# US 2018/0026431 A1 · Process for forming a divided conduit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0026431 A1 - Document ID: US20180026431A1 - Status: Published application - Kind: A1 - Application number: 15/653,885 - Filed: 2017-07-19 - Published: 2018-01-25 - Earliest claimed: 2016-07-20 - Assignees: Milliken & Company - Applicants: Milliken & Company - Inventors: David Drew Morris - Web page: https://patentgrep.com/patent/US20180026431A1 ## CPC - B29C 48/11: comprising two or more partially or fully enclosed cavities, e.g. honeycomb-shaped - B29C 48/303: {using dies or die parts movable in a closed circuit, e.g. mounted on movable endless support (B29C48/35 takes precedence)} - B29C 48/34: Cross-head annular extrusion nozzles, i.e. for simultaneously receiving moulding material and the preform to be coated - H02G 1/08: through tubing or conduit, e.g. rod or draw wire for pushing or pulling {(inserting electrical cables into tubes using wallbores E21B17/206; for optical cables G02B6/4401)} - H02G 3/0468: {Corrugated} - H02G 3/0481: {with a circular cross-section (H02G3/0468, H02G3/0475 take precedence)} - H02G 9/065: {Longitudinally split tubes or conduits therefor} - B29C 48/16: Articles comprising two or more components, e.g. co-extruded layers - B29C 48/2883: {of preformed parts, e.g. inserts, retaining their shape during the extrusion process} - B29C 48/3001: {characterised by the material or their manufacturing process} - B29C 48/32: with annular openings, e.g. for forming tubular articles - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - H02G: INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES ## Abstract A process for extruding a divided conduit comprising obtaining an extrusion die head, inserting a strip-shaped substrate into the extrusion die head such that the strip shaped substrate is located within the tip gap and extends at least partially out of the tip gap such that the longitudinal edges are located in the die gap, and flowing molten polymer through die gap, encapsulating the longitudinal edges of the strip-shaped substrate in molten polymer. The extrusion die head contains a tip region and a bushing. The tip region contains at least 2 tips separated by a tip gap. The bushing extends around the tip region and the distance between the tip region and the inner surface of the bushing is defined to be the die gap and the die gap varies around the bushing. ## Claims ### Claim 1 A process for extruding a divided conduit comprising: obtaining an extrusion die head comprising: a tip region comprising at least two tips, wherein each tip has a cross-sectional shape comprising a curved portion and between 1 to 2 mating portions, wherein the tips are oriented such that the mating portions of each tip adjacent to the mating portions of adjacent tips and are separated by a distance defined to be a tip gap, and wherein the curved portions of the tips together in the tip region form a generally circular cross-sectional shape; and, a bushing having an inner surface, wherein the bushing extends around the tip region, wherein the distance between the tip region and the inner surface of the bushing is defined to be the die gap, and therein the locations where the tip gap and the die gap intersect are defined to be the tip gap exits, wherein the die gap has a first width measured at the tip gap exit locations and a second width measured at the midpoint between the tip gap exit locations, wherein the first width is between about 10 and 75% larger than the second width; forming a strip-shaped substrate having at least two longitudinal edges, wherein the substrate is selected from the group consisting of a strip-shaped textile and a strip-shaped film, wherein the strip-shaped substrate varies in thickness along the width of the strip-shaped substrate, wherein the thickness is greatest at the longitudinal edges forming enlarged regions; inserting the strip-shaped substrate into the extrusion die head such that the strip shaped substrate is located within the tip gap and extends at least partially out of the tip gap such that the longitudinal edges are located in the die gap; flowing molten polymer through die gap, encapsulating the longitudinal edges of the strip-shaped substrate in molten polymer; and, at least partially cooling and solidifying the molten polymer. ### Claim 2 (depends on 1) The process for extruding a divided conduit of claim 1, wherein the tip region comprises 2 tips and each tip comprises a curved portion and a mating portion. ### Claim 3 (depends on 1) The process for extruding a divided conduit of claim 1, wherein the tip region comprises 3 tips and each