Novel filtering sealing type die head of extruder

Abstract

The utility model discloses a novel filtering sealed mould head of an extruder, which comprises a mould head body, the mould head body is internally provided with a conical extrusion cavity with a small left part and a large right part and a heat conduction oil heating cavity positioned outside the excircle of the extrusion cavity, the left end of the extrusion cavity is provided with an extrusion hole, and the right end of the extrusion cavity is provided with a circular mounting chamber; a filtering honeycomb plate, a filter screen and a pressing ring are sequentially installed in the circular installation chamber from left to right, the right outer circle of the filtering honeycomb plate and the left end of the pressing ring are in press connection through a spigot structure, the circumferential edge of the filter screen is in press connection in the spigot structure, and the right end face of the pressing ring protrudes out of the right side face of the die head body. By improving the structure of the filtering honeycomb plate and changing the position of the pressing ring, the butt joint centrality and the sealing effect of all parts are improved, the pressing ring is taken out and waste is cleaned more conveniently and quickly during maintenance, the structural strength of the filtering honeycomb plate is improved, the filtering area is increased, and the material passing efficiency is improved; and the quality of the filtered material is also greatly improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of PVC calendering film production, and specifically relates to a novel filtering and sealing die head for an extruder. Background Art

[0002] The extruder is one of the most important equipment in the production process of PVC calendered film. It carries the functions of homogenizing, plasticizing, heat preservation, and filtering impurities of the material. The die head is an important part of the extruder. The overall shape of the die head is a conical structure with a small left side and a large right side. The die head is equipped with a filter honeycomb plate and a filter screen. The filter screen is pressed to the right side of the filter honeycomb plate through a pressure ring. The pressure ring is not set in the die head. The pressure ring is set in the head of the extruder and connected to the left end of the material guide barrel. The front or rear side of the die head is connected to the head of the extruder through a hinge. A heat transfer oil heating chamber is set in the die head. The corresponding surfaces of the filter honeycomb plate and the pressure ring are concentric by a stop. This structure of the existing die head has the following disadvantages or shortcomings:

[0003] 1) The right end face of the pressure ring on the right side of the filter honeycomb plate in the die head is pressed against the left end face of the guide barrel in the die head under the locking action of the oblique iron of the die head, forming an end face seal to prevent the molten material from leaking out along the contact surface between the pressure ring and the guide barrel. Because the sealing surface is inside the die head (the left end of the guide barrel does not extend out of the left end of the die head, and the pressure ring is inside the die head), it is not easy to check whether the sealing surface is good or not. Moreover, once there is leakage on the sealing surface, the pressure ring is easily stuck to the inside of the die head by the leaked material, which increases the workload of removing the pressure ring and cleaning the scraps leaked into the annular step groove in the die head.

[0004] 2) Hundreds of conical discharge holes are opened on the filter plate body of the honeycomb filter plate. If the size, taper and distribution density of the discharge holes are not designed properly, the filtering effect will be directly affected. Because the discharge holes are distributed linearly on the filter plate body, the dead angle of filtration (the area between holes on the surface of the filter plate body) is linear and flake-shaped, especially the outer circle is easy to retain coke material in this area, which is easy to retain and produce coke material, affecting product quality. In addition, because the extruder outputs a large thrust of PVC molten material on the filter plate body, the filter plate body is 40-50mm thick, and the discharge hole diameter is 8-10mm. The PVC molten material passes through hundreds of slender discharge holes. The resistance is very large, requiring the filter plate body to have a large mechanical strength, otherwise the filter plate body will be deformed, the discharge hole will be out of roundness and deformed, and the material will be more difficult to extrude, especially the outer circle two to three circles, the discharge is particularly unfavorable, the material will be carbonized if it stays in the discharge hole for a long time, and if the carbonized material stays in the discharge hole, it will produce resistance to the discharge, and the discharge into the calender will affect the product quality. Utility Model Content

[0005] The utility model aims to provide a new type of filtering sealed die head for an extruder with a small filtering dead angle area and a high strength filtering honeycomb plate structure, and a pressure ring is arranged inside the die head, and a butt joint between a right end face of the pressure ring and a left end face of a material guide barrel in the die head is located outside the die head, so that it is easier to take out the pressure ring and clean the molten material when opening and closing the die head.

