CN211753125U - Expanded perlite fiber composite filter material - Google Patents
Expanded perlite fiber composite filter material Download PDFInfo
- Publication number
- CN211753125U CN211753125U CN202020446012.8U CN202020446012U CN211753125U CN 211753125 U CN211753125 U CN 211753125U CN 202020446012 U CN202020446012 U CN 202020446012U CN 211753125 U CN211753125 U CN 211753125U
- Authority
- CN
- China
- Prior art keywords
- polytetrafluoroethylene
- coating
- filter material
- expanded perlite
- perlite fiber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Filtering Materials (AREA)
Abstract
The application provides an expanded perlite fiber composite filter material which comprises an expanded perlite fiber base layer; one side of the expanded perlite fiber base layer is compounded with a front polytetrafluoroethylene binding layer, a front polytetrafluoroethylene foaming coating and an expanded polytetrafluoroethylene microporous membrane layer which are sequentially contacted, and the other side of the expanded perlite fiber base layer is compounded with a back polytetrafluoroethylene binding layer and a back polytetrafluoroethylene foaming coating which are sequentially contacted; the pore diameter of the bubbles of the polytetrafluoroethylene foaming coating on the front surface is smaller than that of the bubbles of the polytetrafluoroethylene foaming coating on the back surface. The composite filter material has high strength, stable structure and high temperature resistance, and can stably work in a high-temperature environment below 280 ℃; acid corrosion resistance, good filtering performance and long service life, and can meet the use requirements of special working conditions.
Description
Technical Field
The application relates to the technical field of environment-friendly dedusting filter materials, in particular to a high-filtering-precision expanded perlite fiber composite filter material.
Background
High-temperature smoke dust (above 240 ℃) generated under some special working conditions mainly comprises smoke dust and SO2、NOXToxic or corrosive substances such as CO, fluorides, and heavy metals. Such conditions place high demands on the filter material for dust removal, including the need for high strength, low elongation, high temperature resistance, acid corrosion resistance, etc.
In an organic synthetic fiber filter material, a Polytetrafluoroethylene (PTFE) material has excellent characteristics of high and low temperature resistance, corrosion resistance, weather resistance, high lubrication, non-adhesion and the like, and is widely applied to the field of environmental protection and dust removal in recent years. Meanwhile, the polytetrafluoroethylene filter material for filtering high-temperature gas has limited its wide industrial application due to high cost. The inorganic fiber is used as a high-temperature flue gas filtering material, and has great advantages compared with synthetic fibers such as PTFE and the like. The inorganic fiber material comprises glass fiber, basalt fiber, perlite fiber and the like, and is a filter material with high cost performance. The inorganic fiber material has the characteristics of high temperature resistance, chemical corrosion resistance, hydrolysis resistance, high strength, small elongation and the like, and is a high-quality material for filtering high-temperature corrosive gas and smoke dust and filtering corrosive liquid at present. The perlite fiber is a novel high-performance inorganic fiber in recent years, has the characteristics of high strength, low elongation, temperature resistance, corrosion resistance, high cost performance and the like, and particularly has outstanding acid resistance.
Compared with other materials, the two materials have outstanding comprehensive advantages as industrial smoke dust filtering materials, but have the problems of high cost, partial performance index defects and the like, and the popularization and application of the two materials in the field of industrial environment-friendly dust removal are seriously influenced. If the polytetrafluoroethylene material and the inorganic materials such as perlite fiber are simply superposed to form the composite filter material, the filtering performance is difficult to ensure, the service life is short, and the composite filter material is not suitable for long-term application of dust removal under special working conditions such as acid corrosion resistance and the like.
SUMMERY OF THE UTILITY MODEL
In view of this, the application provides an expanded perlite fiber composite filter material, which has the advantages of stable structure, high strength, acid corrosion resistance, good filtering performance, long service life and capability of meeting the use requirements of special working conditions.
The application provides an expanded perlite fiber composite filter material which comprises an expanded perlite fiber base layer; one side of the expanded perlite fiber base layer is compounded with a front polytetrafluoroethylene binding layer, a front polytetrafluoroethylene foaming coating and an expanded polytetrafluoroethylene microporous membrane layer which are sequentially contacted, and the other side of the expanded perlite fiber base layer is compounded with a back polytetrafluoroethylene binding layer and a back polytetrafluoroethylene foaming coating which are sequentially contacted;
the pore diameter of the bubbles of the polytetrafluoroethylene foaming coating on the front surface is smaller than that of the bubbles of the polytetrafluoroethylene foaming coating on the back surface.
Preferably, the expanded perlite fiber base layer is formed by expanding, processing and weaving 5-7 micron fine-denier perlite fiber yarns.
Preferably, the bubble diameter of the front polytetrafluoroethylene foam coating is less than or equal to 30 microns.
Preferably, the thickness of the polytetrafluoroethylene foam coating on the front surface is greater than that of the polytetrafluoroethylene foam coating on the back surface.
Preferably, the thickness of the front polytetrafluoroethylene foam coating is 20-200 microns.
Preferably, the thickness of the expanded polytetrafluoroethylene microporous membrane layer is 5-10 microns.
Preferably, the front polytetrafluoroethylene foam coating and the back polytetrafluoroethylene foam coating independently comprise graphene with the diameter of 0.1-3 microns. The graphene is a particulate matter mixed in the coating agent added to the coating, and can be uniformly distributed in a mode of uniform stirring and the like.
Preferably, the expanded perlite fiber composite filter material is in a bag shape sewn by PTFE sewing threads.
The application provides a preparation method of an expanded perlite fiber composite filter material, which comprises the following steps:
s1, dipping the perlite fiber bulked cloth with polytetrafluoroethylene emulsion, and then sequentially drying and sintering to form polytetrafluoroethylene bonding layers on two sides of the perlite fiber bulked cloth;
s2, performing front-side foaming coating treatment on the pearl fiber expanded cloth forming the polytetrafluoroethylene bonding layer by using a first coating agent, wherein the first coating agent comprises polytetrafluoroethylene and a first foaming agent, and forming a front-side polytetrafluoroethylene foaming coating on the front-side polytetrafluoroethylene bonding layer;
and, carrying out reverse side foam coating treatment by using a second coating agent, wherein the second coating agent comprises polytetrafluoroethylene and a second foaming agent, the first coating agent and the second coating agent independently and optionally comprise graphene, and a reverse side polytetrafluoroethylene foam coating is formed on the reverse side polytetrafluoroethylene bonding layer;
the pore diameter of the bubbles of the polytetrafluoroethylene foaming coating on the front surface is smaller than that of the bubbles of the polytetrafluoroethylene foaming coating on the back surface;
and S3, compounding the expanded polytetrafluoroethylene microporous film on the front polyethylene foam coating in a hot-pressing film covering mode to prepare the expanded perlite fiber composite filter material.
