MXPA00011279A - Methods and apparatus for the formation of heterogeneous ion-exchange membranes - Google Patents

Abstract

The present invention provides methods and apparatus for the formation of heterogeneous ion-exchange membranes by prescribed in-line compounding and extrusion of a polymeric binder and heat sensitive ion-exchange resin. The ion-exchange resin is incorporated, at a late process stage, into the melted matrix polymer at relatively low temperature and residence time prior to transfer to a die head for extrusion. In the presently preferred embodiment, the in-line compounding apparatus comprises a twin-screw compounding extruder, for effecting late stage kneading and mixing of ion-exchange resin and optional additives to the polymer melt, prior to compression to transfer the blended polymer melt to a die head for extrusion. Accordingly, the final properties of the resultant heterogeneous ion-exchange membrane are enhanced as the blended polymer melt material is not exposed to excessive heat and shear history. Resultant heterogeneous ion-exchange membranes and apparatus for treatment of flui d streams utilizing such membranes are also provided.

Description

METHODS AND APPARATUS FOR THE FORMATION OF MEMBERS OF EXCHANGE OF HETEROGENEOUS IONS DESCRIPTION OF THE INVENTION The present invention provides unique heterogeneous ion exchange membranes, methods and apparatus for producing such membranes, and apparatus for ion removal using such membranes. The purification of such fluids such as water, beverages, chemicals and waste streams can be carried out in a variety of different systems for a plurality of different end results. For purposes of ultra pure water and drinking, purification may require the removal of substantial amounts of ions contained within salt or brackish water, may require the removal of turbidity and large particles, or may require the destruction of living organisms. Such purification may also require elimination of substantial amounts of reverse osmosis permeate and DI permeate ions. For ion removal, several basic systems have found commercial acceptance: ion exchange, reverse osmosis, electro dialysis and electrodeionization. In general, established methods for deionization fluids include: distillation, ion exchange, electro dialysis and reverse osmosis. Distillation separates water from contaminants by transferring water in the vapor phase, leaving most of the contaminants behind. Ion exchange removes ions from solutions by exchange of salts with hydrogen and hydroxide ions. Electro dialysis uses 5 membranes that remove salts by ion transfer under the influence of a direct electric current. Reverse osmosis uses membranes that are permeable to water but not solutes, with water that is purified as soon as it is activated by pressure through the membranes. Electrodeionization (EDI) processes combine the use of resins and ion exchange membranes to deionize water. The EDI equipment is capable of efficient deionization of a wide range of feedings from the removal of bulk salt to polish the water of the reverse osmosis product. Typically, in electrodeionization, number of flat sheets of cation exchange membranes and alternating anions are placed between two electrodes with mixed bed of ion exchange resins alternately aggregated between the membranes. 20 The compartments containing the resin beads are generally referred to as the diluted compartments. The adjacent compartments in which the ions are transferred for disposal are referred to as the concentrated compartments. The concentrated compartments are usually much thinner than the diluted compartments, and serve to collect the concentrated ions that are transferred from the diluted compartments. The diluted compartment may or may not contain additional ion exchange resin. When the fluid flow is fed through the system, and electrical potential (voltage) is applied, the ions begin to migrate towards the electrodes; the anions to the anode and the cations to the cathode. In the diluted compartments, the ions are able to cross within the compartments of the near concentrate only when they are in the "correct" membrane; that is, when the anions find the anionic membranes and the cations find the cationic membranes. In the concentrate compartment, the ions continue their migration to the electrodes, but do not find the "opposite" membranes; that is, the anions find the cationic membranes while the cations find the anionic membranes. These membranes block their movement, they trap them in the concentrate compartment where they are rinsed. The net result of the EDI process is that the water is continuously deionized in the diluted compartments, with unwanted ions coming out of the concentrate compartments.

