CN212860356U

CN212860356U - Device for assisting polymer extrusion blending by liquid additive

Info

Publication number: CN212860356U
Application number: CN202020916323.6U
Authority: CN
Inventors: 李东; 马鹏涛; 叶南飚; 黄险波; 廖洋威; 于亚勇
Original assignee: Kingfa Science and Technology Co Ltd
Current assignee: Kingfa Science and Technology Co Ltd
Priority date: 2020-05-26
Filing date: 2020-05-26
Publication date: 2021-04-02
Anticipated expiration: 2030-05-26

Abstract

In order to solve the problem that vaporization, uneven distribution easily take place and lead to the product quality to descend when using the additive among the prior art, the utility model provides a device that blending is extruded to liquid additive auxiliary polymer, its technical scheme lies in: a plasticizing unit for preparing a target product and an injection unit are included; the injection unit is arranged in the plasticizing unit and communicated with the area where the raw materials form the melt, and is used for injecting the liquid additive into the plasticizing unit. The utility model discloses the device is simple, can directly modify on current double helix pole extruder and can realize, and the change volume is little, and the operation is stable, and the fault rate is low, and product quality is reliable and stable, has solved the problem that exists among the prior art.

Description

Device for assisting polymer extrusion blending by liquid additive

Technical Field

The utility model belongs to the technical field of macromolecular material, concretely relates to device that blending is extruded to liquid additive auxiliary polymer.

Background

Polymeric materials often need to be modified to make blends to meet different product requirements. In general, other components such as a polymer, a filler, a reinforcement, and a flame retardant are added to the polymer, and the resulting mixture is subjected to melt-kneading, extrusion-granulation, and the like by a twin-screw extruder, a single-screw extruder, an internal mixer, and the like to prepare a modified polymer material.

The conventional extrusion blending adopts equipment and process conditions of changing the screw combination, the screw rotating speed, the feeding mode, the processing temperature and the like of a double-screw extruder to realize stable extrusion blending and achieve the required product performance. Before extrusion blending, materials are dried and dehydrated, such as polyamide, acrylonitrile-butadiene-styrene terpolymer, polyacrylate and other resins, so as to avoid the defects of material degradation, color change and the like in the processing process. For a hydrolysis-resistant multiphase unstable polymer system, the modes of vacuumizing and the like are often adopted in the blending modification processing process to discharge moisture, volatile components and the like in the material. For polypropylene materials which are applied to automobile interior and are subjected to toughening, strengthening and other modification by various components, a certain amount of water can be added into a particle mixture of the polypropylene materials to improve the smell sense, but the water in the particle mixture is often contacted with a high-temperature machine barrel and then becomes water vapor, most of the water vapor is dissipated, the action effect is limited, the dissipated water vapor is discharged through a feed inlet of an extruder, the smooth feeding of the materials is influenced, and the yield and the production stability are influenced to a certain extent. In addition, for some additives which are melted by heating, decomposed easily by heating and volatilized easily by heating, such as low-melting-point additives, flame retardants, processing oil and the like, the blending of materials is limited by the fact that the materials are difficult to be uniformly mixed, and the properties are changed in the adding process, so that the product quality is influenced.

At present, as in chinese patent application CN11082007, a method for preparing high-performance nano polyester filament, in the step (2), a method of "putting dried polyester chips and additives into a screw extruder for melting" is adopted to add additives. The processing of the polymer by the screw extruder is realized under the double action of the shear heat generated by the rotation of the screw and the external heating, and the shear heat accounts for a large proportion. The polymer is a poor thermal conductor, excessive shearing heat cannot be timely transferred to the screw and is taken away by cooling water, so that the temperature of a melt material is often higher than the display temperature, distribution of the temperature inside the melt is caused due to the structural characteristics of the screw, local overhigh temperature even at the top of a screw edge occurs, an additive is vaporized, and the poor thermal stability component in the blend is not favorable. The viscosity of the polymer is greatly affected by temperature, and the product quality is affected by non-uniform temperature and local high temperature during processing.