Preferably, in step S3, the temperature of the hot-pressing coating is 370 to 415 ℃, and the speed of the hot-pressing coating is 2 to 7 m/min.
Compared with the prior art, the expanded perlite fiber composite filter material that this application provided mainly comprises six layers, wherein uses expanded perlite fiber substrate as the basis, openly is in proper order from the filter material: the expanded polytetrafluoroethylene microporous membrane layer, the front polytetrafluoroethylene foam coating, the front polytetrafluoroethylene bonding layer, the expanded perlite fiber base layer, the back polytetrafluoroethylene bonding layer and the back polytetrafluoroethylene foam coating; and the pore diameter of the bubbles of the front polytetrafluoroethylene foam coating is smaller than that of the bubbles of the back polytetrafluoroethylene foam coating. This application adopts expanded perlite fiber substrate, and acid corrosion resistance is excellent. In this application, the polytetrafluoroethylene anchor coat not only to the comprehensive infiltration protection of filter material perlite fiber, reinforcing wearability and folding endurance, can play the effect of bridging moreover, will expand perlite fiber basic unit and polytetrafluoroethylene foam coating firm consolidation together. The application adopts a double-sided foaming coating technology, and the polytetrafluoroethylene foaming coating with smaller pore diameter is prepared on the front surface of the filter material, so that the conversion from deep filtration to surface filtration is realized; the pore diameter of the polytetrafluoroethylene foam coating on the back side is slightly larger, so that the air permeability and the wear resistance are ensured, extremely fine dust is easy to pass through, and the phenomenon that the pressure difference of a system is increased due to dust accumulation in the filter material is prevented. The positive expanded polytetrafluoroethylene microporous membrane layer of filter material of this application has the gas permeability, also has the guard action to the filter material inside. In operation, even if the film is broken, the filter material with the double-sided coating can still maintain high-efficiency filtration for a long time, and the normal operation of a dust removal system is ensured. Meanwhile, the expanded perlite composite filter material can stably work at a high temperature of 280 ℃, and has good wear resistance, good acid corrosion resistance, good high strength and good low elongation performance. The acid corrosion resistance of the filter material is improved by more than 3 times compared with the conventional filter material, and the wear resistance is improved by more than 50%.
The expanded perlite fiber composite filter material has the advantages of stable structure, high filter precision, high temperature resistance and good acid corrosion resistance, can be used in various complex working environments, and can realize a high-efficiency filter function even if a film is damaged. The expanded perlite fiber composite filter material can be made into an environment-friendly high-efficiency expanded perlite fiber composite filter bag through the working procedures of cutting, sewing and the like.
Further, the added graphene can improve the flexibility of the coating, and the folding resistance is improved by 10-30%; the uniformly coated graphene has good conductivity, and can form a conductive net on the filter material to achieve antistatic performance.
Drawings
FIG. 1 is a schematic structural view of an expanded perlite fiber composite filter material provided in the examples of the present application;
FIG. 2 is a flow chart of a process for making an expanded perlite fiber composite filter according to some embodiments of the present application.
Detailed Description
The technical solutions in the embodiments of the present application are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The application provides an expanded perlite fiber composite filter material which comprises an expanded perlite fiber base layer; one side of the expanded perlite fiber base layer is compounded with a front polytetrafluoroethylene binding layer, a front polytetrafluoroethylene foaming coating and an expanded polytetrafluoroethylene microporous membrane layer which are sequentially contacted, and the other side of the expanded perlite fiber base layer is compounded with a back polytetrafluoroethylene binding layer and a back polytetrafluoroethylene foaming coating which are sequentially contacted;
the pore diameter of the bubbles of the polytetrafluoroethylene foaming coating on the front surface is smaller than that of the bubbles of the polytetrafluoroethylene foaming coating on the back surface.
Aiming at the defects of the existing filtering material, the application provides the expanded perlite fiber composite filtering material which has high strength, high temperature resistance, acid corrosion resistance, good filtering performance and long service life, and the advantages of perlite fibers and polytetrafluoroethylene materials are effectively combined to meet the use requirements of special working conditions.
Referring to fig. 1, fig. 1 is a schematic structural diagram of an expanded perlite fiber composite filter material provided in the embodiments of the present application; wherein, 1 is expanded perlite fiber base layer, 2 is front polytetrafluoroethylene combined layer, 3 is reverse side polytetrafluoroethylene combined layer, 4 is front polytetrafluoroethylene foam coating, 5 is reverse side polytetrafluoroethylene foam coating, 6 is expanded polytetrafluoroethylene microporous membrane layer.
The embodiment of the application the composite filter material of the expanded perlite fibers comprises an expanded perlite fiber base layer 1, wherein expanded cloth which is formed by expanding and processing and weaving 5-7 mu m fine-denier perlite fiber yarns is mainly preferred, and the composite filter material has excellent performance of perlite fiber filter materials, and particularly has outstanding acid resistance.
The perlite fiber has the characteristics of high strength, low elongation, temperature resistance, acid corrosion resistance, high cost performance and the like. The expanded perlite fiber base layer is preferably made of fine-denier perlite fiber yarns, and the diameter of each monofilament is 5-7 microns, preferably 6 microns. In the examples of the present application, the yarn was subjected to a spinning-puffing processWarping, weaving and other conventional processes, and according to a weaving process, the expanded perlite fiber cloth is made by a loom and is a base material of an expanded perlite fiber base layer. Through the bulking processing, bulked yarns which have larger apparent volume and are bulkier than the original yarns can be obtained; the weight per unit area of the perlite fiber expanded fabric manufactured by the embodiment of the application can be 300-900g/m2Preferably 450 to 750g/m2E.g. 450, 500, 550, 600g/m2、650g/m2、700g/m2、750g/m2And the like. In addition, the fabric weave structure of the woven perlite fiber bulked cloth is generally double twill weave, the parameters of the front side and the back side of the cloth are the same, and the thickness range is 1.6-2.2 mm.
