MXPA01000255A - Laminate product, pulse jet filter bag, and methods for manufacturing - Google Patents

Abstract

A laminate product is provided. The laminate product includes a first layer of porous expanded polytetrafluoroethylene membrane, and a second layer of woven fabric of polytetrafluoroethylene containing yarn. The membrane preferably has an air permeability of at least 0.01 cfm/ft2 at 0.5 inch water gauge, and a thickness of greater than about 0.5 mil. The woven fabric preferably has a weight of between about 15 ospy and about 30 ospy. The laminate product can be sewn to provide a filter bag for use in pulse jet filter applications.

Description

LAMINATED PRODUCT; BAG FOR PULSATION FILTERS TO AIR JET; AND METHODS FOR MANUFACTURE FIELD OF THE INVENTION This invention relates to a laminated product, a filter bag of pu 's a c i an s to air jet. In particular, this invention relates to a laminate comprising a membrane layer extended, porous polytetrafluoroethylene and a woven fabric including polytetrafluoroethylene containing a spunbond layer.

BACKGROUND OF THE INVENTION Fabric filter bags are often used for the separation of particulate impurities from industrial fluid streams. These filters tend to accumulate a particulate cake which is removed occasionally, or the filter is replaced. It is common in the industrial filtration market to characterize the type of bag for REF NO. 126559 filter by the cleaning method. The most common types of cleaning techniques are inverted air, shaker and air jet pulsation. The inverted air and shaker techniques are considered low energy cleaning techniques. The inverted air technique is a gentle countercurrent of air in a filter bag which collects the dust inside. The countercurrent collapses the bag and the powder cake fractures which leaves the bottom of the bag to a hopper. The shaker mechanisms clean the filter cake that is collected inside the bag as well. The upper part of the bag is attached to an oscillating arm which creates a sine wave in the bag to dislodge the powder cake. The air jet pulsation cleaning techniques employ a short press of compressed air that enters the upper interior portion of the filter. When the pulsating cleaning air passes through the venturi it sucks the secondary air and the resulting air mass violently expands the bag and discards the collected dust cake. The bag will typically creak from the right backrest to Support the box and go to the right backrest in particle collection service. Of the three cleaning techniques, the pulsation by air jet is the most agitated in the filtering media. In addition to the agitation endurance provided during cleaning, the aligned air jet pulsation bag filter is generally subjected to higher fabric area / volumetric airflow ratios compared to the inverter and inverter filter bags. The filtering means commonly used in filter bags for pulse jet air include polytetrafluoroethylene (PTFE), fiberglass, polyimides, polyesters, acrylics, and polypropylenes. When the air jet pulsation bag is used to filter high temperature industrial streams including oxidizing agents, acids or bases, there is a tendency for some of the filter media to fail prematurely. PTFE is advantageous in its ability to counteract an environment that includes high temperatures and oxidizing agents. '^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ s ^^ ^^ a ^ If currently the filtering means with PTFE Available for use in air jet pulsation dust precipitator applications are based on felts stitched with PTFE needle. For example, U.S. Pat. No. 4,983,434 to Sassa discloses a bag for air jet pulsation filter prepared from a membrane laminate of expanded porous polytetrafluoroethylene and polytetrafluoroethylene felt reinforced with a woven fabric. Filters prepared from felts sewn with needles of PTFE fibers are available. These felts typically weigh 20-26 oz / yd2 (678.12-881.56 gr / m2) and are reinforced with woven canvas (2-6 oz / yd2 67.81-203.43 gr / m: Felts can be made up of staple fibers (usually 6.7 denie r / fi 1 ament, or 7.4 dt ex / fi 1 amen to) which are 2-6 inches (5.08-15.24 cm) in length.Feathers sewn with a PTFE needle tend to exhibit a contraction when first They are exposed to high temperatures and tend to lengthen longer because of the contraction of the felt sewn with a PTFE needle.

They are often placed at twice the heat prior to use.

