Patent ID: 8641946
Filing Date: 2014-02-04
Classification: B01D,B29C,B29K,B29L,Y10T

Abstract:
1. A method for producing an extrudate product including a plurality of capillary channels therealong from a molten extrudable material, the method comprising the steps of: a) providing an extrusion apparatus comprising an extruder configured for extruding an extrudate from a molten extrudable material, said extruder having an inlet, a die including an entry portion, a convergent portion and an orifice located at an exit of the die, the orifice having a predetermined outer shape and cross-section, a plurality of needles each needle having a body including an internal first conduit for fluid flow, each needle further comprising an outlet from the internal first conduit at an outlet end, the outlet end of each needle of said plurality of needles being arranged in a predetermined pattern, wherein the outlet end of each needle is arranged such that the outlet end of each needed is located within the orifice of the die, the internal first conduit of each needle being fluidly connected to a fluid source by a second conduit passing through an exterior wall of said die and around which a molten extrudable material flows to pass to said orifice of said die; b) feeding said molten extrudable material into the extruder through the inlet; c) using the extruder to force the molten extrudable material to flow towards the die, over and around the plurality of needles and corresponding second conduit and fluidly connecting each needle to a fluid source, and through the orifice in the die to produce an extrudate initially generally having the predetermined outer shape and cross-section of the orifice located at the exit of the die; d) allowing a fluid medium to flow from the fluid source through the second conduit to the internal first conduit and needle outlet of each of said plurality of needles, whereby the fluid medium forms capillaries such that the extrudate includes capillaries therealong in the same predetermined pattern as the plurality of needles, wherein said needle outlet of each of the plurality of needles has a diameter of 2 mm or less, and wherein said diameter of said capillaries in said extrudate is directly related to the diameter of the needle outlets of each of said plurality of needles; and e) using a draw down apparatus to draw down the extrudate thereby altering the initial predetermined outer shape and cross-section of the extrudate to form an extrudate product having a finished predetermined outer shape and cross-section which is different from said initial predetermined outer shape and cross-section.