CN1170370A - Conductive filter laminate - Google Patents
Conductive filter laminate Download PDFInfo
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- CN1170370A CN1170370A CN 95196899 CN95196899A CN1170370A CN 1170370 A CN1170370 A CN 1170370A CN 95196899 CN95196899 CN 95196899 CN 95196899 A CN95196899 A CN 95196899A CN 1170370 A CN1170370 A CN 1170370A
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- B01D2201/00—Details relating to filtering apparatus
- B01D2201/50—Means for dissipating electrostatic charges
Abstract
This invention is an improved electrically conductive filter media particularly suitable for use in applications where static electricity must be dissipated. The media comprises a microporous filtration layer having electrically conductive particles embedded therein. When attached to support media, this structure provides exceptional filtration efficiency while assuring a consistent and evenly distributed electrical pathway to ground.
Description
Background of invention
1. invention field
The present invention relates to a kind of filter medium, relate in particular to a kind of anlistatig conducting filtration material.
2. the description of prior art
Control static can be very important in many industrial plants, and this is can cause serious destruction because of uncontrolled Electrostatic Discharge in these facilities or spark.For example, in some production phase of integrated circuit, static discharge can cause the damage of integrated circuit.At explosive atmosphere (as grain warehouse), or in the based process process of Flammable atmosphere (as the oil drilling cramp), oil plant and solvent, static discharge is extremely dangerous.In order to protect lives and properties must prevent static discharge.
Because the organic polymer textile material static discharge that uses in these facilities is insulating properties normally, so these materials can be the static discharge sources.In addition, unless the electric charge that forms on these material surfaces is leaked away and these materials are changed preventing to set up in its surface electric charge with a kind of controlled way, such material can have higher characteristic impedance value, usually 10
12On the ohm-cm or the higher order of magnitude.A kind of filter medium of special recommendation is intumescent PTFE, and that is disclosed in the United States Patent (USP) 3,953,566 as Gore is such.This material has good filter efficiency, but it is reactive, can not leak static if do not add processing.
In order to control the electrostatic charge that forms in the textile material, can be by textile material being carried out antistatic finish or by in textile material, introducing the electric conductivity that the partially conductive fiber increases the organic polymer textile material at least.The also useful external device (ED) of additive method that is used for controlling electrostatic charge makes the electric charge inflow place (for example ground strip or earth connection) that forms on the textile material.
Making a kind of method of electrostatic charge discharge is that the organic polymer textile material is carried out antistatic finish.This can carry out when the organic polymer textile material is fibers form or form of fabric.This has increased the ionic conductivity of carrying out the surface of antistatic finish usually, thereby quickens electrostatic leakage.Yet this antistatic finish does not resemble the polymer weaving material itself that carried out antistatic finish durable usually.Wash or only will make the antistatic finish disappearance of fabric face, cause material that the ability that electrostatic charge is leaked is lost owing to use organic polymer textile material.
Another kind method is metallizing or a conductive carbon on the fiber outer surface that uses when producing the organic polymer textile material.But if the coating of using is soft unlike the fiber of applying coating, the inflection meeting of fiber makes coating failure, thereby the conductive path that is formed by coating is interrupted or damage.
Also having a kind of method of leaking electrostatic charge is to produce, and conductive fiber is admixed to textile material in the non-braiding filter medium.The example of conductive fiber comprises expanded polytetrafluoroethyl,ne (PTFE) fiber of carbon fiber, metallic fiber or filling, and that is disclosed in the United States Patent (USP) 5,229,200 as Sassa is such.
Although above-mentioned material is functional in some application scenario, they are not all requirements of all satisfying electrostatic leakage in all application scenarios.People's such as Sassa United States Patent (USP) 5,229,200 have adopted a kind of filter medium, and this medium comprises the non-braiding textile material (supporting course) that can leak static, this material layer is stacked in the porous polymer film (filter course) of electric insulation, particularly on an expanded polytetrafluoroethyl,ne (ePTFE) film.This medium can satisfy the requirement of filtration efficiency and electrostatic leakage.Yet the porous polymer film of insulation has limited the ability of filter medium conduct charges, therefore, this medium is being restricted to the use in the extremely responsive environment of spark.In addition, some industrial circle has been set up and has been required surface impedance to have the standard of the filter medium of minimum of a value.Because the high resistivity of film, the insulation porous polymer that uses in the existing stacked filter medium can not satisfy these requirements.
Therefore, an object of the present invention is to provide a kind of conductive filter media, this medium had both had filtration efficiency, had effective electrostatic leakage performance simultaneously again.
