CA1144709A - Flaked metal powders and method of making same - Google Patents
Flaked metal powders and method of making sameInfo
- Publication number
- CA1144709A CA1144709A CA000331297A CA331297A CA1144709A CA 1144709 A CA1144709 A CA 1144709A CA 000331297 A CA000331297 A CA 000331297A CA 331297 A CA331297 A CA 331297A CA 1144709 A CA1144709 A CA 1144709A
- Authority
- CA
- Canada
- Prior art keywords
- particles
- flaked
- finely divided
- divided metal
- weight ratio
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/06—Metallic powder characterised by the shape of the particles
- B22F1/068—Flake-like particles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
- B22F2009/043—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling by ball milling
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
- Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]
Abstract
Abstract of the Disclosure The disclosure describes a method of making flaked metal powders having a narrow particle size distribution, a whiter color and a very high sparkle effect. A heterogeneous liquid system comprising an inert liquid and a lubricant and including a finely divided metal is subjected to attrition in an enclosure in which there are a plurality of attritive elements. An agitator is moved through the elements to dis-place those in its path. In this method, the weight ratio of attritive elements to finely divided metal is between 70:1 and 90:1, the weight ratio of finely divided metal to lubricant is between 100:1 to 20:1 and the weight ratio of inert liquid to finely divided metal is between 0.5:1 to 2.5:1. Flaked Al, Cu, brass, stainless steel, nickel, cupro nickel powders and the like are obtained by this method.
Description
~L 4~
This invention relates to the production of flaked metal powders, especially those having a narrow particle size distribution, whiter color, and a very high sparkle effect. More particularly, the invention relates to aluminum, nickel, stainiess ste~l, brass, cupro nickel, and bronze powders having the above characteristics.
b. Description of Prior Art In my United States Patent No. 3,995,815, entitled "PRODUCTION OF FLAKED METALLIC POWDERS`' there is described a method of making these powders in which the ratio of attri-tive elements to finely divided metal is between 37:1 and 10:1 by weight. As a preferred condition, the ratio of inert liquid to finely divided metal is between 0.5:1 and 1:4 by weight and the ratio of finely divided metal to lubri~
cant is between 30:1 and 1:1 by weight. Although khis process has been found to be quite efficient, it is not possible to produce "flaked metal powders" with a narrow particle size distribution, an improved whiteness, and a very high sparkle ef~ect as required in today's applications, such as in decorative finishes, automotive and appliance applications, paints, inks, plastics, and the like. Recently, there has been disclosed in United States Patent ~o. 3,776,473 and its division U.S. Patent No. 3,901,688, that it is possible to produce aluminum flaked powders with high specular reflectivity by the wet ball milling process. The process is carried out using grinding balls to powder a volume ratio which varies between about 15:1 and 75:1 and grinding balls to milling li~uid volume ratio in the range of about 75)9
This invention relates to the production of flaked metal powders, especially those having a narrow particle size distribution, whiter color, and a very high sparkle effect. More particularly, the invention relates to aluminum, nickel, stainiess ste~l, brass, cupro nickel, and bronze powders having the above characteristics.
b. Description of Prior Art In my United States Patent No. 3,995,815, entitled "PRODUCTION OF FLAKED METALLIC POWDERS`' there is described a method of making these powders in which the ratio of attri-tive elements to finely divided metal is between 37:1 and 10:1 by weight. As a preferred condition, the ratio of inert liquid to finely divided metal is between 0.5:1 and 1:4 by weight and the ratio of finely divided metal to lubri~
cant is between 30:1 and 1:1 by weight. Although khis process has been found to be quite efficient, it is not possible to produce "flaked metal powders" with a narrow particle size distribution, an improved whiteness, and a very high sparkle ef~ect as required in today's applications, such as in decorative finishes, automotive and appliance applications, paints, inks, plastics, and the like. Recently, there has been disclosed in United States Patent ~o. 3,776,473 and its division U.S. Patent No. 3,901,688, that it is possible to produce aluminum flaked powders with high specular reflectivity by the wet ball milling process. The process is carried out using grinding balls to powder a volume ratio which varies between about 15:1 and 75:1 and grinding balls to milling li~uid volume ratio in the range of about 75)9
2:1 to about 1:1.25. This process is very uneconomical, time consuming and, although it produces powders of high sparkle, it has been found that its brightness is not sufficient in thlat when the pigment is treated, the powder i~ not sufficiently white. Furthermore, the size distri-bution is not narrow enough to fully satisfy modern requirements, such as in the automotive paint industry.
It has also been found that while the ratios of ingredients mentioned in U.S. 3,776,473 may be useful for tube mills, the products obtained with the equipment described in my U.S. Patent 3,995,815 using the ratios defined in U.S. 3,776,473 are of very limited value because the fineness range makes them unacceptable.
The applicant has found that it is possible to obtain flaked metal powders having a narrow particle size distri-bution, an improved color and a very high sparkle effect us-ing a combination of weight ratios for attritive elements to finely divided metal, finely divided metal to lubricant and inert liquid to finely divided metal which have not been dis-closed in the prior art.