tip comprises a curved portion and two mating portions. ### Claim 4 (depends on 1) The process for extruding a divided conduit of claim 1, wherein the tip region comprises 4 tips and each tip comprises a curved portion two mating portions. ### Claim 5 (depends on 1) The process for extruding a divided conduit of claim 1, wherein the second width is between about 20 and 50% larger than the first width. ### Claim 6 (depends on 1) The process for extruding a divided conduit of claim 1, wherein at least one of the mating portions is flat. ### Claim 7 (depends on 1) The process for extruding a divided conduit of claim 1, wherein the inner surface of the bushing extends 360 degrees around the tip region, wherein the inner surface of the bushing comprises non-circular cross-sectional regions corresponding to the tip gap exit locations and have a width of between 10 and 135 degrees centered on the tip gap exit. ### Claim 8 (depends on 7) The process for extruding a divided conduit of claim 7, wherein the regions of the inner surface of the bushing outside of the non-circular cross-sectional regions have a generally circular cross-sectional shape. ### Claim 9 (depends on 7) The process for extruding a divided conduit of claim 7, wherein the inner surface of the bushing comprises non-circular cross-sectional regions corresponding to the tip gap exit locations and have a width of between 20 and 90 degrees centered on the tip gap exit. ### Claim 10 (depends on 7) The process for extruding a divided conduit of claim 7, wherein the inner surface of the bushing comprises non-circular cross-sectional regions corresponding to the tip gap exit locations and have a width of between 30 and 60 degrees centered on the tip gap exit. ### Claim 11 An extrusion die head comprising: a tip region comprising at least two tips, wherein each tip has a cross-sectional shape comprising a curved portion and between 1 to 2 mating portions, wherein the tips are oriented such that the mating portions of each tip adjacent to the mating portions of adjacent tips and are separated by a distance defined to be a tip gap, and wherein the curved portions of the tips together in the tip region form a generally circular cross-sectional shape, a bushing having an inner surface, wherein the bushing extends around the tip region, wherein the distance between the tip region and the inner surface of the bushing is defined to be the die gap, and therein the locations where the tip gap and the die gap intersect are defined to be the tip gap exits, wherein the die gap has a first width measured at the tip gap exit locations and a second width measured at the midpoint between the tip gap exit locations, wherein the first width is between about 10 and 75% larger than the second width. ### Claim 12 (depends on 11) The extrusion die head of claim 11, wherein the tip region comprises 2 tips and each tip comprises a curved portion and a mating portion. ### Claim 13 (depends on 11) The extrusion die head of claim 11, wherein the tip region comprises 3 tips and each tip comprises a curved portion and two mating portions. ### Claim 14 (depends on 11) The extrusion die head of claim 11, wherein the tip region comprises 4 tips and each tip comprises a curved portion two mating portions. ### Claim 15 (depends on 11) The extrusion die head of claim 11, wherein the second width is between about 20 and 50% larger than the first width. ### Claim 16 (depends on 11) The extrusion die head of claim 11, wherein at least one of the mating portions is flat. ### Claim 17 (depends on 11) The extrusion die head of claim 11, wherein the inner surface of the bushing contains extends 360 degrees around the tip region, wherein the inner surface of the bushing comprises non-circular cross-sectional regions corresponding to the tip gap exit locations and have a width of between 10 and 135 degrees centered on the tip gap exit. ### Claim 18 (depends on 17) The extrusion die head of claim 17, wherein the regions of the inner surface of the bushing outside of the non-circular cross-sectional regions have a generally circular cross-sectional shape. ### Claim 19 (depends on 17) The extrusion die head of claim 17, wherein the inner surface of the bushing comprises non-circular cross-sectional regions corresponding to the tip gap exit locations and have a width of between 20 and 90 degrees centered on the tip gap exit. ### Claim 20 (depends on 17) The extrusion die head of claim 17, wherein the inner surface of the bushing comprises non-circular cross-sectional regions corresponding to the tip gap exit locations and have a width of between 30 and 60 degrees centered on the tip gap exit.