TH80331A - Method of product extrusion - Google Patents

Abstract

DC60 (17/03/49) The method described in this invention is directly concerned with the co-extrusion of a predetermined initial molten stream through an insert of at least one contoured die, the inlet of which is shaped to form a nonlinear molten stream from the initial incoming molten stream. The inlet of the die insert has a nonlinear opening in which the die insert opening structure is positioned between the upper and lower boundaries. The die insert is positioned to redirect one or more molten streams or regions of the incoming molten stream. The initial molten stream at the die insert inlet is generally redirected transversely to the original molten stream path. The nonlinear molten stream formed at the die insert inlet then converges into the die insert to form a molten stream. A more linear or Cartesian flow of molten material is introduced through the outlet opening of the insert of the die. At least one layer or part of the initial molten material flow is partitioned into different proportions in different regions along the width or transverse direction of the material or film through extrusion. The invention also focuses directly on the product which is extruded using the method described. The method described in this invention focuses directly on the co-extrusion of a predetermined initial molten material flow through at least one structured insert of the die, in which the insert inlet of the die is shaped to form a nonlinear molten material flow from the initial molten material flow. The insert inlet of the die has a nonlinear opening in which the insert inlet structure is arranged between the upper and lower boundaries. The insert of the die is positioned to redirect one or more molten material flows or regions of the initial molten material flow. The initial molten material flow at the insert inlet of the die The insert of the die is generally redirected transversely to the original flow path of the molten material stream. The nonlinear molten material stream that forms at the insert inlet converges into the insert outlet, becoming a more linear or Cartesian molten material stream. At the insert outlet, at least one layer or portion of the initial molten material stream is segmented into different proportions in different regions along the width or transverse direction of the material or film through extrusion. The invention also focuses directly on the product extruded using the method described.

Claims (24)

1. The method for forming a product by extrusion involves (a) extrusion of the molten material flow path in the mold; (b) preparation of the mold insert with an inlet and outlet opening, the inlet opening not being square and protruding between the upper and lower boundaries; (c) extrusion of the molten material flow path in the mold into the mold insert in such a way that at least part of the flow path at the mold insert inlet is obstructed by at least part of the molten material flow, causing at least part of the molten material flow to be redistributable; (d) recombination of the molten material flow through redistribution within the mold insert; and (e) formation at the mold insert outlet opening of at least one or more areas of the molten material flow that change properties or material due to redistribution of the molten material flow in the mold insert. 2. Method of Claim 1, where the flow path of molten material and the insert are arranged within the mold. 3. Method of claim 2, where the flow path of molten material and the insert are arranged at the outlet channel of the mold. 4. Method of claim 3 where the flow path of molten material and the grommet are arranged within the feed block. 5. Method of claim 3 where a molten material flows through the outlet, the polymer product is extruded. 6. Method of claim 2 where the molten material flow at the insert outlet is extruded into an additional flow path within the mold. 7. Method of Claim 1 where the molten material flow is a multi-component molten material flow in which two or more regions have different compositions. 8. The method of claim 7, where the molten material flow is a multilayered molten material flow in which the different components are different polymer materials or mixtures. 9. The method of claim 2, where the far path of the molten material flow at the inlet of the feed block is truly linear. 10. The method of claim 9, where the flow path of the molten material at the insert inlet channel is a true curve. 11. Method of Claim 1 where the insertion channel has an entrance opening which is a dimensionally non-planar structure defined by an upper boundary and a lower boundary, the boundary area of which comprises the open area forming the insertion channel and the closed area. 12. The method of claim 11, whereby the closed area of the insert inlet obstructs some of the molten material flow, redirects some of these obstructed molten material flows towards the insert opening, and whereby the open area of the insert inlet comprises 10 to 90 percent of the boundary area in at least some part of the insert inlet. 13. The method of claim 12, where the entrance opening of the interlocking section has a perimeter ratio for equivalent rectangular openings between 1.1 and 10 in at least some parts of the interlocking section. 14. The method of claim 13, where the entrance opening of the interconnected section has a perimeter ratio of at least 1.5 in at least some parts of the interconnected section. 15. Method of claim 13 where the opening of the insert has a protruding channel segment between the top and bottom boundary with a height "h" which is less than or equal to the distance "H" between the top and bottom boundary. 16. The method of claim 15 where the height "h" of the opening section ranges from 20 to 90 percent of "H", at least some opening section protrudes at an angle from 2 to 90 degrees from the average flow path between the top and bottom boundaries, and the opening section has a characteristic ratio of height 'h' to height "H" greater than 10 percent. 17. The method of claim 13 in which the insert is progressively and truly reduced from the insert's inlet opening to the insert's outlet opening by at least a portion of the mold's insert. 18. Method of claim 13 where the ratio of entrance openings to exit openings is in the range from 0.9 to 10. 19. Method of claim 1 where the entrance opening of the interlocking part is discontinuous. 20. Method of claim 1 where at least some portion of the inlet opening of the interconnected section has a flow deviation factor of at least 0.2 and less than 3. 21. Method of Claim 1 where at least some portion of the outlet opening of the corresponding section has a flow deviation factor of at least 50 percent less than the corresponding inlet opening. 22. The extruded product consists of at least one layer of polymer material, which has varying degrees of inductive flow arrangement of the molten material along the length of the product. 23. The extruded product of claim 22 has two or more aligned regions with different polymers. 24. The extruded product of claim 22 has two or more contiguous regions with different relative polymer ratios.