An extruder

Abstract

The present application proposes an extruder, which includes a cylindrical barrel. In the axial direction, the barrel includes a feeding section, a solid conveying section, a melting section and a homogenizing section connected in sequence; an axially extending screw is arranged in the inner cavity of the barrel bushing; a left spiral ridge extending from a first starting point to a first end point is protrudingly arranged on the inner wall of the barrel bushing, and the left spiral ridge is multiple and axially spaced; a right spiral ridge extending from a second starting point to a second end point is protrudingly arranged on the inner wall of the barrel bushing, and the right spiral ridge is multiple and axially spaced; wherein the left spiral ridge and the right spiral ridge are axially spaced, the first starting point and the second starting point are axially spaced on the same axis, and the first end point and the second end point are axially spaced on the same axis, the extruder makes the material mixing more sufficient, and the plasticization of the extruded product is more uniform and the quality is more stable.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer extrusion, and in particular relates to an extruder. Background Art

[0002] There are many types of mechanical equipment used for polymer molding, such as extruders, injection molding machines, internal mixers, open mixers, calenders, etc. Among them, extruders occupy an important position in polymer molding machinery and equipment. Extrusion molding has the advantage of completing a series of physical and chemical changes of polymers in one go on the extruder, and is an important method for polymer molding. According to statistics, in the polymer molding industry, the output of extruded products ranks first. As a common polymer extrusion equipment, single-screw extruders are tending to develop in a high-speed, high-efficiency and large-scale manner, and the solid melt plasticizing capacity is an important factor restricting its development.

[0003] Therefore, it is necessary to design an extruder to improve the material mixing effect so that the extruded product is plasticized more uniformly and the quality is more stable. Summary of the invention

[0004] Aiming at part or all of the above technical problems existing in the prior art, an extruder is provided, which can make the materials mixed more fully, and the extruded products plasticized more evenly and with more stable quality.

[0005] According to the present invention, the proposed technical solution is:

[0006] An extruder, comprising:

[0007] The cylindrical body includes a feeding section, a solid conveying section, a melting section and a homogenizing section connected in sequence in the axial direction.

[0008] A cylinder liner is sleeved in the inner cavity of the cylinder in a contact manner,

[0009] an axially extending screw disposed in the inner cavity of the barrel bushing,

[0010] A left-hand spiral ridge extending from a first starting point to a first end point is protrudingly provided on the inner wall of the cylinder liner, and the left-hand spiral ridge is multiple and axially spaced.

[0011] A right spiral ridge extending from a second starting point to a second end point is protrudingly provided on the inner wall of the cylinder liner, and the right spiral ridge is multiple and axially spaced.

[0012] The left spiral edge and the right spiral edge are arranged axially at intervals, the first starting point and the second starting point are arranged axially at intervals on the same axis, and the first end point and the second end point are arranged axially at intervals on the same axis.

[0013] In one embodiment, in the direction from the feeding section to the homogenizing section, the distribution density of the left-hand spiral edges and the right-hand spiral edges gradually increases.

[0014] In one embodiment, the maximum distance between adjacent left-handed spiral edges is 15-20% of the average diameter of the barrel bushing, while the minimum distance between adjacent left-handed spiral edges is 10-15% of the average diameter of the barrel bushing, and the width of each left-handed spiral edge is 1-5% of the average diameter of the barrel bushing.

[0015] In one embodiment, the height of each of the left-hand spiral ridge and the right-hand spiral ridge is 1-5% of the average diameter of the barrel bushing.

[0016] In one embodiment, the helix angle of each of the left-hand helical edge and the right-hand helical edge is 40-60 degrees.

[0017] In one embodiment, a protruding nail is provided on the section of the screw corresponding to the melting section and the homogenizing section, and an avoidance groove for avoiding the protruding nail is provided on the left spiral edge and the right spiral edge corresponding to the protruding nail.

[0018] In one embodiment, the protruding nail includes a fixing column for connecting to the screw rod and a plow-shaped member arranged on the fixing column, and a pointed end of the plow-shaped member passes through the avoidance groove first relative to a wide end.

[0019] In one embodiment, the plow comprises:

[0020] An arcuate surface extending from the pointed end to the wide end away from the fixing column, the arcuate surface protruding in a direction away from the fixing column,

[0021] Two connecting surfaces are arranged at two axial ends of the arc-shaped surface, and the two connecting surfaces gradually approach and overlap in a direction gradually approaching the fixing column.

[0022] In one embodiment, a plurality of the protruding nails are provided on the outer wall of the screw rod, and a group of the protruding nails in the same circumferential line and another group of the protruding nails in the adjacent same circumferential line are arranged in a plum blossom shape.

[0023] In one embodiment, the width of the avoidance groove is 1.1-1.5 times the maximum width of the plow.