It can be seen that in the prior art, when the additive is used, vaporization and uneven distribution are easy to occur, which leads to the reduction of product quality.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem that vaporization, uneven distribution easily take place and lead to the product quality to descend when using the additive among the prior art, the utility model provides a device that blending is extruded to liquid additive auxiliary polymer can effectively solve above-mentioned problem.

In order to achieve the above object, the utility model discloses a concrete scheme does:

the device for extruding and blending the liquid additive auxiliary polymer comprises a plasticizing unit and an injection unit, wherein the plasticizing unit is used for preparing a target product; the method is characterized in that: the injection unit is arranged on the plasticizing unit and is communicated with the area where the raw materials form the melt, and the injection unit is used for injecting the liquid additive into the plasticizing unit.

The plasticizing unit comprises a screw barrel, a screw rod arranged in the screw barrel and a feeding component arranged at the feeding end of the screw barrel; wherein, the screw barrel is provided with exhaust ports which are arranged at intervals and are close to the discharge end; and the exhaust port and the vacuum chamber are respectively communicated, and a negative pressure area is formed in the negative pressure area.

The screw barrel is provided with a mixing area for mixing the melt and the liquid additive, and the mixing area is internally provided with a sensor for detecting the pressure and the temperature in the barrel; the vacuum chamber is communicated with an external negative pressure system, and an instrument is arranged to detect the pressure in the vacuum chamber.

The injection unit comprises a compounding device for mixing two additives, a storage device and a conveying device; wherein the output end of the compounding device is connected with the input end of the storage device and is used for quantitatively conveying the mixed additive to the conveying device through a pipeline; the output end of the conveying device is communicated with a region of the plasticizing unit where the raw materials form the melt.

The compounding device comprises a stock bin I, a stock bin II, a container, a stirring paddle and a metering module; the output ends of the bin I and the bin II are communicated with the input end of the container; a stirring paddle is arranged in the container; the bottom of the container is provided with a metering module for weighing; wherein, the output end of the container is connected with a storage device.

The storage device comprises a storage container, a stirrer and a metering unit; wherein the input of the storage vessel is connected to the output of the compounding device; a stirrer is arranged in the storage container; the bottom of the storage container is provided with a metering unit for weighing; wherein the output end of the storage container is connected with the input end of the conveying device.

The conveying device comprises a high-pressure metering pump; the input end of the high-pressure metering pump is connected with the output end of the storage device, and the output end of the high-pressure metering pump is communicated with a region of the plasticizing unit where the raw materials form melts through a one-way liquid injection valve.

The utility model discloses a basic theory of operation of device that liquid additive assisted polymer extrudes blend is: adding a raw material mixture of a solvent-resistant multiphase unstable polymer through a feed inlet of a double-screw extruder, conveying, melting and mixing under the action of a screw, forming a hole in a region of a screw cylinder, which is corresponding to the region where the mixture is changed into a melt, installing a one-way injection unit, completely filling the space between a screw groove and the cylinder with the melt in the region, and enabling a liquid additive to be deep into the melt corresponding to specific propulsion structures such as a spiral propulsion structure of a liquid injection valve and the like; then, the liquid additive or the non-liquid additive is added into the solvent to form a solution or a suspension, so as to form the liquid additive, and the liquid additive is continuously and quantitatively pumped into the melt through an injection unit by a pump and a pipeline system with metering function and high-pressure conveying capacity. Under the action of pressure, the liquid additive and the solvent at room temperature do not vaporize immediately after being heated in a high-temperature melt, but exist in an overheated state, for example, exist in the form of overheated water, namely subcritical water when water is used as the solvent. Meanwhile, under the action of the screw rotating at high speed, the additive and the solvent components in a superheated state are uniformly dispersed and distributed in the melt and conveyed to a downstream area along with the screw. At least 1 air outlet connected with atmosphere or negative pressure system is set on the downstream screw cylinder to reduce the pressure of the fused material and vaporize the solvent in the additive, so that the fused material is extruded into strips and then granulated.

It is to be understood that: subcritical water means: the boiling point of water is about 220 ℃ when the pressure is 2.4 MPa; the boiling point of water is about 230 ℃ when the pressure is 2.9 MPa; the boiling point of water is about 251 ℃ when the pressure is 4 MPa; the boiling point of water is about 300 ℃ when the pressure is 8 MPa.