The embodiment of the application takes an expanded perlite fiber base layer 1 as a base, and a front polytetrafluoroethylene combining layer 2 and a back polytetrafluoroethylene combining layer 3 are respectively compounded on two surfaces of the expanded perlite fiber base layer. Next, in the present embodiment, a front polytetrafluoroethylene foam coating 4 and a back polytetrafluoroethylene foam coating 5 are correspondingly compounded.
The front polyvinyl chloride bonding layer is arranged between the front surface of the expanded perlite fiber base layer and the front polyvinyl chloride foamed coating; the front face is typically the dust-facing face. The polyvinyl chloride binding layer is mainly formed by impregnating or coating the surface of the filter material base layer with polyvinyl chloride emulsion, and preferably forms a polyvinyl chloride impregnated layer through impregnation treatment. In the embodiment of this application, polyvinyl chloride impregnated layer's effect form the protective layer on the fibre surface firstly, during polytetrafluoroethylene emulsion had fully filled the inner structure of filter material basic unit to polytetrafluoroethylene emulsion was the impregnation treatment liquid, to the comprehensive infiltration protection of filter material basic unit, formed compact protection film on the fibre surface, the wearability and the folding endurance of multiplicable filter material. The polyvinyl chloride impregnation layer plays a role of bridging, and the filter material base layer and the polytetrafluoroethylene foaming coating layer are firmly bonded together.
The reverse side polyvinyl chloride bonding layer is arranged between the expanded perlite fiber base layer and the reverse side polyvinyl chloride foaming coating and is also preferably formed by polyvinyl chloride emulsion dipping treatment. Specifically, the solid content of the polytetrafluoroethylene emulsion is generally 60%, and the polytetrafluoroethylene emulsion can comprise additives such as a silane coupling agent and the like; the weight gain range after dipping treatment is 5-15%.
The application adopts a double-sided coating process technology, wherein the front surface of the filter material is made into a polytetrafluoroethylene foam coating, the porosity is high, the pore diameter is small, and the conversion from deep filtration to surface filtration is realized. The porosity of the polytetrafluoroethylene foam coating on the back surface of the filter material is slightly lower than that of the front surface and the pore size is slightly larger, so that the air permeability, the wear resistance and the like of the filter material are ensured, extremely fine dust is easy to pass through, and the phenomenon that the pressure difference of a system is increased due to dust accumulation in the filter material is prevented. In operation, this application the filter material with double-sided coating can keep high-efficient filtration for a long time, guarantees dust pelletizing system normal operating.
The single-sided coating finishing is a process of uniformly coating the polytetrafluoroethylene material on the surface layer of the filter material, and a layer of air-permeable and hydrophobic coating is formed on the surface of the filter material by adopting a coating finishing technology, so that the physical and chemical properties of the filter material can be improved, and the product performance can meet the use requirements of special working conditions. For example, the front coating may serve to cushion and protect the filter media when high temperature dust impacts the filter media.
In the application, the front polytetrafluoroethylene foam coating is a dust-facing subsurface layer of the filter material, and is a foam coating film formed by coating finishing (or called foaming coating treatment) of a coating agent containing polytetrafluoroethylene and a foaming agent. The reverse polytetrafluoroethylene foam coating is an air purification surface layer of the filter material and is also a polytetrafluoroethylene foam coating structure. Moreover, the pore diameter of the bubbles of the front polytetrafluoroethylene foam coating is smaller than that of the bubbles of the back polytetrafluoroethylene foam coating; the thickness of the front polytetrafluoroethylene foam coating is larger than that of the back polytetrafluoroethylene foam coating.
Specifically, the bubble diameter of the front polytetrafluoroethylene foam coating can be controlled to be less than or equal to 30 micrometers, such as 1-20 micrometers. Here, the bubble diameter is generally in the range of a minimum diameter to a maximum diameter. The thickness of the front polytetrafluoroethylene foaming coating can be controlled to be 20-200 mu m, and preferably 50-180 mu m. The front coating is thicker and has smaller aperture, thereby preventing dust and airflow from scouring and improving the filtering precision. Preferably, the thickness of the back polytetrafluoroethylene foam coating is 50-300 μm, for example 100-150 μm. The reverse side coating is thin and large in pore size, and is mainly capable of protecting the filter material body from being corroded, ensuring clean air flow to pass smoothly and preventing the filter material from being blocked.
The filter material of some embodiments of the present application comprises an impregnation layer and a double-sided coating, and the acid corrosion resistance is improved by more than 3 times compared with the conventional filter material; the dew condensation resistance is outstanding. The reverse side is mainly used for protecting the filter material base material, corrosion resistance and abrasion resistance are improved, meanwhile, the aperture of the reverse side is consistent with the aperture of the filter material after dipping treatment, and pressure difference rising caused by filter material blockage is avoided, and even the filter material is ineffective.
The coating agent in the embodiment of the application can be prepared by mixing polytetrafluoroethylene emulsion, a foaming agent and some additives; the quantity of the bubbles and the size of the bubbles can be controlled by adding and adjusting the amount of the foaming agent. In a preferred embodiment of the present application, the coating agent comprises graphene; the addition of the graphene can improve the physical and chemical properties of the product. Namely, the front polytetrafluoroethylene foam coating and the back polytetrafluoroethylene foam coating preferably independently contain graphene, and the diameters of the graphene and the back polytetrafluoroethylene foam coating are 0.1-3 micrometers.
After the coating agent is coated on the two sides of the filter material, the filter material structure is firmer, the strength of the filter material is improved, and the wear resistance of the filter material is improved by more than 50%. Moreover, the added graphene can improve the flexibility and the like of the coating, and the folding resistance is improved by 10-30%. In addition, the uniformly coated graphene has good conductivity, and can form a conductive net on the filter material to have antistatic performance.