[0006] In order to solve the above technical problems, the utility model adopts the following technical solutions: a new type of filtering sealed die head for an extruder, including a die head body, a conical extrusion chamber which is smaller on the left and larger on the right, and a heat transfer oil heating chamber located outside the outer circle of the extrusion chamber, an extrusion hole is provided at the left end of the extrusion chamber, and a circular installation chamber is provided at the right end of the extrusion chamber. A filter honeycomb plate, a filter screen and a pressure ring are installed in the circular installation chamber from left to right in sequence, the right outer circle of the filter honeycomb plate and the left end of the pressure ring are crimped with a stop structure, the circumferential edge of the filter screen is crimped in the stop structure, and the right end face of the pressure ring protrudes out of the right side face of the die head body.

[0007] The filter honeycomb plate includes a filter plate body that is generally disc-shaped, and a plurality of left and right transparent discharge holes are opened on the filter plate body. The center line of one discharge hole coincides with the center line of the filter plate body, and the centers of the other discharge holes are evenly arranged on a plurality of concentric circles with the center of the filter plate body as the center.

[0008] All the discharge holes are conical holes with a small right end and a large left end. The filter plate body is a plane structure on one side of the right end of the discharge hole, and is a spherical structure with a raised middle part on one side of the left end of the discharge hole.

[0009] The inlet diameter of all discharge holes is 8mm, the taper of the discharge holes on the two outermost concentric circles is 1:30, and the taper of the other discharge holes is 1:50.

[0010] The left side of the die head body is provided with guide wheels above and below the extrusion hole, respectively, and the top of the die head body is provided with a temperature gauge for monitoring the temperature of the heat transfer oil heating cavity.

[0011] The circumferential surface of the stop structure is a conical surface with a small left side and a large right side, and the pressure ring is composed of two semicircular rings with the same structure.

[0012] By adopting the above technical scheme, on the head of the extruder that is rotatably connected to the front or rear side of the die head of the utility model by a hinge, the right end face of the die head is buckled to the left end of the head, and the right end face of the pressure ring is butted and sealed with the left end face of the guide barrel protruding from the left end of the head. The inner diameter of the pressure ring is slightly smaller than the inner diameter of the guide barrel, so that even if the pressure ring and the guide barrel have a slight eccentricity deviation, the pressure ring will not block the movement of the material from right to left, thereby avoiding the generation of a filtering dead angle. In addition, when the die head is opened, due to the viscosity of the molten material, the pressure ring and the filter honeycomb plate are bonded together, so that the pressure ring and the die head are separated from the guide barrel together, and it is more convenient and quick to remove the pressure ring on the die head. A planar crimping seal is adopted between the pressure ring and the guide barrel, and the annular sealing surface is outside the head, and the molten material bonded here is also convenient to clean.

[0013] The left half of the pressure ring is installed in the circular installation chamber of the mold head body, which positions the pressure ring in the radial direction and makes the crimping concentricity between the pressure ring and the filter honeycomb plate better. The left end of the pressure ring presses the filter screen to the right side of the filter honeycomb plate through the stop structure. The stop structure is located inside the mold head body, and the sealing effect is better.