Has the advantages that: the utility model adds the additive into the solvent to form the liquid additive, which is helpful to reduce the local high temperature in the melt, so that the overall temperature is reduced and more uniform, which is beneficial to the mixing uniformity of the components; under the action of the screw, the liquid additive and the solvent component in the superheated state are uniformly dispersed and distributed in the melt formed by the raw materials; when the mixture is conveyed to the rear end of the spiral cylinder, the mixture is vaporized into solvent vapor to be discharged or pumped away by a negative pressure system, a great amount of bubbles in the mixture are broken, the interface updating effect is improved, residual monomers and small molecular components in the mixture are removed, and a product with good smell and sense is obtained; even for the filler and the reinforcing component on the polar surface, the method of the utility model can also increase the miscibility with the matrix, improve the dispersion distribution and the interface effect in the non-polar matrix, thereby improving the quality of the product. The liquid additive generates a large amount of bubbles and breaks in the process of evaporation and dissipation, and the mixing effect of the fusion is improved. In addition, the additives which are easily melted by heating, easily decomposed by heating and easily volatilized by heating are liquefied by means of the solvent, can be accurately added on the basis of ensuring the characteristics of the additives, and are uniformly mixed.

The device of the utility model is simple in structure, can directly modify on current double helix pole extruder, the change volume is little, and the operation is stable, and the fault rate is low, and product quality is reliable and stable, has solved the problem that exists among the prior art.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Wherein, the area 1021 in fig. 1 is an area where the raw material is not completely melted; 1023 refers to the region where the liquid additive in a superheated state is merged with the raw material in a molten state.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

As shown in fig. 1, an apparatus for extrusion blending of a liquid additive-assisted polymer comprises a plasticizing unit 1 and an injection unit 2 for preparing a target product, wherein:

preferably, the plasticizing unit 1 can be modified from an existing double-screw extruder, and specifically comprises a screw barrel 101, a screw 102 arranged in the screw barrel 101, and a feeding assembly arranged at the feeding end of the screw barrel 101; for the convenience of dehydration and devolatilization, the screw cylinder 101 is provided with

exhaust ports

1012 and 1013 which are arranged at intervals near the discharge end; the

exhaust ports

1012 and 1013 are connected to vacuum systems which are respectively connected to the

vacuum chambers

107 and 109 and in which the

vacuum chambers

107 and 109 are located outside, and the

negative pressure meters

108 and 1010 are respectively provided to detect pressures in the

vacuum chambers

107 and 109.

It is important that a mixing region 1022 for mixing the molten material and the liquid additive is provided in the screw barrel 101, and a pressure sensor 105 and a temperature sensor 106 for detecting the pressure and temperature in the barrel are provided in the mixing region 1022.

It is to be understood that: the mixing region 1022 described above can be flexibly set according to actual conditions.

Wherein the injection unit 2 comprises a compounding device 201 for mixing two additives, a storage device 202 and a conveying device 204; wherein the output end of the compounding device 201 is connected to the input end of the storage device 202, and is used for quantitatively delivering the mixed additive to the delivery device 204 through the pipeline 203; the output end of the conveying device 204 is communicated with the mixing region 1022, and is used for injecting the liquid additive into the melt in the mixing region 1022, further mixing, and forming uniform fusion through the action of the screw 102.

The conveying device 204 comprises a high-pressure metering pump 2041; the input end of the high-pressure metering pump 2041 is connected to the output end of the storage device 202, and the output end of the high-pressure metering pump 2041 can be communicated with the area of the plasticizing unit 1 where the raw material forms the melt through the one-way liquid injection valve 205.

Specifically, if the liquid additive is a solution or a suspension of two liquid additives or a non-liquid additive and a solvent, the compounding device 201 includes a bin I2011, a bin II2012, a container 2013, a stirring paddle 2014 and a metering module 2015; the output ends of the bin I2011 and the bin II2012 are communicated with the input end of the container 2013; a stirring paddle 2014 is arranged in the container 2013; a metering module 2015 for weighing is arranged at the bottom of the container 2013;

wherein, the output end of the container 2013 is connected with the storage device 202.