In the embodiment of the application, the expanded perlite fiber composite filter material comprises an expanded polytetrafluoroethylene microporous membrane layer 6 which is compounded on the front polytetrafluoroethylene foam coating 4, so that the filter material filtering precision is improved. The expanded polytetrafluoroethylene microporous membrane layer is prepared by biaxially stretching a polytetrafluoroethylene base belt at high temperature; the thickness of the expanded polytetrafluoroethylene microporous membrane layer can be 5-15 microns, and the pore diameter range is 0.02-1.8 microns.
The overall thickness range of the expanded perlite fiber composite filter material is generally 2.3-3.2 mm; the filter can stably work in a high-temperature environment below 280 ℃, has high filtering precision, good abrasion resistance, acid corrosion resistance, high strength and low elongation, long service life and can be used in various complex working environments. This application can make environmental protection and use compound filter bag through processes such as cutting, sewing. For example, the expanded perlite fiber composite filter material is cut and slit according to the specification of the filter bag, and then the filter material is sewn into the filter bag by using PTFE sewing threads. The product is mainly used for filtering and collecting industrial dust such as acid flue gas and the like, and has good application functionality.
The embodiment of the application provides a preparation method of an expanded perlite fiber composite filter material, which comprises the following steps:
s1, dipping the perlite fiber bulked cloth with polytetrafluoroethylene emulsion, and then sequentially drying and sintering to form polytetrafluoroethylene bonding layers on two sides of the perlite fiber bulked cloth;
s2, performing front-side foaming coating treatment on the pearl fiber expanded cloth forming the polytetrafluoroethylene bonding layer by using a first coating agent, wherein the first coating agent comprises polytetrafluoroethylene and a first foaming agent, and forming a front-side polytetrafluoroethylene foaming coating on the front-side polytetrafluoroethylene bonding layer;
and, carrying out reverse side foam coating treatment by using a second coating agent, wherein the second coating agent comprises polytetrafluoroethylene and a second foaming agent, the first coating agent and the second coating agent independently and optionally comprise graphene, and a reverse side polytetrafluoroethylene foam coating is formed on the reverse side polytetrafluoroethylene bonding layer;
the pore diameter of the bubbles of the polytetrafluoroethylene foaming coating on the front surface is smaller than that of the bubbles of the polytetrafluoroethylene foaming coating on the back surface;
and S3, compounding the expanded polytetrafluoroethylene microporous film on the front polyethylene foam coating in a hot-pressing film covering mode to prepare the expanded perlite fiber composite filter material.
Referring to fig. 2, fig. 2 is a flow chart of a process for making an expanded perlite fiber composite filter according to some embodiments of the present application. The preparation process of the embodiment of the application specifically comprises the following steps: perlite fiber expanded base material-polytetrafluoroethylene emulsion dipping treatment-coating agent preparation-front coating processing (also called dust facing coating processing) -back coating processing-coating agent solidification-front film covering processing-inspection and detection-cutting-filter bag sewing.
The preparation of the perlite fiber expanded fabric is carried out according to the conventional method in the field in the embodiment of the application: in the embodiment of the application, fine-denier perlite fiber yarn (the diameter of a single filament can be 5-7 microns) is preferably adopted, the procedures of spinning, puffing processing, warping, weaving and the like are carried out, and according to the weaving process, a weaving machine is adopted to prepare the perlite fiber yarn with the mass per unit area of 300-900g/m2The perlite fiber bulked cloth.
Wherein, the puffing processing and the warping are all processing procedures well known in the field; the unit area weight of the perlite fiber bulked cloth woven by the method is preferably 450-750 g/m2The fabric weave structure comprises structures such as double twill and satin, and the parameters of the front and the back are the same.
Then, the examples of the present application were subjected to polytetrafluoroethylene impregnation treatment: and introducing the prepared perlite fiber expanded cloth into a post-treatment production line, and impregnating the expanded cloth with polytetrafluoroethylene emulsion. The dipping temperature can be 50-70 ℃, and the production line speed is 2-8 m/min. Then, the embodiment of the application can be sequentially subjected to volatilization, drying and sintering setting, so that polytetrafluoroethylene binding layers are respectively formed on two sides of the perlite fiber expanded fabric.
Specifically, the polytetrafluoroethylene emulsion has a solid content of generally 60%, and may include an auxiliary composition such as a silane coupling agent, for example, a commercially available product from the Japan Dajin company; the weight gain range after dipping treatment is 5-15%.
After perlite fiber expanded cloth is subjected to PTFE emulsion dipping treatment, expanded cloth forming a polytetrafluoroethylene combining layer is sent into coating equipment in the embodiment of the application, and a coating agent is adopted to carry out double-sided foaming coating treatment to respectively form a front polytetrafluoroethylene foaming coating and a back polytetrafluoroethylene foaming coating.
Wherein, the coating agent comprises polytetrafluoroethylene and a foaming agent and can be prepared by a conventional mixing mode. For example, polytetrafluoroethylene emulsion and additives such as foaming agent are mixed at the room temperature of 20-26 ℃, and uniform PTFE coating solution (coating agent) is prepared after 5-10 min. Specifically, the solid content of the polytetrafluoroethylene emulsion is generally 50 wt% to 70 wt%, the amount of the polytetrafluoroethylene emulsion in the coating agent is more than 80 wt%, preferably 83 wt% to 91 wt%, and polytetrafluoroethylene is the main component of the coating. The quantity and the size of the bubbles are controlled by adding the foaming agent and adjusting the using amount; the foaming agent can be fatty acid amide derivative, and the content of the foaming agent is more than 1.5 wt%. In addition, the coating agent also contains a thickening agent, a foam stabilizer and the like. Such thickeners include, but are not limited to, acrylic emulsions, polyvinyl alcohols, and polyacrylamides; the viscosity of the coating solution can be adjusted by controlling the addition and the dosage of the thickening agent, and the thickness of the polytetrafluoroethylene coating on the surface of the filter material is controlled. The coating can also be added with fluorine-containing auxiliary agents such as tetrafluoroethylene, hexafluoroethylene and the like, so that the combination of the base material and the coating is facilitated.
For the sake of distinction, the coating agent for the front side is referred to as first coating agent, and accordingly comprises a first blowing agent; for the opposite side, a second coating agent, a second blowing agent. Preferably, the first coating agent and the second coating agent independently optionally comprise graphene, in particular in the form of a dispersion; the addition of the graphene can improve the physical and chemical properties of the product.