More particularly, the present invention relates to a method of making flaked metal powders with a narrow particle siz~ distribution, an improved color, and a very high sparkle effect wherein a heterogenous liquid system comprising an inert liquid and a lubricant and including at least one finely divided metal capable of being flaked, is subjected to attrition in an enclosure in which there are a plurality of attritive elements, an agitator being moved throug~
the elements to displace those in its path, wherein the weight ratio of attritive elements to finely divided metal is between 70:1 and 90:1, the weight ratio of finely ~L~4~7()S~
divided metal to lubricant is between 100:1 ~o 20:1, and the weight ratio of inert liquid to finely divided metal is between 0.5:1 to'2.5:1.
The invention also relates to a method wherein said finely divided metal is aluminum.
The invention is also directed to a method wherein said finely divided metal is selected from the group con-sisting of copper, brass, bronze, stainless steel, nickel, cupro nickel.
The invention is further directed to a method wherein said attritive elements comprise metallic balls having diameters between about 0.8 mm and 25.0 mm.
The invention is illustrated by means of the annexed drawing, in which:
FIGURES lA and lB are schematic illustrations of devices used for the continuous recirculation of insufficiently flaked particles, with a bottom or top feed, FIGURE 2 is a schematic illustration of a device according to another embodiment, FIGURE 3 is a schematic illustration of a device according to yet a~other embodiment, FIGURE 4 is a schematic illustration of a device according to a further embodiment, and FIGURE 5 is a curve comparing the whiteness obtained using the present invention and the teaching of the prior art.
~he production of flaked metal powders in accordance with the present invention can be carried out in a suitable apparatus, such as the one disclosed in my United States Patent No. 3,99S,815 dated ~ecember 7, 1976. When utiliz-47~)9 ing such an apparatus, it will be realized that the agitator is made up of a plurality of rotating arms. It has been found to be ad~antageous if the attritive elements are present in the enclosure in an amount to substantially cover the uppermost arm. The attritive elements which are used preferably consist of suitable grinding media such as steel balls.
Preferably, the weight ratio of attritive elements to finely divided metal is about 78:1 to 85:1, the weight ratio of finely divided metal to lubricant is about 20:1 and the weight ratio of inert liquid to finely divided metal is about 0.5:1 to about 1:1, and the volume ratio of attritive elements to inert liquid is about ~:1.
Best results are obtained when the attrition lasts between about 5 minutes and about 120 minutes and when the temperature is maintained at between about 38C and about 50C.
In accordance with a preferred embodiment, the volume ratio of attritive elements to inert liquid is preferably between 70:1 and 3:1.
Preferably, the weight ratio of inert liquid to finely divided metal is 0.5:1 to 2.0:1.
In accordance with yet another preferred embodiment of the invention, the weight ratio of attritive elements to finely divided metal is between 75:1 to 87:l, the weight ratio of finely divided metal to lubricant is between 30:1 to 20:1, the weight ratio of inert liquid to finely divided metal is between 0.5:1 to 1.5:1 and the volume ratio of attritive elements to inert liquid is 40:1 to 5:1.
In accordance with a preferred embodiment of the invention, a separate container is provided for the un-finished flaked metal powders. The flaked metal powders 7~
are continuously fed into this separat~ container and are recirculated from the separate container into the enclosure where grinding takes place, until a uniform size distribution is obtained.
Recirculation from the separate container to the enclos-ure can be carried out by any known means such as with a pump.
The milled product is then pumped to a separation container from which one fraction is separated. The other fraction is further classified through a screen. The oversize is return-ed back to the enclosure for further milling.
According to another embodiment of the invention, after grinding the particles may be subjected to a preliminary screening step in order to separate the particles which have been milled to required size. The oversize particles can then be sent to the separate container from which they are pumped towards the enclosure for further milliny. The screened particles are then pumped into a separation tank where they are further classified into at least two separate sizes:-Product (A) and Product (B).
In accordance with another embodiment of the invention, the ground particles are pumped from the bottom part of the enclosure to be sent to the separate container where the uni-form size flaked particles are separated and those ~hich are insufficiently flaked are recirculated to the enclosure by means of a pump. !
In accordance with another embodiment of the invention, the finely divided metal which is capable of being flaked has been subjected to a preliminary pre-milling treatment in a tube mill before being introduced in the enclosure.
In accordance with yet another embodiment of the inven-tion, there is provided a suspension of the particles which have been subjected to attrition and flaked metal powders 7~3~
having a narrow particle size distribution are removed there-from.
Although this method is applicable mostly to aluminum because of its commercial application, it is understood that it can also be used with copper, brass, bronze, stainless steel, nickel, cupro nickel, ferrochrome, etc. or any metal or alloy which could be flaked.
In accordance with yet another embodiment of the inven-tiDn, the-attritive elements which are used for grinding are made of metallic balls, pre~erably through hardened steel, having diameters between about 0,8 mm and 25.0 mm.
Referring to FIGURES 1 to 4 of the drawings, it will first of all be note~ that the like parts in allIthe Figures are identified by the same references.
FIGURE lA illustrates an enclosure 1 in w~ich there is an agitator 3. The enclosure 1 contains an inert li~uid, a lubricant, a finely divided metal and grinding media such as steel balls. Flaked metal powders are produced by agitating the mixture by means o the agitator 3~ The powders are then allowed to flow down through gravity via overflow drain 4, into a separation tank 4a from which the flaked metal powders having narrow particle size distribution are removed. The particles of a given size are removed using a separator or a screen as taught in my U.S. Patent No~ 3,995,815 and those which are insufficiently flaked are recirculated via duct 7, pump 9 and duct 11 where they are re-introduced into the en-closure 1 through the bottom thereof, in which a new attrition will take place in the enclosure 1.
