System and Method For Extruding Parts Having Microstructures

Abstract

A manufacturing apparatus for manufacturing extruded parts having microstructures comprising: a support structure; a hopper carried by the support structure for receiving feedstock; an extrusion chamber operatively associated with the hopper for receiving the feedstock from the hopper and melting the feedstock above a feedstock melting temperature; a die carried by the support structure having die microstructures disposed on an inner surface of the die, the die microstructures having a plurality of microfeatures each having an upper surface and a lower surface, the melted feedstock being forced through the die to produce an extrudate having extrudate microstructures; and, a cooling assembly wherein the extrudate microstructures of the pre-cooled extrudate have larger physical dimensions than that of the extrudate microstructures of the cooled extrudate.

What is claimed is: 
     
         1 . An extruded part having microstructures comprising:
 an extrudate;   the extrudate having pre-cooled extrudate microstructures when the extrudate is in a pre-cooled state,   the extrudate having post-cooled extrudate microstructures when the extrudate is in a post-cooled state wherein the post-cooled extrudate microstructures have a height in the range of 70 to 90 μm, a width in the range of 120 to 160 μm, and a general slope shape, and,   wherein the pre-cooled extrudate microstructures have larger physical dimensions than that of the post-cooled extrudate microstructures.   
     
     
         2 . The extruded part of  claim 1  wherein the post-cooled extrudate has a physical shape taken from the group consisting of a film, a square column, rectangular column, trapezoidal column, asymmetrical column, circular column, oval column, triangular column and any combination of these. 
     
     
         3 . The extrude part of  claim 1  wherein the extrudate includes:
 the extrudate having pre-gathered extrudate microstructures when the extrudate is in a pre-gathered state; 
 the extrudate having gathered extrudate microstructures state wherein the extrudate is in a gathered state; and, 
 wherein the pre-gathered extrudate microstructures have larger physical dimensions than that of the gathered extrudate microstructures. 
 
     
     
         4 . The extrude part of  claim 1  wherein the post-cooled extrudate microstructures include physical characteristics selected from the group consisting of: hydrophobicity, hydrophilicity, self-cleaning, decreased or increased hydro-dynamic drag coefficients, decreased or increased aerodynamic drag coefficients, increased friction, reduced friction, optical effects, increased adhesion, decreased adhesion, oleophobicity, oleophillicity, tactile effects, anti-blocking and any combination of these. 
     
     
         5 . The extruded part of  claim 1  wherein the extrudate has post extrusions assemble extrudate microstructures after the extrudate is passed through a post extrusion assembly. 
     
     
         6 . The extruded part of  claim 5  wherein the post-cooled extrudate microstructures have larger physical dimensions than that of post extrusions assemble extrudate microstructures. 
     
     
         7 . The extruded part of  claim 6  where the extrudate is altered by the post extrudate assembly in a manner taken from the group consisting of: drawing down, flattening, stretching, embossing, coating, stamping, rolling, spiraling, heating, freezing and any combination of these 
     
     
         8 . The extruded part of  claim 1  where the post-cooled extrudate microstructures are disposed on the exterior walls of the extrudate. 
     
     
         9 . The extruded part of  claim 7  including an interior cavity defined in the extrudate. 
     
     
         10 . The extruded part of  claim 8  including microstructures disposed on an inner surface of the interior cavity. 
     
     
         11 . An extruded part having microstructures comprising:
 an extrudate;   the extrudate having pre-cooled extrudate microstructures when the extrudate is in a pre-cooled state;   the extrudate having post-cooled microstructures when in a post-cooled state, wherein the post-cooled extrudate microstructures have dimensions in the range of 0.1 and 500 μm; and,   wherein the pre-cooled extrudate microstructures have a larger physical dimensions than that of the post-cooled extrudate microstructures.   
     
     
         12 . The extruded part of  claim 11  wherein the post-cooled extrudate microstructures are selected from the group consisting of: pillers, voids, steps, ridges, curved regions, recessed regions, columns, cross-section shapes comprising circles, ellipses, triangles, squares, rectangles, polygons, stars, hexagons, letters, numbers, symbols, and any combination of these. 
     
     
         13 . The extruded part of  claim 11  including a channel defined by the post-cooled extrudate microfeatures. 
     
     
         14 . The extruded part of  claim 13  wherein the channel defined by the post-cooled extrudate microfeatures has a depth between 300 μm and 400 μm. 
     
     
         15 . The extruded part of  claim 13  wherein the channel defined by the post-cooled extrudate microfeatures has a width between 100 μm and 160 μm. 
     
     
         16 . The extruded part of  claim 11  wherein area of the post-cooled extrudate microstructures is 0.5 to 25 times smaller when compared to an area of the pre-cooled extrudate microfeatures. 
     
     
         17 . The extruded part of  claim 11  wherein the post-cooled extrudate microfeatures includes a first region of microfeatures having physical dimensions between 10 nm and 1 μm and a second region of microfeatures having physical dimensions between 1 μm and 100 μm. 
     
     
         18 . An extruded part having microstructures comprising:
 an extrudate;   the extrudate having pre-cooled extrudate microstructures when the extrudate is in a pre-cooled state,   the extrudate having post-cooled extrudate microstructures when the extrudate is in a post-cooled state; and,   wherein the ratio of the size of the pre-cooled extrudate microstructures to the post-cooled extrudate microstructures is in the range of 1:1 to 7:1.   
     
     
         19 . The extruded part of  claim 18  wherein the post-cooled extrudate microstructures have a width in the range of 7 μm to 10 μm. 
     
     
         20 . The extruded part of  claim 18  wherein the post-cooled extrudate microstructures defined a channel having a width in the range of 0.25 mm to 1.25 mm.