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CN-117507308-B - Extrusion screw and manufacturing method thereof

CN117507308BCN 117507308 BCN117507308 BCN 117507308BCN-117507308-B

Abstract

The extrusion screw comprises a screw body and screw edges, wherein the screw edges comprise a feeding section, a melting section, a transition section and a discharging section, the melting section is a double screw edge, the melting section comprises a melting section I, a melting section II and a melting section III, the screw pitch of a main screw edge of the melting section I is smaller than the screw pitch of a secondary screw edge of the melting section I, the screw pitch of a main screw edge of the melting section II is equal to the screw pitch of a secondary screw edge of the melting section II, the screw pitch of a main screw edge of the melting section III is smaller than the screw pitch of a secondary screw edge of the melting section III, the screw pitch of a main screw edge of the melting section I is kept unchanged, the screw pitch of a secondary screw edge of the melting section III is larger than the screw pitch of a secondary screw edge of the melting section II. The manufacturing method comprises the steps of manufacturing a rod-shaped structure, manufacturing a transition section, manufacturing a feeding section screw edge, a main screw edge and a secondary screw edge, and manufacturing a discharging section screw edge.

Inventors

  • XIA YUJIAN
  • XIA ZENGFU

Assignees

  • 浙江华业塑料机械股份有限公司

Dates

Publication Date
20260508
Application Date
20231222

Claims (10)

  1. 1. The extrusion screw comprises a screw body (1) and screw edges arranged on the screw body (1), wherein the screw edges comprise a feeding section (A), a melting section (B), a transition section (C) and a discharging section (D), and the extrusion screw is characterized in that the melting section (B) is a double screw edge, the melting section comprises a melting section one (B1), a melting section two (B2) and a melting section three (B3), the screw pitch of a main screw edge of the melting section one is smaller than the screw pitch (S2) of a secondary screw edge of the melting section one, the screw pitch of the main screw edge of the melting section two is equal to the screw pitch (S3) of a secondary screw edge of the melting section two, the screw pitch of the main screw edge of the melting section three is smaller than the screw pitch (S4) of a secondary screw edge of the melting section three, the screw pitch (S4) of the secondary screw edge of the melting section three is larger than the screw pitch (S2) of the secondary screw edge of the melting section one, and the screw edge of the melting section one is larger than the screw pitch (S3) of the secondary screw edge of the melting section two.
  2. 2. The extrusion screw according to claim 1, wherein the depth of the secondary groove (12) formed by the front side of the primary flight and the rear side of the secondary flight on the melting section (B) increases gradually, and then the depth of the secondary groove (12) decreases gradually from the middle position of the melting section (B3).
  3. 3. The extrusion screw according to claim 2, wherein the depth of the main groove (11) formed by the front side of the auxiliary screw flight and the rear side of the main screw flight on the melting section (B) is gradually reduced, and the depth reduction speed of the main groove (11) is greater than that of the auxiliary groove at the position where the depth of the auxiliary groove (12) starts to be reduced.
  4. 4. An extrusion screw according to claim 3, wherein the width of the primary flight (13) of the melt section is greater than the width of the secondary flight (14) of the melt section, the height of the top surface of the primary flight (13) of the melt section being greater than the height of the top surface of the secondary flight (14) of the melt section.
  5. 5. Extrusion screw according to any of claims 1 to 4, wherein the feed section (a) is a single flight and the feed section flights are joined smoothly end to end with the main flights (13) of the melt section.
  6. 6. The extrusion screw according to claim 5 wherein the main flight of the melt section has a greater pitch (S1) than the flight of the feed section.
  7. 7. The extrusion screw according to claim 5 wherein the discharge section (D) has a single flight, the flight pitch of the flight being equal to the flight pitch of the flight of the feed section, the diameter of the rod corresponding to the discharge section being greater than the diameters of the rods corresponding to the feed section and the melt section.
  8. 8. Extrusion screw according to any one of claims 1 to 4, characterized in that the transition section (C) is three barrier discs arranged at intervals, on the outer wall of which spiral grooves (15) are circumferentially distributed.
  9. 9. Extrusion screw according to any one of claims 1 to 4, characterized in that a flow guide head (2) is detachably screwed to one end of the rod body (1), and a retaining groove and a transmission spline (16) are provided at the other end of the rod body (1).
  10. 10. A method of producing an extrusion screw according to any one of claims 1 to 9, comprising the steps of, 1. The blank is manufactured into a rod-shaped structure according to the size; 2. a transition section (C) is manufactured at a position close to one end of the rod-shaped structure; 3. Manufacturing a feeding section screw rib and a main screw rib (13) of a melting section on a rod body (1) positioned at the rear side of the transition section, wherein the screw pitch of the feeding section screw rib and the screw pitch (S1) of the main screw rib of the melting section are kept unchanged, so that the main screw rib (13) of the melting section at the connection position of the melting section (B) and the feeding section (A) is smoothly connected with the screw rib of the feeding section; 4. The pitch of the primary screw rib of the melting section is smaller than the pitch (S2) of the secondary screw rib of the melting section, the pitch of the primary screw rib of the melting section is equal to the pitch (S3) of the secondary screw rib of the melting section, the pitch of the primary screw rib of the melting section is smaller than the pitch (S4) of the secondary screw rib of the melting section, wherein the pitch (S4) of the secondary screw rib of the melting section is larger than the pitch (S2) of the secondary screw rib of the melting section, and the pitch (S2) of the secondary screw rib of the melting section is larger than the pitch (S3) of the secondary screw rib of the melting section; 5. And manufacturing a discharge section screw edge on a rod body (1) positioned at the front side of the transition section, namely finishing the manufacturing of the extrusion screw.

