LAMINATES WITH FLUOROPOLYMER CLOTH

A laminate includes a first layer of a first fluoropolymer. The laminate can further include a second layer of at least one ply of a fluoropolymer fabric overlying the first layer. The laminate can further include a third layer of a second fluoropolymer overlying the second layer opposite to the first layer. The laminate can have a strain of not more than 50% at a stress of 15 MPa as measured by DIN EN ISO 527 with a sample width of about 1 inch, at a clamp distance of about 50 mm, and a speed of about 50 mm/min. Embodiments of such laminates can find applications, for example, as diaphragm membranes, solenoid valves, conveyor belts, or bearings.

DETAILED DESCRIPTION

In an embodiment, a laminate includes a first layer of a first fluoropolymer. The laminate can further include a second layer of at least one ply of a fluoropolymer fabric overlying the first layer. The laminate can further include a third layer of a second fluoropolymer overlying the second layer opposite to the first layer. The laminate can have a strain of not more than 50% at a stress of 15 MPa as measured by DIN EN ISO 527 with a sample width of about 1 inch, at a clamp distance of about 50 mm, and a speed of about 50 mm/min.

Referring toFIG. 1, the laminate includes a fluoropolymer layer102. The fluoropolymer layer102can be selected from any fluoropolymer. In one embodiment, layer102can include a polytretrafluoroethylene (PTFE) or modified polytetrafluoroethylene (mPTFE). In one embodiment, layer102consists essentially of PTFE or mPTFE. In further embodiments, the PTFE or mPTFE can be skived tape or a cast film. In another embodiment, layer102can include an extruded fluoropolymer. The extruded fluoropolymer can include tetrafluoroethylene-hexafluoropropylene (FEP), perfluoroalkoxyethylene (PFA), ethylene-tetrafluoroethylene (ETFE), tetrafluoro-ethylene-perfluoro(methyl vinyl ether) (MFA), polyvinylidene fluoride (PVDF), ethylene-chlorotrifluoroethylene (ECTFE), or any mixture thereof.

Layer102can have a thickness of at least about 0.05 mm, such as of at least about 0.1 mm, at least about 0.15 mm, at least about 0.2 mm, at least about 0.25 mm, at least about 0.3 mm, at least about 0.35 mm, at least about 0.4 mm, or at least about 0.45 mm. In another embodiment, the thickness of layer102is not greater than about 2 mm, such as not greater than about 1.8 mm, not greater than about 1.6 mm, not greater than about 1.4 mm, not greater than about 1.2 mm, not greater than about 1 mm, not greater than about 0.95 mm, not greater than about 0.9 mm, not greater than about 0.85 mm, not greater than about 0.8 mm, not greater than about 0.75 mm, not greater than about 0.7 mm, not greater than about 0.65 mm, not greater than about 0.6 mm, not greater than about 0.55 mm, not greater than about 0.5 mm, not greater than about 0.4 mm, or not greater than about 0.3 mm. In one particular embodiment, the thickness of layer102ranges from about 0.4 mm to about 0.55 mm.

The laminate further includes a second layer including at least one ply of fluoropolymer fabric. The fluoropolymer fabric can include PTFE. In one embodiment, the ply can include expanded PTFE. In another embodiment, the fluoropolymer fabric of the ply can include modified polytetrafluoroethylene (mPTFE), ethylene-tetrafluoroethylene (ETFE), perfluoroalkoxyethylene (PFA), tetrafluoroethylene-hexafluoropropylene (FEP), tetrafluoro-ethylene-perfluoro (methyl vinyl ether) (MFA), polyvinylidene fluoride (PVDF), ethylene-chlorotrifluoroethylene (ECTFE), or any combination thereof. In one embodiment, the fluoropolymer fabric consists essentially of polytetrafluoroethylene (PTFE). In another embodiment, the fluoropolymer fabric consists essentially of modified polytetrafluoroethylene (mPTFE).

In an embodiment, the ply of fluoropolymer fabric can have a thickness of at least about 0.04 mm, such as of at least about 0.08 mm, at least about 0.12 mm, at least about 0.16 mm, at least about 0.20 mm, at least about 0.24 mm, at least about 0.28 mm, at least about 0.32 mm, or at least about 0.36 mm. In another embodiment, the ply of fluoropolymer fabric can have a thickness of not greater than about 1 mm, such as not greater than about 0.8 mm, not greater than about 0.6 mm, not greater than about 0.55 mm, not greater than about 0.5 mm, not greater than about 0.45 mm, not greater than about 0.4 mm, not greater than about 0.38 mm, not greater than about 0.34 mm, not greater than about 0.3 mm, not greater than about 0.26 mm, or not greater than about 0.22 mm. In a particular embodiment, the thickness can be in a range from about 0.22 mm to about 0.28 mm.

