A high-pressure homogenizing extrusion system for the production of thermal insulation strips

Abstract

The present invention provides a high-pressure homogenizing extrusion system for producing thermal insulation strips, and belongs to the technical field of thermal insulation strip production equipment. It includes a main barrel and an extrusion screw rotatably connected in the main barrel, and the two ends of the main barrel are respectively provided with a feed port and a pressure regulating head, and the extrusion screw has a heating section, a mixing section and a discharging section in sequence along the material running direction, and the heating section includes a rod section 1 and a spiral guide piece 1 located outside the rod section 1, and the mixing section includes a rod section 2 and two spiral guide pieces 2 located outside the rod section 2, and the discharging section includes a rod section 3 and a spiral guide piece 3 located outside the rod section 3, and the head ends of the two spiral guide pieces 2 are connected and then connected to the end of the spiral guide piece 1, and the ends of the two spiral guide pieces 2 are connected and then connected to the head end of the spiral guide piece 3; at least one spiral guide piece 2 is provided with a plurality of through-flow grooves that penetrate the two sides of the spiral guide piece 2. The present invention has the advantages of being able to improve the homogenization degree of the material.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal insulation strip production equipment and relates to a high-pressure homogenization extrusion system for producing thermal insulation strips. Background Art

[0002] The heat insulation strips used in thermally-insulated aluminum doors and windows can block the heat transfer between the profiles of the main body of the doors and windows, thereby reducing the heat conduction between different spaces, and can play a role in energy conservation and environmental protection. According to the main material, the heat insulation strips are divided into two types: PVC type and PA66 type (also known as polyamide 66 or nylon 66). Since PA66 is significantly better than PVC type in basic performance indicators such as toughness and heat insulation effect, PVC type heat insulation strips are basically eliminated by the market.

[0003] The main materials of PA66 thermal insulation strips are PA66 monomer and glass fiber, as well as auxiliary materials such as lubricants, anti-glass fiber exposure agents, toughening agents, and processing aids. The main materials and auxiliary materials are mixed and then pressurized and melted by an extruder and extruded through the corresponding mold. They are cooled and formed during and after demolding. After traction (applying tension), the materials are collected to form strip blanks, which are then cut according to the designed size. Before entering the extruder, different materials need to be measured and sent to the mixer for mixing and homogenization. Since most of the raw materials are solid and only a small proportion of auxiliary materials are liquid, it is inevitable that the raw materials will "form a mass" (or agglomerate) when they are mixed. It is difficult to completely eliminate the agglomerates by mechanically stirring and homogenizing these raw materials at room temperature (non-molten state); although traditional single-screw extruders can pressurize and guide the materials during the process, Although it can eliminate lumps, it only liquefies the materials that have reached the melting temperature among all the materials, and cannot make these materials homogenized again, especially the existence of glass fiber. The glass fiber is far from reaching the melting (or softening) temperature in the extruder (about 200°C). The glass fiber wrapped in the lump is in a state of flowing along the spiral groove under the material guiding action of the screw. The exchange and flow between the materials are not strong, resulting in the raw materials not being able to be well homogenized before entering the extrusion mold, which affects the performance stability of the insulation strip product; the twin-screw extruder can overcome the problem of lumps due to the bite between the main and auxiliary screws. The original cost and use cost of a single twin-screw extruder are much higher than those of a single screw extruder. Therefore, for the single-screw extrusion in the prior art, there are technical defects.