FIGURE lB is distinguished from Figure lA by the intro-duction of an unfinished product recycle Container 5. The unfinished flakes are continuously recycled in and out of the milling enclosure until a uniform particle size product is obtained. The slurry thus obtained is pumped to a separation container. At least one fraction of uniform size is separated.
The rest is passed through a further classification equip-ment such as a screen. The larger particles which remain after screening are recycled to either the milling enclosure or to the recirculation container.
With reference to FIGURE 2, the ground particles are pumped from the bottom part of the enclosure 1 via duct 11, pump 9 and duct 7, to be sent to the recirculation tank 5 where the insufficiently flaked particles are continuously returned to the milling enclosure until completely milled.
The product thereof is separated as taught in my U.S. Patent ~o. 3,995,815, and those which are insufficiently flaked are recirculated to either the enclosure at the top thereof via duct 17, pump 13 and another duct 19l The screened product can then be introduced into the separation container 5 from where at least two uniform particle siæe fractions could be obtained.
With reference to FIGU~E 3, it will be seen that the particles, after grinding, may be subjected to a preliminary screening step, in order to separate the particles which have been milled to required sizeO These particles can then be sent into a separation container for further classification to at least two products. The oversize particles can then be sent to the enclosure 1 as in the embodiment illustrated in FIGURE 2.
~urnin~ now to FIGURE 4, the finely divided metal which is capable of being flaked is subjected to a preliminary treatment in tube mill 15 before being introduced into the enclosure 1.
The invention will now be illustrated by means of the following examples.
~4~71[)9 EXAMPLE I
A flaking means as described in U.S. Patent 3,995,815 was used. The total volume of the container used was 2 gal.
The speed setting for the rotating arm throughout the pre-sent test series was kept at 185 RPM to standardize the test conditions. Other speed settings could also be used with slight modifications in the other ratios as may be appreciated by anyone skilled in the art. The inert fluid used was varsol* which is a petroleum distillate fraction having a specific gravity of approximately 0.779 gm/cc.
The lubricant used was stearic acid to produce leafing pigments. The feed material used was either atomized or cut foil as per teachings in my above-mentioned U.S. patent.
The attritive elements size used were also standardized to reduce the number of parameters undex consideration. The size was 1/8" or 3.175 mm steel balls.
* trademark 4~139 The time was varied between 5 minut~s and120 minutes.
In all cases, it was kept at not more than 120 minutes, as other tests done with longer times produced products which were unsuitable for the present purpose of obtaining a high :
sparkle.
The series of tests made according to the procedure is tabulated below as TABLE I.
It will be noted that the water coverage was measured by the method described in "Aluminum Paint and Powder" by ~dwards & Roy, Reinhold Publishing Company (1955), pp.
39, 40 and 41.
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Test No. 1 was repeated by varying the metal to lubricant ratio from 20:1 to 40:1 to 60:1 to 80:1 to 100:1. No appreciable differences were observed in the resulting product.
Test No. 2 was repeated by varying the attritive elements to inert liquid ratio from 3:1 by volume to 53:1 by volume or from 19.5~1 to 340:1 by weight.
No appreciable differences were observed in the resulting product.
EXAMPLE II
Standard Conditions for Tube Milling were used with
It has also been found that while the ratios of ingredients mentioned in U.S. 3,776,473 may be useful for tube mills, the products obtained with the equipment described in my U.S. Patent 3,995,815 using the ratios defined in U.S. 3,776,473 are of very limited value because the fineness range makes them unacceptable.
The applicant has found that it is possible to obtain flaked metal powders having a narrow particle size distri-bution, an improved color and a very high sparkle effect us-ing a combination of weight ratios for attritive elements to finely divided metal, finely divided metal to lubricant and inert liquid to finely divided metal which have not been dis-closed in the prior art.
More particularly, the present invention relates to a method of making flaked metal powders with a narrow particle siz~ distribution, an improved color, and a very high sparkle effect wherein a heterogenous liquid system comprising an inert liquid and a lubricant and including at least one finely divided metal capable of being flaked, is subjected to attrition in an enclosure in which there are a plurality of attritive elements, an agitator being moved throug~
the elements to displace those in its path, wherein the weight ratio of attritive elements to finely divided metal is between 70:1 and 90:1, the weight ratio of finely ~L~4~7()S~
divided metal to lubricant is between 100:1 ~o 20:1, and the weight ratio of inert liquid to finely divided metal is between 0.5:1 to'2.5:1.
The invention also relates to a method wherein said finely divided metal is aluminum.
The invention is also directed to a method wherein said finely divided metal is selected from the group con-sisting of copper, brass, bronze, stainless steel, nickel, cupro nickel.
The invention is further directed to a method wherein said attritive elements comprise metallic balls having diameters between about 0.8 mm and 25.0 mm.
The invention is illustrated by means of the annexed drawing, in which:
FIGURES lA and lB are schematic illustrations of devices used for the continuous recirculation of insufficiently flaked particles, with a bottom or top feed, FIGURE 2 is a schematic illustration of a device according to another embodiment, FIGURE 3 is a schematic illustration of a device according to yet a~other embodiment, FIGURE 4 is a schematic illustration of a device according to a further embodiment, and FIGURE 5 is a curve comparing the whiteness obtained using the present invention and the teaching of the prior art.