[0024] Compared with the prior art, the advantages of the present invention are: by arranging spiral edges such as left spiral edges and right spiral edges protruding from the cylinder liner on the inner wall of the cylinder liner, grooves are formed between adjacent left spiral edges or adjacent right spiral edges, which helps to improve the friction between the material and the cylinder liner, thereby improving the conveying efficiency and melt plasticization capacity of the material. Further, by arranging the left spiral edge and the right spiral edge, and because the left spiral edge and the right spiral edge are arranged axially at intervals, during the material extrusion movement, the material is diverted and guided by the left spiral edge or the right spiral edge, and can selectively enter the spiral grooves on both sides from the spiral groove on one side, so that the material can be diverted multiple times during the extrusion movement and move along the spiral grooves in different directions, thereby improving the mixing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0026] Figure 1 A cross-sectional structural diagram of an extruder according to an embodiment of the present invention is schematically shown;

[0027] Figure 2 A cross-sectional view schematically showing a partial structure of an extruder according to an embodiment of the present invention;

[0028] Figure 3 A partial perspective view of an extruder according to an embodiment of the present invention is schematically shown;

[0029] Figure 4 for Figure 2 AA section view;

[0030] Figure 5 A schematic diagram shows a protruding spike according to an embodiment of the present invention;

[0031] Figure 6 for Figure 5 BB view.

[0032] In the drawings, the same reference numerals are used for the same components. The drawings are not drawn to scale. DETAILED DESCRIPTION

[0033] In order to make the technical solutions and advantages of the present invention more clearly understood, the exemplary embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than an exhaustive list of all the embodiments. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0034] The present application provides an extruder. Figures 1 to 4As shown, the extruder includes a barrel 1, a barrel bushing 2, a screw 3, a left spiral rib 4 and a right spiral rib 5. The barrel 1 is cylindrical in shape and mainly serves as a basic support for the main body of the extruder. Figure 3 , the barrel 1 can be designed as a square barrel or a round barrel, etc. according to actual needs. In the axial direction, the barrel 1 includes a feeding section 11, a solid conveying section 12, a melting section 13 and a homogenizing section 14 which are connected in sequence. It can be understood that an opening 15 for connecting to the inner cavity of the barrel sleeve 2 is provided on the feeding section 11 of the barrel 1 for adding materials. The barrel sleeve 2 is contact-type sleeved in the inner cavity of the barrel 1, mainly for contacting with the polymer to form a working cavity to accommodate the extruded material. The screw 3 is inserted into the inner cavity of the barrel sleeve 2. During operation, the screw 3 rotates to convey the material, so that the material entering through the opening 15 moves axially through the feeding section 11, the solid conveying section 12, the melting section 13 and the homogenizing section 14 in sequence. As Figure 3 and 4 As shown, the left spiral ridge 4 is protrudingly arranged on the inner wall of the cylinder bushing 2, and extends in the form of a left spiral line from the first starting point 41 to the first end point 42. The right spiral ridge 5 is protrudingly arranged on the inner wall of the cylinder bushing 2, and extends in the form of a right spiral line from the second starting point 51 to the second end point 52. A left spiral groove 43 is formed between adjacent left spiral ridges 4, and a right spiral groove 53 is formed between adjacent right spiral ridges 5. Therefore, in the process of material transmission, the left spiral ridge 4 and the right spiral ridge 5 play a certain blocking and guiding role, thereby improving the friction between the material and the cylinder bushing 2, and improving the conveying efficiency and melt plasticization ability of the material. According to the present application, the left spiral ridge 4 and the right spiral ridge 5 are arranged axially at intervals. The first starting point 41 and the second starting point 51 are axially spaced on the same axis, and the first end point 42 and the second end point are axially spaced on the same axis. Preferably, a left spiral edge 4 starts to move 180 degrees in a left spiral manner at the first starting point 41 to reach the first end point 42, and a right spiral edge 5 starts to move 180 degrees in a right spiral manner at the second starting point 51 to reach the second end point. Therefore, since the second starting point 51 and the first starting point 41 are staggered in the axial direction, the left spiral groove 43 and the right spiral groove 53 are connected at both the starting point and the end point. Therefore, during the transportation process, the material can be guided by the left spiral edge 4 to enter the left spiral groove 43 at the connection point between the left spiral groove 43 and the right spiral groove 53, and can also be guided by the right spiral edge 5 to enter the right spiral groove 53, and then be divided. Since a plurality of left spiral edges 4 and a plurality of right spiral edges 5 are provided, the material can intersect and be divided multiple times during the movement, which can greatly improve the uniformity of mixing and ensure the mixing effect.