BRIEF DESCRIPTION OF THE INVENTION A laminated product which can be used in filter applications is provided by the present invention. The laminated product includes a first layer comprising a porous expanded porous membrane, a second layer comprising a woven fabric of yarn containing po liv e and f luoroe t i leno. The porous expanded polytetrafluoroethylene membrane preferably has an air permeability of at least 0.01 ft3min / ft2 (0.0050 cm3sec / cm2) to 0.5 inch (1.27 cm) capacity, and a thickness greater than about 0.5 mil (0.0127 cm) of according to ASTM D579-89 sec. 35. The woven fabric of polytetrafluoroethylene containing yarns preferably has a weight between about 15 ospy (508.5 g / m2) and about 30 ospy (1017.1 g / cm2). The polytetrafluoroethylene polymer of the i »d¿ £ &S-8-» -É s ** - ?: > The first layer and the second layer can both be obtained from PTFE treated with silicone. The first layer and the second layer can be thermally bonded together, or joined together using an adhesive. Preferred adhesives include fluoropolymer adhesive, such as fluorinated ethylene propylene copolymer (FEP), tetrafluoroethylene / perfluoropropylene copolymer, and polyvinylidene dilfuoride. The woven fabric is preferably prepared from expanded polytetrafluoroethylene containing yarns having a size between about 600 denier and about 2,400 denier. Preferably, the weight of the woven fabric is between about 18 ospy (610.31 gr / m2) and about 23 ospy (779.84 g / m2). The membrane preferably has a thickness of between about 1 mil (2.540x10 -3 cm, and about 2.5 mil (0.00635 cm).) To work well in a bag application for air jet pulsation filter, the laminate should have an air permeability of between about 7 and a p r o x i ma d ame n t 2 0 p i e 3mi n / p? e '10,161 cm3sec / cm2) in accordance with ASTM D737-75; a stator strength of between approximately 600 lbs / inch (107.1 kg / cm) and 5 1000 lbs / inch (178.6 kg / cm) in accordance with ASTM 3786; a tensile strength of between about 150 lbs / inch (26.79 kg / cm) and about 500 lbs / inch (89.3 kg / cm) in accordance with ASTM D579-89; a minor shrinkage of about 3% when heated to 500 ° F (260 ° C) for 2 hours; a greater bending of approximately 500,000 cycles in accordance with ASTM D2176-63T; and an elongation of less than about 8% at 50 lbs (22.7 kg). It should be appreciated that the laminated product can be used both in dry filter applications and liquid filter applications. In the case of liquid filter applications, it is preferable that laminate 0 has an air permeability of between about 0.01 ft3min / ft2 (0.0050 cm3sec / cm2) and about 7 ft3min / ft2 (3.55 cm3sec / cm2) according to with ASTM D737-75. A bag for 5 air jet pulsation filter is provided herein ^^^ G ^^^^ "« »« wrta, -. .... fájgaar & g,, .. »g« a¡ G * - IB invention. The bag for air jet pulsation filter includes the laminated product having a first porous expanded polytetrafluoroethylene membrane layer and a second woven fabric layer of polytetrafluoroethylene containing yarns, wherein the laminate is secured together to provide a bag for filter. Preferably, the laminate is secured using a feld seam to provide a filter bag which can be used in an air jet pulsation filter application. A method for manufacturing a laminated product is provided by the present invention. The method includes steps that provide a first layer of expanded porous polytetrafluoroethylene membrane, which provides a second layer of woven fabric of polytetrafluoroethylene containing yarns, and joining the first layer and the second layer together. The first and second layers can be joined either thermally to a temperature of at least about 500 ° F (260 ° C), or using an adhesive.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a preferred rolled product according to the principles of the present invention. Figure 2 shows a schematic illustration of an operation of the powder precipitator filter; and Figure 3 shows an illustration schematic of a method for manufacturing the laminated product of Figure 1.