[0014] First, the two semicircular rings of the pressure ring are respectively sleeved on the right stop structure of the filter honeycomb plate in the radial direction, and then the pressure ring and the filter honeycomb plate are easily installed into the inner hole of the mold head body, which makes installation more convenient. After the filter honeycomb plate and the pressure ring are installed into the inner hole of the mold head body, because the right side of the pressure ring is outside the mold head body, the pressure ring has a tendency to move to the right under the action of its own gravity, and a small gap is generated between the left end face of the pressure ring and the vertical surface of the stop structure of the filter honeycomb plate. At the same time, the outer diameters of the two semicircular rings are radially enlarged by the conical stop surface of the filter honeycomb plate, which is smaller on the left and larger on the right, to be consistent with the inner hole of the mold head body. The outer circle of the pressure ring is limited by the inner hole of the mold head body. At the same time, because the circumferential surface of the stop structure is a conical surface with a smaller left and a larger right, it is ensured that the pressure ring is hooked by the conical stop of the filter honeycomb plate and will not automatically fall off from the inner hole of the mold head body to the right. When replacing the filter, the filter honeycomb plate, filter screen and pressure ring need to be removed from the die head body. The removal operation is as follows: first knock the pressure ring to move it to the left, and the outer circle of the pressure ring is separated from the inner circle of the die head body. Then use a long rod to pass through the extrusion hole at the left end of the die head body and extend into the extrusion cavity to press the filter honeycomb plate to the right. In this way, the filter honeycomb plate, filter screen and pressure ring are pressed out of the inner hole of the die head body.

[0015] The discharge hole arrangement structure of the filter honeycomb plate is more uniform and compact, and the spacing between adjacent discharge holes is smaller, which increases the passing area of ​​the filter plate body, makes the discharge smoother, and greatly increases the discharge volume under the same filtration pressure. At the same time, due to the reduction of dead corner area, the carbonization of the material is also reduced or even avoided.

[0016] The raised spherical structure in the middle of the filter plate body makes the middle thick and the edge thin, which improves the mechanical strength. The filter plate body does not deform, ensuring that the slender discharge hole maintains good permeability.

[0017] The taper of the discharge holes on the two outermost concentric circles is 1:30. This structure of the discharge holes makes the outlet diameter larger, so that the material passes through the discharge holes in the two outermost circles more quickly, thereby improving the filtration efficiency and avoiding carbonization of the material.

[0018] Since the number of discharge holes opened on the filter plate body with equal diameter increases, the edge thickness is reduced and the middle thickness is increased, the weight of the entire filter plate body is reduced, thereby reducing the manufacturing cost.

[0019] To sum up, the utility model has a scientific principle and a simple structure. By improving the structure of the filter honeycomb plate and changing the position of the pressure ring, the centrality and sealing effect of the docking between the components are improved. It is more convenient and quick to remove the pressure ring and clean up the waste during maintenance. The structural strength of the filter honeycomb plate is improved, the filtration area is increased, the material passing efficiency is improved, and the quality of the filtered material is also greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the plane structure of the utility model;

[0021] Figure 2 yes Figure 1 A magnified image of the medium filtration honeycomb plate;

[0022] Figure 3 yes Figure 2 Enlarged view of point A in the middle;

[0023] Figure 4 It is a schematic diagram of the plane distribution of the discharge holes of the filter honeycomb plate;

[0024] Figure 5 It is a schematic diagram of the arc-shaped distribution of the center line of the discharge holes;

[0025] Figure 6 It is a structural diagram of the pressure ring. DETAILED DESCRIPTION

[0026] The implementation of the utility model is further described in detail below in conjunction with the drawings and examples.

[0027] like Figure 1-Figure 6As shown, a new type of filtering sealed die head for an extruder of the utility model comprises a die head body 14, an extrusion chamber 15 which is smaller on the left and larger on the right and is in a conical shape is arranged inside the die head body 14, and a heat transfer oil heating chamber 16 is located outside the outer circle of the extrusion chamber 15, an extrusion hole 17 is arranged at the left end of the extrusion chamber 15, and a circular installation chamber is arranged at the right end of the extrusion chamber 15, in which a filter honeycomb plate 18, a filter screen 19 and a pressure ring 20 are sequentially installed from left to right, the outer circle on the right side of the filter honeycomb plate 18 and the left end of the pressure ring 20 are crimped with a stop structure 66, the circumferential edge of the filter screen 19 is crimped in the stop structure 66, and the right end face of the pressure ring 20 protrudes out of the right side face of the die head body 14.

[0028] The filter honeycomb plate 18 includes a filter plate body 21 that is in the shape of a disk as a whole. The filter plate body 21 is provided with a plurality of left and right transparent discharge holes 22. The center line of one discharge hole 22 coincides with the center line of the filter plate body 21. The centers of the other discharge holes 22 are evenly arranged on a plurality of concentric circles with the center of the filter plate body 21 as the center. The center lines of the discharge holes 22 on the concentric circles extending outward from the center of the filter plate body 21 are distributed in an arc shape (e.g., Figure 4 and Figure 5 The arc line in 27).

