阅读说明：本技术 粉末接触构件及粉末接触构件的表面处理方法 (Powder contact member and surface treatment method for powder contact member ) 是由 间瀬恵二 石桥正三 近藤祐介 于 2020-02-27 设计创作，主要内容包括：本发明旨在提供粉末接触构件及粉末接触构件的表面处理方法,即使在与表面接触的粉末不仅是单个颗粒的形式而且是层的形式时,所述粉末接触构件也能够防止粉末的粘附,并且所述粉末接触构件具有高的流动性。本发明的粉末接触构件具有与粉末接触的表面并且在所述表面上进行表面处理,所述粉末接触构件的特征在于,所述表面的算术平均峰曲率Spc(1/mm)为150～400,所述表面的峰密度Spd(个/mm<Sup>2</Sup>)为10000～180000,所述表面的均方根梯度Sdq为0.05～0.30,并且所述表面的算术平均高度Sa(μm)为0.02～3.00。(The present invention aims to provide a powder contact member capable of preventing adhesion of powder even when the powder in contact with a surface is not only in the form of a single particle but also in the form of a layer, and having high fluidity, and a surface treatment method of the powder contact member. Powder contact of the inventionThe member has a surface in contact with a powder and is subjected to a surface treatment on the surface, the powder contact member being characterized in that the surface has an arithmetic mean peak curvature Spc (1/mm) of 150 to 400 and a peak density Spd (number/mm) of the surface 2 ) 10000 to 180000, the root mean square gradient Sdq of the surface is 0.05 to 0.30, and the arithmetic average height Sa (mum) of the surface is 0.02 to 3.00.)

1. A powder contact member which has a surface to be brought into contact with a powder and on which surface treatment is performed, wherein

Arithmetic mean peak curvature Spc of said surface(1/mm) is 150 to 400, and the peak density Spd (pieces/mm) of the surface²) 10000 to 180000, the root mean square gradient Sdq of the surface is 0.05 to 0.30, and the arithmetic average height Sa (mum) of the surface is 0.02 to 3.00.

2. The powder contact member of claim 1, wherein

The powder contact member is formed of a steel material.

3. The powder contact member of claim 1, wherein

The powder contact member is formed of a ceramic material.

4. The powder contact member according to any one of claims 1 to 3, wherein

The surface treatment is a sand blasting process.

5. The powder contact member according to any one of claims 1 to 3, wherein

The surface treatment is any one of hand polishing, grinding, buffing, CMP, laser processing, etching, and cutting.

6. A method of surface treating a powder contact member having a surface in contact with a powder, the method comprising:

subjecting the surface to a surface treatment so that the arithmetic mean peak curvature Spc (1/mm) of the surface is 150 to 400 and the peak density Spd (pieces/mm) of the surface is 150 to 400²) 10000 to 180000, the root mean square gradient Sdq of the surface is 0.05 to 0.30, and the arithmetic average height Sa (mum) of the surface is 0.02 to 3.00.

7. The surface treatment method of a powder contact member according to claim 6, wherein

The surface treatment is a sand blasting process.

8. The surface treatment method of a powder contact member according to claim 7, wherein

The abrasive used in the blasting process is: an elastic abrasive obtained by dispersing abrasive grains into an elastic material; or a resilient abrasive obtained by adhering the abrasive grains to the surface of a core formed of the elastic material.

9. The surface treatment method of a powder contact member according to claim 7, wherein

The abrasive used in the blasting process is a metal-based abrasive or a ceramic-based abrasive.

10. The surface treatment method of a powder contact member according to any one of claims 7 to 9, wherein

The grain size of the abrasive used in the sand blasting process is #30 to # 20000.

11. The surface treatment method of a powder contact member according to any one of claims 7 to 9, wherein

The abrasive used in the sand blasting process is sprayed under the conditions that the spraying pressure is 0.01-0.5 MPa and the spraying distance is 50-150 mm.

12. The surface treatment method of a powder contact member according to claim 10, wherein

The abrasive used in the sand blasting process is sprayed under the conditions that the spraying pressure is 0.01-0.5 MPa and the spraying distance is 50-150 mm.