The ply includes warp yarns1042and weft yarns1044. In embodiments, the warp and the weft can be in an orthogonal orientation, i.e., the angle between all the warp direction and the weft direction is about 90°. In another embodiment, the angle between the warp direction and the weft direction can be non-orthogonal, i.e. the angle is between 0° and 90°. For example, in one embodiment, a skewed angle between the warp direction and weft direction can be about 45°. It is also contemplated the laminate includes at least two plies of fluoropolymer fabric overlying each other. Accordingly, it is also contemplated that in cases of at least two plies, the assembly can include of orthogonal warp/weft fabrics and non-orthogonal warp/weft fabrics.

In embodiments the warp yarn1042or weft yarn1044can have the same thickness or different thickness. In embodiments, either thickness can be at least about 0.02 mm, such as at least about 0.04 mm, at least about 0.06 mm, at least about 0.08 mm, at least about 0.1 mm, at least about 0.12 mm, at least about 0.14 mm, or at least about 0.16 mm. In another embodiment, the yarn thickness can be not greater than about 0.3 mm, such as not greater than about 0.28 mm, not greater than about 0.26 mm, not greater than about 0.24 mm, not greater than about 0.22 mm, not greater than about 0.2 mm, or not greater than about 0.18 mm. In one particular embodiment, the yarn thickness can range from about 0.16 mm to about 0.18 mm.

Each ply according to embodiments can have a weight of at least about 100 g/m2, such as at least about 120 g/m2, at least about 140 g/m2, at least about 160 g/m2, at least about 180 g/m2, at least about 200 g/m2, at least about 220 g/m2, at least about 240 g/m2, at least about 260 g/m2, at least about 280 g/m2, or at least about 300 g/m2. In another embodiment, the ply can have a weight of not greater than about 500 g/m2, not greater than about 480 g/m2, not greater than about 460 g/m2, not greater than about 440 g/m2, not greater than about 420 g/m2, not greater than about 400 g/m2, not greater than about 380 g/m2, not greater than about 360 g/m2, not greater than about 340 g/m2, or not greater than about 320 g/m2. In one particular embodiment, the weight can range from about 280 g/m2to about 340 g/m2.

Addressing the thread counts of the fluoropolymer fabric, the ply has a warp thread count and a weft thread count. The warp thread count and the weft thread count can be the same or different. Either thread count can be at least about 100 threads/10 cm, such as at least about 125 threads/10 cm, at least about 150 threads/10 cm, at least about 175 threads/10 cm, at least about 200 threads/10 cm, at least about 225 threads/10 cm, at least about 250 threads/10 cm, at least about 275 threads/10 cm, at least about 300 threads/10 cm, at least about 325 threads/10 cm, or at least about 350 threads/10 cm. In another embodiment, either thread count, warp or weft thread count, can be not greater than about 600 threads/10 cm, such as not greater than about 575 threads/10 cm, not greater than about 550 threads/10 cm, not greater than about 525 threads/10 cm, not greater than about 500 threads/10 cm, not greater than about 475 threads/10 cm, not greater than about 450 threads/10 cm, not greater than about 425 threads/10 cm, not greater than about 400 threads/10 cm, or not greater than about 375 threads/10 cm. In one particular embodiment, the thread count for both yarns are the same and range from about 325 threads/10 cm to 425 threads/10 cm.

Still referring toFIG. 1, the laminate can include a third layer106overlying the ply and opposite to layer102. In one embodiment, layer106can be of the same material and thickness as layer102. In another embodiment, layer106can differ from layer102either in type of fluoropolymer, in mode of applying the layer, or in thickness. For example, layer102can be a skived PTFE layer and layer106can be a cast mPTFE layer, or vice versa. In another example, layer102can have skived PTFE layer and layer106can have an extruded layer, wherein the extruded layer can include tetrafluoroethylene-hexafluoropropylene (FEP), perfluoroalkoxyethylene (PFA), ethylene-tetrafluoroethylene (ETFE), tetrafluoro-ethylene-perfluoro(methyl vinyl ether) (MFA), polyvinylidene fluoride (PVDF), ethylene-chlorotrifluoroethylene (ECTFE), or any mixture thereof.

In embodiments, the filler can be present in an amount of at least about 1% by volume, such as at least about 2% by volume, at least about 3% by volume, at least about 5% by volume, at least about 7% by volume, at least about 10% by volume, at least about 12% by volume, at least about 15% by volume, at least about 17% by volume, or at least about 20% by volume. In another embodiment, the filler can be present in an amount of at not greater than about 40% by volume, such as not greater than about 35% by volume, not greater than about 30% by volume, not greater than about 27% by volume, not greater than about 25% by volume, not greater than about 22% by volume, not greater than about 20% by volume, not greater than about 17% by volume, or not greater than about 15% by volume.