U.S. Patent No. 4,465,573 assigned to Harry O'Haré for Method and Apparatus for the Water Purification describes such devices and the vision of electrodeionization that continues to gain commercial acceptance among several end users. A critical element of such purification devices is the membrane that selectively allows the diffusion and adsorption of ions while excluding certain other non-ionized ions and solutes and solvents. These membranes have been commonly referred to as ion exchange membranes and are used in a wide variety of devices for fractionation, transport depletion and electro regeneration, purification for water treatment, food, beverages, chemicals and waste streams. Such membranes are also used in electrochemical and electrophoresis devices as well as analytical equipment and for treatment applications. Commercially available ion exchange membranes are generally classified as two types: homogeneous membranes and heterogeneous membranes. A homogeneous membrane is one in which the total volume of the membrane (excluding any support material that can be used to improve the resistance) is made of the reactive polymer. The heterogeneous membranes, on the other hand, are formed of a compound that contains an ion exchange resin to impart electrochemical properties and a binder to impart physical strength and integrity. The ion exchange resin particles serve as a path for ion transfer that serves as a bridge of increased conductivity between the membranes to promote the movement of ions. Under conditions of reduced liquid salinity, high voltage and low flux, the resins also convert to the H + and OH- forms due to the division of water into their ions in a thin layer on the surface of the resin particles or membranes. This also improves the obtainable quality of water. During electrodeionization, the concentration of ions within the resin particles remains relatively constant and the migration of ions from the resin particles in the concentration compartments is substantially balanced by the migrations thereof, or similar ions of the water that is present. purifies in the resin particles. Such membranes must be resistant to high temperatures, result in a low pressure loss, and result in low internal and external leaks. The low pressure loss reduces the pumping requirements and also allows the membranes to be spaced closer together, thereby reducing the energy consumption caused by the electrical resistance of the water currents. For selective ion electrodialysis, the selective ion exchange resins can be used as the resin component of the inventive membrane. For transport depletion electrodialysis, anion resins and mixed cations, or amphoteric resins can be used in place of the resin component of one of the anion or cation membranes. For transport of large diffusion, multivalent or lens ions, low ion crosslink ion exchange resin can be used in the membrane. Typically, the starting ion exchange resin bead has the physical characteristic in appearance as a translucent, spherical bead with an effective size of about 0.25 to about 0.75 mm. The chemical stability of ion exchange resins is dependent on, among other factors of operating temperatures that generally should not exceed 285 degrees F (140.5 ° C) for cation exchange resin and 195 degrees F (90.55 ° C) for anion exchange resin. The resin beads 20 are generally produced by a process incorporating the crosslinked polystyrene with an active functional group such as sulfonic acid (cation) or quaternary ammonium functional groups (anions). A wide variety of such membranes are known in the art. In this regard, such membranes are described, for example, United States Patent No. 3,627,703; 4,167,551; 3,876,565; 4,294,933; 5,089,187; 5,346,924; 5,683,634; 5,746,916; 5,814,197; 5,833,896; and 5,395,570. 5 U.S. Patent No. 5,346,924 assigned to Giuffrida discloses a heterogeneous ion exchange membrane using a binder comprising a linear low density polyethylene (LLDPE) or a high molecular weight high density polyethylene (HM HDPE) and methods jM. 10 to do the same. The membrane is made of granules or ion exchange resin tablets and either LLDPE or HMWHDPE binders that are used as a raw material in a thermoplastic extrusion process, a heat pressing process, or another, similar process that uses pressure And heat to create a dry composite sheet of constant width and thickness or having other controlled, formed dimensions. The membrane sheets formed by such processes • they are then conditioned and activated using a water treatment. Conventionally, heterogeneous ion exchange membranes are manufactured by providing polymer binder powder or granulate to a mixer and heating until the material becomes molten. The ion exchange resins are then added in powder form and the resulting composition is then mixed to evenly distribute the ion exchange resins throughout the melt. The molten mold mixture can then be molded or alternatively sent to an extruder. 5 Where the molten mixture is molded to form a chain, the chain is generally cooled and then granulated. The granules are thereafter fed to an extruder or other polymer processing device that combines heat and pressure. The formation of fused and jA. The film is generally made at relatively high temperatures, for example, 300-350 ° F (148.8-176.6 ° C). Kojima, et al., In U.S. Patent No. 3,627,703 discloses a polypropylene resin composite which comprises a polypropylene resin matrix that is both microscopically foamed and molecularly oriented in three dimensions and the exchange material of ions dispersed in it. In a By way of example, the compound is produced by a process which comprises subjecting a precursor compound comprising a solid polypropylene matrix and an ion exchange material of greater swelling capacity to a chemical treatment comprising an acid and an alkaline treatment. . In