~he production of flaked metal powders in accordance with the present invention can be carried out in a suitable apparatus, such as the one disclosed in my United States Patent No. 3,99S,815 dated ~ecember 7, 1976. When utiliz-47~)9 ing such an apparatus, it will be realized that the agitator is made up of a plurality of rotating arms. It has been found to be ad~antageous if the attritive elements are present in the enclosure in an amount to substantially cover the uppermost arm. The attritive elements which are used preferably consist of suitable grinding media such as steel balls.
Preferably, the weight ratio of attritive elements to finely divided metal is about 78:1 to 85:1, the weight ratio of finely divided metal to lubricant is about 20:1 and the weight ratio of inert liquid to finely divided metal is about 0.5:1 to about 1:1, and the volume ratio of attritive elements to inert liquid is about ~:1.
Best results are obtained when the attrition lasts between about 5 minutes and about 120 minutes and when the temperature is maintained at between about 38C and about 50C.
In accordance with a preferred embodiment, the volume ratio of attritive elements to inert liquid is preferably between 70:1 and 3:1.
Preferably, the weight ratio of inert liquid to finely divided metal is 0.5:1 to 2.0:1.
In accordance with yet another preferred embodiment of the invention, the weight ratio of attritive elements to finely divided metal is between 75:1 to 87:l, the weight ratio of finely divided metal to lubricant is between 30:1 to 20:1, the weight ratio of inert liquid to finely divided metal is between 0.5:1 to 1.5:1 and the volume ratio of attritive elements to inert liquid is 40:1 to 5:1.
In accordance with a preferred embodiment of the invention, a separate container is provided for the un-finished flaked metal powders. The flaked metal powders 7~
are continuously fed into this separat~ container and are recirculated from the separate container into the enclosure where grinding takes place, until a uniform size distribution is obtained.
Recirculation from the separate container to the enclos-ure can be carried out by any known means such as with a pump.
The milled product is then pumped to a separation container from which one fraction is separated. The other fraction is further classified through a screen. The oversize is return-ed back to the enclosure for further milling.
According to another embodiment of the invention, after grinding the particles may be subjected to a preliminary screening step in order to separate the particles which have been milled to required size. The oversize particles can then be sent to the separate container from which they are pumped towards the enclosure for further milliny. The screened particles are then pumped into a separation tank where they are further classified into at least two separate sizes:-Product (A) and Product (B).
In accordance with another embodiment of the invention, the ground particles are pumped from the bottom part of the enclosure to be sent to the separate container where the uni-form size flaked particles are separated and those ~hich are insufficiently flaked are recirculated to the enclosure by means of a pump. !
In accordance with another embodiment of the invention, the finely divided metal which is capable of being flaked has been subjected to a preliminary pre-milling treatment in a tube mill before being introduced in the enclosure.
In accordance with yet another embodiment of the inven-tion, there is provided a suspension of the particles which have been subjected to attrition and flaked metal powders 7~3~
having a narrow particle size distribution are removed there-from.
Although this method is applicable mostly to aluminum because of its commercial application, it is understood that it can also be used with copper, brass, bronze, stainless steel, nickel, cupro nickel, ferrochrome, etc. or any metal or alloy which could be flaked.
In accordance with yet another embodiment of the inven-tiDn, the-attritive elements which are used for grinding are made of metallic balls, pre~erably through hardened steel, having diameters between about 0,8 mm and 25.0 mm.
Referring to FIGURES 1 to 4 of the drawings, it will first of all be note~ that the like parts in allIthe Figures are identified by the same references.
FIGURE lA illustrates an enclosure 1 in w~ich there is an agitator 3. The enclosure 1 contains an inert li~uid, a lubricant, a finely divided metal and grinding media such as steel balls. Flaked metal powders are produced by agitating the mixture by means o the agitator 3~ The powders are then allowed to flow down through gravity via overflow drain 4, into a separation tank 4a from which the flaked metal powders having narrow particle size distribution are removed. The particles of a given size are removed using a separator or a screen as taught in my U.S. Patent No~ 3,995,815 and those which are insufficiently flaked are recirculated via duct 7, pump 9 and duct 11 where they are re-introduced into the en-closure 1 through the bottom thereof, in which a new attrition will take place in the enclosure 1.
FIGURE lB is distinguished from Figure lA by the intro-duction of an unfinished product recycle Container 5. The unfinished flakes are continuously recycled in and out of the milling enclosure until a uniform particle size product is obtained. The slurry thus obtained is pumped to a separation container. At least one fraction of uniform size is separated.
The rest is passed through a further classification equip-ment such as a screen. The larger particles which remain after screening are recycled to either the milling enclosure or to the recirculation container.
With reference to FIGURE 2, the ground particles are pumped from the bottom part of the enclosure 1 via duct 11, pump 9 and duct 7, to be sent to the recirculation tank 5 where the insufficiently flaked particles are continuously returned to the milling enclosure until completely milled.
The product thereof is separated as taught in my U.S. Patent ~o. 3,995,815, and those which are insufficiently flaked are recirculated to either the enclosure at the top thereof via duct 17, pump 13 and another duct 19l The screened product can then be introduced into the separation container 5 from where at least two uniform particle siæe fractions could be obtained.