DETAILED DESCRIPTION OF THE INVENTION A laminated product is provided which is useful in a bag for air jet pulsation filter. The laminated product includes a porous expanded polyfluoroethylene (PTFE) membrane. a woven fabric including yarn containing polytetrafluoroethylene. The expanded porous PTFE membrane can be referred to as the membrane, and the woven fabric of PTFE containing yarn can be referred to herein as the fabric knitted. The membrane and the woven fabric are joined thermally together or united with adhesive. The porous expanded PTFE membrane includes commercially available PTFE membranes available for industrial filtering applications and which can be prepared by a number of different known processes, but is preferably prepared by expanding the polyethylene terephthalate as describes in the 10 US Patents Nos. 4,945,125 to Dillon et al and 5,066,683 to Dillon et al., Full disclosure of which are incorporated herein by reference. In general, the term porous expanded PTFE membrane is intended to be included within the scope of microporous PTFE and microporous treated PTFE, an example of which is PTFE treated with silicone as described in U.S. Pat. Nos. 4,945,125 and 5,066,683. The expanded porous PTFE can be prepared further according to the techniques provided in U.S. Pat. Nos. 4,187,390; 4,110,392; and 3,953,566. By "porous" it is meant that the membrane has an air permeability of at least 0.01 cubic feet per minute per square foot * ¡¿^ * Jl &.- * »- £ (ft3min / ft2) (0.0050 cm3sec / cm2) to 0.5 inches (1.27 cm) of water capacity. The air permeabilities of 300 ft3min / ft2 (152.4 cm sec / cm 's) can be used The pores are micropores formed by the protuberances and fibrils of the expanded PTFE The membrane can preferably have an air permeability of between about 7 foot3min / foot2 (3.55 cm3sec / cm2) and approximately 75 ft 3mi n / ft 2 (3 8 .1 0 cm 3 sec / cm2 to 0.5 inch (1.27 cm) water capacity, for use in gas stream filtration.) Membranes with low air permeability are useful in liquid stream applications 15 Preferably, membranes for use in liquid stream applications have an air permeability of between about 0.01 ft3min / ft2 (0.0050 cm3sec / cm2) and about 7 ft3min / ft2 (3.55 cm3sec / cm2). membranes which are preferably used according to the invention are those which can withstand the effort involved in a bag for air jet pulsation filter when applied to the woven fabric according to the present invention. That is, the preferred membranes will resist decomposition under normal use in an application of the air jet pulsation filter bag. In general, the membrane which can be used according to the invention can be characterized by a thickness which is greater than about 0.5 mil (0.0127 cm) as determined in accordance with ASTM D579-89 sec. 35 or ASTM D1777-64. It will be understood that the thickness of the expanded PTFE membranes is difficult to measure exactly because the membrane has expanded and the thickness across the membrane varies as a result of elongation. In addition, the expanded film includes fibrils and protuberances which produce the thickness, and the film is compressible. In general, the thickness of expanded PTFE membranes is often expressed in terms of ranges. Membranes having a thickness of approximately 0.5 mil (0.0127 cm) or less are generally characterized as light membranes. Preferably, the expanded PTFE membrane has a thickness of between about 1 mil (2.540 × 10 ~ 3 cm) and about 2 mil ^^ ^^^. ^^, ^. ^^ iJ (1.61xl0 ~ 5 cm) and is characterized as a medium weight membrane, and more preferably the expanded PTFE membrane has a thickness of between about 1.5 mil (0.00381 cm ) and 5 approximately 2.5 thousand (0.00635 cm) and can be categorized as a heavy membrane. Expanded PTFE membranes which can be used in the present invention are available from Donaldson Company, Inc. of Bloomingt on, Minnesota under the name Tetratex (R >..) The discovered applications using a woven fabric which can be characterized as heavy and tightly woven, stress on 5 the membrane is reduced without sacrificing the characteristics of air permeability. it is understood that a heavy woven fabric generally refers to a woven fabric having a weight of at least about 15 0 oz / yd2 (ospy) (508.5 gr / m2) If the fabric is larger than 15 oz / yd2 (508.5 gr / m2), it is expected that the yarns could slide on themselves and strain the membrane.This is the problem expressed by the Patent US No. 4,983,434 in 5 column 2, lines 17-27. ^ ^ ^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ woven may not be weighed so that the rolled product is also difficult to clean in an application of air jet pulsations, or heavy so that the permeability of the woven fabric is poor. It is expected that very heavy weight woven fabrics require more energy to move the woven fabric to clean the filter bag. Preferably, the woven fabric has a weight of which 