In some preferred embodiments of the present application, the formulation components and proportions of the first coating agent can be found in table 1:
TABLE 1 PTFE coating solution formulation
| Component name | Class of component | Content (%) |
| Polytetrafluoroethylene emulsion | The solid content is 60 percent | 83-91 |
| Fluorine-containing auxiliary agent | Tetrafluoroethylene, hexafluoropropylene | 2-6 |
| Foam stabilizer | Soap ammonia, carboxymethyl cellulose, polyvinyl alcohol | 4-7 |
| Foaming agent | Fatty acid amide derivatives | 1.5-3 |
| Thickening agent | Acrylic emulsion, polyvinyl alcohol, polyacrylamide | 1.2-2 |
| Graphene dispersion liquid | The solid content is 0.4-0.5%, and the particle diameter of graphene is as follows: 0.1-3 μm | 1-5 |
After the coating agent is manufactured, the front surface foaming coating and the back surface coating are synchronously performed in the embodiment of the application. The foaming coating on the front surface in the embodiment of the application adopts a foaming sprayer and precision scraper combined process: firstly, spraying a polytetrafluoroethylene coating solution on a filter material through a spraying device; then the coating agent is evenly spread by a precision scraper, and a compact and even polytetrafluoroethylene foam coating is formed on the surface of the filter material. The compactness is foaming porosity, and the filtering precision is improved.
Wherein the coating solution is injected into the foaming tank at a rate of 30-50L/min by a screw feeder. The gas is introduced into the stirrer by a gas supply system via a rotating shaft, the rotation speed in the stirring chamber is one of the key parameters determining the size distribution of the bubbles, and the size of the bubbles decreases with the increase of the rotation speed. The foaming sprayer generally operates at a constant speed of 0.8-2.0m/min, and bubbles are reduced by controlling the rotating speed of a foaming machine and controlling the size distribution of bubbles, wherein the rotating speed of the foaming machine (different from that of the sprayer) is increased. Preferably, the diameter of bubbles initiated by the coating solution is controlled to be less than or equal to 40 mu m; the thickness of the coating on the front surface of the composite filter material is controlled to be 20-200 mu m. The front coating is thicker and the aperture is smaller in the application, so that dust and airflow scouring can be prevented, and the filtering precision is improved.
The foamed coating on the reverse side in the embodiment of the application adopts a combined process of a roller type coating and a precision scraper, the prepared coating agent can be placed in a slurry tank, the coating agent is taken up by rotating a slurry roller to coat the surface of the filter material, and the coating agent is uniformly coated by the precision scraper, so that the reverse side coating with the thickness of 50-300 mu m is obtained preferably. The reverse side coating is thin and large in pore size, and is mainly capable of protecting the filter material body from being corroded, ensuring clean air flow to pass smoothly and preventing the filter material from being blocked.
In the specific embodiment of the application, the front and back coating agent curing processes of the perlite fiber bulked cloth are synchronously performed, namely, the perlite fiber bulked cloth is sequentially subjected to volatilization, drying, sintering, sizing and other processes to prepare the composite filter material comprising the double-sided coating. Preferably, the volatilization temperature is 91-99 ℃; the drying temperature is 180-220 ℃. The curing temperature of the sintering is 370-400 ℃, and the curing time is 2-8 min. At the setting temperature of 220-260 ℃, the surface layer of the filter material is pressed and flattened by the pressure of 15-25PSI, so that the front surface of the filter material forms a coating of 20-200 mu m, and the back surface forms a coating of 50-300 mu m.
Finally, the embodiment of the application carries out film coating processing: and (3) synchronously introducing the perlite fiber expanded cloth and the expanded polytetrafluoroethylene microporous film which are coated on the two sides into a film laminating machine, and firmly compounding the expanded polytetrafluoroethylene microporous film on the front polyethylene foam coating by adopting a hot-pressing film laminating mode to prepare the expanded perlite fiber composite filter material.
Wherein, the porosity of the expanded polytetrafluoroethylene microporous membrane is more than 85 percent, and the pore diameter is 0.02-1.8 μm. Preferably, the temperature of the hot-pressing film covering is 370-415 ℃, the speed of the film covering is 2-7m/min, and the high fastness and uniform air permeability of the film covering are favorably ensured.
The application also provides an expanded perlite fiber composite filter bag and a manufacturing method thereof, namely, the expanded perlite fiber composite filter material manufactured by the processing technology is cut and cut according to the specification of the filter bag, then the filter bag is sewn by polytetrafluoroethylene sewing threads, and the expanded perlite fiber composite filter bag is mainly used for filtering acid smoke and collecting products.
In the embodiment of the application, the acid corrosion resistance of the filter material base material is improved by more than 3 times compared with that of the conventional filter material by immersion treatment and double-sided coating treatment; the dew condensation resistance is outstanding. After the coating agent is coated on the two sides, the filter material structure is more stable, the strength of the filter material can be improved, and the wear resistance of the filter material is improved by more than 50%. The reverse side of the filter material is mainly used for protecting the filter material base material, corrosion resistance and abrasion resistance are improved, meanwhile, the aperture of the reverse side is consistent with that of the filter material after dipping treatment, and pressure difference rising caused by filter material blockage is avoided, and even the filter material is ineffective.
According to the application, the graphene is preferably added into the foaming coating, so that the tensile fracture strength, the temperature resistance, the corrosion resistance and the like of the environment-friendly filter material can be obviously improved. The graphene can improve the flexibility of the coating, and the folding resistance is improved by 10-30%; the uniformly coated graphene has good conductivity, and can form a conductive net on the filter material to achieve antistatic performance. This application the electric conductive property, the filtration deashing performance of the filter material that contains graphite alkene promote to some extent, have still improved the pliability of fibre and filter material, improve inorganic fiber material's resistance to folding and wearability. Experiments prove that the comprehensive performances of the environment-friendly filter material, such as physical performance, chemical performance, application performance and the like, can be improved by more than 15% by adding the graphene.
For a further understanding of the present application, the expanded perlite fiber composite filter material provided herein is described in detail below with reference to the examples. It should be understood, however, that these examples are for illustrative purposes only and are not intended to limit the scope of the present application, which is defined by the following examples.