[0035] Preferably, in the direction from the feeding section 11 to the homogenizing section 14, the distribution density of the left spiral ribs 4 and the right spiral ribs 5 gradually increases. That is to say, in the axial direction, the width (axial dimension) of the left spiral groove 43 formed between adjacent left spiral ribs 4 is variable, and this change makes the width of the left spiral groove 43 smaller and smaller in the direction from the feeding section 11 to the homogenizing section 14. This setting adaptively meets the needs of material extrusion. The increasingly dense left spiral ribs 4 and right spiral ribs 5 at the downstream end can relatively increase the speed of diversion and mixing, which is helpful for melting or improving the homogenizing effect. For example, the maximum value of the distance between adjacent left spiral ribs 4 is 15-20% of the average diameter of the barrel liner 2 (the average value of the inner diameter and the outer diameter of the barrel liner 2), for example 18%. The minimum value of the distance between adjacent left spiral ribs 4 is 10-15% of the average diameter of the barrel liner 2, for example 18%. The width of each left spiral rib 4 is 1-5% of the average diameter of the barrel liner 2, for example 3%. The height of the left spiral rib 4 is 1-5% of the average diameter of the barrel liner 2. It can be understood that the setting of the right spiral rib 5 matches the setting of the left spiral rib 4, and the height and width of the two can be the same. The above structure is reasonable and easy to manufacture.

[0036] There are multiple left spiral edges 4 and right spiral edges 5, for example 4-20 each. Of course, it can be understood that the present application is not limited to the above settings, and the specific number can be planned and set according to the specific size of the extruder, etc.

[0037] The helical angle of each left-hand spiral edge 4 and right-hand spiral edge 5 is 40-60 degrees. This setting can ensure the smooth extrusion of the material on the one hand, and on the other hand, it can ensure that the spiral edge has an optimized blocking and guiding effect on the material, and play the purpose of setting the spiral edges 4 and 5. It should be noted that the helical angles of different left-hand spiral edges 4 set on the same extruder can be the same or different, and similarly, the helical angles of each right-hand spiral edge 5 can be the same or different, and the helical angles of the left-hand spiral edge 4 and the right-hand spiral edge 5 that are adjacent to each other are preferably the same, but of course they can also be different.

[0038] The screw 3 is provided with a protruding nail 6 on the section corresponding to the melting section 13 and the homogenizing section 14. And the left spiral edge 4 and the right spiral edge 5 corresponding to the protruding nail 6 are provided with an avoidance groove 44 for avoiding the protruding nail. On the one hand, the protruding nail 6 stirs the material to improve the material mixing effect, thereby ensuring the uniformity of the material plasticization and improving the quality of the extruded product; on the other hand, especially at the bottom of the left spiral groove 43 and the right spiral groove 53, there is a "dead zone" for the material flow, and the protruding nail 6 can clean up the material gathered in the "dead zone" to avoid the problem of poor mixing effect and long residence time of the gathered material, further improve the material mixing effect, thereby ensuring the uniformity of the material plasticization and improving the quality of the extruded product.

[0039] Preferably, if Figure 5 and 6 As shown, the protruding nail 6 includes a fixed column 61 and a plow-shaped member 62. The fixed column 61 is columnar and is used to connect to the screw. The plow-shaped member 62 is arranged at the free end of the fixed column 61. In addition, the plow-shaped member 62 is constructed in a plow shape, and the pointed end passes through the avoidance groove 44 first relative to the wide end. The pointed end contacts the material first compared to the wide end. At this time, the contact area is small and the friction is low. As the plow-shaped member 62 gradually penetrates into the material, the contact area increases, and the friction also increases accordingly, and the stirring effect on the material is also strengthened. The plow-shaped member 62 of the plow-shaped structure can penetrate into the material more easily and stir the material, reducing the torque requirement of the screw 3. At the same time, during the rotation process, the contact area of ​​the plow-shaped member 62 with the material is constantly changing, which can not only push the material but also turn the material, thereby improving the stirring efficiency and ensuring that the material is mixed more evenly.

[0040] Further preferably, the plow-shaped member 62 includes an arcuate surface 621 extending from the pointed end to the wide end away from the fixed column 61, and two connecting surfaces 622 arranged at the axial ends of the arcuate surface 621. The two connecting surfaces 622 gradually approach and overlap in the direction gradually approaching the fixed column 61. The arcuate surface 621 protrudes in the direction away from the fixed column 61, and is used to better fit the arcuate inner wall of the cylinder bushing 2, thereby improving the cleaning and stirring effects. The connecting surface 622 extends in a sloped manner, which is used to increase the width and strength of the plow-shaped member 62 itself, thereby increasing the stirring effect and ensuring the service life.