[0004] In addition, the control of extrusion pressure during the production of thermal insulation strips is particularly critical. At present, the way to control the extrusion pressure is generally to replace the extrusion head (or replace the pressure regulating filter plate and filter screen at the extrusion head) and adjust the size of the material flow cross-section output by the extruder to adjust the extrusion pressure. This method is particularly cumbersome for the debugging work before the production of thermal insulation strips of different models (such as the cross-sectional shape of the thermal insulation strip, different material ratios, etc.), and it is impossible to adjust the extrusion pressure without stopping the machine. Simply controlling the speed of the extrusion screw to achieve pressure regulation is very dependent on the operator's experience (because simply controlling the change in the speed of the extrusion screw will cause a change in the feed speed. At this time, the raw material heating temperature, the extrusion mold cooling temperature, etc. all need to be adjusted). Summary of the invention

[0005] The purpose of the present invention is to provide a high-pressure homogenizing extrusion system for the production of thermal insulation strips in view of the above-mentioned problems existing in the prior art. The technical problem to be solved by the present invention is how to achieve re-mixing of materials in a molten state in a single-screw extrusion system.

[0006] The object of the present invention can be achieved through the following technical solutions: a high-pressure homogenizing extrusion system for producing thermal insulation strips, comprising a main barrel and an extrusion screw rotatably connected in the main barrel, the two ends of the main barrel respectively having a feed port and a pressure regulating head, characterized in that the extrusion screw has a heating section, a mixing section and a discharging section in sequence along the material running direction, the heating section comprises a rod section one and a spiral guide vane one located outside the rod section one, the mixing section comprises a rod section two and two spiral guide vanes two located outside the rod section two, the discharging section comprises a rod section three and a spiral guide vane three located outside the rod section three, the head ends of the two spiral guide vanes two are connected to the end of the spiral guide vane one, the ends of the two spiral guide vanes two are connected to the head end of the spiral guide vane three; at least one spiral guide vane two is provided with a plurality of flow grooves running through the two side surfaces of the spiral guide vane two.

[0007] Furthermore, the through-flow grooves are distributed on one of the spiral guide vanes 2, and the spiral guide vane 2 on which the through-flow grooves are distributed is located behind the other spiral guide vane 2.

[0008] Furthermore, the rod segment one, the rod segment two and the rod segment three are of the same diameter and axis.

[0009] Furthermore, the spiral pitch of the spiral guide blade 1 gradually decreases from the head end to the tail end, and the spiral pitch of the spiral guide blade 3 gradually decreases from the head end to the tail end.

[0010] Furthermore, the spiral guide vane 2 on which the through-flow grooves are distributed has a plurality of peak values ​​in the spiral pitch from the head end to the tail end; and the spiral pitch at each location of the other spiral guide vane 2 is a fixed value.

[0011] Furthermore, the flow groove is arranged at the connection between the second spiral guide vane and the second rod segment.

[0012] After preliminary homogenization, the mixed material enters the heating section, where it is heated and PA66 is melted. Under the action of hot melting, pressurization and material guiding in the heating section, after the material enters the mixing section, the end of the spiral guide blade 1 is divided into two to form two spiral guide blades 2. During the process of the change of the spiral pitch of the two spiral guide blades 2, the pressure between the two spiral guide blades 2 also changes accordingly, so that the material flows back and forth between the two sides of the spiral guide blade provided with the through-flow groove through the through-flow groove, including the downstream flow from the two spiral guide blades 2 to the outside and the countercurrent flow from the outside into the two spiral guide blades, thereby realizing the forced exchange of fluid materials, overcoming the problem in the traditional single-screw extrusion system that the fluid materials only flow downstream in the extrusion direction, causing the powder materials to be in blocks and cannot be well exchanged and mixed with other materials during the extrusion process; and improving the product stability of the single-screw extrusion system.

[0013] Furthermore, the pressure regulating head includes a temporary storage box, a shrinking cylinder connecting the main barrel and the temporary storage box, and a connecting rod rotatably connected to the end of the extrusion screw, a coil spring is sleeved on the connecting rod, and both ends of the shrinking cylinder respectively have a flare, and both ends of the coil spring extend to the two flares respectively; the spiral groove formed by the gap between adjacent circles of the coil spring is a flow channel between the two flares; the connecting rod is slidably connected with a pressure regulating plate that rests on one end of the coil spring close to the temporary storage box, and the pressure regulating plate is controlled by a driving unit that can drive the pressure regulating plate to slide on the connecting rod, and the coil spring is in a compressed state.