one embodiment, the polypropylene resin and the ion exchange material are kneaded at a temperature above the melting point of the polypropylene resin. Subsequent to kneading at high temperature, the mixture is thereafter formed or molded and thereafter chemically treated. • While recognizing the virtues of Polypropylene as a binder, Kojima, et al., In U.S. Patent No. 3,627,703 discloses a manufacturing process for an ion exchange membrane to expose the resinous material to multiple melting points and temperature cycles. jj ^ 10 Accordingly those skilled in the art have recognized a significant need for an efficient process for the manufacture of heterogeneous ion exchange membranes that exactly control processing parameters to preserve the active ion sites and Other desired characteristics of the resinous material incorporated at the same time, provide a heterogeneous ion exchange membrane with the structural integrity required to demand environment such as electrodeionization. The present invention fulfills these needs. The present invention provides unique methods and apparatus for the formation of ion exchange membranes by prescribed composition and in-line extrusion of a polymeric binder and ion exchange resin. sensitive to heat. The ion exchange resin is incorporated, in a late process step, into the molten matrix polymer at relatively low temperature and residence time prior to transfer to a mold head # for extrusion. In the presently preferred embodiment, the in-line composite apparatus comprises a twin-screw composite extruder, performing kneading and late-stage mixing of the ion exchange resin and optional additives to the polymer melt, prior to compression to transfer the molten mass of polymer 10 mixed to a mold head for extrusion. By Accordingly, the final properties of the resulting heterogeneous ion exchange membrane are improved as soon as the mixed polymer melt material is not exposed to excessive heat and shear history. The resulting heterogeneous ion exchange membranes and apparatus for the treatment of fluid streams using such membranes are also provided. In a currently preferred mode, the inventive method comprises: a) feeding a supply of polymer binder to an in-line composite extruder, which has a means for melting, kneading and transferring the polymer binder to a mold head for extrusion; The extruder also has a means to feed additives to the polymer molten binder to a prescribed processing step. b) Maintaining the polymer binder within the extruder in a temperature range or between approximately the softening point of the binder of polymer at the melting point of the polymer binder to form a molten matrix polymer; c) Knead the molten matrix polymer to form a homogeneous matrix; d) Subsequent addition and mixing of resin-ion exchange powder to the molten matrix polymer derived from step c) to form a homogeneous mixed matrix within the extruder during a relatively limited residence time; and e) Transporting the molten mixed polymer matrix derived from step d) to a mold head for extrusion to form a heterogeneous ion exchange membrane. After extrusion, the single membranes are preferably washed in a bath of deionized water at a temperature of about 180 ° F (82.2 ° C) for at least two hours until the expansion is effected. In a presently preferred embodiment, the inventive apparatus comprises a twin screw compounding extruder, the extruder having one. first zone of , a second melting zone, a third zone for kneading the melt homogeneously, a means for feeding selective additives to the molten stream downstream of the polymer or the third zone, a fourth zone for • further effecting the kneading and mixing of additives to the molten mass 5 of the preferred polymer, a fifth zone for mixing extrudates into the mixed polymer melt and a sixth compression to transfer the mixed polymer melt to a head of mold for extrusion. < ^ ft 10 An optional computer processing unit can continuously monitor and correct the equilibrium of the extrusion system to effect the method for the formation of heterogeneous membranes according to the present invention. The control software uses Preferably an algorithm program for analyzing the prescribed entries of the key points in the extrusion system, makes numerical calculations, and makes any necessary corrections to the screw RPM of the extruder, temperature range, residence time and speed of power. The preferred polymer matrix comprises about 20% to about 80% by weight of the preferred polymer melt to be extruded from the mold head. The preferred polymer binder for the matrix is Polymer of propylene and metallocene based on catalysis of a site that produces polymers with very narrow molecular weight distribution (MWD), distributions of uniform composition (CD) and distributions of narrow tacticity (TD). The preferred polymer has a relatively low melting point within a range of about 125 to about 130 degrees centigrade. The narrow molecular weight distribution of the propylene and metallocene polymer provides a unique rheology allowing the extrusion of thin films. On the other hand, the melt flow rate (MFR) can be objectively precisely in the reactor which reduces the downstream processing variability and which eliminates the need for post-reactor controlled rheology (CR). The molecular weight capacity has an MFR range of between about 0.01 to about 5,000. The typical molecular weight distribution of the preferred polymer is about 2.0. The narrow molecular weight distribution and the narrow tacticity distribution coupled with the elimination of CR processing, substantially reduces molecules of low molecular weight in this way significantly the extraction products. The ion exchange resin to be dispersed in the polymer binder can be any ion exchange material which is anionic, cationic, amphoteric or other ionic type can be used.