0 is not heavier than 30 ospy (1017.1 g / m2), and more preferably within the range of about 18 to about 23 ospy (779.84 g / m2). For the improvement of the heavy and tight woven fabric, it is desirable to use yarns which are as long as possible. It will be understood that while the weight of the yarns is expressed in terms of denier, the yarn may include folds of two or more yarns of very light weight to provide a yarn of very heavy weight. The heavy threads are advantageous to resist the stress which occurs in the operation of the box of an air jet pulsation filter bag. In general, it is expected that the yarn which is woven into a fabric ^^^^^^^^^^^^^^^^ Aj ^? Tes¡j | í? Fei £ > ^ ¡^ H will have a size between approximately 600 denier to approximately 2,400 denier. If the yarn weight is less than about 600 denier, it is expected that the woven fabric will not provide the desired level of stress resistance for air jet pulsation applications. If the yarn size is greater than about 2,400 denier, it is expected that the number of weft yarns per inch of woven fabric will decrease thereby decreasing the weight of the woven fabric and decreasing the air permeability of the woven fabric. . Preferably, the yarn will weigh between about 1,000 and about 1,600 denier. A preferred yarn will have a weight of about 1,200 denier. Of course, two folds of 400 denier yarn can be combined to provide an 800 denier yarn for the fabric. Similarly, two folds of the 600 denier yarn can be combined to provide a 1200 denier yarn for the fabric. The way of weaving can be adjusted depending on the desired permeability and the weight of the woven fabric. The ways of weaving Ah » V. '^^ ^^^ ^^ ^ l ^ A ^ Jí¡ ^^ - ^^ ~ ^ ^ Jí as, FLF - ^^^^^^^^^ A% ^^ = ^ Sá¿. ^ 1 ^ r., '** ^ * ^ to E? ^ 2 L typical which can be used for preparing the woven fabric of the invention include ranúculos broken, twill 3 x 1, 4 x 1 twill, and satin. A preferred form of weaving is 3 x 1 cross-polyester. The yarn used in the preparation of the woven fabric is a yarn containing PTFE. That is, the yarn includes at least about 50 percent, by weight, of yarn with PTFE or yarn with expanded PTFE. The yarn may include a PTFE fold and a PTFE-free yarn fold such as glass fiber or polyphenyl sulfide. It will be appreciated that the warp and the filling threads can be the same or different material. Preferably, both the warp and the filling threads are threads containing PTFE. More preferably, the warp and the fill yarns are 100% PTFE or PTFE treated. The yarns which can be used for the preparation of the woven fabric can be purchased under the name Profilen of Lenzing A.G. of Austria. Preferably, the yarn can be prepared from a non-expanded or expanded PTFE film. For example, PTFE films can be prepared according to the techniques described in U.S. Pat. Nos. 4,945,125 and 5,066,683. Preferably, the film is prepared from interpenetration matrices of PT FE / s and 1 icone. Alternatively, the film can be prepared in accordance with U.S. Pat. Us.' 4,187,390; and 3,953,566. The resulting film can then be cut to provide the thickness of the desired yarn 0. The yarn may be provided as an extended or shaped yarn to provide a round yarn. The resulting yarn is then woven to provide the woven fabric. The techniques for woven fabrics are well known. 5 The membrane and the woven fabric are laminated together. Preferably, the laminate and the woven fabric are thermally bonded together at a temperature between about 500 ° F (260 ° C) and about 0 700 ° F (371.1 ° C) to provide sufficient adhesion. Preferably, the processing temperature is approximately 700 ° F (371.1 ° C). Alternatively, the membrane and the woven fabric can be joined together using a conventional adhesive for the bonding of the fabric. ^ jfej - asa? ~: - Á ±.? PTFE materials. Exemplary adhesives include fluoropolymer adhesive, such as fluorinated ethylene-propylene (FEP) copolymer, tetraf-1-ene-1-ene / pe-1-oppo-11-ene copolymer, and polyvinyl difluoride 1 ideno . When conventional adhesive is used, it is desirable to heat the adhesive to a temperature sufficient to bind both the membrane and the woven fabric. In the case of PTFE adhesive, it is desirable to heat to a temperature of about 600 ° F (315.5 ° C). It will be appreciated that when an adhesive is used, such as FEP adhesives, the bonding temperature may be lower than generally required for the thermal bonding of the membrane and the woven fabric together. The laminated product of the invention preferably has certain physical properties that make it advantageous for use in an air jet pulsation filter bag. The filter can be used for either dry filtration or liquid filtration. Preferably, the permeability of the laminate product by dry filtration is between about 7 ft3min / ft2 (3.55 cm3sec / cm) and about 20 ft3min / ft2 (10.161 cm3sec / cm2) according to ASTM D737-75, and the permeability