In the following examples, all materials are commercially available.
Example 1
The specific manufacturing scheme of the expanded perlite fiber composite filter bag is as follows:
1. and (5) manufacturing perlite fiber expanded cloth. The perlite fiber yarn with the fine denier of 6 mu m is adopted to be made into the perlite fiber yarn with the mass per unit area of 550g/m by adopting double twill weave and a rapier loom through the working procedures of spinning, bulking processing, warping, weaving and the like2The thickness of the perlite fiber expanded cloth is 1.7 mm.
2. And (4) dipping treatment. The prepared perlite fiber expanded cloth is introduced into a post-treatment production line, and is firstly impregnated with polytetrafluoroethylene emulsion at the impregnation temperature of 50 ℃ and the speed of 4m/min, and then is subjected to volatilization, drying and sintering setting in sequence.
3. And (4) preparing a coating agent. Uniformly mixing polytetrafluoroethylene emulsion and some additives for 5min at the room temperature of 26 ℃ to prepare a coating solution; the formulation and proportions are detailed in table 2:
TABLE 2 PTFE coating solution formulation components and proportions
| Component name | Class of component | Content (%) |
| Polytetrafluoroethylene emulsion | The solid content is 60 percent | 85 |
| Fluorine-containing auxiliary agent | Tetrafluoroethylene | 4 |
| Foam stabilizer | Soap ammonia | 5 |
| Foaming agent | Fatty |
2 |
| Thickening agent | Acrylic emulsion | 1.5 |
| Graphene dispersion liquid | Solid content 0.5%, graphene particle diameter: 1.1 μm | 2.5 |
4. Front side foamed coating
The perlite fiber expanded cloth enters coating equipment after being subjected to the PTFE emulsion dipping treatment, the front coating treatment adopts a combined process of a foaming sprayer and a precision scraper, firstly, coating solution is sprayed on the filter material through a spraying device, then, the coating solution is uniformly spread through the precision scraper, and a compact and uniform polytetrafluoroethylene foaming coating is formed on the surface of the filter material base material.
Wherein the coating solution was injected into the foaming tank at a rate of 30L/min by a screw feeder. Introducing gas through a gas supply system via a rotary shaft to the stirrer; the running speed of the foaming sprayer is 1.0 m/min.
The bubbles initiated by the coating solution are controlled to be 5-15 μm in diameter;
the thickness of the coating on the front surface of the expanded perlite fiber filter material is controlled to be 145 mu m.
5. Reverse side coating
The back side adopts a roller coating and precision scraper combined process, the prepared coating agent is placed in a slurry tank, the coating agent is taken up by a roller with slurry to coat the back side of the filter material, and the coating agent is uniformly coated by the precision scraper, wherein the thickness of the back side coating is 120 mu m, and the diameter of air bubbles is 18 mu m-30 mu m.
6. Curing of coatings
The coating processing of the front surface and the back surface of the expanded perlite fiber base material is synchronously carried out, and then the expanded perlite fiber double-sided coating filter cloth is prepared by processing the expanded perlite fiber base material sequentially through the working procedures of volatilization treatment, drying treatment, sintering treatment, shaping treatment and the like.
Wherein the volatilization temperature is 98 ℃, and the drying temperature is 210 ℃. The sintering curing temperature is 380 ℃, and the curing time is 2 min. And (3) flattening the surface layer of the filter material by the pressure of 15PSI while shaping at the shaping temperature of 260 ℃, and finally forming a 145-micron coating on the front surface and a 120-micron coating on the back surface.
7. Film coating process
Expanded perlite fiber double-sided coating filter cloth and an expanded polytetrafluoroethylene microporous film (the porosity is 90 percent, and the pore diameter is 0.02 mu m-1.6 mu m) are synchronously introduced into a film laminating machine for film laminating processing. The expanded polytetrafluoroethylene microporous film and the expanded perlite fiber double-sided coating filter cloth are firmly covered together by adopting a high-temperature hot pressing mode to prepare the expanded perlite fiber composite filter material. Wherein the film coating temperature is 405 ℃, and the film coating speed is 3 m/min.
8. Manufacturing method of expanded perlite fiber composite filter bag
The expanded perlite fiber composite filter material 685 prepared by the processing technology is +/-5 g/m2The filter material is cut and cut according to the specification of the filter bag, and then the filter material is sewn into the filter bag by PTFE sewing threads.
Example 2
The specific manufacturing scheme of the expanded perlite fiber composite filter bag is as follows:
1. and (5) manufacturing perlite fiber expanded cloth. The perlite fiber yarn with the fine denier of 5.5 mu m is adopted to be made into the perlite fiber yarn with the mass per unit area of 600g/m by adopting double twill weave and a rapier loom through the working procedures of spinning, bulking processing, warping, weaving and the like2The thickness of the perlite fiber expanded cloth is 1.8 mm.
2. And (4) dipping treatment. The prepared perlite fiber expanded cloth is introduced into a post-treatment production line, and is firstly impregnated with polytetrafluoroethylene emulsion at the impregnation temperature of 50 ℃ and the speed of 4m/min, and then is subjected to volatilization, drying and sintering setting in sequence.
3. And (4) preparing a coating agent. Uniformly mixing polytetrafluoroethylene emulsion and some additives for 5min at the room temperature of 26 ℃ to prepare a coating solution; the formulation and proportions are detailed in table 3:
TABLE 3 PTFE coating solution formulation components and proportions
| Component name | Class of component | Content (%) | |
| Polytetrafluoroethylene emulsion | The solid content is 60 percent | 86 | |
| Fluorine-containing | Hexafluoropropylene | 3 | |
| Foam stabilizer | Carboxymethyl cellulose | 4 | |
| Foaming agent | Fatty acid amide derivatives | 2.5 | |
| Thickening | Polyvinyl alcohol | 2 | |
| Graphene dispersion liquid | Solid content is 0.5%, graphene particle diameter: 0.8 μm | 2.5 |
4. Front side foamed coating
The perlite fiber expanded cloth enters coating equipment after being subjected to the PTFE emulsion dipping treatment, the front coating treatment adopts a combined process of a foaming sprayer and a precision scraper, firstly, coating solution is sprayed on the filter material through a spraying device, then, the coating solution is uniformly spread through the precision scraper, and a compact and uniform polytetrafluoroethylene foaming coating is formed on the surface of the filter material base material.