Preferably, ion exchange resins that are stable in the melting point range of the preferred polypropylene resins are used to prepare the matrix • of mixed polymer. Accordingly, the heterogeneous ion exchange membranes according to the present invention are particularly useful for manufacturing electrodeionization modules. Inventive methods provide an effective and cost-effective process for forming such membranes that exhibit improved properties since the resinous ion exchange material is not exposed to excessive heat and shear history. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic block diagram illustrating multiple zones for the in-line composite apparatus exemplified according to the presently preferred embodiment of the present invention. • The present invention provides unique methods and apparatus for the formation of exchange membranes of heterogeneous ions by in-line compound formation and extrusion prescribed a polymeric binder and heat-sensitive ion exchange resin. The ion exchange resin is incorporated, in a late process step, into the molten matrix polymer at temperature relatively low and residence time short before transfer to transfer to an extrusion sheet mold head. Therefore, the final properties of the • heterogeneous ion exchange membrane are increased as the mixed polymer melt material is not exposed to excessive heat and shear history. Typically, organic molecules are composed of a skeleton of carbon atoms, retracted in hydrogen atoms, with clusters composed of other atoms attached to that skeleton. These united groups are referred to as functional groups, since they are always the sites of reactivity or chemical function. In this regard, the 15 energies involved in keeping two atoms together in a covalent bond are generally recognized as follows: 1. Kinetic energy (movement) and heat (essentially molecular motion). 2. Potential energy that originates from 20 a) Electric forces (attraction of repulsion of similar, different charges) At higher temperature, the energy of random molecular motion increases and can often exceed certain binding energies and thus causes 25 covalent bond break.

In a currently preferred embodiment, the inventive method comprises: ^^ a) feeding a supply of polypropylene binder to a compound extruder, having a means for melting, kneading and transferring the polymer binder to a mold head sheet for extrusion; the extruder further having a means for feeding and mixing active additives in line to the molten polymer binder at a prescribed point fl 10 along the extruder; b) maintaining the polymer binder within the extruder in a temperature range of between about the softening point of the polymer binder and the melting point of the polymer binder. polymer binder to form a molten matrix polymer; c) kneading the molten matrix polymer to form a homogeneous matrix; d) adding and mixing 20-ion powder exchange resin, to the molten matrix polymer derived from step c) to form a homogeneous mixed melt within the extruder during relatively limited residence time; and e) compressing and transporting the melt 25 derived from step d) directly to a head of * & > * •. • ** -, "** sheet mold for extrusion to form a heterogeneous ion exchange membrane." After extrusion, the single membranes are preferably washed in a bath of deionized water at a temperature of about 180.degree. F (82.2 ° C) for at least two hours until total expansion and hydration are carried out. It is critical in accordance with the present invention that the ion exchange resins be added to the polymer matrix after the matrix has undergone melting and initial kneading. This last step of processing the ion exchange resins minimizes the occurrence of covalent bond destruction of active functional groups. The exchange material of: ions to be dispersed in the compound, it can be any ion exchange material which is anionic, cationic, amphoteric, or another ionic type can be used. Resins of representative particulates which may be used in accordance with this invention include gel and macroporous ion exchange resins such as sulfonated polystyrene-divinylbenzene and aminated polystyrene-divinylbenzene either in pure form or in mixtures (Type I, Type II or Type III) such as those available under the DOWEX trademark of the Dow Chemical Company; Y; chromatographic resins; bifunctional ion exchange resins such as ion retardant resins (Biord AG11A8) or ion exchange resins that • contain both quaternary and sulfonated amine functionality, sulfonated phenolic resin, polystyrene phosphoric acid or imidodiacetic acid resins, aminated acrylic or methacrylic resins, epoxy polyamine resins, aminoethyl