13. The surface treatment method of a powder contact member according to claim 6, wherein

The surface treatment is any one of hand polishing, grinding, buffing, CMP, laser processing, etching, and cutting.

Technical Field

The present invention relates to a powder contact member (e.g., a hopper, etc.) for a portion that comes into contact with powder in a device or an apparatus that handles supply, conveyance, or measurement of powder, and that has a surface that prevents adhesion of powder by surface treatment and has improved powder flowability, and a surface treatment method of the powder contact member.

Background

The powder often tends to adhere to and accumulate on the surface of the component in contact with the powder, causing various problems. For example, in the case of repeatedly supplying a predetermined amount of powder stored in a hopper, when the powder adheres to the surface of the hopper and accumulates, the following problems occur: the flow rate of the powder becomes unstable and a predetermined amount of the powder cannot be repeatedly supplied.

In order to cope with the above problems, various inventions for solving the problems caused by the above-described powder adhesion and accumulation have been proposed.

For example, japanese patent No. 4064438 discloses an invention relating to a steel member for a powder processing apparatus, which enhances the ability to peel and slide powder from a steel surface by providing predetermined protrusions and depressions on the steel surface in contact with the powder, thereby preventing adhesion of the powder. Specifically, the following steel member for a powder treatment apparatus is disclosed: the steel member has a surface that is in contact with a powder that includes particles or aggregates of particles having an average particle diameter or an average outer diameter of 20 μm or less. Further, on the surface in contact with the powder, predetermined projections and depressions are formed. The pitch of the protrusions and depressions is smaller than the average particle diameter or average outer diameter of the particles or particle aggregates constituting the powder, the pitch of the protrusions and depressions is in the range of 1 μm or less, and the ratio between the height of the protrusions and depressions and the pitch of the protrusions and depressions is 0.0005 or more, so that the particles or particle aggregates can make point contact with the protrusions.

Further, japanese patent application laid-open No. 2015-189030 discloses an invention relating to a powder adhesion preventing member that prevents adhesion of powder even in the case where the particle diameter of the powder is small. Specifically, a powder adhesion preventing member having the following structure is described: wherein at least one surface of the base body has a minute projection structure including a minute projection group in which a plurality of minute projections are closely arranged and each of the minute projections is formed of a hardened material having a resin component, an average value of distances between adjacent minute projections is 500nm or less, a cross-sectional area occupancy rate of a material portion forming the minute projections in a horizontal cross section gradually and continuously increases as approaching a deepest portion of the minute projection from a top of the minute projection when the minute projections are assumed to be cut by a horizontal plane orthogonal to a depth direction of the minute projection, and a static contact angle of pure water on a surface on a side of the minute projection structure is 60 ° or less as measured by a half angle method. Further, with respect to the particle diameter of the powder to be treated, publication 2015-189030 describes that the powder adhesion preventing member is suitable for use with a powder having a particle diameter of 0.1 μm to 30 μm.

Further, japanese patent application laid-open No. 2017-119902 discloses an invention relating to a powder adhesion preventing titanium member capable of preventing powder adhesion while maintaining the strength of a surface in contact with powder. Specifically, a powder adhesion preventing titanium member is described that includes a surface layer portion that is formed of any one of nitride, carbide, and carbonitride, and that has a hardness higher than that of an inner portion and has an uneven surface that contacts the powder. The uneven surface has an arithmetic average roughness Ra of 0.4 [ mu ] m or more and 2.0 [ mu ] m or less, and a Vickers hardness of a surface layer portion of 400 or more. Further, with respect to the powder to be treated, publication 2017-119902 describes silver particles having a median diameter of 1.5 μm, nickel particles having a median diameter of 2.5 μm, a powder coating having a median diameter of 23 μm, and alumina having a median diameter of 8 μm in examples.

Japanese patent application laid-open No. 2017-128101 discloses an invention relating to a powder adhesion preventing member capable of preventing powder adhesion while maintaining the strength of a surface in contact with powder. Specifically, a powder adhesion preventing member is described which includes: the film has nickel as a main component (may further contain at least one of phosphorus, boron, tungsten, molybdenum, and cobalt), and has an uneven surface in contact with the powder. The uneven surface has an arithmetic average roughness Ra of 0.2 [ mu ] m or more and 1.6 [ mu ] m or less, and the Vickers hardness of the film is 400 or more. It is to be noted that publication 2017-128101 describes that the film may contain inorganic fine particles exhibiting wear resistance or fine particles exhibiting lubricity, and with respect to the powder to be treated, silver particles having a median diameter of 1.5 μm, copper particles having a median diameter of 22.3 μm, PTFE particles having a median diameter of 0.3 μm, and alumina particles having a median diameter of 8 μm are also described in the examples.