[0014] Furthermore, the coil spring is a hollow tube, comprising two mutually parallel coil sections, the connection point of the two coil sections being fixed on a connecting rod, and the two free ends of the coil spring being respectively connected to a liquid inlet hose and a liquid return hose, and the temperature intervention of the extruded material is achieved by circulating liquid heating medium into the hollow cavity of the coil spring.

[0015] Furthermore, the driving unit is a magnetic driving component.

[0016] Furthermore, the driving unit is a hydraulic cylinder.

[0017] By adjusting the extrusion force applied to the coil spring, the distance between adjacent coils of the coil spring is controlled, thereby changing the flow channel of the discharge material. Under the condition of a constant extruder screw speed, the discharge resistance and thus the discharge pressure can be controlled by simply changing the size of the flow channel. This pressure regulation method can be carried out without stopping the machine, and this pressure regulation has little effect on the variation of supporting parameters in the production process of other thermal insulation strips. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a high-pressure homogenizing extrusion system used in the production of the thermal insulation strip.

[0019] Figure 2 yes Figure 1 sectional view of .

[0020] Figure 3 It is a schematic diagram of the structure of the extrusion screw.

[0021] Figure 4 yes Figure 2 Enlarged view of part A in the figure.

[0022] Figure 5 yes Figure 3 Enlarged view of part B in the middle.

[0023] In the figure, 1. main barrel; 11. feed inlet; 2. extrusion screw; 21. heating section; 21a. rod section one; 21b. spiral guide vane one; 22. mixing section; 22a. rod section two; 22b. spiral guide vane two; 23. discharge section; 23a. rod section three; 23b. spiral guide vane three; 3. flow channel; 4. temporary storage box; 5. shrinking cylinder; 51. flaring; 6. connecting rod; 7. spiral spring; 71. circulation channel; 72. pressure regulating plate; 73. liquid inlet hose; 74. liquid return hose; 8. driving unit. DETAILED DESCRIPTION

[0024] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0025] like Figure 1 , Figure 2 , Figure 3 and Figure 5 As shown, a high-pressure homogenizing extrusion system for producing insulation strips comprises a main barrel 1 and an extrusion screw 2 rotatably connected in the main barrel 1. Both ends of the main barrel 1 are provided with a feed inlet 11 and a pressure regulating die head. The difference from the traditional single-screw extrusion system is that the extrusion screw 2 has a heating section 21, a mixing section 22 and a discharging section 23 in sequence along the material running direction. The heating section 21 comprises a rod section 21a and a spiral guide piece 21b located outside the rod section 21a. The mixing section 22 comprises Rod segment two 22a and two spiral guide blades two 22b located outside rod segment two 22a, the discharge segment 23 includes rod segment three 23a and a spiral guide blade three 23b located outside rod segment three 23a, the head ends of the two spiral guide blades two 22b are connected and then connected to the end of the spiral guide blade one 21b, the ends of the two spiral guide blades two 22b are connected and then connected to the head end of the spiral guide blade three 23b; at least one spiral guide blade two 22b is provided with a plurality of flow grooves 3 that pass through the two sides of the spiral guide blade two 22b.

[0026] The specific description of the extrusion screw 2 is: the rod segment 1 21a, the rod segment 22a, the rod segment 3 23a, the spiral guide blade 1 21b, the spiral guide blade 22b and the spiral guide blade 3 23b are an integrated structure, and the end of the spiral guide blade 1 21b is divided into two to form two spiral guide blades 22b. The two spiral guide blades 22b are contracted at the early ends and smoothly connected with the head ends of the spiral guide blade 3 23b.

