500 μm, and a number of irregularities of 10 to 100 / mm 2 .

3. 3. The faucet member according to claim 1, wherein the base material body is a copper alloy containing 50% or more copper, the remainder being lead, zinc, tin, iron, nickel, and antimony.

4. A method for manufacturing a water faucet member, comprising: a blasting process for forming a roughened surface of the base material having countless minute irregularities by blasting the entire surface of a predetermined surface of the base material body; a mirror-finishing process for mirror-finishing the rough surface of the base material by performing another blasting process on the rough surface of the base material; and a decorative layer forming step of forming a decorative layer on the rough surface of the base material by laminating a DLC coating classified as ta-C on the surface of a metallic intermediate coating on the specified surface of the base material body, thereby forming a decorative layer on the rough surface of the base material with a decorative roughened surface that has countless fine irregularities that depend on the irregular shape of the rough surface of the base material.

Images