cellulose or the like. The polymer matrix comprises from about 10-20% to about 80% by weight of the polymer melt to be extruded from the mold head. The preferred polymer for the matrix is polypropylene polymer and metallocene based on single site catalysis which produces preferred polymers with very high molecular weight distribution. narrow (MWD), uniform composition distributions (CD) and narrow tacticity distributions (TD). The preferred polymer has a melting point within a range of about 125 to about 130 degrees centigrade. The narrow molecular weight distribution of the polymer of Polypropylene and metallocene provides a unique rheology that allows the extrusion of thin films. On the other hand, the melt flow rate (MFR) can be accurately objectified in the downstream processing variability reduction reactor and eliminating the need for post-reactor controlled rheology (CR). The molecular weight capacity has an MFR range of between about 0.01 to about 5,000. The typical molecular weight distribution of the preferred polymer is • approximately 2.0. The narrow molecular weight distribution and narrow tacticity distribution coupled with the CR processing elimination substantially reduces the low molecular weight molecules in this way by reducing the extractables in the resulting membrane. A preferred polymer for the matrix is a polymer < t-10 of polypropylene sold by EXXON under the brand name ACHIEVEMR. The capacity of an EXXPOL catalyst site results in a narrow tacticity (TD) distribution and also results in a narrow composition (CD) distribution in random copolymers (RCP). The capacity of a single site gives rise to 15 polymer behavior advantage in the general cleaning area. In the currently preferred embodiment, the in-line composite apparatus comprises a twin-screw composite extruder for effecting kneading and mixing of the last stage of ion exchange resin and optional additives to the polymer melt, prior to compression for Transfer the mixed polymer melt to an extrusion sheet mold head. The twin-screw extruder can be either coiled or counter-rotating. The process parameters can be controlled manually or automatically including screw rpm, feeding speed, temperatures along the barrel and mold, and vacuum level for devolatization. The • readings preferably include melt pressure, melt temperature, and motor amperage. The motor input power in the screws and the rotation screws impart shear and energy in the process to mix the components, devolatize and pump as required. ß-i, 10 The feeder system for the twin screw extruder must ensure pressure stability obtainable at the front end of the extruder to ensure dimensional stability of the resulting membrane. Preferably gravimetric feeders are used for extrusion direct from the twin screw extruder for inherent compositional accuracy enhanced with its use. The means for mixing the additives to the matrix can be dispersive or distributive. Preferably, the narrowest mixing elements are used in the system inventive since they are more distributive with high speeds of melt division with minimum elongation and planar shear stress. The distributive mixing elements allow many melting divisions without extensional shear stress. 25 The pressure gradient in the twin screw extruder will be determined by the selection of screws. The fin elements can be strategically placed in such a way that the screw channels are not filled and • they will have a zero pressure below the current below the vent / feed barrel sections, which facilitates the downstream sequential supply and avoids the flooded vent. Preferably the powder ion exchange material which is sized to smaller than 100 mesh, or preferably sized to smaller than 32 mesh, is added to the molten matrix polymer through a side filling means to enter a second mixing and kneading zone. The second mixing zone is provided with a side feed inlet port, i.e. polymer of homogeneous polypropylene. The second kneading zone is maintained and mixed to a; temperature above the melting point of polypropylene with atmospheric venting. After • this, the mixed molten polymer matrix and the ion exchange material is fed to a third zone of kneading and mixing where the extrusion agents can be added. Typically, such extrusion agents comprise glycerin and the like to further facilitate processing and extrusion transfer through the mold head. The third mixing and mixing zone is maintained Preferably under vacuum conditions to remove the gas and the molten mixture is thereafter transferred through a compression section to the mold head. The unique heterogeneous polypropylene ion exchange membranes according to the present