The storage device 202 comprises a storage container 2021, a stirrer 2022 and a metering unit 2023; wherein the input of the storage vessel 2021 is connected to the output of the compounding device 201; a stirrer 2022 is arranged in the storage container 2021; a metering unit 2023 for weighing is provided at the bottom of the storage container 2021; wherein the output end of the storage container 2021 is connected with the input end of the conveying device 204; the conveying device 204 comprises a high-pressure metering pump 2041; the input of the high-pressure metering pump 2041 is connected to the output of the storage device 202, and the output of the high-pressure metering pump 2041 injects the liquid additive into the melt in the mixing region 1022 via the regulating valve 2043.

In order to ensure safety, the output end of the high-pressure metering pump 2041 is also provided with a pressure relief pipe in parallel connection with the safety valve 2042 to form a pressure relief pipeline, so that when the pressure in the high-pressure metering pump 2041 is too high, pressure relief is performed, and the safety of a pipeline system is ensured.

During operation, the material 104 is fed into the barrel 101 by the metering feeder 103, conveyed forward by the screw 102, plasticized and melted by the screw 102 in the mixing region 1022 to form a melt, and pressurized by the screw 102 in the mixing region 1022. Multi-component additives are placed in bin I2011 and bin II2012, respectively, added in proportions to compounding vessel 2013, compounded into a homogeneous mixture by paddle 2014, and metering module 2015 is used to indicate the additive proportions and mixture weight. The uniform mixture is delivered to a storage vessel 2021 where the compounded additive is stored, kept uniform by the stirrer 2022, and the dosing unit 2023 indicates the weight of the additive mixture. The additive mixture in the storage device 202 is conveyed to the high-pressure metering pump 2041 through the conveying pipeline 203, the additive mixture is quantitatively output to the mixing area 1022 by the high-pressure metering pump 2041, the liquid additive is guaranteed to be injected into the melt, the pressure sensor 206 can be arranged at the output end of the high-pressure metering pump 2041, the internal pressure of the additive mixture during injection into the melt in the extruder is collected, and in addition, when the pressure is too high, the safety valve 2042 on the pressure relief pipe triggers a protection effect. The mixed materials of the additives and the melt are mixed in the mixing zone 1022 by the action of the screw 102 to form a uniform melt. The fused material is transported by the screw 102, and moves to the areas of the

exhaust ports

1012 and 1013, and water, volatile matters and the like in the fused material are extracted by a vacuum system until the fused material added with the additive is transported to the granulating unit by the screw 102.

Detailed example 1 this example provides an example of using a single water as an additive, namely a water assisted polymer extrusion blending process to improve the odor of the product and produce a high grade product with low odor.

Specifically, as shown in fig. 1, the material 104 is fed into the barrel 101 by the metering feeder 103, and is conveyed forward by the screw 102, and the material is plasticized and melted by the screw 102 in the mixing region 1022 to form a melt, and is pressurized by the screw 102 in the mixing region 1022. Multi-component additives are placed in bin I2011 and bin II2012, respectively, added in proportions to compounding vessel 2013, compounded into a homogeneous mixture by paddle 2014, and metering module 2015 is used to indicate the additive proportions and mixture weight. The uniform mixture is delivered to a storage vessel 2021 where the compounded additive is stored, kept uniform by the stirrer 2022, and the dosing unit 2023 indicates the weight of the additive mixture. The additive mixture in the storage device 202 is conveyed to the high-pressure metering pump 2041 through the conveying pipeline 203, the additive mixture is quantitatively output to the mixing area 1022 through the high-pressure metering pump 2041, the liquid additive is guaranteed to be injected into the melt, the pressure sensor 206 can be arranged at the output end of the high-pressure metering pump 2041, the internal pressure of the additive mixture during injection into the melt in the extruder is collected, and in addition, when the pressure is too high, the safety valve 2042 on the pressure relief pipe triggers the pressure relief protection function. The mixed materials of the additives and the melt are mixed in the mixing zone 1022 by the action of the screw 102 to form a uniform melt. The fused material is transported by the screw 102, and moves to the areas of the

exhaust ports

1012 and 1013, and water, volatile matters and the like in the fused material are extracted by a vacuum system until the fused material added with the additive is transported to the granulating unit by the screw 102. In this embodiment, by means of injecting water into the melt quantitatively, the superheated water and the melt are dispersed uniformly by the screw shearing action of the screw 102, and then the water is vaporized and discharged with the volatile substances in the melt through the

exhaust ports

1012 and 1013, so as to realize devolatilization and obtain a high-grade low-odor product.