With reference to FIGU~E 3, it will be seen that the particles, after grinding, may be subjected to a preliminary screening step, in order to separate the particles which have been milled to required sizeO These particles can then be sent into a separation container for further classification to at least two products. The oversize particles can then be sent to the enclosure 1 as in the embodiment illustrated in FIGURE 2.
~urnin~ now to FIGURE 4, the finely divided metal which is capable of being flaked is subjected to a preliminary treatment in tube mill 15 before being introduced into the enclosure 1.
The invention will now be illustrated by means of the following examples.
~4~71[)9 EXAMPLE I
A flaking means as described in U.S. Patent 3,995,815 was used. The total volume of the container used was 2 gal.
The speed setting for the rotating arm throughout the pre-sent test series was kept at 185 RPM to standardize the test conditions. Other speed settings could also be used with slight modifications in the other ratios as may be appreciated by anyone skilled in the art. The inert fluid used was varsol* which is a petroleum distillate fraction having a specific gravity of approximately 0.779 gm/cc.
The lubricant used was stearic acid to produce leafing pigments. The feed material used was either atomized or cut foil as per teachings in my above-mentioned U.S. patent.
The attritive elements size used were also standardized to reduce the number of parameters undex consideration. The size was 1/8" or 3.175 mm steel balls.
* trademark 4~139 The time was varied between 5 minut~s and120 minutes.
In all cases, it was kept at not more than 120 minutes, as other tests done with longer times produced products which were unsuitable for the present purpose of obtaining a high :
sparkle.
The series of tests made according to the procedure is tabulated below as TABLE I.
It will be noted that the water coverage was measured by the method described in "Aluminum Paint and Powder" by ~dwards & Roy, Reinhold Publishing Company (1955), pp.
39, 40 and 41.
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~1 ~1 ~1 1~ 1 o O O O O O O O O
1:~ a) Il Ln .,1 3 N N N N N N ~ ~J N N N N N ~J N t~l ,~ _ ODo _ ~ 11 . ~ t~ Ln ~ 0 Ln o l~ Ln Ln Ln n Ln Ln n n ~ ~ ~ I
.
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a) ~ ~ ~ ~ Ln ~D 1` 00 ~ o~I ~ ~ ~ n m E~ E~
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I ~ ~ W ~ ~ ~ ~ ~ t~> ~ ~ ~
0~ I
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.~ OOOOoOOOOOOOOO.
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8 ~
o c~ ~ ~ o o o o o o o o o o ~ ~ o o ~ ~ . I ~ ~ ~ ~ ~ ~ ~ ~ ~i ,~ o o ~ ~
ooo ~ O ~ 3 ~ ~ oo 0 oO ~ 1~ ~ r co ~ ~ m l ~d I 1~ CO ~ O ~ ~ ~ ~ u~ CO a~ o ~ ~ l ~4~9 ~ ~
Test No. 1 was repeated by varying the metal to lubricant ratio from 20:1 to 40:1 to 60:1 to 80:1 to 100:1. No appreciable differences were observed in the resulting product.
Test No. 2 was repeated by varying the attritive elements to inert liquid ratio from 3:1 by volume to 53:1 by volume or from 19.5~1 to 340:1 by weight.
No appreciable differences were observed in the resulting product.
EXAMPLE II
Standard Conditions for Tube Milling were used with
3/16ll (3.175 mm) steel balls in a ratio to the metal of 40:1 by weight. The inert suspending fluid (in this case Varsol*) ratio to metal was 1:1, and the metal to lubricant (stearic acid) ratio was 10:1. The temperature range was 105 - 110F. (40.6 - 43.3C.), and the Milling Time 2 hours.
The speed of the agitators was the maximum possible (in this case 100 RPM). No attachment of prongsl rods or baffles was used. The resulting material displayed no flaking or leafing. The resulting product consisted of a wide assort~
ment of particle sizes which impaired the high sparkle effect and rendered a poor colorO
EXAMPLE III
A flaking means as in Example I. The metal, lubricant, - inert fluid, and flaking media ratios used were taken from prior art as applicable to tube mills.
Tha resulting product consisted of a wide assortment of particle sizes which impaired the high sparkle effect and rendered a poor color.
_AMPLE IV
The flaking means were those described in Example I.
The metal, lubricant, inert fluid and flaking media ratios, * trademark 1~4~
as well as the other conditions used were similar to Runs 1, 11 and 15 described in both U.S. Patents 3,776,473 and 3,901,668 and are tabulated below.
Coarse products were obtained in spite of the extended time in Run 15. The quantity of metal to be flaked had to be reduced to accommodate the excessive volume of fluid used. Hence the ratios were of limited usefulness, very uneconomical, and did not yield an acceptable commercial range of products, unlike those products obtained through Example I above.
TA~LE I
Balls to Liquid Metal to Ball to W/Coverage Weight Metal to Metal Lubricant Liquid (-~00 mesh Ratios (weiqht3 (weiqht) (weiqht) (volume) fraction) Run ~1 116.44:1 11.41:1 100:1 1:1 7440 Run ~11 87.36 8.56:1 100:1 1:1 6480 Run ~15 174.72 17.12:1 100:1 1:1 8340 These tests show the higher efficiency of the apparatus used in Example I. However the various combinations of ratios are still not completely satisfactory.
EXAMPLE V
Example I is repeated using other lubricants. The same results are obtained.