[0029] All the discharge holes 22 are conical holes with a small right end and a large left end. The filter plate body 21 has a plane structure 24 on one side of the right end of the discharge hole 22 and a spherical structure 23 with a raised middle portion on one side of the left end of the discharge hole 22.

[0030] The inlet diameters of all the discharge holes 22 are 8 mm, the tapers of the discharge holes 22 on the two outermost concentric circles are both 1:30, and the tapers of the other discharge holes 22 are all 1:50.

[0031] A guide wheel 25 is provided on the left side of the die head body 14 above and below the extrusion hole 17 , respectively. A temperature gauge 26 for monitoring the temperature of the heat transfer oil heating chamber 16 is provided on the top of the die head body 14 .

[0032] The circumferential surface of the stop structure 66 is a conical surface 67 that is smaller on the left and larger on the right. The pressure ring 20 is composed of two semicircular rings 68 with the same structure.

[0033] On the head of the extruder that is connected to the front or rear side of the die head of the utility model by hinge rotation, the right end face of the die head is buckled to the left end of the head, and the right end face of the pressure ring 20 is butted and sealed with the left end face of the guide barrel protruding from the left end of the head. The inner diameter of the pressure ring 20 is slightly smaller than the inner diameter of the guide barrel, so that even if the pressure ring 20 and the guide barrel have a slight non-concentric deviation, the pressure ring 20 will not block the movement of the material from right to left, thereby avoiding the generation of a filtering dead angle. In addition, when the die head is opened, due to the viscosity of the molten material, the pressure ring 20 and the filter honeycomb plate 18 are bonded as one, so that the pressure ring 20 and the die head are separated from the guide barrel, and it is more convenient and quick to remove the pressure ring 20 on the die head. The pressure ring 20 and the guide barrel are sealed by a flat crimping method, and the annular sealing surface is outside the head, and the molten material bonded here is also convenient to clean.

[0034] The left half of the pressure ring 20 is installed in the circular installation chamber of the mold head body 14, and the pressure ring 20 is positioned in the radial direction, so that the concentricity of the crimping fit between the pressure ring 20 and the filter honeycomb plate 18 is better. The left end of the pressure ring 20 presses the filter screen 19 to the right side of the filter honeycomb plate 18 through the stop structure 66. The stop structure 66 is located inside the mold head body 14, and the sealing effect is better.

[0035] First, the two semicircular rings 68 of the pressure ring 20 are respectively sleeved on the right stop structure 66 of the filter honeycomb plate 18 along the radial direction, and then the pressure ring 20 and the filter honeycomb plate 18 are easily installed into the inner hole of the mold head body 14, which is more convenient for installation. After the filter honeycomb plate 18 and the pressure ring 20 are installed into the inner hole of the die head body 14, since the right side of the pressure ring 20 is outside the die head body 14, the pressure ring 20 tends to move to the right under the action of its own gravity, and a small gap is generated between the left end face of the pressure ring 20 and the vertical surface of the stop structure 66 of the filter honeycomb plate 18. At the same time, the outer diameters of the two semicircular rings 68 are radially enlarged by the conical stop surface of the filter honeycomb plate 18 with a smaller left and a larger right, so as to be consistent with the inner hole of the die head body 14, and the outer circle of the pressure ring 20 is limited by the inner hole of the die head body 14. At the same time, since the circumferential surface of the stop structure 66 is a conical surface with a smaller left and a larger right, it is ensured that the pressure ring 20 is hooked by the conical stop of the filter honeycomb plate 18 and will not automatically fall off from the inner hole of the die head body 14 to the right. When replacing the filter screen 19, it is necessary to remove the filter honeycomb plate 18, the filter screen 19 and the pressure ring 20 from the die head body 14. The removal operation is as follows: first knock the pressure ring 20 to move it to the left, and the outer circle of the pressure ring 20 is separated from the inner circle of the die head body 14. Then use a long rod to pass through the extrusion hole at the left end of the die head body 14 and extend it into the extrusion cavity to press the filter honeycomb plate 18 to the right. In this way, the filter honeycomb plate 18, the filter screen 19 and the pressure ring 20 are pressed out of the inner hole of the die head body 14.

