Extruder screw, extruder, and extrusion method

Patent metadata

Field	Value
Publication number	US-2016332331-A1
Application number	US-201615221277-A
Country	US
Kind code	A1
Filing date	Jul 27, 2016
Priority date	Apr 24, 2014
Publication date	Nov 17, 2016
Grant date	—

Abstract

An extruder screw conveying raw materials while kneading them includes a screw main body, conveyance portions, barrier portions, and paths. The conveyance portions convey the raw materials in an axial direction. The paths each include an entrance and an exit. The raw materials, the conveyance of which is limited by the barrier portions, flow in from the entrance. The raw materials flowing in from the entrance flow through the paths in the same direction as a conveyance direction of the conveyance portions. The exit is opened in the outer circumferential surface of the screw main body at a position outside the conveyance portions in which the entrance is opened.

First claim

1 . An extruder screw configured to convey a raw material while kneading the raw material, comprising:
a screw main body having a straight axial line in a conveyance direction of the raw material, and configured to rotate on the axial line; conveyance portions provided with a space between the conveyance portions in an axial direction of the screw main body, and configured to convey the raw material in the axial direction along an outer circumferential surface extending in a circumferential direction of the screw main body with rotation of the screw main body; barrier portions provided on the screw main body, and configured to limit conveyance of the raw material at positions adjacent to the conveyance portions; and paths provided inside the screw main body, and each comprising an entrance and an exit, wherein the entrance is opened in the outer circumferential surface of the screw main body in the conveyance portions to cause the raw material, the conveyance of which is limited by the barrier portions to increase pressure on the raw material, to flow in, the raw material flowing in from the entrance flows through each of the paths toward the exit in a same direction as the conveyance direction of the conveyance portions, and the exit is opened in the outer circumferential surface of the screw main body at a position outside the conveyance portions in which the entrance is opened.

2 . The extruder screw of claim 1 , wherein a bore of each of the paths is set to be less than or equal to a bore of the entrance in each of the paths.

3 . The extruder screw of claim 1 , wherein a bore of each of the paths is set to be greater than or equal to 1 mm but less than 6 mm.

4 . The extruder screw of claim 1 , wherein the screw main body extends in the axial direction from a basal end coupled to a rotating device to a tip,
each of the conveyance portions is provided with a flight spirally twisted along the outer circumferential surface of the screw main body, and from a perspective of a basal end side, the flight is twisted from the basal end toward the tip of the screw main body in an opposite direction to a rotation direction of the screw main body.

5 . The extruder screw of claim 1 , wherein the screw main body extends in the axial direction from a basal end coupled to a rotating device to a tip,
each of the conveyance portions is provided with a flight spirally twisted along the outer circumferential surface of the screw main body, and from a perspective of a basal end side, the flight is twisted from the basal end toward the tip of the screw main body in a same direction as a rotation direction of the screw main body.

6 . The extruder screw of claim 4 , wherein each of the barrier portions is provided with a barrier annular body continuing in the circumferential direction along the outer circumferential surface of the screw main body, and
the barrier annular body is formed to have a cylindrical surface concentrically continuing in the circumferential direction with the axial line as a center.

7 . The extruder screw of claim 4 , wherein each of the barrier portions is provided with a barrier flight spirally twisted along the outer circumferential surface of the screw main body, and
from the perspective of the basal end side, the barrier flight is twisted from the basal end toward the tip of the screw main body in a same direction as the rotation direction of the screw main body.

8 . The extruder screw of claim 5 , wherein each of the barrier portions is provided with a barrier annular body continuing in the circumferential direction along the outer circumferential surface of the screw main body, and
the barrier annular body is formed to have a cylindrical surface concentrically continuing in the circumferential direction with the axial line as a center.

9 . The extruder screw of claim 5 , wherein each of the barrier portions is provided with a barrier flight spirally twisted along the outer circumferential surface of the screw main body, and
from the perspective of the basal end side, the barrier flight is twisted from the basal end toward the tip of the screw main body in an opposite direction to the rotation direction of the screw main body.

10 . An extruder comprising the extruder screw of claim 1 and configured to knead the raw material with the screw and continuously produce and extrude the kneaded material, the extruder comprising:
a barrel comprising a cylinder in which the screw is rotatably inserted;
a supply port through which the raw material is supplied to the cylinder, the supply port being provided in the barrel; and
a discharge port through which the kneaded material is extruded, the discharge port being provided in the barrel.

11 . An extrusion method of kneading the raw material with the extruder screw of claim 1 and continuously producing and extruding the kneaded material, the extrusion method comprising:
conveying the raw material in the axial direction by the conveyance portions of the screw main body;
limiting the conveyance of the raw material by the barrier portions of the screw main body to increase the pressure on the raw material;
causing the raw material, the pressure on which is increased, to flow into the paths provided inside the screw main body and flow through the paths in the same direction as the conveyance direction of the conveyance portions; and
returning the raw material flowing through the paths to the outer circumferential surface of the screw main body at the position outside the conveyance portions in which the entrance is opened.

12 . An extruder screw configured to convey a raw material while kneading the raw material, the extruder screw comprising
a screw main body having a straight axial line in a conveyance direction of the raw material, and configured to rotate on the axial line, wherein a conveyance portion configured to convey the raw material, a barrier portion configured to limit conveyance of the raw material, and a path through which the raw material flow are provided at places of the screw main body, and in at least one of the places, the path is provided inside the screw main body, and comprises an entrance and an exit, the entrance is opened in an outer circumferential surface of the screw main body in the conveyance portion to cause the raw material, the conveyance of which is limited by the barrier portion to increase pressure on the raw material, to flow in, the raw material flowing in from the entrance flows through the path toward the exit in a same direction as the conveyance direction of the conveyance portion, and the exit is opened in the outer circumferential surface of the screw main body at a position outside the conveyance portion in which the entrance is opened.

Assignees

• Toshiba Machine Co Ltd
• Hsp Tech Inc

Inventors

• Kobayashi Akiyoshi
• Fujii Shigeyuki
• Sameshima Takafumi
• Shimizu Hiroshi

Classifications

• B29B7/426

  with consecutive casings or screws, e.g. for charging, discharging, mixing · CPC title

• B29B7/42 Primary

  with screw or helix · CPC title

• B29C48/402

  the screws having intermeshing parts · CPC title

• B29B7/38

  rotary (B29B7/52 takes precedence) · CPC title

• B29B7/7485

  with consecutive mixers, e.g. with premixing some of the components · CPC title