FIG. 2depicts one further embodiment of a laminate. This laminate includes top and bottom layers102and106and a ply made of yarns1042and1044. In contrast toFIG. 1, the ply is embedded in an elastomer matrix208. Accordingly, layers102and106adhere to the elastomer of matrix208. In embodiments, the elastomer of layer208can be thermosetting elastomers. In a particular embodiment, the elastomer comprising matrix208can be a fluoroelastomers. For example, the fluoroelastomers can include copolymers of hexafluoropropylene (HFP), vinylidene fluoride (VDF), tetrafluoroethylene (TFE), and perfluoromethylvinylether (PMVE).

Referring toFIGS. 3A and 3B, in another embodiment, there can be an adhesive layer308between layer102and the ply made of yarns1042and1044. In another embodiment as displayed inFIG. 3B, there can be one adhesive layer310between layer102and the ply made of yarns1042and1044, and also an adhesive layer312between the ply and layer106. The adhesive layers308,310, and312can include tetrafluoroethylene-hexafluoropropylene (FEP), modified tetrafluoroethylene-hexafluoropropylene (mFEP), perfluoroalkoxyethylene (PFA), modified perfluoroalkoxyethylene (mPFA), polyimide (PI), polyamidimide (PAI), polyphenylene sulfide (PPS), polyphenylene sulfone (PPSO2), liquid crystal polymers (LCP), polyether ether ketones (PEEK), aromatic polyesters (Ekonol), ethylene-tetrafluoroethylene (ETFE), tetrafluoro-ethylene-perfluoro (methyl vinyl ether) (MFA), modified polytetrafluoroethylene (mPTFE), polyvinylidene fluoride (PVDF), ethylene-chlorotrifluoroethylene (ECTFE), polyethersulfone (PES), polyetherketone (PEK), and any combination thereof. In embodiments, layer310and312can be the same material or different material. Still referring toFIG. 3B, in one particular embodiment, layers102and106can include the same fluoropolymer selected from mPTFE or PTFE, yarns1042and1044includes PTFE, and layers310and312both include PFA.

Referring toFIGS. 1-3, laminates as displayed can have a total thickness of at least about 0.3 mm, such as at least about 0.4 mm, at least about 0.5 mm, at least about 0.6 mm, at least about 0.7 mm, at least about 0.8 mm, at least about 0.85 mm, at least about 0.9 mm, or at least about 0.95 mm. In another embodiment, the total thickness is not greater than about 2.0 mm, such as not greater than about 1.8 mm, not greater than about 1.6 mm, not greater than about 1.5 mm, not greater than about 1.4 mm, not greater than about 1.3 mm, not greater than about 1.2 mm, not greater than about 1.15 mm, or not greater than about 1.1 mm. In one particular embodiment, the total thickness can range from about 0.85 mm to about 1.15 mm.

Referring toFIGS. 1-3, laminates as displayed can be prepared by a time, temperature, and pressured controlled lamination process, wherein layer102, the ply comprising the fluoropolymer fabric, and layer106are assembled, optionally including precursor material to form matrix208, or adhesive layers308,310, and312. For example, such precursor can be powdered forms of the matrix or adhesion material.

According to one embodiment, the process for manufacturing the laminate includes applying a first adhesive, which will result in layer310, onto the first layer of a first fluoropolymer, which will result in layer102. Then, at least one ply of a fluoropolymer fabric comprising yarns1042and1044is applied onto the first adhesive. Then a second layer of adhesive, which will result in layer312is applied onto the ply. Afterwards, a layer of a second fluoropolymer, which will become layer106upon completion of the process, is applied. Accordingly, the assembly of first fluoroploymer, adhesives, ply, and second fluoropolymer form a pre-lamination stack.

In the time-pressure-temperature controlled lamination process. The pre-lamination stack is compressed to at least about 0.5 MPa, such as at least about 0.7 MPa, at least about 1.0 MPa, at least about 1.2 MPa, at least about 1.5 MPa, at least about 1.6 MPa, at least about 1.7 MPa, at least about 1.8 MPa, at least about 1.9 MPa, at least about 2.0 MPa, at least about 2.05 MPa, at least about 2.10 MPa, or at least about 2.15 MPa. In another process example, the pressure is not greater than about 4.0 MPa, such as not greater than about 3.5 MPa, not greater than about 3.0 MPa, not greater than about 2.5 MPa, not greater than about 2.4 MPa, not greater than about 2.35 MPa, not greater than about 2.30 MPa, not greater than about 2.25 MPa, or not greater than about 2.20 MPa.

