Screw cylinder structure capable of stably recycling powder

Abstract

The utility model relates to the technical field of extrusion production, and discloses a screw cylinder structure capable of stably recovering powder, which comprises a screw cylinder body, the screw cylinder body comprises a feed end and a discharge end, a blanking hole is arranged on the screw cylinder body, the blanking hole is communicated with the inside of the screw cylinder body, and the feed end is communicated with the discharge end. A chamfer is arranged at the position, at the discharging hole, of the inner wall of the screw cylinder body, and the chamfer inclines outwards in the process of extending from the discharging end to the feeding end. The chamfers are arranged at the discharging positions of the discharging holes formed in the screw cylinder body, the chamfers enable the space of the screw cylinder body at the discharging port to be enlarged, and when molten plastic flows back to the feeding end due to the fact that pressure changes occur in the screw cylinder body in the feeding process of the screw cylinder body; the space increased through the chamfer can provide sufficient space when the plastic flows back, and the chance that the molten plastic is extruded to flow back to the discharge port to form a bridge and block the discharge port is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of extrusion production, in particular to a screw barrel structure for stably recovering powder. Background Art

[0002] Extrusion molding is one of the common processes for producing plastic films. Extrusion molding is mainly completed by an extruder. The plastic is fed into the barrel from the feed hole of the extruder, and the plastic is melted by the stirring of the screw in the barrel and extruded through the head of the barrel, and formed into a specific shape through a mold. Extrusion molding is usually used for film processing. The materials fed into the barrel are mainly divided into powder and granular materials. The molecular weight of the powder is relatively small, and the mechanical properties are poor, but the dispersion and fluidity are good. For granular materials, since they have been granulated, they have better fluidity and stability, so they are more convenient in extrusion processing and are not easy to generate dust.

[0003] For extruders that need to be mixed with recycled powder, due to the mismatch in the mixing ratio of granular materials and crushed materials, as well as the mismatch in the speed of the main screw and the stirring screw, it is very easy to cause the powder at the discharge hole of the extruder to cool after being heated and melted. The solidified bridge formed between the discharge hole and the screw will hinder the speed of plastic being put into the discharge hole, causing blockage. Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the background technology.

[0005] The utility model provides a screw barrel structure for stably recovering powder, comprising a screw barrel body, wherein the screw barrel body comprises a feed end and a discharge end, a discharge hole is provided on the screw barrel body, the discharge hole is communicated with the interior of the screw barrel body, and an inner wall of the screw barrel body is provided with a chamfer at the discharge hole, wherein the inclination direction of the chamfer is inclined to the outside in the process of extending from the discharge end to the feed end.

[0006] The beneficial effects of the utility model are as follows: the feed hole arranged on the barrel body is chamfered at the discharge position, and the chamfer increases the space of the barrel body at the discharge port. When the pressure inside the barrel body changes during the feeding process of the barrel body, causing the molten plastic to flow back to the feed end, the space increased by the chamfer can provide sufficient space for the plastic to flow back, thereby reducing the chance of the molten plastic being squeezed and flowing back to the discharge port to form a bridge and block the discharge port.

[0007] As some sub-solutions of the above technical solution, the chamfer angle is 20° to 40°.

[0008] As some sub-solutions of the above technical solution, the chamfer angle is 30°.

[0009] As some sub-solutions of the above technical solution, the distance between the chamfered outer end and the outer surface of the barrel body is taken as a retention value, and the retention value is between 2.5 and 4.5 mm.

[0010] As some sub-solutions of the above technical solution, the retention value is 3.9 mm.

[0011] As some sub-solutions of the above technical solution, the feed hole is square.

[0012] As some sub-schemes of the above technical scheme, the barrel body includes an inner hole, the diameter of the inner hole is 125mm, the chamfer is arranged on the side of the feed hole adjacent to the discharge end, and both ends of the chamfered surface are transitionally connected to a side surface extending along the axial direction of the feed hole through a rounded corner, and the size of the rounded corner is 62.5mm.

[0013] As some sub-schemes of the above technical scheme, the plane passing through the axis of the barrel and extending in the vertical direction is the central axis plane of the barrel, the distance between the left side surface of the feed hole and the central axis plane of the barrel is the left opening distance value, the left opening distance value is 54-58mm, and the distance between the right side surface of the feed hole and the central axis plane of the barrel is 60-65mm.

[0014] As some sub-schemes of the above technical scheme, the distance between the left side surface of the feed hole and the central axis surface of the barrel is taken as the left opening distance value, and the left opening distance value is 56 mm.

[0015] As some sub-schemes of the above technical scheme, the distance between the right side surface of the feed hole and the central axis surface of the barrel is taken as the right opening distance value, and the right opening distance value is 62.5 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0017] Figure 1 A three-dimensional diagram of an embodiment of a screw barrel structure for stabilizing powder recovery;

[0018] Figure 2 for Figure 1 A partial enlarged view of the middle A;

[0019] Figure 3 A front view cutaway diagram of an embodiment of a screw barrel structure for stabilizing powder recovery;

[0020] Figure 4 for Figure 3 Cross-sectional view at DD in the middle.