invention are thus formed by a twin screw compound extruder. In this regard, the twin screw extruder continuously mixes, devolatilizes and processes the binder of polypropylene and metallocene through a compound described with the resinous material by relatively small shear stress and extensional forces. Accordingly, the traditional granulation and remelting step is again passed avoiding excessive heat and shear history. The following is an illustrative example of the inventive method and apparatus. Figure 1 illustrates a schematic block diagram of a currently preferred embodiment of the inventive in-line composite apparatus according to the present invention. As shown in Figure 1, the polymer binder supply is fed, for example, by a gravity feed device 10 to the first zone within the extrusion system. A second zone 14 effects the melting of the binder polymer within the extruder in a temperature range from about the softening point of the polymer binder to the melting point of the polymer binder to form a molten matrix polymer. In a third zone 16, the molten matrix polymer is kneaded to • form a homogeneous matrix. In a fourth zone 18, optional additives 5 can be supplied to the polymer matrix, for example, conventional extrusion agents such as glycerin to increase the malleability of the homogeneous matrix. For a separate gravity feed device 20, an ion exchange resin is added in powder to the molten matrix polymer in the fifth zone 22 and the mixed matrix is further mixed and kneaded before removing gas in the sixth zone 24. In a seventh zone 26, the matrix of the molten, mixed polymer is compressed and fed to a sheet mold head 28 for extrusion for form a heterogeneous ion exchange membrane. A heterogeneous polypropylene ion exchange membrane is produced by feeding a supply of • propylene and metallocene polymer to a twin screw compound extruder, the extruder having a first zone of feed, a second melting zone, a third zone for kneading melt homogeneity, a feed inlet port disposed upstream of the third zone, a fourth zone for effecting kneading and further mixing of the additives to the melt of polymer Preferred, a fifth zone for mixing extrudates into the mixed polymer melt into a sixth zone to remove gas and a seventh compression zone to transfer the mixed polymer melt to a head • sheet mold for extrusion. The binder is held within a polymer melt section of the extruder at a temperature below about 130 degrees centigrade to melt the binder and to knead to form a homogeneous melt. The kneaded fused matrix polymer is then transported to an area of intermediate mixed and exchange resin is added • Powdered ions to the melted matrix polymer with kneading and subsequent mixing of the molten matrix polymer with the ion exchange material at a temperature below about 130 degrees centigrade at atmospheric pressure.

The molten polymer matrix, mixed, is then transported to a compression zone of the extruder. The mixed polymer melt matrix is then transported from the compression zone to a sheet mold head for • extrusion to form a membrane that has a thickness extruded from about 0.001 inches to about 0.050 inches. Preferably, the resulting membrane has a thickness in the range of about 0.005 and 0.025 inches and 0.025 inches. For EDI applications, the member The resulting thickness has a thickness within a range of 0.008 to 0.012 inches. Typically, the residence time of the ion exchange material in the extrusion system will be • under two minutes and preferably less than thirty seconds. Accordingly, the present invention provides an apparatus for the formation of a heterogeneous ion exchange membrane comprising a single machine: a twin screw compound extruder, the extruder having a first feed zone, a second feed zone, melting, a third zone for melt homogeneity of • kneading, and means for feeding selective additives to the polymer melt flowing under the third zone, a fourth zone for effecting the mixing and mixing of additives to the preferred polymer melt, a fifth zone for mixing extrusion agents into the mixed polymer melt, which can be placed on either side after zone three, a sixth compression zone to remove the gas to the mixed polymer melt, and a seventh zone of compression to transfer the mass of polymer mixed to a unit sheet mold head; in addition, an adjustable sheet mold head for extruding thin cast sheet membrane, a stack of rollers for forming, cooling and scheduling the membrane, and a membrane pick-up device; where the residence time of the ion exchange material is kept at a minimum while at elevated temperatures ideally less than two minutes, and preferably less than one minute.