Another object of the present invention provides a kind of conductive filter media, and this medium has intumescent PTFE high filtration efficiency, has sufficient leakage antistatic property simultaneously, thereby can be applied in the environment of fried property.
By following explanation, these purposes of the present invention and other purposes will become and know.
Summary of the invention
The invention provides a kind of filter medium that had not only had filtration efficiency but also had electric conductivity.In order to realize these performances, filter course is preferably formed by expanded polytetrafluoroethyl,ne (ePTFE) film, is filled with conductive particle in this film and/or is coated with thin conductor at least one side.Conductive filter laminate can be transmitted to electrostatic charge on ground, keeps good strainability simultaneously.Supporting course is attached on the conductive filter laminate so that the structural intergrity of filter medium to be provided with its basic pattern.
By comprising a kind of conductance supporting material (for example being filled with the braiding or the non-braided material of conductive particle), can make the filter medium of conduction more.Especially, preferably by conductive layer (for example metal) directly is deposited at least one surface,, make the supporting material conduction for example by plating, sputter or vacuum deposition.
Filter medium of the present invention has high filter efficiency, and conducts electricity simultaneously.Intumescent PTFE filtration membrane not only can provide the filter efficiency up to 99.999%, and the coefficient of friction that has is lower, and surface tension is lower, and filtered particle can be discharged from the surface of filter medium.Can produce better release performance by the many methods that produce electric charge by the filter medium induction.
Description of drawings
Present invention is described in conjunction with the drawings, to be expressly understood working condition of the present invention.
Fig. 1 is the front 3-D view that embodies the filter bag of filter medium of the present invention.
Fig. 2 is the sectional view of cartridge filter of the present invention.
Fig. 3 is the sectional view of an embodiment of filter of the present invention, has wherein adopted conductive filter laminate and supporting material.
Fig. 4 is the sectional view of another embodiment of filter medium of the present invention, has wherein adopted the film, the supporting material that are filled with conductive particle, and is formed on the conductive coating between filter course and the supporting course.
Fig. 5 is the sectional view of another embodiment of filter medium of the present invention, has wherein adopted film, supporting material and has been deposited on two lip-deep conductive coatings of supporting material.
Fig. 6 is the sectional view of another embodiment of filter medium of the present invention, has wherein adopted film, supporting material and has been deposited on conductive coating on the supporting material relative with filter medium one side.
The detailed description of invention
Describe the present invention in detail below in conjunction with accompanying drawing.
The present invention comprises a conductive filter media, and this medium has good filtering characteristic and effective electric conductivity.
As shown in Figure 1, the present invention comprises the conductive filter media 10 with filter bag 12 patterns.Filter medium 10 of the present invention comprises as the supporting course 14 of inner surface 16 with as the electric leakage filter course 18 of outer surface 20.The structure of supporting course 14 and filter course 18 can be put upside down as requested.
In order to realize special performance of the present invention, filter course 20 must have effective and lasting electric leakage performance.Electric leakage filter course 18 preferably comprises the microporous membrane structure of expanded polytetrafluoroethyl,ne (ePTFE).Apply a side of film at least by filled conductive particle in film and/or with conductive coating (for example metal), can make ePTFE filter course 18 conductions.The ePTFE film also comprises aggregation and interconnected fubril.By forming filter course, can reduce or eliminate many problems that run in the past with this conductive material.For example, also be conductive layer by making filter course, surface electrostatic lotus etc. is leaked away very effectively.In addition, two kinds of functions (for example electric conductivity and filtration) being melted is that an individual layer has been guaranteed can not separate or lose electrical conductance.
Preferably produce the filter course 18 of ePTFE in the following manner.
Conductive particle is joined water to be divided in the PTFE resin (aqueous dispersion PTFE resin) of diffusion.Mixture is to coagulate altogether, that is, by the THE ADIABATIC SHEAR IN of water dispersion or by making the water dispersion unstable with salt, acid, polymine or similar material, the PTFE resin is condensed.Form the coagulation of fine powder PTFE resin and conductive particle subsequently, and be dried to piece.When dry, block is pulverized, the lubricated and mixing with solvent naphtha makes to form uniform mixture.
Employed conductive particle can comprise any suitable material in the formation conduction ePTFE film, as metal, metallic compound, graphite or carbon black.Preferably adopt the Ketjenblack carbon black in the present patent application, because it has high electrical conductivity, and because coating of particles and size help manufacture process." particle " speech refers to such an extent that be the particle one by one with any aspect ratio, therefore comprises flocculus (flock), thin slice (flake) and powder (powder).