However, the invention described in the above-described related art has the following problems.

First, the invention described in patent 4064438 has the problem of not being applicable to powders having a size greater than 20 μm. For example, the size of the edible flour is about 30 μm to 40 μm.

Further, the invention described in publication 2015-.

The invention described in publication 2017-119902 can be applied to a member made of titanium, but has a problem that the invention cannot be applied to a member made of SUS (stainless steel) which is generally used as a material of a powder processing apparatus.

The invention described in publication 2017-128101 has a problem that the film may peel off and become foreign matter.

Further, in each of the inventions described in the patents 4064438, 2015-189030, 2017-119902, and 2017-128101, the shape of the surface in contact with the powder is determined by using a two-dimensional index (two-dimensional roughness parameter) representing the uneven state of a cross section orthogonal to the surface.

When the influence of the Surface Roughness and Type of the Substrate Material "(Measurement of the Adhesive Force between particles and Substrate by Impact Separation method) of the Measurement of the Impact Force between the particles and the Substrate Material and the Type of the Substrate Material (chem. phase. Bull.41(9)1621-1625(1993) https:// www.jstage.jst.go.jp/particle/cpb 1958/41/9/41_9_ 1621// pdf/-char/en) are taken as examples, it is reported that the adhesion between a flat Surface with a certain degree of Roughness and individual particles decreases sharply when the arithmetic average Roughness Ra (two-dimensional Roughness parameter) increases and gradually decreases as the adhesion increases from a certain value.

Also in the present invention, the surface in contact with the powder requires a two-dimensional roughness of a certain degree or more, and therefore, in the case of regarding the powder as a single particle, each of the above-described prior arts has an effect of reducing the adhesion.

However, as a result of intensive studies conducted by the inventors, it has been found that, at a position where powder is actually handled, the powder flows on a hopper or a chute in a state where the powder is not in the form of individual particles but in the form of a layer (particle layer), and therefore, it is necessary to consider surface contact between the particle layer and a contact surface (flat surface), and in the case of considering the surface contact, a two-dimensional index (two-dimensional roughness parameter) such as a line roughness parameter (JISB0601) which is generally used in the existing papers and the above-described related art is not appropriate.

Disclosure of Invention

Technical problem to be solved by the invention

In view of the above-described problems, as a result of extensive research and development to be described later, the present invention has been made by focusing attention on a three-dimensional roughness parameter (texture, in other words, intrinsic quality) of a surface in contact with a powder, and an object of the present invention is to provide a powder contact member which prevents powder from adhering even when the powder in contact with the surface is not only in the form of a single particle but also in the form of a layer (particle layer), and which has high fluidity, and a surface treatment method of the powder contact member.

Technical scheme for solving technical problem

In order to achieve the above object, the powder contact member according to the present invention has a surface to be in contact with powderAnd a surface treatment is performed on the surface, the powder contact member being characterized in that the surface has an arithmetic mean peak curvature Spc (1/mm) of 150 to 400, and a peak density Spd (number/mm) of the surface²) 10000 to 180000, the root mean square gradient Sdq of the surface is 0.05 to 0.30, and the arithmetic average height Sa (mum) of the surface is 0.02 to 3.00.

The powder contact member may be formed of a steel material or a ceramic material.

Preferably, the surface treatment is a sand blasting process, however, any one of hand polishing (hand polishing), grinding (lapping), buffing, CMP, laser processing, etching, and cutting may be also used.

The surface treatment method of a powder contact member having a surface in contact with a powder according to the present invention includes:

subjecting the surface to a surface treatment so that the arithmetic mean peak curvature Spc (1/mm) of the surface is 150 to 400 and the peak density Spd (pieces/mm) of the surface is 150 to 400²) 10000 to 180000, the root mean square gradient Sdq of the surface is 0.05 to 0.30, and the arithmetic average height Sa (mum) of the surface is 0.02 to 3.00.