Claims (17)

CLAIMS 1. A method for the formation of a heterogeneous ion exchange membrane characterized in that • comprises: a) feeding a supply of propylene binder to an in-line compounding extruder, having a means for melting, kneading and transferring the polymer binder to a sheet mold head for extrusion; the extruder having a medium jB 10 for feeding and mixing active additives in line to the molten polymer binder in a prescribed processing step; b) maintaining the polymer binder within the extruder in a temperature range of between 15 about the softening point of the polymer binder and the melting point of the polymer binder to form a molten matrix polymer; • c) kneading the molten matrix polymer to form a homogeneous matrix; D) subsequently adding and mixing a powder ion exchange resin to the molten matrix polymer derived from step c) to form a homogeneous mixed melt within the extruder for a relatively limited residence time; and e) transporting the mixed molten polymer matrix derived from step d) directly to an extrusion sheet mold head to form a heterogeneous ion exchange membrane. • The method for the formation of a heterogeneous ion exchange membrane according to claim 1, characterized in that the powder ion exchange resin is added to the molten matrix polymer in a range of about 20% to about 80% by weight. 3. The method for the formation of a heterogeneous ion exchange membrane according to claim 1, characterized in that the polymer binder is a polypropylene polymer. 4. The method for the formation of a heterogeneous ion exchange membrane according to claim 1, characterized in that the ion exchange resin has an average mesh size of 200. • 5. The method for the formation of a heterogeneous ion exchange membrane in accordance with the
1. Claim 1, characterized in that the polymer binder is polypropylene and metallocene polymer having a broad molecular weight distribution and having a melting point below about 130 degrees C. 6. The method for the formation of a membrane of 25 heterogeneous ion exchange according to claim 1, characterized in that the powder ion exchange resin has an average mesh size 325. 7. The method for the formation of a heterogeneous ion exchange membrane according to claim 1 , characterized in that the powder ion exchange resin is Type I. 8. The method for the formation of a heterogeneous ion exchange membrane according to claim 1, characterized in that the resin ion exchange powder is Type II .. 9. The method for the formation of an exchange membrane of heterogeneous ions according to claim 1, characterized in that the resin ion exchange powder is of Type III. 10. The method for the formation of a heterogeneous ion exchange membrane according to claim 1, characterized in that the ion exchange resin powder is anionic. 11. The method for the formation of a heterogeneous ion exchange membrane according to claim 1, characterized in that the ion exchange resin in powder form is cationic. 12. The method for the formation of a heterogeneous ion exchange membrane according to claim 1, characterized in that the ion exchange resin powder is amphoteric. 13. The method for the formation of a heterogeneous ion exchange membrane in accordance with claim 5, characterized in that the powder ion exchange resin is a mixture of ion exchange materials selected from the group consisting of: Type I, Type III, anionic, cationic, amphoteric, and mixtures thereof, ifl: 10 A heterogeneous ion exchange membrane characterized in that it is formed by the process according to claim 1. 15. The heterogeneous ion exchange membrane according to claim 14, 15 characterized in that it has a thickness within a range of about 0.001 inches to about 0.05 inches (0.0025-0.127 cm). 16. The heterogeneous ion exchange membrane according to claim 14, 20 characterized in that it has a thickness in the range of about 0.005 inches to about 0.020 inches (0.0127-0.050 cm). 17. An apparatus for the formation of the prescribed in-line compound and extrusion of a polymeric binder and 25 heat-sensitive ion exchange resin to form a heterogeneous membrane, the apparatus characterized in that it comprises in combination with a twin screw compound extruder, the extruder having a first feed zone, a second melting zone, a third zone 5 to homogeneity melt kneading, means for feeding selective additives to the melt flow polymer below the third zone, a fourth zone pair making kneading and mixing of additives to the melt of preferred polymer further, a fifth zone for mixing the extrusion agents within the mixed polymer mass and a sixth compression zone for transferring the mixed polymer melt to an extrusion mold head.