Description

Extrusion screw and manufacturing method thereof Technical Field The invention relates to the technical field of screw rod manufacturing, in particular to an extrusion screw rod and a manufacturing method thereof. Background The prior Chinese patent application with the application number of CN201410591589.7 being a polyolefin extrusion screw discloses a polyolefin extrusion screw, a main body of the screw is sequentially provided with a feeding section, a compression section, a metering section, a barrier section and a mixing section, wherein the feeding section and the metering section are of a single-thread structure, the compression section is provided with main threads and additional threads with different screw pitches, a solid phase groove connected with the feeding groove and a liquid phase groove connected with the metering groove are respectively formed on the compression section, the outer diameter of the additional threads is smaller than that of the main threads, the shielding section is provided with a plurality of pairs of feeding spiral blind grooves and discharging spiral blind grooves which are respectively surrounded by non-common threads and common threads, the inlet of each pair of feeding spiral blind grooves and discharging spiral blind grooves are separated by the common threads, the inlet of each feeding spiral blind groove is connected with the metering groove, the outlet of each discharging spiral blind groove is connected with the mixing section, the outer diameter of the common threads is smaller than that of the non-common threads, the outer diameter of the mixing section is provided with parallel convex teeth, and the length of the screw is 42 times that of the outer diameter of the screw. The invention has high screw rotation speed, high yield and good plasticizing quality. However, the bottom diameter of the groove of the right double-screw-edge structure of the barrier section of the extrusion screw has small change, and the extrusion mixing effect of materials is still improved, so that the structure of the extrusion screw needs to be further improved. Disclosure of Invention The first technical problem to be solved by the invention is to provide an extrusion screw with sufficient material melting, good mixing effect, compact extrusion material and smooth extrusion material aiming at the current state of the art. The extrusion screw is characterized in that the melting section comprises a melting section, a second melting section and a third melting section, the pitch of a main screw rib of the first melting section is smaller than the pitch of a secondary screw rib of the first melting section, the pitch of a main screw rib of the second melting section is equal to the pitch of a secondary screw rib of the second melting section, the pitch of a main screw rib of the third melting section is smaller than the pitch of a secondary screw rib of the third melting section, the pitch of a main screw rib of the third melting section is kept unchanged, the pitch of a secondary screw rib of the third melting section is larger than the pitch of a secondary screw rib of the first melting section, and the pitch of a secondary screw rib of the first melting section is larger than the pitch of a secondary screw rib of the second melting section. As an improvement, the depth of the secondary groove formed by the front side surface of the main screw rib and the rear side surface of the secondary screw rib on the melting section can be increased gradually, and then the depth of the secondary groove is reduced gradually from the middle position of the melting section. Further, the depth of the main screw groove formed by the front side surface of the auxiliary screw rib and the rear side surface of the main screw rib on the melting section can be preferably gradually reduced, and the depth reduction speed of the main screw groove is larger than that of the auxiliary screw groove at the position where the depth of the auxiliary screw groove starts to be reduced. Further improvements may be made in that the width of the primary flight of the melting section may preferably be greater than the width of the secondary flight of the melting section, and the top surface height of the primary flight of the melting section may preferably be greater than the top surface height of the secondary flight of the melting section. As an improvement, the feeding section can be preferably a single screw flight, and the screw flight of the feeding section and the main screw flight of the melting section are connected together in a head-tail smooth manner. Further improvements may be made in that the pitch of the main flight of the melting section is preferably greater than the pitch of the flight of the feed section. Further improved, the discharging section can be preferably a single screw edge, the screw pitch of the screw edge of the discharging section is equal to that of the screw edge of the feeding secti