Then, will be compressed into billet, and then push by a mould, form an extrudate that links up with hammer ram type extruder with the mixture that preceding method makes.The extruding object of Xing Chenging is squeezed into rod or band shape usually like this.Simultaneously, solvent naphtha also is used as the extruding lubricating oil of compound.
The extrudate that links up is compressed between a pair of calender subsequently, to reduce its thickness.Then, coherent extrudate is passed through on the calender of a series of heating, got on to desolventize oil from the extrudate that links up through calendering.With the calender of heating remain on the solvent naphtha boiling point temperature or on, calender makes solvent naphtha volatilization, stays the extrudate of the dry calendering that links up.
Be used in the method that PTFE is expanded that discloses in the United States Patent (USP) 3,543,566 of Gore, the dry calendering extrudate that links up that stretches, this patent is for reference in this citation.Sheet material through calendering subsequently should heat treatment under 35 to 327 ℃ temperature, and stretch along one or more dimensions, produces intumescent PTFE array.Stretching be preferably near under 240 ℃ the temperature and 1.1 to 1 to 200 to 1 or bigger ratio under carry out.The expansion of using among the present invention is preferably between 5 to 1 to 100 to 1.The speed that expands can be between per second 2 to 10,000%, and rate of extension of the present invention is preferably per second about 2 to 1000%.Like this, just made intumescent porous Teflon (ePTFE) matrix with the continuous film pattern that the distribution of conductive particle filler is wherein arranged.
Expanded polytetrafluoroethyl,ne (ePTFE) should have following final performance: pore volume is about 10 to 99%, preferably is about 75 to 95%; The percentage of PTFE is 5 to 99%, preferably is about 60 to 95%; Thickness is 0.2 to 125 mil (5.0 to 3200 microns), is preferably about 0.50 to 10.0 mil (12.7 to 254 microns).
By other processing procedures except that filling, for example,, also can make conduction micropore filtering film conduction (or more conducting electricity) by plating on film, sputter or vacuum deposited metal or other conductor.For example, with the technology that discloses in the United States Patent (USP) 4,720,400 of Manniso, electroplate at the enterprising row metal of ePTFE.The film of electroplating has high electric conductivity.The filter membrane of electroplating through metal can be used in special application scenario, causes the moderate situation of stress that scratch causes as gauffer with in using, and resistivity must extremely low situation under.
That Fig. 2 describes is another embodiment of filter medium 22 of the present invention, here, makes medium 22 pleating, or spirals, and be installed on the case 24, on gauze.Pleating medium 22 and case 24 form a cartridge filter 26, can be used in the application scenario that needs the maximum filtering surface area.
The simplest form of filter medium of the present invention comprises a filter cloth 30 that has filter course 32 and supporting course 34 shown in Fig. 3 sectional view.Two-layer laminate or bonds together together, thereby prevents that filter course 32 is out of shape during use.By filling metal and/or with at least one side of conductive material (particularly metal) coating filter course, can make filter course 32 make conduction.Fig. 4 A illustrates conductive layer 35 and is formed on the filter course 37, and filter course 37 is in turn attached on the supporting course 39.Fig. 4 B also illustrates another kind of embodiment, and wherein, conductive layer 38 is formed on the filter course 42, and supporting course 40 is attached on the conductive layer 38.In addition, conductive layer also can be formed on the both sides of filter course.
Above-mentioned intumescent electrically conductive PTFE filter membrane can be superimposed upon and form filter medium of the present invention on the supporting course fabric.Supporting course can be made up of fabric, fabric can be weaving or nonwoven, felt (felt), spunbond, braiding etc.Fabric can be made by any industrial fiber or plastics (comprising that polyester, polypropylene, acrylic fibers, registration mark are the felt of NOMEX etc.).In addition, filter course can be added on wire netting or the gauze.When filter medium of the present invention when applications is filtered in industry (having potential explosion danger herein), especially be desirable to provide a kind of antistatic supporting course.Anti-static fabric comprises a kind of like this as the conductive material of description in people's such as Sassa the United States Patent (USP) 5,213,882 or the fabric of conductive layer.
The ePTFE filter course preferably is attached on the supporting course by lamination process.By the method for crossing through the pressure roller and the roll gap passage between the flexible silicon silicone pressure roller of heating, heating is in the same place two superimposed with pressurization.The scope that the ePTFE filter course is added on the supporting course will depend on employed supporting course.Usually, stacked condition is: temperature is preferably between 180 to 350 ℃ between 100 to 450 ℃; Pressure is between 2 to 100psi (pound/square inch) (14 to 689kPa), be preferably between 15 to 50psi (103 to 345kPa), and braiding speed is preferably between 20 to 80fpm (6 to 24 meters/minute) 2 to 150fpm (feet per minute) (0.6 to 46 meter/minute).