In the method of the present invention, the surface treatment is preferably a sand blasting process.

Preferably, the abrasive used in the blasting process is: an elastic abrasive obtained by dispersing abrasive grains into an elastic material; or a resilient abrasive obtained by adhering the abrasive grains to the surface of a core formed of the elastic material.

Alternatively, the abrasive used in the blasting process may be a metal-based abrasive or a ceramic-based abrasive.

The particle size of the abrasive used in the blasting process is preferably #30 to # 20000.

Preferably, the abrasive used in the blasting process is sprayed under a spraying pressure of 0.01 to 0.5MPa and a spraying distance of 50 to 150 mm.

The surface treatment may be any of manual polishing, grinding, buffing, CMP, laser processing, etching, and cutting, in addition to the blasting process.

Effects of the invention

The above-described powder contact member of the present invention includes a surface (texture) having a predetermined three-dimensional roughness parameter, whereby the powder contact member is advantageous in that adhesion can be effectively prevented, fluidity on the surface is improved, and a particle size range of the powder for the powder contact member can be widely applied not only in the case where the powder on the surface is in the form of a single particle but also in the case where the powder is in the form of a particle layer (layer form).

Further, by using the existing means, the surface treatment for forming the surface (texture) having the three-dimensional roughness parameter defined in the present invention can be performed, and the treatment can be easily performed in a short time.

Further, the present invention is advantageous in that the present invention can be applied to a powder contact member regardless of the material or shape of the powder contact member, and the present invention can be even applied to an existing product (powder contact member) (only a surface having the three-dimensional roughness parameter defined in the present invention needs to be formed by surface treatment).

Furthermore, the present invention has an advantage in that it is not necessary to form a film on the surface, that is, it is not necessary to reform a substance that may cause mixing of foreign substances.

Detailed Description

Hereinafter, embodiments of the present invention will be described.

The present invention forms a surface (texture) having a predetermined three-dimensional roughness parameter described later by surface-treating a surface of the powder contact member, which is in contact with the powder, to prevent adhesion of the powder.

The powder contact member of the present invention is not particularly limited as long as the powder contact member is used for a portion (e.g., a hopper or a chute) that comes into contact with the powder in a device or an apparatus that handles supply, conveyance, and measurement of the powder. Further, the powder contact member may be formed of, for example, metal or ceramic.

Examples of the metal include stainless steel, titanium alloy, aluminum alloy, nickel-based alloy, and various iron alloys, and examples of the ceramic include zirconia, alumina, silicon carbide, quartz, and glass.

Further, as described above, in order to improve the effect of preventing the powder from adhering to the powder contact member, the present inventors have intensively studied the three-dimensional roughness parameter of the surface in contact with the powder and have conducted detailed studies. Based on the knowledge thus obtained, it has been found that, on the surface (texture) of the powder contact member, the number of contact points with the powder present in the form of a particle layer (layer form) is small, and the flow of the particle layer can be improved by providing a space between the particle layer and the surface where an air layer can be present.

Further, however, it has been found that when the curvature of a point at which the particle layer and the flat surface contact each other is high or sharp, the particle layer is easily caught on the tip of the point, and thus a certain degree of roundness (curvature) is required. Further, it has been found that when the gradient of the peak on the surface (texture) is steep, the frictional resistance tends to increase, and therefore the gradient requires a certain degree of softness. Furthermore, it has been found, however, that when the gradient is very moderate or too moderate, there cannot be an air layer between the particle layer and the surface (textured surface), and therefore the gradient needs to have a value within a specific range.

As a result of exhaustive studies based on the above knowledge, it has been found that the surface (texture) in contact with the powder has a predetermined three-dimensional roughness parameter, that is, from the viewpoint of preventing powder adhesion, it is preferable that the arithmetic mean peak curvature Spc of the surface is 150 to 400, the peak density Spd of the surface is 10000 to 180000, the root-mean-square gradient Sdq of the surface is 0.05 to 0.30, and the arithmetic mean height Sa of the surface is 0.02 to 3.00.