[0027] In order to avoid material clogging and retention at the beginning and end of the two spiral guide vanes 21b where the spiral pitch gradually disappears, it is best to have a flow groove 3 at the place where the gradual disappearance occurs to avoid smooth flow of material at this place. Furthermore, the structure can be adjusted so that the beginning and end of the two spiral guide vanes 21b are arranged in a smooth curved shape due to the gradual change of the spiral pitch, so that there is no gradual minimal gap structure at the ends of the two spiral guide vanes 22b.

[0028] The through-flow grooves 3 are distributed on one of the spiral guide vanes 22b, and the spiral guide vane 22b on which the through-flow grooves 3 are distributed is located behind the other spiral guide vane 22b.

[0029] The rod section 1 21a, the rod section 22a and the rod section 3 23a are of the same diameter and axis; the pitch of the spiral guide blade 1 21b gradually decreases from the beginning to the end, and the pitch of the spiral guide blade 3 23b gradually decreases from the beginning to the end. Of course, based on other properties, the extrusion screw 2 can also be a multi-diameter variable diameter structure, but it is necessary to generally maintain a certain pressure when the material enters the mixing section 22 to increase the strength of the material exchange flow, and the pressure required when discharging the material must be maintained.

[0030] The spiral guide blade 2 22b with the through-flow groove 3 has multiple peaks in the pitch from the head end to the tail end; the pitch of the other spiral guide blade 2 22b at each location is a fixed value. The so-called peaks refer to the location where the pitch of the two spiral guide blades 2 2b is larger, which can make the change of the pitch of the two spiral guide blades have multiple cycles from small to large and then from large to small, so as to increase the frequency of material squeeze and mixing.

[0031] The through-flow groove 3 is arranged at the connection between the spiral guide blade 22b and the rod segment 22a. Arranging the through-flow groove 3 at the bottom of the spiral guide blade 22b can avoid the friction of the material caused by the rotation of the extrusion screw 2 relative to the inner wall of the main barrel 1 at the notch compared to setting it at the top, and compared to setting it in the middle of the spiral guide blade 22b, it can reduce the probability of the material being retained at the bottom of the groove between the two spiral guide blades.

[0032] After preliminary homogenization, the mixed material enters the heating section 21, where it is heated and the PA66 is melted. Under the heat melting, pressurization and material guiding action of the heating section 21, the material enters the mixing section 22. Since the end of the spiral guide blade 1 21b is divided into two, two spiral guide blades 22b are formed. During the process of the change of the spiral pitch of the two spiral guide blades 22b, the pressure between the two spiral guide blades 22b also changes accordingly, so that the material flows back and forth between the two sides of the spiral guide blade provided with the through-flow groove 3 through the through-flow groove 3, including the downstream flow from the two spiral guide blades 22b to the outside and the countercurrent flow from the outside into the two spiral guide blades, thereby realizing the forced exchange of the fluid material, overcoming the problem in the traditional single-screw extrusion system that the fluid material only flows downstream in the extrusion direction, causing the powder to be in a block and cannot be well exchanged and mixed with other materials during the extrusion process; and improving the product stability of the single-screw extrusion system.

[0033] like Figure 2 and Figure 4 As shown, the pressure regulating die head includes a temporary storage box 4, a shrinking cylinder 5 connecting the main barrel 1 and the temporary storage box 4, and a connecting rod 6 rotatably connected to the end of the extrusion screw 2, a coil spring 7 is sleeved on the connecting rod 6, and both ends of the shrinking cylinder 5 have a flare 51, and both ends of the coil spring 7 extend to the two flares 51 respectively; the spiral groove formed by the gap between adjacent circles of the coil spring 7 is a flow channel 71 between the two flares 51; the connecting rod 6 is slidably connected with a pressure regulating plate 72 that abuts against one end of the coil spring 7 close to the temporary storage box 4, and the pressure regulating plate 72 is controlled by a driving unit 8 that can drive the pressure regulating plate 72 to slide on the connecting rod 6, and the coil spring 7 is in a compressed state;

[0034] The spiral direction of the spiral spring 7 is opposite to that of the extrusion screw 2, which can buffer the material extruded by the extruder and reduce the fluid flow shock, especially in the initial startup and exhaust stages, and can reduce the negative impact of the flow shock on the pressure regulation.