At the same time, the compressed pre-lamination stack is heated to at least the glass transition temperature Tgof the fluoropolymer fabric. In another process example, the compressed pre-lamination stack is heated to at least the melting temperature Tmof the first adhesive or the second adhesive. For example the compressed pre-lamination stack can be heated to at least about 320° C., such as at least about 330° C., at least about 340° C., at least about 350° C., at least about 360° C., at least about 370° C., at least about 375° C., at least about 380° C., at least about 385° C., at least about 390° C., at least about 395° C., at least about 400° C., or at least about 405° C. In another process example, the compressed pre-lamination stack can be heated to not more than about 420° C., such as not more than about 415° C., not more than about 410° C., not more than about 405° C., not more than about 400° C., not more than about 395° C., not more than about 390° C., or not more than about 385° C.

It was found that for a pre-lamination stack comprising mPTFE or PTFE skived fluoropolymers (thickness 0.42 mm and 0.5 mm, respectively), PFA as an adhesive (thickness 0.025 mm) and a PTFE fabric (Gore-Rastex® CCC 216, thickness 0.25 mm), the stress-strain curve of the resulting laminate and the peel strength of the resulting laminate show a correlation to the temperature applied in the heating process in the range from 375° C. to 415° C. In general, the tensile strength of the laminate decreases with increasing process temperature, while the peel strength increases with increasing temperature. Accordingly, the process allows for optimization for laminates of a desired tensile strength or desired peel strength.

Referring further to the lamination process, the pre-lamination stack can be compressed and heated as described above for a duration of at least 100 seconds, such as at least about 110 seconds, such as at least about 120 seconds, at least about 130 seconds, at least about 140 seconds, or at least 145 seconds. The first duration can be not greater than about 250 seconds, such as not greater than about 220 seconds, not greater than about 200 seconds, not greater than about 180 seconds, not greater than about 170 seconds, not greater than about 160 seconds, or not greater than about 150 seconds.

In another process example, after the heating, the stack can be cooled to a second temperature. For example the stack can be cooled to not greater than about 100° C., such as not greater than about 90° C., not greater than about 80° C., not greater than about 70° C., not greater than about 60° C., not greater than about 50° C., not greater than about 40° C., not greater than about 35° C., or not greater than about 30° C. The cooling can occur at a cooling rate of at least 0.0001° C./s and not greater than 2° C./s. In one process example, the cooling rate can be not greater than 1.8° C./s, such as not greater than 1.6° C./s, not greater than 1.4° C./s, not greater than 1.2° C./s, not greater than 1.0° C./s, not greater than 0.8° C./s, not greater than 0.6° C./s, not greater than 0.5° C./s, not greater than 0.4° C./s, not greater than 0.3° C./s, not greater than 0.2° C./s, or not greater than 0.1° C./s.

As described above, the process for manufacturing the laminates allow for adjusting the tensile strength of the laminate. For example, high tensile strength is desired for applications such as conveyor belts where forces are predominantly applied along the longitudinal axis. Contrary thereto, softer materials with lower tensile strength is desired for expansion joints, where forces from pressure or temperature changes act predominantly perpendicular to the major surface of the laminate. Accordingly, the laminates for expansion joints can be designed to be softer but with a higher peel strength. For membranes of diaphragm pumps on the other hand, there are forces which hold the membrane in its frame, i.e. forces that act within the plane of the laminate, and there are forces during the pumping process that act perpendicular to the membrane surface. Accordingly, for diaphragms, a laminate having appropriate tensile strength and appropriate peel strength can be designed by choice of the material, their dimensions, and the time-pressure-temperature controlled lamination process. Similarly, bearings can be manufactured as to specification.

In one embodiment, the laminates show not more than 50% at a stress of 15 MPa as measured by DIN EN ISO 527. According to DIN EN ISO 572, a sample width of about 1 inch, at a clamp distance of about 50 mm, is pulled at a speed of about 50 mm/min during the measurement of the stress strain curve. In other embodiments, the strain is not more than 50% at a stress of 20 MPa, not more than 50% at a stress of 25 MPa, not more than 50% at a stress of 30 MPa, not more than 50% at a stress of 32 MPa, not more than 50% at a stress of 34 MPa, or not more than 50% at a stress of 36 MPa.

In yet other embodiments, laminates when exposed to a stress of 15 MPa can have a strain of not more than 45%, such as not more than 40%, not more than 35%, not more than 30%, not more than 25%, not more than 24%, not more than 23%, not more than 22%, not more than 21%, or not more than 20%. In yet even other embodiments, laminates when exposed to a stress of 25 MPa can have a strain is not more than 45%, such as not more than 40%, not more than 39%, not more than 38%, not more than 37%, not more than 36%, or not more than 35%.

In one embodiment, the laminates have a Deformation under Load as measured after 24 hours at a load of 25 MPa and a 15 minutes after removal of the load in accordance with ASTM D621 of not greater than 150 microns, such as not greater than 140 microns, not greater than 130 microns, not greater than 120 microns, not greater than 110 microns, not greater than 100 microns, not greater than 98 microns, not greater than 96 microns, not greater than 94 microns, not greater than 92 microns, not greater than 90 microns, not greater than 85 microns, not greater than 80 microns, or not greater than 70 microns. In one embodiment, the Deformation under Load is at least 1 microns. In yet one further embodiment, the Deformation under Load ranges from 1 micron to 150 microns, from 5 microns to 120 microns, from 20 microns to 100 microns, or from 50 microns to 95 microns.