Wherein the coating solution was injected into the foaming tank at a rate of 30L/min by a screw feeder. Introducing gas through a gas supply system via a rotary shaft to the stirrer; the foaming sprayer was operated at a constant speed of 1.2 m/min.
The bubbles initiated by the coating solution are controlled to be 5-12 μm in diameter;
the thickness of the coating on the front surface of the expanded perlite fiber filter material is controlled to be 160 mu m.
5. Reverse side coating
The back side adopts a roller coating and precision scraper combined process, the prepared coating agent is placed in a slurry tank, the coating agent is taken up by a roller with slurry to coat the back side of the filter material, and the coating agent is uniformly coated by the precision scraper, wherein the thickness of the back side coating is 150 mu m, and the diameter of air bubbles is 15-22 mu m.
6. Curing of coatings
The coating processing of the front surface and the back surface of the expanded perlite fiber base material is synchronously carried out, and then the expanded perlite fiber double-sided coating filter cloth is prepared by processing the expanded perlite fiber base material sequentially through the working procedures of volatilization treatment, drying treatment, sintering treatment, shaping treatment and the like.
Wherein the volatilization temperature is 97 ℃, and the drying temperature is 215 ℃. The sintering curing temperature is 390 ℃, and the curing time is 2 min. The setting temperature is 260 ℃, the surface layer of the filter material is flattened by 16PSI pressure during setting, and finally a coating with the thickness of 160 mu m is formed on the front surface and a coating with the thickness of 150 mu m is formed on the back surface.
7. Film coating process
Expanded perlite fiber double-sided coating filter cloth and an expanded polytetrafluoroethylene microporous film (porosity 88%, pore diameter 0.02-1.5 mu m) are synchronously introduced into a film laminating machine for film laminating processing. The expanded polytetrafluoroethylene microporous film and the expanded perlite fiber double-sided coating filter cloth are firmly covered together by adopting a high-temperature hot pressing mode to prepare the expanded perlite fiber composite filter material. Wherein the film coating temperature is 411 ℃ and the film coating speed is 3.5 m/min.
8. Manufacturing method of expanded perlite fiber composite filter bag
The expanded perlite fiber composite filter material prepared by the processing technology is 745 +/-5 g/m2Cutting and cutting according to the specification of the filter bag, and sewing the filter material into the filter bag by using a polytetrafluoroethylene sewing thread.
Example 3
The specific manufacturing scheme of the expanded perlite fiber composite filter bag is as follows:
1. and (5) manufacturing perlite fiber expanded cloth. The perlite fiber yarn with the fine denier of 6 mu m is adopted to be made into the perlite fiber yarn with the mass per unit area of 750g/m by adopting double twill weave and a rapier loom through the working procedures of spinning, bulking processing, warping, weaving and the like2The thickness of the perlite fiber expanded cloth is 2.0 mm.
2. And (4) dipping treatment. The prepared perlite fiber expanded cloth is introduced into a post-treatment production line, and is firstly impregnated with polytetrafluoroethylene emulsion at the impregnation temperature of 45 ℃ and the speed of 3m/min, and then is subjected to volatilization, drying and sintering setting in sequence.
3. And (4) preparing a coating agent. Uniformly mixing polytetrafluoroethylene emulsion and some additives for 5min at the room temperature of 26 ℃ to prepare a coating solution; the formulation and proportions are detailed in table 4:
TABLE 4 PTFE coating solution formulation components and proportions
| Component name | Class of component | Content (%) | |
| Polytetrafluoroethylene emulsion | The solid content is 60 percent | 83 | |
| Fluorine-containing auxiliary agent | Tetrafluoroethylene | 5 | |
| Foam stabilizer | Polyvinyl alcohol | 5 | |
| Foaming agent | Fatty acid amide derivatives | 2.5 | |
| | Polyacrylamide | 2 | |
| Graphene dispersion liquid | Solid content is 0.5%, graphene particle diameter: 1.5 μm | 2.5 |
4. Front side foamed coating
The perlite fiber expanded cloth enters coating equipment after being subjected to the PTFE emulsion dipping treatment, the front coating treatment adopts a combined process of a foaming sprayer and a precision scraper, firstly, coating solution is sprayed on the filter material through a spraying device, then, the coating solution is uniformly spread through the precision scraper, and a compact and uniform polytetrafluoroethylene foaming coating is formed on the surface of the filter material base material.
Wherein the coating solution was injected into the foaming tank at a rate of 50L/min by a screw feeder. Introducing gas through a gas supply system via a rotary shaft to the stirrer; the foaming sprayer is typically operated at a constant speed of 0.8 m/min.
The bubbles initiated by the coating solution are controlled to be 3-11 μm in diameter;
the thickness of the coating on the front surface of the expanded perlite fiber filter material is controlled to be 180 mu m.
5. Reverse side coating
The back side adopts a roller coating and precision scraper combined process, the prepared coating agent is placed in a slurry tank, the coating agent is taken up by a roller with slurry to coat the back side of the filter material, and the coating agent is uniformly coated by the precision scraper, wherein the thickness of the back side coating is 130 mu m, and the diameter of air bubbles is 15 mu m-22 mu m.
6. Curing of coatings
The coating processing of the front surface and the back surface of the expanded perlite fiber base material is synchronously carried out, and then the expanded perlite fiber double-sided coating filter cloth is prepared by processing the expanded perlite fiber base material sequentially through the working procedures of volatilization treatment, drying treatment, sintering treatment, shaping treatment and the like.
Wherein the volatilization temperature is 98.5 ℃, and the drying temperature is 225 ℃. The sintering curing temperature is 385 ℃, and the curing time is 3 min. The setting temperature is 260 ℃, the surface layer of the filter material is flattened by 25PSI pressure while setting, and finally a 180-micrometer coating is formed on the front surface and a 130-micrometer coating is formed on the back surface.