It is to be noted that the arithmetic mean peak curvature Spc (unit: 1/mm) is a parameter representing the average of the principal curvatures of the respective peaks on the surface (i.e., the states of the minute protrusions and depressions on the target surface are evaluated as the average of the curvatures of the respective peaks), and is defined in ISO 25178.

The peak density Spd is a parameter indicating the number of peaks per unit area, and is defined in ISO 25178. When Spd (unit: number)/mm²) A large value of (a) usually implies a large number of contact points with another object.

The root-mean-square gradient Sdq is a parameter calculated from the root mean square of the gradient at all points in the defined area (i.e., corresponds to a parameter obtained by applying the root-mean-square gradient Rdq on the roughness curve to the surface), and is defined in ISO 25178.

The arithmetic average height Sa (unit: μm) is a parameter representing an average value of absolute values of height differences between respective points of the surface and the average surface (i.e., a parameter corresponding to a parameter obtained by applying the arithmetic average height Ra of the roughness curve to the surface), and is defined in ISO 25178.

The above units are the same as those of the three-dimensional roughness parameter described in the present specification.

Next, a surface treatment method for forming the above-described surface (texture) of the present invention will be described. It is to be noted that in the present invention, various surface treatment methods can be used.

First, examples of the surface treatment used in the present invention include a sand blast process.

In the blasting process, the surface (texture) having a predetermined three-dimensional roughness parameter of the present invention described above is formed by using one or more abrasives described below.

As the abrasive used in the blasting process, various abrasives can be used, for example, a metal-based abrasive, a ceramic-based abrasive, and an elastic abrasive are suitably used.

Specifically, examples of the material of the metal-based abrasive include steel, high-speed steel, stainless steel, and ferrochromium boron, and examples of the material of the ceramic-based abrasive include alumina, zirconia, zircon, silicon carbide, and glass.

The elastic abrasive material includes: an elastic abrasive obtained by dispersing abrasive grains into an elastic body (base material) such as rubber or an elastomer ("SIRIUS" (registered trademark) manufactured by nippled company; or an elastic abrasive obtained by attaching abrasive grains to the surface of an elastic body ("SIRIUS Z" (registered trademark) manufactured by kakkiso co. It is to be noted that the elastic abrasive obtained by charging the surface of the elastic body with the abrasive grains may also be an elastic abrasive obtained by adhering and fixing the abrasive grains to the surface of the elastic body having self-adhesiveness. Alternatively, the elastic abrasive obtained by charging the surface of the elastic body with the abrasive grains may also be an elastic abrasive obtained by adhering and fixing the abrasive grains to the surface of the elastic body after applying the adhesive to the surface of the elastic body.

Further, as the above-mentioned elastic abrasive obtained by dispersing abrasive grains into an elastic main body (base material), the following abrasive may be used: for example, an elastic abrasive obtained by mixing and dispersing 10 to 90 wt% of abrasive grains into 90 to 10 wt% of a base material serving as an elastic body; an elastic abrasive obtained by mixing 70 wt% or more of abrasive grains into a matrix material; and elastic abrasive materials obtained by further adding and mixing coloring materials such as dyes or pigments to the above elastic abrasive materials, or elastic abrasive materials obtained by adding and mixing fluorescent coloring agents and/or fragrances and antibacterial agents in addition to the coloring materials to the above elastic abrasive materials.

Further, as the above-mentioned elastic abrasive obtained by charging the surface of the elastic body with abrasive grains, for example, the following elastic abrasive may be used: an elastic abrasive material including a core portion having a rubber hardness of 30 or less and having a predetermined particle diameter, and made of a crosslinked polyrotaxane compound having self-adhesiveness, and an abrasive grain layer formed on a surface of the core portion, and having a masonry structure of a plurality of abrasive grains having an average particle diameter of 0.1 to 12 μm and bonded to each other in a thickness direction by the crosslinked polyrotaxane compound; an elastic abrasive material having a core portion with a compression set of 5% or less and a vibration absorption characteristic of 1Hz to 100kHz (tan) of 0.3 or more; a resilient abrasive having a layer of abrasive particles with a thickness less than 1/4 of the minor axis of the resilient abrasive; an elastic abrasive material having a rubber hardness of 10 or less in the core; an elastic abrasive material having a core compression set of 1% or less; an elastic abrasive of a crosslinked polyrotaxane compound obtained by crosslinking one compound selected from the group consisting of a polycarbonate diol and an acrylate copolymer with a polyrotaxane; an elastic abrasive in which a crosslinked polyrotaxane compound is crosslinked by using a crosslinking agent containing an isocyanate compound; obtaining an elastic abrasive of polyrotaxane by passing polyethylene glycol through an opening of an α -cyclodextrin molecule and coupling an adamantane group to each end of the polyethylene glycol; an elastic abrasive material in which a part of the hydroxyl groups of the α -cyclodextrin molecule is substituted with polycaprolactone groups; and an elastic abrasive in which a silane coupling agent is mixed into a crosslinked polyrotaxane compound.