In one other embodiment the laminates have a water vapor permeability under conditions described in the Examples of not greater than 0.088 g*mm/m2*d, such as not greater than 0.087 g*mm/m2*d, not greater than 0.086 g*mm/m2*d, not greater than 0.085 g*mm/m2*d, not greater than 0.084 g*mm/m2*d, not greater than 0.082 g*mm/m2*d, not greater than 0.080 g*mm/m2*d, not greater than 0.078 g*mm/m2*d, not greater than 0.075 g*mm/m2*d, not greater than 0.070 g*mm/m2*d, or not greater than 0.065 g*mm/m2*d. In one embodiment, the water vapor permeability is at least 0.0001 g*mm/m2*d. In yet another embodiment, the water vapor permeability ranges from 0.001 g*mm/m2*d to 0.088 g*mm/m2*d, from 0.01 g*mm/m2*d to 0.086 g*mm/m2*d, from 0.03 g*mm/m2*d to 0.084 g*mm/m2*d, or from 0.04 g*mm/m2*d to 0.080 g*mm/m2*d.

In one further embodiment the laminates have a oxygen permeability under conditions described in the Examples of not greater than 7800 cc(O2)*mm/m2*d*atm, such as not greater than 7700 cc(O2)*mm/m2*d*atm, not greater than 7600 cc(O2)*mm/m2*d*atm, not greater than 7500 cc(O2)*mm/m2*d*atm, not greater than 7400 cc(O2)*mm/m2*d*atm, not greater than 7200 cc(O2)*mm/m2*d*atm, not greater than 7000 cc(O2)*mm/m2*d*atm, not greater than 6800 cc(O2)*mm/m2*d*atm, not greater than 6600 cc(O2)*mm/m2*d*atm, or not greater than 6400 cc(O2)*mm/m2*d*atm. In one embodiment, the oxygen permeability is at least 100 cc(O2)*mm/m2*d*atm. In another embodiment, the oxygen permeability ranges from 1000 cc(O2)*mm/m2*d*atm to 7800 cc(O2)*mm/m2*d*atm, such as from 1000 cc(O2)*mm/m2*d*atm to 7800 cc(O2)*mm/m2*d*atm, from 2000 cc(O2)*mm/m2*d*atm to 7500 cc(O2)*mm/m2*d*atm, or from 4000 cc(O2)*mm/m2*d*atm to 7000 cc(O2)*mm/m2*d*atm.

Since membranes of diaphragm pumps come at least on one side in contact with the material that is pumped, these parts are exposed to high wear and tear. Accordingly, laminates with long life time are desired. A high frequency flexlife test allows in a lab setting a determination for lifetime and onset of wear or fatigue of laminates.

Referring toFIG. 4A, the high frequency flexlife test uses a disc shape test sample402having a center hole with a hole diameter d1 and a disc diameter d2. While the high frequency flexlife test allows for a variety of size, samples of the high frequency flexlife test herein have a d1 of 18 mm and a d2 of 125 mm.

FIG. 4Bdepicts a top view of the spherical calotte404of the high frequency flexlife apparatus. The spherical calotte is made of metal wherein the metal surface that contacts the sample has a surface roughness Ra. In one embodiment, the spherical calotte is made of AlMg3alloy (industrial standard: 3.3535/EN AW-5754) with a surface roughness of 1.6 microns.FIG. 4Cis a cross-sectional view of the spherical calotte with a detailed mark-up of the dimensions and radii of curvatures (arcs). While any variety of dimensions can be used, spherical calottes of the presently described high frequency flexlife test are: d3=15 mm, h1=4.5 mm, h2=10.9 mm, h3=23.9. mm, h4=50 mm, w1=87.5 mm, w2=70 mm, R1=5 mm arc, R2=75 mm arc, R3=5 mm arc, and CR2 is the center point.

Furthermore,FIG. 4Ddepicts the test set up for the high frequency flexlife test. The sample402is clamped into ring shaped sample fixation408having an upper clamping ring4082and a lower clamping ring4084. The sample fixation408has an inner diameter of about 95 mm. Two spherical calottes as described above are placed above and below the sample402. A set screw4068fixated with fixation nuts4069connects the two spherical calottes through a guide sleeve4066with adapter406.

For the test, adapter406is moved perpendicular to the sample402. The range of one cycle is from the neutral position as depicted inFIG. 4Dabout 15 mm into one direction, back to the neutral position, 15 mm into the opposite direction and back to the neutral position. The high frequency flex test is conducted at a frequency of about 10 Hertz, i.e. 10 cycles per second. A counter records the number of cycles until the sample breaks or a cycle can no longer be completed.