In addition, by shown in Fig. 4 B, 5 and 6, the method depositing metal at least one surface of supporting course with vapor deposition can make supporting fabrics electric conductivity better.
In the embodiment of filter medium 36 of the present invention shown in Fig. 4 B, conductive material coating 38 is formed on the supporting course 40, between supporting course 40 and filter course 42.Coating is preferably formed by a kind of metal, and this metal can choose from a group earth metal and metallic compound.These metals can unrestrictedly comprise aluminium, nickel, copper, vanadium, titanium, silver, palladium, platinum, tin, chromium, nitrogenize tin, manganese, indium, potassium, permanganate and tin oxide.Preferably aluminium, nickel and copper.Equally, metal can apply through sputter, plating or vacuum deposition be to supporting course.In addition, coating 38 can directly be deposited on the filter course 42 before the supporting course that is added to gets on.
Among Fig. 5, show another embodiment of filter medium 42 of the present invention, here, with the be added to both sides of supporting course 50 of conductive layer 44,46.Two conductive layers 44,46 have been formed as mentioned above.Two conductive layers 44,46 have increased the electric conductivity of filter medium 42.
Among Fig. 6, described another embodiment of filter medium 52 of the present invention, among this embodiment, be formed on conductive layer 54 on the supporting course 56 and be on the side opposite with filter course 58.
Under some filtration application occasion, the potential pulse technology can be used for increasing filter effect, and removes the particle of setting up that is filtered from the filter course of the outside.Under potential pulse, the particle that is filtered charged polarity identical with the charge polarity of charged filter before entering dust storage chamber or filtering area.Charged filter media produces an electric field in the surface, in this surface, and the charged particle trend of being ostracised.Like this, the particle of being ostracised can not infiltrate through filter medium, thereby filter effect will increase.Before supporting material stops, just stop the stop of particle by particle, use electric field also to help the release of particle by this way from filter medium.In addition, the charged of filter can be in step with the airwaves (blowing backward by filter) of medium in time, helps from the filter surfaces release particles.
EPTFE filter membrane of the present invention also helps the removal of particle.The ePTFE film is collected its lip-deep particle, thereby has stoped particle to be buried in the supporting course fabric.Simultaneously, because ePTFE has very low surface energy, so particle can not adhere to from the teeth outwards, this makes filtered particle more easily " releases " and pulse and leave (pulse away).
Following Example further illustrates principle of the present invention, but does not limit the scope of the present invention.To one skilled in the art, various modifications and equivalent all can propose and without departing from the spirit and scope of the present invention.Example 1:
The conductive particle layer that is filled with porous expanded polytetrafluoroethyl,ne (ePTFE) is made in the following manner.
Make the material of 87 liters of batches, 10% of its weight is solid, and 90% is water.7.5% is made up of Ketjenblack carbon black (10 microns nominal granular sizes) (from the Akzo Chemical company of New York Dobbsfery) in the solid that adds, 92.5% PTFE by the fine powder PTFE of disperse constitutes (by Wilmington, the E.I.du Pont de Nemours and Co. of DE provides), its weight accounts for 29% of solid greatly.Carbon black is added in the water, and under 180rpm (revolution of per minute), in baffled mixer, mixed 25 minutes.Then, be added to PTFE disperse system in the solution and under 300rpm, mixed about 1 minute.PTFE disperse system is bonding and capture carbon granule.Subsequently, filter bonding mixture, and put into 150 ℃ stove 24 hours.Subsequently, mixture is put into cooler cooling 24 hours.(6 * 6mm) net screens the jointing material that makes cooling by 0.25 * 0.25 inch.With 0.67: 1 weight ratio the adding of hydrocarbon solvent oil is coagulated in the mixture.The lubricated condensation material that coagulates is put back in the cooler at least 8 hours, takes out subsequently, let alone to be trapped in the surrounding environment about 24 hours.Then, about 15 minutes of the condensation material with fixed attention of rolling lubrication evenly distributes lubricating oil.Under about 900psi (6205kPa), made the material globulate about 25 minutes.Subsequently, average pressure 1200psi (pounds per square inch (p.p.s.i)) (8274kPa) under by a mould pressurised material that 6 inches (15.24cm) * 0.030 inch (0.8mm) of penetrating of tube of 4 inches (10.2cm) are arranged.Subsequently, make extrudate pass through calender, make it roll into 0.012 foot (0.3mm).Then, under the speed of about 20FPM (6.1 meters of per minutes), make extrudate carry out drying by about 200 ℃ heated drum through calendering.With the processing speed of 8 feet of about per minutes (2.4 meters/minute), under 265 ℃ of temperature, make about 2 times of the extrudate longitudinal dilatation of drying calendering.With the processing speed of 40 feet per minutes (12.2 meters/minute), under 265 ℃ temperature, material is longitudinally continued to stretch 5.25 times.Subsequently, with the output speed of about 60FPM (18.3 meters of per minutes), with about 8 times of the material lateral expansion that longitudinally expands, formation ePTFE film.Under the pressure reduction of 0.5 inch water, the per 1 square feet of material of the ePTFE film of generation has the air penetration rate of 28cfm (per minute cubic feet per footage).