In FIGURE 5, area A relates to compounds produced by the method of the invention~ Area B relates to commercial products produced by the method according to U.S. 3,776,473 and U.S. 3,901,668. Area C represents products produced under the conditions of the above U.S. patents using the attritor of my U.S. Patent 3,995,815~
With reference to FIGURE 5, it will be observed that two commercial products produced by the method according to U.S. 3,776,473 and 3,901~688 are inferior insofar as ~47()9 whiteness in comparison to the products produced by the process according to the present invention under the conditions defined in tests ~os. 12, 13 and 14.
On the other hand, a product produced according to the method of U.S. 3,776,473 and U.S. 3,901,668, in the apparatus described in my U~S. Patent 3,995,815 is superior to the commercial products produced by the method of U.S. 3,776,473 and 3,901,688. Also the product is of inferior quality to the ones obtained in tests ~os.
12 and 13.
The speed of the agitators was the maximum possible (in this case 100 RPM). No attachment of prongsl rods or baffles was used. The resulting material displayed no flaking or leafing. The resulting product consisted of a wide assort~
ment of particle sizes which impaired the high sparkle effect and rendered a poor colorO
EXAMPLE III
A flaking means as in Example I. The metal, lubricant, - inert fluid, and flaking media ratios used were taken from prior art as applicable to tube mills.
Tha resulting product consisted of a wide assortment of particle sizes which impaired the high sparkle effect and rendered a poor color.
_AMPLE IV
The flaking means were those described in Example I.
The metal, lubricant, inert fluid and flaking media ratios, * trademark 1~4~
as well as the other conditions used were similar to Runs 1, 11 and 15 described in both U.S. Patents 3,776,473 and 3,901,668 and are tabulated below.
Coarse products were obtained in spite of the extended time in Run 15. The quantity of metal to be flaked had to be reduced to accommodate the excessive volume of fluid used. Hence the ratios were of limited usefulness, very uneconomical, and did not yield an acceptable commercial range of products, unlike those products obtained through Example I above.
TA~LE I
Balls to Liquid Metal to Ball to W/Coverage Weight Metal to Metal Lubricant Liquid (-~00 mesh Ratios (weiqht3 (weiqht) (weiqht) (volume) fraction) Run ~1 116.44:1 11.41:1 100:1 1:1 7440 Run ~11 87.36 8.56:1 100:1 1:1 6480 Run ~15 174.72 17.12:1 100:1 1:1 8340 These tests show the higher efficiency of the apparatus used in Example I. However the various combinations of ratios are still not completely satisfactory.
EXAMPLE V
Example I is repeated using other lubricants. The same results are obtained.
In FIGURE 5, area A relates to compounds produced by the method of the invention~ Area B relates to commercial products produced by the method according to U.S. 3,776,473 and U.S. 3,901,668. Area C represents products produced under the conditions of the above U.S. patents using the attritor of my U.S. Patent 3,995,815~
With reference to FIGURE 5, it will be observed that two commercial products produced by the method according to U.S. 3,776,473 and 3,901~688 are inferior insofar as ~47()9 whiteness in comparison to the products produced by the process according to the present invention under the conditions defined in tests ~os. 12, 13 and 14.
On the other hand, a product produced according to the method of U.S. 3,776,473 and U.S. 3,901,668, in the apparatus described in my U~S. Patent 3,995,815 is superior to the commercial products produced by the method of U.S. 3,776,473 and 3,901,688. Also the product is of inferior quality to the ones obtained in tests ~os.
12 and 13.
Claims (21)
1. A method of making flaked metal powders having a narrow particle size distribution and a very high sparkle effect wherein a heterogenous liquid system comprising an inert liquid and a lubricant and including at least one finely divided metal capable of being flaked is subjected to attrition in an enclosure in which there are a plurality of attritive elements, an agitator being moved through the elements to displace those in its path, wherein the weight ratio of attritive elements to finely diviaed metal is between 70:1 and 90:1, the weight ratio of finely divided metal to lubricant is between 100:1 to 20:1 and the weight ratio of inert liquid to finely divided metal is between 0.5:1 to 2.5:1.
2. A method according to claim 1, wherein said agitator is made up of a plurality of rotating arms, said attritive elements are present in said enclosure in an amount sufficient to substantially cover the uppermost arm.
3. A method according to claim 1, wherein the volume ratio of attritive elements to inert liquid is between 70:1 and 3:1.
4. A method according to claim 1, wherein the weight ratio of inert liquid to finely divided metal is 0.5:1 to 2.0:1.
5. A method according to claim 3, wherein the weight ratio of attritive elements to finely divided metal is between 75:1 to 87:1, ths weight ratio of finely divided metal to lubricant is 30:1 to 20:1, the weight ratio of inert liquid to finely divided metal is 0.5:1 to 1.5:1, the volume ratio of attritive elements to inert liquid is 40:1 to 5:1.
6. A method according to claim 3, wherein the weight ratio of attritive elements to finely divided metal is about 78:1 to 85:1, the weight ratio of finely divided metal to lubricant is about 20:1, the weight ratio of inert liquid to finely divided metal is about 0.5:1 to 1:1, and the volume ratio of attritive elements to inert liquid is about 8:1.
7. A method according to claim 2, wherein said attrition lasts between about 5 minutes and about 120 minutes and is carried out at a temperature between about 37°C. and about 50°C.