In one embodiment, the laminates as described herein have life times of at least about 2,500,000 cycles or 2.5 megacycles of the high frequency flexlife test. In another embodiment, the laminates have life times of at least about 3.5 megacycles, at least about 4.0 megacycles, at least about 4.5 megacycles, at least about 5.0 megacycles, at least about 5.5 megacycles, at least about 6.0 megacycles, at least about 6.5 megacycles, at least about 7.0 megacycles, at least about 7.2 megacycles, at least about 7.4 megacycles, at least about 7.6 megacycles, at least about 7.8 megacycles, at least about 8.0 megacycles, or at least about 8.2 megacycles. In order to adjust the life time of the membrane with life times of other parts, the number of a desired lime time can be limited. For example, the life time can not be greater than about 15 megacycles.

It is within the scope of the present disclosure to include further modification and/or apparatuses that include the herein described laminates. For example, a diaphragm membrane can include a laminate having a first layer of a first fluoropolymer, a second layer of at least one ply of a fluoropolymer fabric overlying the first layer, and a third layer of a second fluoropolymer overlying the second layer opposite to the first layer. The laminate can have a strain of not more than 50% at a stress of 15 MPa as measured by DIN EN ISO 527. The diaphragm membrane can further include a backing, the backing having a connector for a piston or a spring. Moreover, a diaphragm pump can include the diaphragm membrane as described herein. In another embodiment, a solenoid valve can include the diaphragm membrane as described herein.

In another embodiment, a conveyor belt can include a laminate, the laminate comprising a first end and a second end. The laminate can have a first layer of a first fluoropolymer, a second layer of at least one ply of a fluoropolymer fabric overlying the first layer, and a third layer of a second fluoropolymer overlying the second layer opposite to the first layer, wherein the laminate has a strain of not more than 50% at a stress of 15 MPa as measured by DIN EN ISO 527 with a sample width of about 1 inch, at a clamp distance of about 50 mm, and a speed of about 50 mm/min. Moreover, the conveyor belt includes a seam connecting the first with the second end.

In yet another embodiment, a bearing including the three layered laminates as described herein can have a substrate, the substrate overlying and in direct contact with the third layer.

FIG. 5depicts an expansion joint assembly500, with flue gas pipe sections510and512. In between the flue gas pipe sections is the expansion joint including the bellow cylinder514made of a laminate as described herein. The expansion joint is supported by support bars516and connected to the adjacent flue gas pipe sections by screws518and519.

Without restricting the scope of the present disclosure, the following item lists reflects some embodiments according to the invention:

Item 1. A laminate comprising:

a first layer of a first fluoropolymer;

a second layer of at least one ply of a fluoropolymer fabric overlying the first layer;

a third layer of a second fluoropolymer overlying the second layer opposite to the first layer;

wherein the laminate has a strain of not more than 50% at a stress of 15 MPa as measured by DIN EN ISO 527 with a sample width of about 1 inch, at a clamp distance of about 50 mm, and a speed of about 50 mm/min.

Item 2. The laminate according to item 1, wherein the strain is not more than 50% at a stress of 20 MPa, wherein the strain is not more than 50% at a stress of 25 MPa, wherein the strain is not more than 50% at a stress of 30 MPa, wherein the strain is not more than 50% at a stress of 32 MPa, wherein the strain is not more than 50% at a stress of 34 MPa, or wherein the strain is not more than 50% at a stress of 36 MPa.

Item 3. The laminate according to item 1, wherein at a stress of 15 MPa, the strain is not more than 45%, such as not more than 40%, not more than 35%, not more than 30%, not more than 25%, not more than 24%, not more than 23%, not more than 22%, not more than 21%, or not more than 20%.

Item 4. The laminate according to item 1, wherein at a stress of 25 MPa, the strain is not more than 45%, such as not more than 40%, not more than 39%, not more than 38%, not more than 37%, not more than 36%, or not more than 35%.

Item 5. The laminate according to item 1 further comprising an adhesive between the first layer and the second layer.

Item 6. The laminate according to item 1 further comprising an adhesive between the third layer and the second layer.

Item 8. The laminate according to item 7, wherein the adhesive comprises perfluoroalkoxyethylene (PFA).

Item 9. The laminate according to item 8, wherein the adhesive consist essentially of perfluoroalkoxyethylene (PFA).

Item 10. The laminate according to any one of the preceding items, wherein the first fluoropolymer and the second fluoropolymer are the same or different and are selected from the group consisting of polytetrafluoroethylene (PTFE), modified polytetrafluoroethylene (mPTFE), ethylene-tetrafluoroethylene (ETFE), perfluoroalkoxyethylene (PFA), tetrafluoroethylene-hexafluoropropylene (FEP), tetrafluoro-ethylene-perfluoro (methyl vinyl ether) (MFA), polyvinylidene fluoride (PVDF), ethylene-chlorotrifluoroethylene (ECTFE), and any combination thereof.