7. Film coating process
Expanded perlite fiber double-sided coating filter cloth and an expanded polytetrafluoroethylene microporous film (the porosity is 90 percent, and the pore diameter is 0.02 mu m-1.6 mu m) are synchronously introduced into a film laminating machine for film laminating processing. The expanded polytetrafluoroethylene microporous film and the expanded perlite fiber double-sided coating filter cloth are firmly covered together by adopting a high-temperature hot pressing mode to prepare the expanded perlite fiber composite filter material. Wherein the film coating temperature is 415 ℃, and the film coating speed is 3.5 m/min.
8. Manufacturing method of expanded perlite fiber composite filter bag
The expanded perlite fiber composite filter material 880 +/-5 g/m prepared by the processing technology2The filter material is cut and cut according to the specification of the filter bag, and then the filter material is sewn into the filter bag by PTFE sewing threads.
The embodiment of the application is compared with the main parameter indexes of the common composite filter material as follows, and the detection is carried out according to the national relevant standards:
TABLE 5 Properties of the composite Filter materials described in the examples of this application
The foregoing is only a preferred embodiment of the present application, and it should be noted that various modifications of the embodiments can be implemented by those skilled in the art without departing from the technical principle of the present application, and these modifications should be considered as the scope of the present application.
Claims (8)
1. The expanded perlite fiber composite filter material is characterized by comprising an expanded perlite fiber base layer; one side of the expanded perlite fiber base layer is compounded with a front polytetrafluoroethylene binding layer, a front polytetrafluoroethylene foaming coating and an expanded polytetrafluoroethylene microporous membrane layer which are sequentially contacted, and the other side of the expanded perlite fiber base layer is compounded with a back polytetrafluoroethylene binding layer and a back polytetrafluoroethylene foaming coating which are sequentially contacted;
the pore diameter of the bubbles of the polytetrafluoroethylene foaming coating on the front surface is smaller than that of the bubbles of the polytetrafluoroethylene foaming coating on the back surface.
2. The expanded perlite fiber composite filter material of claim 1, wherein the expanded perlite fiber base layer is formed by expanding and weaving 5-7 micron fine denier perlite fiber yarn.
3. The expanded perlite fiber composite filter material of claim 1, wherein the bubble diameter of the front polytetrafluoroethylene foam coating is less than or equal to 30 microns.
4. The expanded perlite fiber composite filter material of claim 1, wherein the front polytetrafluoroethylene foam coating has a thickness greater than the thickness of the back polytetrafluoroethylene foam coating.
5. The expanded perlite fiber composite filter material as recited in claim 4, wherein the thickness of the polytetrafluoroethylene foam coating on the front surface is 20-200 μm.
6. The expanded perlite fiber composite filter material as recited in any one of claims 1 to 5, wherein the expanded polytetrafluoroethylene microporous membrane layer has a thickness of 5 to 10 microns.
7. The expanded perlite fiber composite filter material of any one of claims 1-5, wherein the front polytetrafluoroethylene foam coating and the back polytetrafluoroethylene foam coating independently comprise graphene with a diameter of 0.1-3 microns.
8. The expanded perlite fiber composite filter material as recited in any one of claims 1 to 5, wherein the expanded perlite fiber composite filter material is in the form of a bag sewn with PTFE sewing thread.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020446012.8U CN211753125U (en) | 2020-03-31 | 2020-03-31 | Expanded perlite fiber composite filter material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020446012.8U CN211753125U (en) | 2020-03-31 | 2020-03-31 | Expanded perlite fiber composite filter material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211753125U true CN211753125U (en) | 2020-10-27 |
Family
ID=72929107
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202020446012.8U Active CN211753125U (en) | 2020-03-31 | 2020-03-31 | Expanded perlite fiber composite filter material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211753125U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111298519A (en) * | 2020-03-31 | 2020-06-19 | 辽宁新洪源环保材料有限公司 | Expanded perlite fiber composite filter material and preparation method thereof |
-
2020
- 2020-03-31 CN CN202020446012.8U patent/CN211753125U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111298519A (en) * | 2020-03-31 | 2020-06-19 | 辽宁新洪源环保材料有限公司 | Expanded perlite fiber composite filter material and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5180630A (en) | Fibrillated fibers and articles made therefrom | |
| JP6212619B2 (en) | Air filter medium and air filter including the same | |
| US4929502A (en) | Fibrillated fibers and articles made therefrom | |
| KR100934699B1 (en) | Method for producing medium and high temperature flue gas treatment using foam coating and filter medium produced by the same | |
| CN111282344A (en) | Double-side coating permeable membrane filter material and preparation method thereof | |
| CN111298519A (en) | Expanded perlite fiber composite filter material and preparation method thereof | |
| CN211753125U (en) | Expanded perlite fiber composite filter material | |
| CN111038036A (en) | Steel sintered flue gas superfine fiber composite needled filter material and preparation method thereof | |
| CN211836742U (en) | Two-sided coating filter material that permeates membrane | |
| CN111974090A (en) | Preparation method of static-free high-efficiency filter fiber material | |
| JP6087207B2 (en) | Filter material for air filter and method for producing the same | |
| CN117162638B (en) | Preparation method of expanded polytetrafluoroethylene composite heat-insulating film | |
| KR19990085106A (en) | Dust collection filter for filtration of fine dust and its manufacturing method | |
| US5192604A (en) | Fibrillated fibers and articles made therefrom | |
| JP7117174B2 (en) | glass filter | |
| CN112626862A (en) | High-strength yarn and preparation method thereof | |
| KR100450983B1 (en) | Method for preparing foam-coating woven fabrics filter having superior air-permeability | |
| KR101013158B1 (en) | Filtering material for filter and method of preparing thereof | |
| KR100284776B1 (en) | Manufacturing method of nonwoven bag filter | |
| KR101013157B1 (en) | Method for preparing of cartridge filter comprising ultra microscopic pore | |
| CN110280046A (en) | A kind of fire-retardant polyimides oil cotton of insulation high-temperature-resistant | |
| CN115418849B (en) | Flame-retardant fabric and preparation method thereof | |
| CN220878085U (en) | High-temperature needled felt filter material | |
| CN216832641U (en) | Composite tire non-woven fabric with strong pollution resistance | |
| CN115121043B (en) | Microfiber surface layer filter material and production system thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CB03 | Change of inventor or designer information |
Inventor after: Song Pengze Inventor after: Li Gang Inventor before: Song Mingze Inventor before: Li Gang |
|
| CB03 | Change of inventor or designer information |