[0021] In the accompanying drawings: 1-screw barrel body; 11-feeding hole; 12-chamfer; 13-right side; 14-rounded corner;

[0022] b l-retention value; qj-angle;

[0023] d0-inner diameter; d1-left opening distance value; d2-right opening distance value. DETAILED DESCRIPTION

[0024] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0025] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0026] In the description of the present utility model, the meaning of "several" is an indefinite quantity, the meaning of "multiple" is more than two, "greater than", "less than", "exceed" and the like are understood as not including the number itself, and "above", "below", "within" and the like are understood as including the number itself. If there is a description of the first and the second, it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features. The "and / or" that appears in the full text indicates three parallel solutions. For example, A and / or B indicates the solution satisfied by A, the solution satisfied by B, or the solution satisfied by both A and B.

[0027] In the description of the utility model, if there is a short sentence containing multiple parallel features, the attributive defines the closest feature, for example: B, C, and E connected to D are arranged on A, which means that B is arranged on A and E is connected to D, and does not constitute a limitation on C; but attributives that indicate the relationship between features, such as "set at intervals" and "arranged in a ring", do not belong to this category. If the word "all" is preceded by an attributive, it means that all the features in the short sentence are limited, such as B, C, and D are all arranged on A, which means that B, C, and D are all arranged on A. For a sentence with an omitted subject, the omitted subject is the subject of the previous sentence, that is, B is arranged on A, including C, which means that B is arranged on A and A includes C.

[0028] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0029] Combine the following Figures 1 to 4 The embodiments of the utility model are described.

[0030] The present embodiment relates to a screw barrel structure for stabilizing the recovery of powder. The screw barrel structure is applied in an extruder. When a mixture of powder and granular material is extruded, bridges are not easily formed, which is beneficial to improving the stability of plastic melting.

[0031] The screw barrel structure for stably recovering powder includes a screw barrel body 1, which includes a feed end and a discharge end. The screw barrel body 1 is provided with a discharge hole 11, and the discharge hole 11 is connected to the interior of the screw barrel body 1. The inner wall of the screw barrel body 1 is provided with a chamfer 12 at the discharge hole 11, and the inclination direction of the chamfer 12 is inclined to the outside in the process of extending from the discharge end to the feed end.

[0032] The discharge hole 11 provided on the barrel body 1 is provided with a chamfer 12 at the discharge position. The chamfer 12 increases the space of the barrel body 1 at the discharge port. When the pressure inside the barrel body 1 changes during the feeding process of the barrel body 1 and causes the molten plastic to flow back to the feed end, the space increased by the chamfer 12 can provide sufficient space for the plastic to flow back, thereby reducing the chance of the molten plastic being squeezed back to the discharge port to form a bridge and block the discharge port.

[0033] The angle qj of the chamfer 12 is 20° to 40°. The angle qj of the chamfer 12 affects the size of the added space and the effect of the chamfer 12 on the barrel thickness. When the angle qj of the chamfer 12 is large, the length of the chamfer 12 extending on the barrel body is short, and the accommodation space formed by the chamfer 12 on the inner wall of the barrel is small. When the angle qj of the chamfer 12 is small, the end of the chamfer 12 adjacent to the discharge end will extend to a deeper position inside the barrel body 1, so that the barrel body 1 will occupy the part where the chamfer 12 is located when working, and the chamfer 12 cannot effectively form a relatively independent accommodation space inside the barrel body 1, and cannot well accommodate the plastic refluxed from the barrel body 1. Setting the angle qj of the chamfer 12 between 20° and 40° can better take into account the above two effects, that is, it can provide a relatively independent accommodation space, and the size of the accommodation space is also larger.

[0034] The angle qj of the chamfer 12 is 30°. When the angle qj of the chamfer 12 is 30°, a relatively independent accommodation space can be formed at the position of the discharge port, and the size of the accommodation space is also relatively large, which can play a better buffering effect when backflow occurs.

[0035] The spacing between the outer end of the chamfer 12 and the outer surface of the barrel body 1 is a reserved value bl, and the reserved value bl is between 2.5 and 4.5 mm. The reserved value bl is designed for the barrel body 1 at the outer end of the chamfer 12, which can effectively ensure the structural strength of the barrel body 1. The reserved value bl is set between 2.5 and 4.5 mm to ensure the structural strength of the barrel body 1 and to ensure that the accommodating space is not too small.

[0036] The retention value bl is designed to be 3.9 mm, so that the accommodation space is large and the structural strength of the barrel body 1 can be guaranteed.

[0037] The feeding hole 11 is square. When low melt index plastic is used for extrusion, due to the low fluidity of low melt index plastic, the feeding hole 11 is designed to be square, and the chamfer 12 forms a larger accommodating space at the lower edge of the feeding hole 11, which is more suitable for the movement direction of the plastic backflow.