Item 11. The laminate according to item 10, wherein the first fluoropolymer comprises polytetrafluoroethylene (PTFE) or modified polytetrafluoroethylene (mPTFE).

Item 12. The laminate according to item 10, wherein the first fluoropolymer consists essentially of polytetrafluoroethylene (PTFE) or modified polytetrafluoroethylene (mPTFE).

Item 13. The laminate according to item 10, wherein the second fluoropolymer comprises polytetrafluoroethylene (PTFE) or modified polytetrafluoroethylene (mPTFE).

Item 14. The laminate according to item 10, wherein the second fluoropolymer consists essentially of polytetrafluoroethylene (PTFE) or modified polytetrafluoroethylene (mPTFE).

Item 15. The laminate according to any one of the preceding items, wherein the first fluoropolymer or the second fluoropolymer further comprises at least one filler.

Item 17. The laminate according to item 15, wherein the at least one filler is present in an amount of at least about 1% by volume, such as at least about 2% by volume, at least about 3% by volume, at least about 5% by volume, at least about 7% by volume, at least about 10% by volume, at least about 12% by volume, at least about 15% by volume, at least about 17% by volume, or at least about 20% by volume.

Item 18. The laminate according to item 15, wherein the at least one filler is present in an amount of at not greater than about 40% by volume, such as not greater than about 35% by volume, not greater than about 30% by volume, not greater than about 27% by volume, not greater than about 25% by volume, not greater than about 22% by volume, not greater than about 20% by volume, not greater than about 17% by volume, or not greater than about 15% by volume.

Item 19. The laminate according to any one of the preceding items, wherein the fluoropolymer fabric is selected from the group consisting of polytetrafluoroethylene (PTFE), modified polytetrafluoroethylene (mPTFE), ethylene-tetrafluoroethylene (ETFE), perfluoroalkoxyethylene (PFA), tetrafluoroethylene-hexafluoropropylene (FEP), tetrafluoro-ethylene-perfluoro (methyl vinyl ether) (MFA), polyvinylidene fluoride (PVDF), ethylene-chlorotrifluoroethylene (ECTFE), and any combination thereof.

Item 20. The laminate according to item 15, wherein the fluoropolymer fabric comprises polytetrafluoroethylene (PTFE) or modified polytetrafluoroethylene (mPTFE).

Item 21. The laminate according to item 15, wherein the fluoropolymer fabric consists essentially of polytetrafluoroethylene (PTFE).

Item 23. The laminate according to any one of the preceding items wherein the first or the third layer have a thickness of at least about 0.05 mm, such as of at least about 0.1 mm, at least about 0.15 mm, at least about 0.2 mm, at least about 0.25 mm, at least about 0.3 mm, at least about 0.35 mm, at least about 0.4 mm, or at least about 0.45 mm.

Item 24. The laminate according to any one of the preceding items wherein the first or the third layer have a thickness of not greater than about 2 mm, such as not greater than about 1.8 mm, not greater than about 1.6 mm, not greater than about 1.4 mm, not greater than about 1.2 mm, not greater than about 1 mm, not greater than about 0.95 mm, not greater than about 0.9 mm, not greater than about 0.85 mm, not greater than about 0.8 mm, not greater than about 0.75 mm, not greater than about 0.7 mm, not greater than about 0.65 mm, not greater than about 0.6 mm, not greater than about 0.55 mm, not greater than about 0.5 mm, not greater than about 0.4 mm, or not greater than about 0.3 mm.

Item 25. The laminate according to any one of the preceding items wherein the at least one ply of fluoropolymer fabric has a thickness of at least about 0.04 mm, such as of at least about 0.08 mm, at least about 0.12 mm, at least about 0.16 mm, at least about 0.20 mm, at least about 0.24 mm, at least about 0.28 mm, at least about 0.32 mm, or at least about 0.36 mm.

Item 26. The laminate according to any one of the preceding items wherein the at least one ply of fluoropolymer fabric has a thickness of not greater than about 1 mm, such as not greater than about 0.8 mm, not greater than about 0.6 mm, not greater than about 0.55 mm, not greater than about 0.5 mm, not greater than about 0.45 mm, not greater than about 0.4 mm, not greater than about 0.38 mm, not greater than about 0.34 mm, not greater than about 0.3 mm, not greater than about 0.26 mm, or not greater than about 0.22 mm.

Item 27. The laminate according to any one of the preceding items, wherein the fluoropolymer fabric has a yarn thickness of at least about 0.02 mm, such as at least about 0.04 mm, at least about 0.06 mm, at least about 0.08 mm, at least about 0.1 mm, at least about 0.12 mm, at least about 0.14 mm, or at least about 0.16 mm.

