Packaging and Densitization of Micrometric Powders

Abstract

A method for increasing the density of packaged micrometric powders. The method steps include filling a flexible container with a desired amount of micrometric powder, deaerating the flexible container and contained powder to remove substantially all air therein and achieve a desired vacuum, increasing the density of the contained micrometric powder to achieve a desired density and shape using a molding and at least one force concentrating device. The container includes a single layer of co-extruded polymeric material capable of achieving a hermetic seal even in the presence of an amount of powder contamination at the closure area. The level of vacuum may be chosen to achieve the desired malleability of the resulting compressed micrometric powder. Additional steps include sintering the densitized powder to remove substantially all impurities from the powder.

1 . A method for packaging micrometric powders, the method steps comprising:
 filling a flexible container with a predetermined quantity of a micrometric powder, the flexible container wall comprised of a polymeric material, the flexible container further comprising a first opening through which the powder enters, wherein the first opening is capable of mechanical closure to form a substantially airtight seal even in the presence of a detectable amount of the micrometric powder contamination;   deaerating the flexible container and contained micrometric powder to remove substantially all air from within the powder and the container;   sealing the deaerated flexible container to create a hermetic seal; and   densitizing the micrometric powder by compressing the flexible container and contained micrometric powder within a mold with at least one force-concentrating device to achieve a desired micrometric powder density.   
     
     
         2 . The method of  claim 1 , wherein the amount of air remaining in the flexible container after deaeration is adjusted to attain a desired malleability of the resulting deaerated flexible container and the contained micrometric powder. 
     
     
         3 . The method of  claim 1 , wherein the container wall material is capable of vaporization at a temperature lower than the melting point of the micrometric powder. 
     
     
         4 . The method of  claim 1 , wherein the flexible container wail is a single layer of co-extruded polymeric material. 
     
     
         5 . The method of  claim 1 , wherein the flexible container wall is a single layer of co-extruded polymeric material comprising at least one layer of metallocene film. 
     
     
         6 . The method of  claim 1 , wherein the flexible container wall comprises at least one layer of aluminum film and at least one layer of co-extruded polymeric material. 
     
     
         7 . The method of  claim 1 , wherein the flexible container and the micrometric powder are deaerated using porous probes, the probes comprising a micro-porous covering material sufficient to minimize passage of the micrometric powder. 
     
     
         8 . The method of  claim 1 , wherein the flexible container and contained micrometric powder are deaerated within a vacuum chamber enveloping the flexible container. 
     
     
         9 . The method of  claim 1 , the method steps further comprising:
 deaerating the flexible container and contained micrometric powder using porous metal probes, the probes comprising a micro-porous covering material sufficient to minimize passage of the micrometric powder; and   deaerating the flexible container and micrometric powder within a vacuum chamber.   
     
     
         10 . The method of  claim 1 , the method steps further comprising:
 deaerating, within a vacuum chamber, the flexible container and micrometric powder, using porous metal probes, the probes comprising a micro-porous covering material sufficient to minimize passage of the micrometric powder.   
     
     
         11 . The method of  claim 1 , the method steps further comprising:
 using compressed gas to remove substantially all micrometric powder contamination from the first opening prior to forming the mechanical closure.   
     
     
         12 . The method of  claim 1 , the method steps further comprising:
 sintering the densitized micrometric powder to remove the flexible container and substantially all impurities from the micrometric powder.   
     
     
         13 . The method of  claim 1 , wherein the densitized micrometric powder is graphite powder with a density of approximately 55 lbs/ft 3 . 
     
     
         14 . A method for packaging micrometric powders, the method steps comprising:
 filling a flexible container with a predetermined quantity of a micrometric powder, the flexible container having a wall comprised of a single layer of co-extruded polymeric material;   deaerating the flexible container and contained micrometric powder to achieve a desired level of vacuum within the powder;   densitizing the micrometric powder utilizing at least one force concentrating device; and   sintering the resulting densitized micrometric powder to remove substantially all impurities.   
     
     
         15 . The method of  claim 14 , the method steps further comprising:
 mechanically sealing the flexible container to create a hermetic seal by releasing compressed gas in the seal area to remove substantial all of micrometric powder contamination from the seal area prior to forming the mechanical closure.   
     
     
         16 . The method of  claim 14 , wherein the densitized micrometric powder is graphite powder with a density of approximately 55 lbs/ft 3 . 
     
     
         17 . The method of  claim 14 , wherein the flexible container and contained micrometric powder are deaerated using porous metal probes, the probes being covered with a micro-porous material sufficient to minimize passage of the micrometric powder. 
     
     
         18 . The method of  claim 14 , wherein the flexible container and micrometric powder are deaerated within a vacuum chamber. 
     
     
         19 . The method of  claim 14 , the method steps further comprising:
 deaerating the flexible container and micrometric powder using porous metal probes, the probes comprising a micro-porous covering material sufficient to minimize passage of the micrometric powder; and   deaerating the flexible container and micrometric powder within a vacuum chamber.   
     
     
         20 . The method of  claim 14 , the method steps further comprising:
 deaerating, within a vacuum chamber, the flexible container and micrometric powder using porous metal probes, the probes comprising a micro-porous covering material sufficient to minimize passage of the micrometric powder.