for liquid filtration is between about 0.01 ft3min / ft2 (0.0050 cm3sec / cm2) and approximately 7 foot min / foot (3.55 cm3sec / cm2) in accordance with ASTM D373-75. The air permeability is obtained by subjecting the sample to be tested to an air flow and nothing or air velocity that is needed to register 0.5 inches (1.27 cm) over a water capacity pressure. Preferably, the burst strength is between about 600 (0.422 kg / mm2) and about 1,000 lbs / pg2 (.703 kg / mm2) and preferably between about 800 (0.562 kg / mm2) and roughly 900 lbs / pg2 (0.633 kg / mm2) in accordance with ASTM 3786. The tensile strength of the woven laminate is 0 preferably between approximately 150 (26.79 kg / cm) and approximately 500 lbs / pg (89.3 kg / cm) in accordance with STM D579-89. More preferably, the tensile strength is between about 200 (35.74 5 kg / cm) and about 500 lbs / pg (89.3) kg / cm). The breaking of the rolled product should be less than about 3% when heated to 500 ° F (260 ° C) for 2 hours. MIT bending (hardened bending) is preferably greater than about 500,000 cycles in accordance with ASTM D2176-63T. The elongation of the woven fabric or web is preferably less than about 8% at 50 lbs (22.7 kg). The applicants have It has been found that the laminated product of the invention provides improved properties, as described above, compared to filter products sewn with PTFE needle as available. Referring to Figure 1, a preferred rolled product is provided in the reference numeral 10. The rolled product 10 includes a membrane 12 and a woven fabric 14. Preferably, the membrane 12 is a membrane of porous expanded PTFE, and the woven fabric 14 includes yarn containing PTFE. The membrane 12 and the woven fabric 14 adhere together to the laminated boundary 16. The laminated product of the invention is useful in the powder precipitator assemblies of Air jet pulsation filter, and provides good cleaning capabilities by pulsations to air jet. The use of PTFE in the woven fabric provides good heat resistance and chemical resistance. The use of expanded porous PTFE in the yarn provides increased stability and strength compared to yarn that does not contain expanded PTFE. The use of heavy PTFE woven fabric provides a durable material that can flex easily, yet it resists the stress caused by air jet pulsation cleaning. These tensions are of two general types. A type of tension is caused by the sudden expansion during the cleaning by pulsations to air jet. The other type of tension is caused by the sudden collapse of the bag against its rigid support elements. The use of the expanded porous PTFE membrane provides the desired air flow rate, for example, high permeability, which is advantageous for filtration assemblies. The smaller size of the pores, and the fine fibril network of the expanded PTFE membrane interferes with the particulate impurities in the filtration stream from penetration through the filter assembly. The beneficial permeability properties of PTFE membranes as a filter material are widely understood and appreciated in the art. Referring now to Figure 2, a sequence of air jet pulsation cleaning is shown for a dry filtration application. In place of the feeder tank 20, the charged particulate gas stream 21 enters the feed tank at the inlet 22 and passes through the filter bags 23 made of a rolled product 24 according to the present invention. The tube sheet 25 inside the feeder tank 20 prevents the gas stream from passing into the filter bag 23. The filter bags 23 are kept open by the support basket 26. The gas stream, after passing through the the bag and outside the outlet of the bag 29, leaves the compartment for clean air at the outlet 27. In operation, the particulate material forms a powder cake 28 on the outside of the filter bag, as shown in FIG. - * s ** A k * L. »? ^ ... -,. ^? ^. ^. > .* to*? I JI te ^ _. ^^ i, ^ Miál ^ J ^ -. ^ shows in the bag to the left of the figure. In the cleaning to remove the filter cake, the air from the impulse pipe 30 enters the bag. This air pulse 32 expands the bag 5 by loosening the powder cake and thus causing the particulate material 31 to be collected at the bottom of the feeder tank 20. As seen in the bag on the right side of the figure, the jet pulsations of air cause the bag for filter to expand. The repeated expansion and contraction of the bag against its support strut causes wear on the bag. Now referring to Figure 3, a preferred method to provide the product laminate 38 is provided according to the present invention. The method can be characterized as a calendar recording technique. In general, a supply of the membrane 40 is provided on a cylinder 42, and a supply of woven fabric 44 is provided on a cylinder 46. The membrane 40 and the woven fabric 44 are fed to a rolling station 50 wherein a cylinder or hot roll 52 heats the woven fabric 44 to a temperature that allows joining the laminate 40.