The shape of the above abrasive is not particularly limited, and a spherical abrasive or an abrasive having an irregular shape may be used. As for the size of the abrasive, those having a size falling within a range of #30(500 μm to 600 μm, JIS R6000-12017 sieve test, sieve three-stage + fourth stage) to #20000[0.5 μm (median diameter D50) ] are suitably used: abrasives in a range measured by a laser diffraction scattering method (measuring apparatus: Microtrac X100 manufactured by McKilbert Co.).

Further, in the blasting process used as the surface treatment of the present invention, a compressed gas type blasting apparatus is suitably used.

The compressed gas type blasting apparatus ejects an abrasive (medium) toward a workpiece by using the energy of a compressed gas (air, argon gas, or nitrogen gas) using a nozzle to perform processing.

Examples of the compressed gas type blasting apparatus include: a suction type sand blasting device which sucks abrasive by using negative pressure generated by compressed gas injection and injects the abrasive together with compressed air (for example, SFK-2 manufactured by kakkiso corporation); a gravity type blasting device which sprays abrasive dropped from a tank by compressed air carrying the abrasive (example: SGF-4 manufactured by kakkiso corporation); a direct pressure type blasting apparatus in which compressed air is supplied into a tank containing abrasive, the abrasive delivered by the compressed air in the tank is carried by a flow of the additionally supplied compressed air, and the abrasive is ejected from a blasting gun (example: FDQ-2 manufactured by kakkiso corporation); and a blower type sand blast apparatus in which a direct pressure type compressed gas is generated by a blower unit and is injected (example: LDQ-2 manufactured by kakkiso corporation, japan).

As for the blasting ejection conditions in the case of using the above blasting apparatus, as an example, the ejection pressure is preferably 0.04MPa to 0.6MPa, and the ejection distance is preferably 50mm to 150 mm.

Further, as the surface treatment of the present invention, a surface treatment method other than the above-described blasting process may also be used, and the surface shape (texture) having the three-dimensional roughness parameter defined in the present invention may be formed by using, for example, various polishing processes (manual polishing, grinding, lapping, and CMP (chemical mechanical polishing)), laser processing, etching, and cutting.

In practice, a surface having the three-dimensional roughness parameter defined in the present invention is formed by subjecting a surface in contact with the powder to surface treatment, and a judgment test of the effect of preventing the powder from adhering to the surface is performed. The results of the judgment test are shown below.

As for the test method, each of the workpieces (examples 1 to 4) serving as test targets was subjected to surface treatment to form a surface having a predetermined three-dimensional roughness parameter of the present invention, and then the effect of preventing powder from adhering to the surface was observed.

It is to be noted that, as for the measurement method of the surface roughness after the surface treatment, in the present embodiment, measurement was performed at a measurement magnification of 1000 times using a shape analysis laser microscope (VK-X250 manufactured by keyence corporation). Subsequently, the measurement data were subjected to roughness analysis using the analysis software "multi-file analysis application VK-H1 XM" provided by the laser microscope. Regarding the analysis, first, reference surface setting (reference surface setting creates a surface whose height of a reference surface is zero from height data by the least square method) is performed using an "image processing" function, and then, three-dimensional roughness parameters are calculated in a surface roughness mode.

The contents of the surface treatment performed on the workpieces, the roughness parameter of the surface, the type of powder used to determine whether to prevent the adhesion of the powder, and the observation results (effects) for each workpiece are summarized in the first to fourth tables shown below.