8. A method according to claim 1, wherein a separate container is provided for the finished flake metal particles, and comprising the step of feeding said flake metal particles into said separate container and recirculating insufficient-ly flaked particles into said enclosure, until a uniform size distribution is obtained.
9. A method according to claim 6, wherein said in-sufficiently flaked particles are recirculated into said enclosure by means of a pump.
10. A method according to claim 8, wherein after grinding the particles are subjected to a preliminary screening step in order to separate the particles which have been milled to required size, while oversize particles are sent to the separate container from which they are pumped towards the enclosure for further milling.
11. A method according to claim 8, wherein ground particles are pumped from the bottom part of the enclosure to be sent to the separate container where the uniform size flaked particles are separated and those which are insufficiently flaked are recirculated to the enclosure by means of a second pump.
12. A method according to claim 1, wherein said finely divided metal capable of being flaked has been pre-milled in a tube mill before being introduced in said enclosure.
13. A method according to claim 1, wherein said finely divided metal is aluminum.
14. A method according to claim 1, wherein said finely divided metal is selected from the group consisting of copper, brass, bronze, stainless steel, nickel, cupro nickel.
15. A method according to claim 1, wherein said attritive elements comprise metallic balls having diameters between about 0.8 mm and 25.0 mm.
16. A method according to claim 1, which comprises suspending particles which have been subjected to attrition and removing therefrom flaked metal powders having a narrow particle size distribution.
17. Flaked aluminum powders having a narrow particle size distribution and a very high sparkle effect, having color whiteness readings between about 69 and 74, after screen ing, as measured by the Colormaster V, manufactured by MEECO, and, also after screening, having a high uniformity of particles as established by the fact that they contain no more than 0.1% of +325 Mesh particles (44 microns).
18. Flaked nickel powders having a narrow particle size distribution and very high sparkle effect,after screening, a water coverage of between about 3000 and 5000 cm2/g as measured by the method described in "Aluminum Paint and Powder" by Edwards & Roy, Reinhold Publishing Company (1955), pp. 39, 40 and 41, and also after screening, having a high uniformity of particles as established by the fact that they contain no more than 0.1%,of +325 Mesh particles (44 microns).
19. Flaked brass powders having a narrow particle size distribution and very high sparkle effect, after screening, a water coverage of between about 1000 and 5000 cm2/g as measured by the method described in "Aluminum Paint and Powder" by Edwards & Roy, Reinhold Publishing Company (1955), pp. 39, 40 and 41, and also after screening having a high uniformity of particles as established by the fact that they contain no more than 0.1%, of +325 Mesh particles (44 microns).
20. Flaked aluminum powders according to claim 17, having a water coverage of between about 1575 and 12,000 cm2/g as measured by the method described in "Aluminum Paint and Powder" by Edwards & Roy, Reinhold Publishing Company (1955), pp. 39, 40 and 41.
21. Flaked metallic powders selected from the group consisting of aluminum, nickel and brass powders, having a narrow particle size distribution and a very high sparkle effect after screening, and, also after screening, having a high uniformity of particles as established by the fact that they contain no more than 0.1% of +325 Mesh particles (44 microns).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US922,483 | 1978-07-06 | ||
| US05/922,483 US4172720A (en) | 1978-07-06 | 1978-07-06 | Flaked metal powders and method of making same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1144709A true CA1144709A (en) | 1983-04-19 |
Family
ID=25447100
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000331297A Expired CA1144709A (en) | 1978-07-06 | 1979-07-06 | Flaked metal powders and method of making same |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4172720A (en) |
| EP (1) | EP0020350B1 (en) |
| JP (1) | JPS6220244B2 (en) |
| CA (1) | CA1144709A (en) |
| DE (1) | DE2966527D1 (en) |
| WO (1) | WO1980000127A1 (en) |
Families Citing this family (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4482374A (en) * | 1982-06-07 | 1984-11-13 | Mpd Technology Corporation | Production of electrically conductive metal flake |
| US4486225A (en) * | 1982-06-07 | 1984-12-04 | Mpd Technology Corporation | Production of highly reflective metal flake |
| DE3716088A1 (en) * | 1987-04-09 | 1989-02-02 | Muellverbrennungsanlage Wupper | METHOD FOR BURNING IN PARTICULAR MUELL |
| CN1018567B (en) * | 1988-06-30 | 1992-10-07 | 湖南省机械研究所 | Mixed few-differential spider reducer and speed variator |