[0036] The arrangement structure of the discharge holes 22 of the filter honeycomb plate 18 is more uniform and compact, and the spacing between adjacent discharge holes 22 is smaller, which increases the passing area of ​​the filter plate body 21, makes the discharge smoother, and greatly improves the discharge volume under the same filtering pressure. At the same time, due to the reduction of dead corner area, carbonization of materials is also reduced or even avoided.

[0037] The raised spherical structure 23 in the middle of the filter plate body 21 makes the middle thick and the edge thin, thereby improving the mechanical strength. The filter plate body 21 does not deform, ensuring that the elongated discharge hole 22 maintains good permeability.

[0038] The tapers of the discharge holes 22 on the two outermost concentric circles are both 1:30. This structure of the discharge holes 22 makes the outlet diameter larger, so that the material passes through the two outermost circles of discharge holes 22 more quickly, thereby improving the filtration efficiency and avoiding carbonization of the material.

[0039] Since the number of discharge holes 22 opened on the filter plate body 21 of equal diameter increases, the edge thickness is reduced and the middle thickness is increased, the weight of the entire filter plate body 21 is reduced, thereby reducing the manufacturing cost.

[0040] The above embodiments illustrate the basic principles and features of the utility model, but the above only illustrates the preferred embodiments of the utility model and is not limited by the embodiments. Under the inspiration of this patent, ordinary technicians in this field can also make many forms of deformation and improvement without departing from the purpose of the utility model and the scope of protection of the claims, which are all within the scope of protection of the utility model. Therefore, the patent and protection scope of the utility model shall be subject to the attached claims.

Claims

1. A novel filter-sealed die head for an extruder, comprising a die head body, a conical extrusion cavity with a small left side and a large right side, and a heat transfer oil heating cavity located outside the outer circle of the extrusion cavity, an extrusion hole is arranged at the left end of the extrusion cavity, and a circular installation chamber is arranged at the right end of the extrusion cavity, characterized in that: A filter honeycomb plate, a filter screen and a pressure ring are installed in the circular installation chamber from left to right. The right outer circle of the filter honeycomb plate and the left end of the pressure ring are crimped with a stop structure, the circumferential edge of the filter screen is crimped in the stop structure, and the right end face of the pressure ring protrudes from the right side face of the mold head body.

2. The novel filter sealing die head for extruder according to claim 1, characterized in that: The filter honeycomb plate includes a filter plate body that is generally disc-shaped, and a plurality of left and right transparent discharge holes are opened on the filter plate body. The center line of one discharge hole coincides with the center line of the filter plate body, and the centers of the other discharge holes are evenly arranged on a plurality of concentric circles with the center of the filter plate body as the center.

3. The novel filter sealing die head for extruder according to claim 2, characterized in that: All the discharge holes are conical holes with a small right end and a large left end. The filter plate body is a plane structure on one side of the right end of the discharge hole, and is a spherical structure with a raised middle part on one side of the left end of the discharge hole.

4. The novel filter sealing die head for extruder according to claim 3, characterized in that: The inlet diameter of all discharge holes is 8mm, the taper of the discharge holes on the two outermost concentric circles is 1:30, and the taper of the other discharge holes is 1:

50.

5. A novel filter sealing die head for an extruder according to any one of claims 1 to 4, characterized in that: The left side of the die head body is provided with guide wheels above and below the extrusion hole, respectively, and the top of the die head body is provided with a temperature gauge for monitoring the temperature of the heat transfer oil heating cavity.

6. A novel filter sealing die head for an extruder according to any one of claims 1 to 4, characterized in that: The circumferential surface of the stop structure is a conical surface with a small left side and a large right side, and the pressure ring is composed of two semicircular rings with the same structure.

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