Specific example 2: the main differences between this embodiment and embodiment 1 are: a single liquid auxiliary agent, such as a flame retardant, a coupling agent, processing oil and the like, is used as an additive, so that a better material mixing effect is obtained.

Referring to fig. 1, the liquid additive is similar to water in example 1 in addition, and mainly aims to solve the processing difficulties and risks of adding the liquid additive into an extruder after being mixed with materials conventionally, such as uneven mixing with the materials, caking after mixing, volatilization of the liquid additive, odor of the liquid additive, advanced decomposition of the heat sensitive additive, environmental problems and the like.

Other features of this embodiment are the same as those of embodiment 1, and are not described again.

Specific example 3: the main differences between this example and example 1 and 2 are: the method uses powder additive, such as nano filler, dispersant, colorant, reaction assistant, etc. and liquid, such as water, water-alcohol mixed solution, etc., to form suspension as additive, i.e. the powder additive is changed into liquid additive to assist the polymer extrusion blending.

In this embodiment, as shown in fig. 1, an additive and a liquid auxiliary additive are added into a silo I2011 and a silo II2012 respectively, a container 2013 for compounding is added in proportion, the mixture is compounded into a uniform mixture under the action of a stirring paddle 2014, a metering module 2015 is used for indicating the proportion of the additive and the weight of the mixture, the uniform mixture compounded by the compounding device 201 is conveyed to a storage container 2021 for storing the compounded additive, the uniform mixture is kept under the action of a stirrer 2022, a metering unit 2023 indicates the weight of the additive mixture, and then the additive mixture in the storage device 202 is conveyed to a conveying device 204 through a conveying pipeline 203. Other features of this embodiment are the same as those of embodiments 1 and 2, and are not described again.

The embodiment mainly solves the problem that a small amount of powder additives such as nano-filler and toner are difficult to fully disperse in a melt, and solves the problem that the quality of a blending extrusion product is fluctuated due to uneven mixing of a small amount of additives and materials in the conventional mixing process. A small amount of powder additive uses a liquid additive as a carrier, and is separately metered and injected into a polymer melt for full mixing, so that the uniform mixing effect, stable product quality and convenient operation are realized, the odor of the product can be further reduced, and the production of polymers such as high-grade low-odor-grade products and the like is realized.

Specific example 4: the main differences between this example and examples 1, 2 and 3 are: the method of extruding and blending polymer is carried out by using gaseous additive, such as carbon dioxide, and liquid, such as water, water-alcohol mixed solution, etc., as additive, namely, changing the gaseous additive into liquid additive.

In the embodiment, as shown in fig. 1, a gaseous additive and a liquid auxiliary additive are respectively added into a storage bin I2011 and a storage bin II2012 which can be sealed and pressure-maintained, and are proportionally added into a compounding container 2013, gas is dissolved in liquid under the action of a stirring paddle 2014, so that a uniform mixture with certain gas solubility is compounded, a metering module 2015 is used for collecting the additive proportion and the mixture weight, the mixture is compounded into a uniform mixture through a compounding device 201 which can be sealed and pressure-maintained, the uniform mixture is conveyed to a storage container 2021 which can be sealed and pressure-maintained, and a metering unit 2023 indicates the weight of the additive mixture. The additive mixture in the storage device 202, which can be pressure-sealed, is transported to the transport device 204 via the transport line 203. Other features of this embodiment are the same as those of embodiments 1, 2 and 3, and are not described again.