| JPH0711005B2 (en) * | 1988-09-09 | 1995-02-08 | 昭和アルミパウダー株式会社 | Size-controlled metal powder for metallic pigment and method for producing size-controlled metal powder |
| JPH05506886A (en) * | 1990-03-06 | 1993-10-07 | ユナイテッド ステーツ ブロンズ パウダーズ インコーポレイテッド | Powder metallurgy compositions and improvements thereto |
| JP2575516B2 (en) * | 1990-04-11 | 1997-01-29 | 旭化成メタルズ株式会社 | Aluminum pigment |
| HU208842B (en) * | 1992-04-15 | 1994-01-28 | Miklos Hauska | Method for manufacturing metal paste of caminary structure in mixing mill |
| JP3954024B2 (en) * | 2001-09-06 | 2007-08-08 | 東洋アルミニウム株式会社 | Aluminum flake pigment production method, aluminum flake pigment obtained by the production method, and grinding media used in the production method |
| JP4536075B2 (en) * | 2001-09-06 | 2010-09-01 | 東洋アルミニウム株式会社 | Method for producing aluminum flake pigment |
| GB0502166D0 (en) * | 2005-02-02 | 2005-03-09 | Effectology Ltd | Ink-jet printing process |
| WO2007020364A1 (en) * | 2005-08-12 | 2007-02-22 | Dunwilco (1198) Limited | Process for producing metal flakes |
| GB0516968D0 (en) * | 2005-08-18 | 2005-09-28 | Dunwilco 1198 Ltd | Process |
| GB2440140A (en) * | 2006-07-17 | 2008-01-23 | Dunwilco | Method of making flakes |
| EP2128203A1 (en) * | 2008-05-28 | 2009-12-02 | Eckart GmbH | Die-form metal effect pigments containing copper, method for their manufacture and use |
| KR100901018B1 (en) * | 2008-11-19 | 2009-06-04 | 티엔씨 주식회사 | Apparatus for preparing zinc flake |
| US9321700B2 (en) | 2011-08-04 | 2016-04-26 | University Of Utah Research Foundation | Production of nanoparticles using homogeneous milling and associated products |
| CN105363543A (en) * | 2015-12-16 | 2016-03-02 | 苏州中亚油墨有限公司 | Multi-stage grinding horizontal printing ink grinding machine |
| CN108421983A (en) * | 2018-05-29 | 2018-08-21 | 曲源 | The method for preparing the device of Metal Flake powder and preparing Metal Flake powder using the device |
| CN116571753B (en) * | 2023-07-13 | 2023-10-20 | 长春黄金研究院有限公司 | Preparation method of flaky metal powder |
Family Cites Families (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2002891A (en) * | 1931-06-04 | 1935-05-28 | Metals Disintegrating Co | Bronze, bronze powders, and method of making the same |
| US2017850A (en) * | 1932-03-10 | 1935-10-22 | Aluminum Co Of America | Manufacture of aluminum bronze powder |
| US2080346A (en) * | 1932-06-11 | 1937-05-11 | Tainton Res Corp | Metallic paint |
| US3008656A (en) * | 1958-10-07 | 1961-11-14 | Fred H Jowsey | Grinding |
| US3238048A (en) * | 1963-01-23 | 1966-03-01 | Gen Motors Corp | Ceramics |
| US3322582A (en) * | 1964-07-23 | 1967-05-30 | Beryllium Corp | Process for controlled surface oxidation of beryllium powders |
| US3295766A (en) * | 1964-09-08 | 1967-01-03 | Dow Chemical Co | Grinding of solids |
| US3360203A (en) * | 1965-06-28 | 1967-12-26 | Edward J Smoke | Prereacted raw materials technique for attaining high quality ceramics |
| US3353753A (en) * | 1965-07-22 | 1967-11-21 | Motorola Inc | Cathode ray tube manufacture |
| US3436026A (en) * | 1965-10-13 | 1969-04-01 | Hans Michael Worwag | Method of comminuting solid particles in liquids |
| US3476325A (en) * | 1967-08-01 | 1969-11-04 | British Petroleum Co | Method of grinding metal powder |
| DE1583746A1 (en) * | 1967-09-30 | 1970-09-24 | Metallgesellschaft Ag | Process for the production of aluminum powder for sintering purposes |
| US3539114A (en) * | 1968-05-23 | 1970-11-10 | Du Pont | Milling process for preparing flake gold |
| US3901688A (en) * | 1972-03-27 | 1975-08-26 | Int Nickel Co | Highly reflective aluminum flake |
| US3776473A (en) * | 1972-03-27 | 1973-12-04 | Int Nickel Co | Highly reflective aluminum flake |
| DE2334804B1 (en) * | 1973-07-09 | 1975-01-02 | Pluss Stauffer Ag | Process for the wet grinding of minerals |
| US3941584A (en) * | 1972-09-29 | 1976-03-02 | The International Nickel Company, Inc. | Production of reflective metal flake pigments |
| US3995815A (en) * | 1974-10-25 | 1976-12-07 | International Bronze Powders Ltd. | Production of flaked metallic powders |
| FR2291793A1 (en) * | 1974-11-20 | 1976-06-18 | Alcan Aluminium France | PROCESS FOR GRINDING MATERIAL PARTICLES AND BALL CRUSHER PERFECTED FOR IMPLEMENTING THIS PROCESS |
-
1978
- 1978-07-06 US US05/922,483 patent/US4172720A/en not_active Expired - Lifetime
-
1979
- 1979-07-06 JP JP54501099A patent/JPS6220244B2/ja not_active Expired
- 1979-07-06 CA CA000331297A patent/CA1144709A/en not_active Expired
- 1979-07-06 DE DE7979900780T patent/DE2966527D1/en not_active Expired
- 1979-07-06 WO PCT/US1979/000491 patent/WO1980000127A1/en unknown
-
1980
- 1980-02-12 EP EP79900780A patent/EP0020350B1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| WO1980000127A1 (en) | 1980-02-07 |
| JPS55500504A (en) | 1980-08-07 |
| US4172720A (en) | 1979-10-30 |
| DE2966527D1 (en) | 1984-02-16 |
| JPS6220244B2 (en) | 1987-05-06 |
| EP0020350A4 (en) | 1980-09-29 |
| EP0020350A1 (en) | 1981-01-07 |
| EP0020350B1 (en) | 1984-01-11 |
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