A back stretching cylinder 54 is provided to maintain the pressure between the laminate 40 and the woven fabric 44. In general, the roll or hot cylinder 52 should be maintained at a temperature of at least about 450 ° F (232.22 ° C), and most preferably between about 575 ° F (301.6 ° C) and about 700 ° F (371.1 ° C). The pressure provided by the cylinder The porter 54 should be greater than about 20 psi and is preferably between approximately 60 psi and approximately 80 psi. Laminated product 38 is raised by the cylinder 56 and it is stored for subsequent use. Preferably, the distance between the recovery or elevation of the cylinder 56 and the hot cylinder 52 is sufficient to allow the rolled product 38 to cool. In In general, the distance can be approximately 3 feet (91.44 cm) when the method is conducted in a medium at room temperature.

It is noted that in relation to this date the best method known by the applicant to carry out the aforementioned invention, is the one that is clear from the present description 4¡_É & the invention. Having described the invention as above, the content of the following is claimed as property "^ í« fe-fe fe fe ^ i i i a a a a. ^ ^ ^ ^ ^. ^ ¡.i ^ r ¡».'Aa-ftfi > ^ B, i k. & ,; ~.

Claims (22)

1. A laminated product characterized in that it comprises: (a) a first layer comprising a porous expanded polytetrafluoroethylene membrane having an air permeability of at least 0.01 cubic feet per square foot (0.0050 cm3sec / cm2) to 0.5 inches (1.27 cm) ) from 10 water capacity, and a thickness greater than approximately 0.5 mil (0.0127 cm) in accordance with ASTM D579-89 sec. 35; (b) a second layer comprising a woven fabric of yarn containing Pol 15 11 e t r a t i Luor f oe-1-ene, wherein the woven fabric has a weight of between about 15 ospy (508.5 g / m2) and about 30 ospy (1017.1 g / m)

2. A laminated product according to claim 1, characterized in that the yarn containing polytetrafluoroethylene comprises a yarn containing 25 expanded polytetrafluoroethylene having a size between approximately 600 denier and approximately 2,400 denier.

3. A laminate according to claim 1, wherein the woven fabric has a weight of between about 18 ospy (610.31 g / m2) and about 23 ospy (779.84 g / m2).

4. A laminated product according to claim 1, characterized in that the membrane has a thickness between approximately one thousand (2.540x10 'cm approximately 2 thousand (1.61x10 -' 5 cm)

5. A laminated product according to claim 1, characterized in that the membrane has a thickness between about 1.5 mil (0.00381 cm) and about 2.5 mil (0.00635 cm). ^^^^ g ^ j '^^^ g ^^ j ^ ^^^ ¿¿^^^^^^

6. A laminate according to claim 1, wherein the laminate has a air permeability of between about 7 ft3min / ft2 (3.55 cm3sec / cm2) and about 20 ft3mm / ft2 (10.161 cm3sec / cm2) in accordance with ASTM D737-75; a stator strength of between about 600 (107.1 kg / cm) and about 1000 lbs / inch (178.6 kg / cm) in accordance with ASTM 3786; a tensile strength of between about 150 (26.79 kg / cm) and about 500 lbs / inch (89.3 kg / cm) in accordance with ASTM D579-89; a shrinkage less than about 3% when heated to 500 ° F (260 ° C) for 2 hours; a greater bending of approximately 500,000 cycles in accordance with ASTM D2176-63T; and an elongation of less than about 8% at 50 lbs (22.7 kg).

7. A product l P? swimming according to claim 1, characterized in that the first layer and the second layer are jointly thermally bonded. '

8. A laminated product according to claim 1, characterized in that the first layer and the second layer are together 10 joined by an adhesive.

9. A laminated product according to claim 1, characterized in that the The porous expanded polytetrafluoroethylene membrane comprises PTFE treated with silicone.

10. A laminated product according to claim 1, characterized in that the yarn containing polytetrafluoroethylene comprises PTFE treated with silicone.