[0038] The barrel body 1 includes an inner hole, the diameter of the inner hole is 125 mm, the chamfer 12 is set on the side of the discharge end of the discharge hole 11, and both ends of the chamfer surface are transitionally connected with a side extending along the axial direction of the discharge hole 11 through a fillet 14, and the size of the fillet 14 is 62.5 mm. When the diameter of the inner hole is set to 125 mm, the size of the fillet 14 is 62.5 mm. When the plastic is pushed by the screw in the barrel, when the plastic is squeezed at the intersection of the chamfer surface and a side extending along the axial direction of the discharge hole 11, due to the large size of the fillet 14, the plastic that has entered the accommodation space due to the backflow caused by the extrusion pressure fluctuation is not easy to be accumulated at the above-mentioned intersection position, and can slide into the pushing space inside the barrel along the chamfer 12 with the pushing and rotating movement of the screw, thereby improving the uniformity of the barrel feeding. In this embodiment, only the junction between the right side surface 13 and the chamfered surface is chamfered 12. The reason is that the spiral movement of the screw when pushing the material will drive the material to leave the accommodation space from the junction between the chamfered surface and the right side surface 13. Only chamfering 12 at the junction between the right side surface 13 and the chamfered surface is beneficial to reducing the processing difficulty of the screw barrel and reducing the processing cost.

[0039] The plane passing through the axis of the barrel and extending in the vertical direction is the central axis of the barrel, the distance between the left side of the feed hole 11 and the central axis of the barrel is the left opening distance value d1, the left opening distance value d1 is 54-58mm, and the distance between the right side 13 of the feed hole 11 and the central axis of the barrel is 60-65mm. After the size of the feed hole 11 is set in this way, the distances between the two sides of the feed hole 11 and the central axis of the barrel are not equal. The side corresponding to the spiral movement, that is, the right side, is designed with a larger size, which is conducive to increasing the entry capacity of the plastic on this side when feeding from the hopper.

[0040] The distance between the left side of the feed hole 11 and the central axis of the barrel is the left opening distance value d1, and the left opening distance value d1 is 56 mm. The distance between the left side of the feed hole 11 and the central axis of the barrel is 56 mm, which matches the barrel with an inner hole diameter (i.e., the inner diameter d0 of the barrel) of 125 mm. The feed speed can better meet the feeding capacity of the barrel, and the structural strength of the barrel is less affected after the feed hole 11 is opened.

[0041] The distance between the right side 13 of the feed hole 11 and the central axis of the barrel is the right opening distance d2, and the right opening distance d2 is 62.5 mm. Similarly, when matched with a barrel with an inner hole diameter of 125 mm, the feed speed can better meet the feeding capacity of the barrel, and the structural strength of the barrel is less affected after the feed hole 11 is opened.

[0042] The preferred implementation methods of the present invention are specifically described above, but the present invention is not limited to the described embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention, and these equivalent modifications or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. The barrel structure for stable powder recovery is characterized by : It comprises a screw barrel body (1), the screw barrel body (1) comprises a feed end and a discharge end, the screw barrel body (1) is provided with a discharge hole (11), the discharge hole (11) is connected with the interior of the screw barrel body (1), the inner wall of the screw barrel body (1) is provided with a chamfer (12) at the discharge hole (11), and the inclination direction of the chamfer (12) is inclined to the outside in the process of extending from the discharge end to the feed end.

2. The barrel structure for stable powder recovery according to claim 1 is characterized in that :The angle (qj) of the chamfer (12) is 20° to 40°.

3. The barrel structure for stable powder recovery according to claim 2 is characterized in that :The angle (qj) of the chamfer (12) is 30°.

4. The barrel structure for stable powder recovery according to claim 1 is characterized in that : The distance between the outer end of the chamfer (12) and the outer surface of the barrel body (1) is taken as the retention value (bl), and the retention value (bl) is between 2.5 and 4.5 mm.

5. The barrel structure for stable powder recovery according to claim 4 is characterized in that :The retention value (bl) is 3.9 mm.

6. The barrel structure for stable powder recovery according to claim 1 is characterized in that The feeding hole (11) is square.

7. The barrel structure for stable powder recovery according to claim 1 is characterized in that : The plane passing through the axis of the barrel and extending in the vertical direction is the central axis of the barrel, the distance between the left side surface of the feed hole (11) and the central axis of the barrel is the left opening distance value (d1), the left opening distance value (d1) is 54-58mm, and the distance between the right side surface (13) of the feed hole (11) and the central axis of the barrel is 60-65mm.

8. The barrel structure for stable powder recovery according to claim 7, characterized in that : The distance between the left side surface of the feed hole (11) and the central axis surface of the barrel is the left opening distance value (d1), and the left opening distance value (d1) is 56 mm.

9. The barrel structure for stable powder recovery according to claim 8, characterized in that : The distance between the right side surface (13) of the feed hole (11) and the central axis surface of the screw barrel is taken as the right opening distance value (d2), and the right opening distance value (d2) is 62.5 mm.

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