[0035] Due to the rotational connection between the connecting rod 6 and the end of the extrusion screw 2, the rotation of the extrusion screw 2 will not cause friction between the coil spring 7 and the inner wall of the shrinking tube 5, so that the coil spring 7 may only wear against the inner wall of the shrinking tube 5 during the pressure adjustment process; in addition, in the present application, there may be a certain gap between the coil spring 7 and the connecting rod 6, and between the coil spring 7 and the inner wall of the shrinking tube 5. In this case, the circulation channel 71 is the main channel, and the above-mentioned gap is an auxiliary circulation channel for logistics; since the two ends of the coil spring 7 extend to the two expansions 51, the inlet and outlet of the circulation channel 71 are smooth, which is also the premise that the coil spring 7 can still fully occupy the shrinking tube 5 after being squeezed and deformed, and the condition that the end of the coil spring 7 is irregular and needs to be away from the shrinking tube 5, so that the liquid inlet hose 73 and the liquid return hose 74 are easy to set and pull, and the middle fixed point of the coil spring 7 will not affect the discharge of materials.

[0036] The coil spring 7 is a hollow tube. The coil spring 7 includes two parallel spiral sections. The connection between the two spiral sections is fixed on the connecting rod 6. The two free ends of the coil spring 7 are respectively connected to a liquid inlet hose 73 and a liquid return hose 74. The temperature intervention of the extruded material is achieved by circulating a liquid heating medium into the hollow cavity of the coil spring 7. The liquid inlet hose 73 and the liquid return hose 74 are respectively connected to the inlet and outlet of an oil tank, and a temperature-controlled hot fluid is circulated into the coil spring 7, so that the discharge temperature of the extruder can be intervened.

[0037] The driving unit 8 is a magnetic driving member; that is, an electromagnetic driving block sliding on the connecting rod 6 is provided on the connecting rod 6 outside the voltage regulating plate 72, and the electromagnetic driving block is driven by the magnetic force generated by the electromagnet.

[0038] The driving unit 8 is a hydraulic cylinder; the cylinder body is outside the temporary storage box 4, and the push rod is extended into the temporary storage box 4 through a sealing process and is connected to the pressure regulating plate 72.

[0039] The material extruded by the extruder enters the temporary storage box 4 through the expansion 51 on the side away from the temporary storage box 4 through the circulation channel 71, and is fed to the extrusion die after being transferred through the temporary storage box 4. By adjusting the extrusion force applied to the spiral spring 7, the spacing between adjacent coils of the spiral spring 7 is controlled, thereby realizing the change of the discharge circulation channel 71. Under the condition of a constant extruder screw speed, the resistance of the discharge can be controlled by simply changing the size of the circulation channel 71, thereby controlling the discharge pressure. This pressure regulation method can be carried out without stopping the machine, and this pressure regulation has little effect on the variation of supporting parameters in the production process of other thermal insulation strips. In the process of passing through the circulation channel 71, the material can be fully in contact with the outer wall of the spiral spring 7 through the spiral circulation channel 71, thereby making the temperature control of the material more effective and uniform. The cross section of the spiral spring 7 can be circular or rectangular. Since the pressure regulation amplitude is not large, that is, the deformation amplitude of the spiral spring 7 is not large, the part of the connecting hose will hardly have a large rotation amplitude around the circumference of the connecting pipe, and thus will not affect the overall reliability.