11. A laminated product characterized in that it comprises: (a) a first layer comprising an expanded polytetrafluoroethylene membrane 5 porous; and (b) a second layer comprising woven cloth of yarn containing polytetrafluoroethylene; wherein the laminated product has: 10 an air permeability of between about 7 ft3min / ft2 (3.55 cm3sec / cm2) and about 20 ft3mm / p2e2 (10.161 cm3sec / cm2) in accordance with ASTM D737-75; a stator strength of between about 600 (107.1 kg / cm) and about 1000 lbs / inch (178.6 kg / cm) according to ASTM 3786; a tensile strength of between about 150 (26.79 kg / cm) and about 500 lbs / inch (89.3 kg / cm) in accordance with ASTM D579-89; a shrinkage less than about 3% when heated to 500 ° F (260 ° C) for 2 hours; a maximum bending of approximately 500,000 cycles in accordance with ASTM D2176-63T; and an elongation of less than about 8% at 50 lbs (22.7 kg).

12. A laminated product characterized in that it comprises: (a) a first layer comprising a porous expanded porous membrane; and (b) a second layer comprising woven cloth of yarn containing polytetrafluoroethylene; wherein the laminated product has: an air permeability of between about 0.01 ft3min / ft2 (0.0050 cm3sec / cm2) and about 7 ft3min / ft2 (3.55 cm3sec / cm2) in accordance with ASTM D737-75; a stator strength of between about 600 (107.1 kg / cm) and about 1000 lbs / inch (178.6 kg / cm) in accordance with ASTM 3786; a strength, at a tension of between about 150 (26.79 kg / cm) and about 500 lbs / inch (89.3 kg / cm) in accordance with ASTM D579-89; a shrinkage less than about 3% when heated to 500 ° F (260 ° C) for 2 hours; a greater bending of approximately 500,000 cycles in accordance with ASTM D2176-63T; 10 and an elongation of less than about 8% at 50 lbs (22.7 kg).

13. An air jet pulsation filter bag characterized in that it comprises: a laminated product stitched together by means of a feld seam to provide a bag, the product The laminate comprises: (a) a first layer comprising a porous expanded polytetrafluoroethylene membrane having an air permeability of at least 0.01 cubic feet per square foot 25 (0.0050 cm3sec / cm2) to 0.5 inch (1.27 cm) of water capacity, P a thickness greater than about 0.5 mil (0.0127 cm); and (b) a second layer comprising a woven fabric of yarn containing polytetrafluoroethylene, wherein the woven fabric has a weight between about 15 ospy (508.5 g / m2) and about 30 ospy (1017.1 g / m2).

14. A bag for air jet pulsation filter according to claim 13, characterized in that the yarn containing polytetrafluoroethylene comprises a yarn containing expanded polytetrafluoroethylene having a size between about 600 and about 2,400 denier.

15. A bag for air jet pulsation filter according to claim 13, characterized in that the woven fabric has a weight between approximately 18 (610.31 gr / m2) and approximately 23 ospy (779.84 gr / m2)

16. A bag for air jet pulsation filter according to claim 13, characterized in that the membrane has a thickness between approximately mi 1 (2.540x10 'cm) and approximately 2 thousand (1.61x10' cm,

17. A bag for air jet pulsation filter according to claim 13, characterized in that the membrane has a thickness of between about 1.5 mil (0.00381 cm) and about 2.5 mil (0.00635 cm).

18. A bag for air jet pulsation filter according to claim 13, characterized in that the laminate has a permeability of between about 8 (4.06 cm3sec / cm2) and approximately 16 ft3min / ft2 12 cm3sec / cm) in accordance with ASTM D737-75;

19. A method for manufacturing a laminated product, the method is characterized in that it comprises steps of: (a) providing a first layer comprising a polytetrafluoroethylene membrane 10 expanded porous having an air permeability of at least 0.01 ft3min / ft2 (0.0050 cm3sec / cm2) to 0.5 inches (1.27 cm) of water capacity, and a thickness greater than about 0.5 mil (0.0127 cm); 15 (b) providing a second layer comprising a woven fabric of yarn containing polytetrafluoroethylene, wherein the woven fabric has a weight between about 15 ospy (508.5 g / m2) and about 30 ospy (1017.1 20 gr / m2); and (c) joining the first layer to the second layer. -feg; 1r * j? ~ S? *? * I? Al * ¿- * ****** ts k ?? áíM

20. A method for manufacturing a laminated product according to claim 19, characterized in that the joining step comprises thermal bonding at a temperature of at least about 500 ° F (260 ° C).

21. A method for manufacturing a laminated product according to claim 19, characterized in that the joining step comprises providing an adhesive between the first layer and the second layer.

22. A method for manufacturing a laminated product according to claim 19, characterized in that the adhesive comprises fluorinated ethylene propylene.