[0041] A plurality of protruding nails 6 are arranged on the outer wall of the screw 3. The protruding nails 6 in the same circumferential line are defined as a group, for example, a group may include 3-10 protruding nails 6. The protruding nails 6 between adjacent protruding nail groups are arranged in a plum blossom shape. This arrangement can increase the stirring capacity and help the material to be more uniform. Of course, a plum blossom arrangement can also be made between two groups.

[0042] like Figure 3 As shown, the extension direction of the avoidance groove 44 is perpendicular to the axial direction, and is used to avoid the protruding nail 6. In addition, the width of the avoidance groove 44 is 1.1-1.5 times the maximum width of the plow-shaped member 62. The height of the avoidance groove 44 is consistent with the height of the spiral ridge. The above-mentioned structure is optimized and easy to implement.

[0043] The diameter of the screw 3 may be, for example, 20-200 mm, and the aspect ratio may be 5-40, and the number of thread starts may be single, double or multiple.

[0044] The extruder of the present application, by setting the spiral ridges 4, 5, forms a friction shearing effect with the material during the material extrusion process, provides heat for material melting, enhances the melting and plasticizing ability of the extruder, and reduces the specific energy consumption of the extruder; in addition, the material is continuously diverted by the protruding spiral ridges 4, 5 in the barrel liner 2, and can selectively enter the two spiral grooves from one thread groove to achieve full mixing of the material. The setting of the protruding nail can generate friction shearing force with the material, improve the fluidity of the material, reduce the flow "dead zone" and realize the self-cleaning ability of the extruder.

[0045] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and / or modifications that fall within the scope of the present invention, and changes and / or modifications made according to the embodiments of the present invention should be included within the scope of protection of the present invention.

Claims

1. An extruder, characterized in that: include: The cylindrical body includes a feeding section, a solid conveying section, a melting section and a homogenizing section connected in sequence in the axial direction. A cylinder liner is sleeved in the inner cavity of the cylinder in a contact manner, an axially extending screw disposed in the inner cavity of the barrel bushing, A left-hand spiral ridge extending from a first starting point to a first end point is protrudingly provided on the inner wall of the cylinder liner, and the left-hand spiral ridge is multiple and axially spaced. A right spiral ridge extending from a second starting point to a second end point is protrudingly provided on the inner wall of the cylinder liner, and the right spiral ridge is multiple and axially spaced. Among them, the left-hand spiral edge and the right-hand spiral edge are arranged axially at intervals, the first starting point and the second starting point are axially at intervals on the same axis, the first end point and the second end point are axially at intervals on the same axis, the left-hand spiral edge starts from the first starting point and moves 180 degrees in a left-hand spiral manner to reach the first end point, the right-hand spiral edge starts from the second starting point and moves 180 degrees in a right-hand spiral manner to reach the second end point, and the spiral angle of each of the left-hand spiral edge and the right-hand spiral edge is 40-60 degrees.

2. The extruder according to claim 1, characterized in that In the direction from the feeding section to the homogenizing section, the distribution density of the left-hand spiral edges and the right-hand spiral edges gradually increases.

3. The extruder according to claim 2, characterized in that The maximum distance between adjacent left-handed spiral edges is 15-20% of the average diameter of the barrel bushing, while the minimum distance between adjacent left-handed spiral edges is 10-15% of the average diameter of the barrel bushing, and the width of each left-handed spiral edge is 1-5% of the average diameter of the barrel bushing.

4. The extruder according to any one of claims 1 to 3, characterized in that The height of each of the left-hand spiral ridge and the right-hand spiral ridge is 1-5% of the average diameter of the barrel bushing.

5. The extruder according to claim 2 or 3, characterized in that Protruding nails are arranged on the sections of the screw corresponding to the melting section and the homogenizing section, and avoidance grooves for avoiding the protruding nails are arranged on the left spiral ridge and the right spiral ridge corresponding to the protruding nails.

6. The extruder according to claim 5, characterized in that The protruding nail includes a fixing column for connecting to the screw rod and a plow-shaped piece arranged on the fixing column, wherein the pointed end of the plow-shaped piece passes through the avoidance groove first relative to the wide end.

7. The extruder according to claim 6, characterized in that The plow-shaped member comprises: An arcuate surface extending from the pointed end to the wide end away from the fixing column, the arcuate surface protruding in a direction away from the fixing column, Two connecting surfaces are arranged at two axial ends of the arc-shaped surface, and the two connecting surfaces gradually approach and overlap in a direction gradually approaching the fixing column.

8. The extruder according to claim 5, characterized in that A plurality of the protruding nails are arranged on the outer wall of the screw rod, and a group of the protruding nails in the same circumferential line and another group of the protruding nails in the adjacent same circumferential line are arranged in a plum blossom shape.

9. The extruder according to claim 6 or 7, characterized in that The width of the avoidance groove is 1.1-1.5 times the maximum width of the plow-shaped member.

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