Extrusion die head

Patent metadata

Field	Value
Publication number	US-8985992-B2
Application number	US-201113808797-A
Country	US
Kind code	B2
Filing date	Jul 7, 2011
Priority date	Jul 26, 2010
Publication date	Mar 24, 2015
Grant date	Mar 24, 2015

Abstract

When extrusion molding is conducted continuously for a long period of time, in order to prevent a die drool from being generated at an outlet of an extruder, to a shell 2 in which an outlet 3 , through which a melt-kneaded resin material is extruded by an extruder, is formed, a plate-like shell tip 6 in which an opening 7 which is arranged such that it surrounds the outlet 3 along the circumference thereof is detachably attached, and non-sticky coating is applied at least along the outer surface of the core tip.

First claim

The invention claimed is:

1. An extrusion die head adapted to attach to a front end part of an extruder, comprising:
a shell having an outlet for extruding a resin material which has been melt-kneaded by means of the extruder;
a plate-like shell tip having an opening to be arranged along a circumference of the outlet in such a manner that the opening surrounds the outlet, the shell tip being detachably attached to the shell;
a tapered part provided in an opening side of the shell tip and having a diameter increasing along an extrusion direction of the resin; and
a non-sticky coating applied at least along an inner circumference of the opening formed in the shell tip,
wherein an angle of inclination of the tapered part relative to a surface of the shell tip on which the shell tip is attached to the shell is equal to or smaller than 20°.

2. The extrusion die head according to claim 1 , wherein an inner surface of the opening of the shell tip has a thickness of 0.1 to 0.5 mm which is in parallel with the extrusion direction of the resin.

3. The extrusion die head according to claim 1 , wherein a diameter of the outlet formed in the shell (øA) and a diameter of the opening formed in the shell tip (øB) satisfy following relationship:
(ø A )≦(ø B ).

4. The extrusion die head according to claim 3 , wherein the diameter of the outlet formed in the shell (øA) and the diameter of the opening formed in the shell tip (øB) satisfy following relationship:
(ø B )≦(ø A )+0.2 mm.

5. The extrusion die head according to claim 1 , further comprising:
a core provided in the shell with a predetermined gap being formed between the outlet formed in the shell such that the resin which has been melt-kneaded by means of the extruder is extruded in a hollow shape;
a plate-like core tip covering a front surface of the core;
the core tip detachably attached to the core; and
a non-sticky coating applied at least along an outer surface of the core tip.

6. The extrusion die head according to claim 5 , wherein a tapered part which is decreased in a diameter along the extrusion direction of the resin is provided on an outer circumference side of the core tip.

7. The extrusion die head according to claim 6 , wherein an angle of inclination of the tapered part relative to a surface of the core tip on which the core tip is attached to the core is equal to or smaller than 20°.

8. The extrusion die head according to claim 5 , wherein an outer circumference of the core tip includes an outside surface having a thickness of 0.1 to 0.5 mm which is in parallel with the extrusion direction of the resin.

9. The extrusion die head according claim 5 , wherein an outer diameter of a front surface of the core øC and an outer diameter of the core tip (øD) satisfy a following relationship:
(ø D )≦(ø C ).

10. The extrusion die head according to claim 9 , wherein the outer diameter of the front surface of the core øC and the outer diameter of the core tip (øD) satisfy a following relationship:
(ø C )≦(ø D )+0.2 mm.

11. The extrusion die head according to claim 1 , further comprising;
a core provided in the shell with a predetermined gap being formed between the outlet formed in the shell such that the resin which has been melt-kneaded by means of the extruder is extruded in a hollow shape;
wherein a non-sticky coating is applied at least along a front edge part of the core.

12. The extrusion die head according to claim 1 , wherein the non-sticky coating is a burned coating film comprising a fluorine-based resin.

13. The extrusion die head according to claim 12 , wherein the burned coating film comprising the fluorine-based resin is a PFA-PEEK composite coating film.

14. The extrusion die head according to claim 1 , wherein the angle of inclination of the tapered part is an angle between the surface of the shell tip contacting the shell and a surface of the tapered part directly linearly crossing the surface of the shell tip.

Assignees

• Kuwazuru Mitsuo
• Honda Jou
• Hashimoto Takuji
• Toyo Seikan Kaisha Ltd

Inventors

• Kuwazuru Mitsuo
• Honda Jou
• Hashimoto Takuji

Classifications

• B29C48/272

  of dies · CPC title

• B29C48/327

  with centering means · CPC title

• B29C48/2566

  Die parts · CPC title

• B29C48/27

  Cleaning; Purging; Avoiding contamination · CPC title

• B29C48/3003

  Materials, coating or lining therefor · CPC title