Supporting course is formed by spunbond polyester textile, and the vacuum deposition processes with the Dunmore company of Binzhou Newtown on the fabric applies the thick aluminium lamination of about 350 dusts.The antistatic spunbond polyester textile (AXTAR B2270-BKO) that the ePTFE film is placed on New York Toray Ind.Inc. and provides is coated with above the side of aluminium.With heating by the gap between heated roller and the elasticity silicone cylinder and pressurization gathers into folds two kinds of material layers.Bowl temperature is about 250 ℃, and pressure is 30psi (207kPa), and the fabric feed rate is 30 to 50 feet per minutes (9 to 15 meters/minute).The fabric laminate that makes has good adhesion strength between ePTFE film and nonwoven polyester.The air penetration rate of the final lamination of ePTFE and textile support layer is under 0.5 inch (12.7mm) water column pressure reduction, and the material of per 1 square feet (0.0929 square metre) is about 10 cubic feet of per minutes (0.283mm).
Use efficiency tester, the filter efficiency of test layer laminate materials.In the test, specimen material is placed in the test cabinet in two test cabinets.Atomizing NaCl solution be used for producing the specimen medium must smoke particles; The size of smoke particles has 0.10 to 1.0 micron big, and the smoke particles in 0.25 to 0.35 micron granular size scope, aerial concentration are about 5500 particle/cc.The size of smoke particles is the same with flow velocity, room temperature and humidity with quantity to be controlled.Filtering reservation efficient (filtrationretention efficiency) is to calculate in filtered sample fore-and-aft survey smoke particles concentration (playing the function of granular size) at the LAS-X laser particle counter made from PMS.Adopt these particle sizing values, to the efficient of given granular size scope with the percentage calculation sample filtering.Under the diameter sample size of the flow velocity of about 10.5fpm (3.2 meters of per minutes) and 4 inches (102mm), stacked average efficiency is 85.71 under 0.25 to 0.35 micron granular size.As a comparison, testing the nonwoven polyester (promptly having only supporting course) of coated with aluminum in the same way, only is 18.99 0.25 to 0.35 micron granular size scope internal efficiency.So compare with the situation of having only bonded polyester (supporting course), stacked efficient has increased by 400%.
To the polyester of nonwoven polyester, coated with aluminum and the stacked test surfaces impedance of forming by polyester that has applied aluminium and the ePTFE filter course film that is filled with carbon respectively.Be installed on the insulating frame with the 3478A of Hewlett-Packard type universal meter, two, size 1 " * 1/4 (the square surface electrode of 25.4mm * 6.35mm) is perpendicular to 1 " electrode spacing on the electrode direction is 1 " (25.4mm) on electrode, add the weight of 16psi (110kPa) and as the device to test surface impedances such as insulation transparent vinyl disc of workbench.Adopt this equipment, the surface impedance of nonwoven polyester is greater than 10
10Ohm has surpassed the range ability of equipment.The average surface impedance of the polyester of coated with aluminum is 12.2 ohm of every squares, and standard deviation is 1.6 ohm of every squares.Above-mentioned stacked average surface impedance is 3164 ohm of every squares, and standard deviation is 2921 ohm of every squares.Owing to be filled with the ePTFE film of carbon and the variation contact resistance of electrode, stacked resistance has bigger changeability.Yet, this stacked every square 10 of having an appointment
4The surface impedance of ohm is generally every square 10 than the PTFE pellicular cascade of common filling
12To 10
14Ohm is wanted little 8 orders of magnitude.Example 2:
To be added to according to the ePTFE film stack that is filled with conductive particle that the process of describing in the example 1 is made on the antistatic non-woven polyester fabric ID#AXTAR B2270-BK0 of the Toray Industries Inc. manufacturing of using New York.In this case, under the processing speed of 13.3 feet per minutes (4 meters/minute), 265 ℃ temperature, make 2 times of extrudate longitudinal dilatations through calendering, and 3 times of longitudinal dilatations under the temperature of the processing speed of 40 feet per minutes (12.2 meters/minute) and 265 ℃ subsequently, the ePTFE filtration membrane formed.