The embodiment mainly solves the problems that gaseous additives such as carbon dioxide are difficult to add and difficult to fully disperse in a melt, and by controlling the solubility, the additives are accurately metered and injected into a polymer melt by taking liquid auxiliary additives as carriers to be fully mixed, so that volatile matters in the materials are further carried and stripped, the odor of the product is further reduced, and the production of high-grade low-odor products is realized.

It is to be understood that: the metrology module 2015 and metrology unit 2023 described herein can be pressure sensors; the paddles 2014 and the agitator 2022 may have the same structure.

It is to be understood that: the single liquid adjuvant described herein may be an aqueous liquid adjuvant.

The above description is only the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily change or replace the technical scope of the present invention. Therefore, the protection scope of the present invention is subject to the protection scope of the claims.

Claims

1. An apparatus for extrusion blending of liquid additive assisted polymers comprises a plasticizing unit (1) and an injection unit (2) for preparing target products; the method is characterized in that: the injection unit (2) is arranged on the plasticizing unit (1), is communicated with the area where the raw materials form the melt, and is used for injecting the liquid additive into the plasticizing unit (1).

2. The apparatus for extrusion blending of a liquid additive-assisted polymer according to claim 1, wherein: the plasticizing unit (1) comprises a screw cylinder (101), a screw (102) arranged in the screw cylinder (101) and a feeding assembly arranged at the feeding end of the screw cylinder (101);

wherein, the screw barrel (101) is provided with exhaust ports (1012, 1013) which are arranged at intervals near the discharge end; the exhaust ports (1012, 1013) are provided so as to communicate with the vacuum chambers (107, 109), respectively.

3. The apparatus for extrusion blending of a liquid additive-assisted polymer according to claim 2, wherein: a mixing area (1022) for mixing the molten material and the liquid additive is arranged on the screw barrel (101), and a sensor for detecting the pressure and the temperature in the barrel is arranged in the mixing area (1022); the vacuum chambers (107, 109) are communicated with an external negative pressure system, and meters are arranged to detect the pressure in the vacuum chambers (107, 109).

4. The apparatus for extrusion blending of a liquid additive-assisted polymer according to claim 1, wherein: the injection unit (2) comprises a compounding device (201) for mixing two additives, a storage device (202) and a conveying device (204);

wherein the output end of the compounding device (201) is connected with the input end of the storage device (202) and is used for quantitatively conveying the mixed additive to the conveying device (204) through a pipeline (203); the output end of the conveying device (204) is communicated with a region of the plasticizing unit (1) where the raw materials form the melt.

5. The apparatus for extrusion blending of liquid additive-assisted polymers as claimed in claim 4, wherein: the compounding device (201) comprises a bin I (2011), a bin II (2012), a container (2013), a stirring paddle (2014) and a metering module (2015);

the output ends of the bin I (2011) and the bin II (2012) are communicated with the input end of the container (2013); a stirring paddle (2014) is arranged in the container (2013); a metering module (2015) for weighing is arranged at the bottom of the container (2013);

wherein the output end of the container (2013) is connected with a storage device (202).

6. The apparatus for extrusion blending of liquid additive-assisted polymers as claimed in claim 4, wherein: the storage device (202) comprises a storage container (2021), a stirrer (2022) and a metering unit (2023);

wherein the input of the storage vessel (2021) is connected to the output of the compounding device (201); a stirrer (2022) is arranged in the storage container (2021); a metering unit (2023) for weighing is arranged at the bottom of the storage container (2021);

wherein the output of the storage container (2021) is connected to the input of the conveying device (204).

7. The apparatus for extrusion blending of liquid additive-assisted polymers as claimed in claim 4, wherein: the conveying device (204) comprises a high-pressure metering pump (2041);

the input end of the high-pressure metering pump (2041) is connected with the output end of the storage device (202), and the output end of the high-pressure metering pump (2041) is communicated with a region of the plasticizing unit (1) where the raw materials form the melt through a one-way liquid injection valve (205).

8. The apparatus for extrusion blending of a liquid additive-assisted polymer of claim 7, wherein: the output end of the high-pressure metering pump (2041) is also provided with a pressure relief pipeline in parallel.