[0040] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A high-pressure homogenizing extrusion system for producing thermal insulation strips, comprising a main barrel (1) and an extrusion screw (2) rotatably connected to the main barrel (1), wherein both ends of the main barrel (1) are provided with a feed inlet (11) and a pressure regulating die, respectively. It is characterized in that The extrusion screw (2) has a heating section (21), a mixing section (22) and a discharging section (23) in sequence along the material running direction; the heating section (21) comprises a rod section 1 (21a) and a spiral guide vane 1 (21b) located outside the rod section 1 (21a); ​​the mixing section (22) comprises a rod section 2 (22a) and two spiral guide vanes 2 (22b) located outside the rod section 2 (22a); the discharging section (23) comprises a rod section 2 (22a) and a spiral guide vane 2 (22b) located outside the rod section 2 (22a); Segment three (23a) and a spiral guide blade three (23b) located outside the rod segment three (23a), the head ends of the two spiral guide blades two (22b) are connected and then connected to the end of the spiral guide blade one (21b), and the ends of the two spiral guide blades two (22b) are connected and then connected to the head end of the spiral guide blade three (23b); at least one spiral guide blade two (22b) is provided with a plurality of through-flow grooves (3) penetrating two side surfaces of the spiral guide blade two (22b); The spiral guide vane 2 (22b) on which the through-flow grooves (3) are distributed has a plurality of peak values ​​in the spiral pitch from the head end to the tail end; the spiral pitch of the other spiral guide vane 2 (22b) at each location is a fixed value; The pressure regulating head comprises a temporary storage box (4), a shrinking cylinder (5) connecting the main barrel (1) and the temporary storage box (4), and a connecting rod (6) rotatably connected to the end of the extrusion screw (2), a coil spring (7) is sleeved on the connecting rod (6), the two ends of the shrinking cylinder (5) are respectively provided with a flared opening (51), and the two ends of the coil spring (7) extend to the two flared openings (51) respectively; the spiral groove formed by the gap between adjacent turns of the coil spring (7) is a flow channel (71) between the two flared openings (51); the connecting rod (6) is slidably connected with a pressure regulating plate (72) abutting against one end of the coil spring (7) close to the temporary storage box (4), the pressure regulating plate (72) is controlled by a driving unit (8) capable of driving the pressure regulating plate (72) to slide on the connecting rod (6), and the coil spring (7) is in a compressed state; The spiral direction of the spiral spring (7) is opposite to the spiral direction of the extrusion screw (2); The coil spring (7) is a hollow tube, comprising two mutually parallel coil sections, the connection point of the two coil sections being fixed on a connecting rod (6), and the two free ends of the coil spring (7) being respectively connected to a liquid inlet hose (73) and a liquid return hose (74), so that the temperature intervention of the extruded material is achieved by circulating a liquid heating medium into the hollow cavity of the coil spring (7).

2. A high pressure homogenizing extrusion system for producing thermal insulation strips according to claim 1, It is characterized in that The through-flow grooves (3) are distributed on one of the spiral guide vanes (22b), and the spiral guide vane (22b) on which the through-flow grooves (3) are distributed is located behind the other spiral guide vane (22b).

3. A high-pressure homogenizing extrusion system for producing thermal insulation strips according to claim 1 or 2, It is characterized in that The rod segment one (21a), the rod segment two (22a) and the rod segment three (23a) are of the same diameter and axis.

4. A high-pressure homogenizing extrusion system for producing thermal insulation strips according to claim 1 or 2, It is characterized in that The spiral pitch of the spiral guide blade 1 (21b) gradually decreases from the head end to the tail end, and the spiral pitch of the spiral guide blade 3 (23b) gradually decreases from the head end to the tail end.

5. A high-pressure homogenizing extrusion system for producing thermal insulation strips according to claim 1 or 2, It is characterized in that The through-flow groove (3) is arranged at the connection between the second spiral guide blade (22b) and the second rod segment (22a).

6. A high-pressure homogenizing extrusion system for producing thermal insulation strips according to claim 1 or 2, It is characterized in that The driving unit (8) is a magnetic driving component.

7. A high-pressure homogenizing extrusion system for producing thermal insulation strips according to claim 1 or 2, It is characterized in that The driving unit (8) is a hydraulic cylinder.

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