It is thick that the film that makes is about 0.002 foot (51 microns), under 0.5 inch (12.7mm) water column pressure, by 1 foot
2Air transmission coefficient during (0.093 square metre) material is 16cfm (0.45 cubic metre).With testing equipment identical shown in example 1, the filter efficiency of test ePTFE film before stacked.Under the situation of 0.25 to 0.35 micron of granular size, flow velocity is still for about 10.5fpm (3.2 meters/minute), and average efficiency is 99.99, and average deviation only is 0.002%.
Also tested the body resistivity of the ePTFE film of filling.Film is placed between the copper electrode of two 11/16 inch (17.5mm) diameter, and puts a weight, so that the pressure of 16 pounds (71N) per square inch to be provided in top of electrodes.Adopt the 3478A universal meter of Hewlett-Packard, measure and penetrate resistance.With the data of this resistance value, sample thickness and electrode size, calculate body resistivity.Average body resistivity is 538 ohm-cms, standard deviation 400 ohm-cms.Here, because the ePTFE film of filling has higher and variable contact resistance, make standard deviation higher.As a comparison, unfilled ePTFE film has and is about 10
12The body resistivity of ohm-cm is compared with the ePTFE film that is filled with carbon of the present invention, exceeds 9 orders of magnitude at least.
Good bonding and excessively do not lose transmitance in order to produce, the ePTFE film stack that will be filled with carbon with enough heats, pressure and the time of staying is added on the bonded polyester.Polyester is heated to the flowable temperature spot of thawing, and is used as the binding agent of the ePTFE film that is filled with carbon.0.5 " under (12.7mm) the water column pressure, by 1 foot
2The final transmissivity of lamination of the medium of (0.093 square metre) is 3.5cfm (0.1 cubic metre/minute).
Subsequently, the filter efficiency of test laminated fabric under the test of simulation industrial filtration applications.Lamination is cut, clamps and be sealed in 12 * 12 inches (in 0.3 * 0.3m) the measuring channel.Be stacked in reception test under the AC FINE test dust of AC Rochester branch of General Motors Corporation of Texas Wichita Falls, this dust has good feature particle size distribution.This dust is very representative in the dust that many industrial filtration applications occasions require to be filtered.Be stacked in when placing, make in the test cabinet of the ePTFE side that the is filled with carbon dust of 2.0 particles in loading is had an appointment every cubic feet air.The flow velocity setting also is controlled under the 6-7fpm (1.8-2.4 rice/minute).Filter produced under an air pulse 0.1 second, 50psi (345kPa) at per 10 seconds and stands " back fluctuation (backpulsed) " (promptly standing to impact from the hyperbar in filter downstream).This pulse application is in many industrial applications, to remove dust and particle from the surface of filter.Many particles that the filter outside is set up have been taken away in this pulse, thereby have prevented that the pressure drop on the filter from increasing too greatly.Test was carried out 168 fens or 1008 pulses.Air downstream is by Gelman science type A/E glass fiber filter, so that collect any dust that may pass through just tested filter lamination.The test before and after, to glass fibre through weighing, so that determine to pass the quality of the dust of just tested filter stack.In addition, the dust in the de-entrainment filter upstream side collection conduit, and the dust that is trapped on the filter weighed.Be used in the quality of dust on the quality of the dust that filter lamination upstream end captures and the glass fiber filter downstream, calculate the efficient of filter.The efficient of filter is 99.99+%.
In addition, analysis and filter device after test is to determine whether test period has damaged the ePTFE film that is filled with carbon.Filter all separates less than tangible damage, pinprick duck eye or lamination at any one.Filter has the function of good eliminating dust, and this only has 5.0% weight to increase (pickup) from filter self is proved.The ePTFE film that is filled with carbon has avoided becoming as non-woven polyester fabric the trap of dust, and dust can easily be escaped from the non-adhering surfaces of film.
Above embodiments of the invention are described, should not to regard as be limitation of the present invention but these are described.Clearly, to all variations of the foregoing description with revise that all should to be considered be the scope that claim of the present invention is protected.
Claims (20)
1. conductive filter media is characterized in that it comprises:
Filter course with microporous membrane structure;
Attached to the supporting course on the filter course;
Wherein, microcellular structure comprises buried conductive particle within it, and conductive particle provides equally distributed electric pathway in whole filter course, thereby the electrostatic charge in the filter medium is leaked.
2. filter medium as claimed in claim 1 is characterized in that the microporous membrane structure comprises expanded polytetrafluoroethyl,ne, and described expanded polytetrafluoroethyl,ne comprises the microcellular structure by the interconnected aggregation of fubril.
3. filter medium as claimed in claim 2 is characterized in that described filter course comprises the carbonaceous conductive particle.
4. filter medium as claimed in claim 1 is characterized in that it also comprises:
Be deposited on the conductive material coating at least one side bearing layer, described coating helps electrostatic charge to leak away from filter medium.
5. filter medium as claimed in claim 4 is characterized in that, described coating comprises attached to the thin metal coating on the supporting course.
6. filter medium as claimed in claim 1 is characterized in that,
Be deposited on the conductive material coating at least one side filter course, described coating helps electrostatic charge to leak away from filter medium.
7. filter medium as claimed in claim 6 is characterized in that, described coating comprises attached to the thin metal coating on the supporting course.
8. filter medium as claimed in claim 1 is characterized in that, described supporting course comprises buried conductive particle within it, and described conductive particle assists in electrostatic charge and leaks away from filter medium.
9. filter medium as claimed in claim 1 is characterized in that, described filter medium is the filter cloth type.
10. filter medium as claimed in claim 1 is characterized in that, described filter medium is the filter bag type.
11. filter medium as claimed in claim 1 is characterized in that, described filter medium is to filter cartridge type.
12. a method of producing conductive filter media is characterized in that it comprises:
Filter course with an inner surface and an outer surface is provided;
The microcellular structure that comprises an expanded polytetrafluoroethyl,ne;
The conductive particle that is buried in the expanded polytetrafluoroethyl,ne filter course is provided, electrostatic charge is leaked away by equally distributed electric pathway in filter course;
Described filter course is installed on the filter, and described filter comprises an electrical connection, makes electrostatic charge be transmitted to ground from filter course; And
During use, by the electric pathway of filter course, electric charge is evenly leaked away from filter course.
13. method as claimed in claim 12 is characterized in that, it also is included on the described supporting course and forms conductive material coating.
14. method as claimed in claim 13 is characterized in that, it also comprises:
The conductive coating that comprises metal is provided; And
With the conductive coating vacuum deposition to described supporting course.
15. method as claimed in claim 13 is characterized in that, it also comprises:
The conductive coating that comprises metal is provided; And
The conductive coating sputter is coated on the described supporting course.
16. method as claimed in claim 13 is characterized in that, it also comprises:
The conductive coating that comprises metal is provided; And
Conductive coating is electroplated onto on the described supporting course.
17. method as claimed in claim 12 is characterized in that, it also comprises:
Fill described supporting course with conductive particle, thereby help electrostatic charge to leak away from filter course.
18. method as claimed in claim 12 is characterized in that, it also comprises filter medium is formed in the filter cloth.
19. method as claimed in claim 12 is characterized in that, it also comprises filter medium is formed in the filter bag.
20. method as claimed in claim 12 is characterized in that, it also comprises described filter medium is formed in the cartridge filter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 95196899 CN1170370A (en) | 1995-10-23 | 1995-10-23 | Conductive filter laminate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 95196899 CN1170370A (en) | 1995-10-23 | 1995-10-23 | Conductive filter laminate |
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| Publication Number | Publication Date |
|---|---|
| CN1170370A true CN1170370A (en) | 1998-01-14 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 95196899 Pending CN1170370A (en) | 1995-10-23 | 1995-10-23 | Conductive filter laminate |
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Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008118256A2 (en) * | 2007-03-22 | 2008-10-02 | Milliken & Company | Two sided conductive filtration media |
| CN101628194A (en) * | 2008-07-18 | 2010-01-20 | Bha控股公司 | Apparatus and system for filtering air |
| CN104245086A (en) * | 2012-04-27 | 2014-12-24 | W.L.戈尔及同仁股份有限公司 | Seam-sealed filters and methods of making thereof |
| CN104275034A (en) * | 2014-09-15 | 2015-01-14 | 天诺光电材料股份有限公司 | Filtering material for surface metallization of non-woven fabrics for normal temperature and preparation method of filtering material |
| CN104275033A (en) * | 2014-09-15 | 2015-01-14 | 天诺光电材料股份有限公司 | Filtering material for surface metallization of non-woven fabrics for medium/high temperature and preparation method of filtering material |
| CN104289038A (en) * | 2014-09-15 | 2015-01-21 | 天诺光电材料股份有限公司 | Filtering material for metallization of non-woven base fabrics for normal temperature and preparation method of filtering material |
| CN104289039A (en) * | 2014-09-15 | 2015-01-21 | 天诺光电材料股份有限公司 | Filtering material for metallization of non-woven base fabrics for medium/high temperature and preparation method of filtering material |
| CN106955529A (en) * | 2015-10-06 | 2017-07-18 | Jp空气技术公司 | Filter medium for removing particle from air-flow and production and preparation method thereof |
| CN107282303A (en) * | 2016-09-13 | 2017-10-24 | 成都创慧科达科技有限公司 | A kind of high-efficiency electromagnetic cleaner conductive fiber |
| CN108554010A (en) * | 2018-05-07 | 2018-09-21 | 江苏灵氟隆环境工程有限公司 | A kind of industrial dedusting device |
| CN109663398A (en) * | 2017-10-16 | 2019-04-23 | 曼·胡默尔有限公司 | Filter core and liquid cleaner |
| CN109821300A (en) * | 2019-03-26 | 2019-05-31 | 东北大学 | A kind of anti-static coated filter material and manufacturing method for flammable explosiveness dust-filtering |
-
1995
- 1995-10-23 CN CN 95196899 patent/CN1170370A/en active Pending
Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008118256A2 (en) * | 2007-03-22 | 2008-10-02 | Milliken & Company | Two sided conductive filtration media |
| WO2008118256A3 (en) * | 2007-03-22 | 2008-11-27 | Milliken & Co | Two sided conductive filtration media |
| CN101628194A (en) * | 2008-07-18 | 2010-01-20 | Bha控股公司 | Apparatus and system for filtering air |
| CN104245086A (en) * | 2012-04-27 | 2014-12-24 | W.L.戈尔及同仁股份有限公司 | Seam-sealed filters and methods of making thereof |
| CN104245086B (en) * | 2012-04-27 | 2016-03-23 | W.L.戈尔及同仁股份有限公司 | Filter of joint seal and preparation method thereof |
| CN104289038B (en) * | 2014-09-15 | 2016-02-10 | 天诺光电材料股份有限公司 | A kind of normal temperature filtering material of non-woven fabricbase cloth metalized and preparation |
| CN104289038A (en) * | 2014-09-15 | 2015-01-21 | 天诺光电材料股份有限公司 | Filtering material for metallization of non-woven base fabrics for normal temperature and preparation method of filtering material |
| CN104289039A (en) * | 2014-09-15 | 2015-01-21 | 天诺光电材料股份有限公司 | Filtering material for metallization of non-woven base fabrics for medium/high temperature and preparation method of filtering material |
| CN104275033A (en) * | 2014-09-15 | 2015-01-14 | 天诺光电材料股份有限公司 | Filtering material for surface metallization of non-woven fabrics for medium/high temperature and preparation method of filtering material |
| CN104289039B (en) * | 2014-09-15 | 2016-02-10 | 天诺光电材料股份有限公司 | A kind of middle high temperature filtering material of non-woven fabricbase cloth metalized and preparation |
| CN104275034A (en) * | 2014-09-15 | 2015-01-14 | 天诺光电材料股份有限公司 | Filtering material for surface metallization of non-woven fabrics for normal temperature and preparation method of filtering material |
| CN104275033B (en) * | 2014-09-15 | 2017-01-11 | 天诺光电材料股份有限公司 | Filtering material for surface metallization of non-woven fabrics for medium/high temperature and preparation method of filtering material |
| CN106955529A (en) * | 2015-10-06 | 2017-07-18 | Jp空气技术公司 | Filter medium for removing particle from air-flow and production and preparation method thereof |
| CN107282303A (en) * | 2016-09-13 | 2017-10-24 | 成都创慧科达科技有限公司 | A kind of high-efficiency electromagnetic cleaner conductive fiber |
| CN109663398A (en) * | 2017-10-16 | 2019-04-23 | 曼·胡默尔有限公司 | Filter core and liquid cleaner |
| CN109663398B (en) * | 2017-10-16 | 2022-08-12 | 曼·胡默尔有限公司 | Filter element and fluid filter |
| CN108554010A (en) * | 2018-05-07 | 2018-09-21 | 江苏灵氟隆环境工程有限公司 | A kind of industrial dedusting device |
| CN109821300A (en) * | 2019-03-26 | 2019-05-31 | 东北大学 | A kind of anti-static coated filter material and manufacturing method for flammable explosiveness dust-filtering |
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