Item 28. The laminate according to any one of the preceding items, wherein the fluoropolymer fabric has a yarn thickness of at not greater than about 0.3 mm, such as not greater than about 0.28 mm, not greater than about 0.26 mm, not greater than about 0.24 mm, not greater than about 0.22 mm, not greater than about 0.2 mm, or not greater than about 0.18 mm.

Item 29. The laminate according to any one of the preceding items, wherein the fluoropolymer fabric has a weight of at least about 100 g/m2, such as at least about 120 g/m2, at least about 140 g/m2, at least about 160 g/m2, at least about 180 g/m2, at least about 200 g/m2, at least about 220 g/m2, at least about 240 g/m2, at least about 260 g/m2, at least about 280 g/m2, or at least about 300 g/m2.

Item 30. The laminate according to any one of the preceding items, wherein the fluoropolymer fabric has a weight of not greater than about 500 g/m2, not greater than about 480 g/m2, not greater than about 460 g/m2, not greater than about 440 g/m2, not greater than about 420 g/m2, not greater than about 400 g/m2, not greater than about 380 g/m2, not greater than about 360 g/m2, not greater than about 340 g/m2, or not greater than about 320 g/m2.

Item 31. The laminate according to any one of the preceding items, wherein the fluoropolymer fabric has a warp thread count of at least about 100 threads/10 cm, such as at least about 125 threads/10 cm, at least about 150 threads/10 cm, at least about 175 threads/10 cm, at least about 200 threads/10 cm, at least about 225 threads/10 cm, at least about 250 threads/10 cm, at least about 275 threads/10 cm, at least about 300 threads/10 cm, at least about 325 threads/10 cm, or at least about 350 threads/10 cm.

Item 32. The laminate according to any one of the preceding items, wherein the fluoropolymer fabric has a warp thread count of not greater than about 600 threads/10 cm, such as not greater than about 575 threads/10 cm, not greater than about 550 threads/10 cm, not greater than about 525 threads/10 cm, not greater than about 500 threads/10 cm, not greater than about 475 threads/10 cm, not greater than about 450 threads/10 cm, not greater than about 425 threads/10 cm, not greater than about 400 threads/10 cm, or not greater than about 375 threads/10 cm.

Item 33. The laminate according to any one of the preceding items, wherein the fluoropolymer fabric has a weft thread count of at least about 100 threads/10 cm, such as at least about 125 threads/10 cm, at least about 150 threads/10 cm, at least about 175 threads/10 cm, at least about 200 threads/10 cm, at least about 225 threads/10 cm, at least about 250 threads/10 cm, at least about 275 threads/10 cm, at least about 300 threads/10 cm, at least about 325 threads/10 cm, or at least about 350 threads/10 cm.

Item 34. The laminate according to any one of the preceding items, wherein the fluoropolymer fabric has a weft thread count of not greater than about 600 threads/10 cm, such as not greater than about 575 threads/10 cm, not greater than about 550 threads/10 cm, not greater than about 525 threads/10 cm, not greater than about 500 threads/10 cm, not greater than about 475 threads/10 cm, not greater than about 450 threads/10 cm, not greater than about 425 threads/10 cm, not greater than about 400 threads/10 cm, or not greater than about 375 threads/10 cm.

Item 35. A composite diaphragm comprising:

a first layer of skived polytetrafluoroethylene (PTFE) or skived modified polytetrafluoroethylene (mPTFE);

a second layer of at least one ply of a fluoropolymer fabric overlying the first layer wherein the fluoropolymer fabric comprises polytetrafluoroethylene (PTFE) or modified polytetrafluoroethylene (mPTFE);

a third layer of skived polytetrafluoroethylene (PTFE) or skived modified polytetrafluoroethylene (mPTFE) overlying the second layer opposite to the first layer;

wherein the composite has a life time of at least about 2.5 megacycles in a high frequency flexlife test.

Item 36. The composite diaphragm according to item 35, wherein the life time is at least about 3.0 megacycles, such as at least about 3.5 megacycles, at least about 4.0 megacycles, at least about 4.5 megacycles, at least about 5.0 megacycles, at least about 5.5 megacycles, at least about 6.0 megacycles, at least about 6.5 megacycles, at least about 7.0 megacycles, at least about 7.2 megacycles, at least about 7.4 megacycles, at least about 7.6 megacycles, at least about 7.8 megacycles, at least about 8.0 megacycles, or at least about 8.2 megacycles; but not greater than about 15 megacycles.

Item 37. The composite diaphragm according to item 35 further comprising an adhesive between the first layer and the second layer.

Item 38. The composite diaphragm to item 35 further comprising an adhesive between the third layer and the second layer.

Item 40. The composite diaphragm according to item 39, wherein the adhesive comprises perfluoroalkoxyethylene (PFA).

Item 41. The composite diaphragm according to item 40, wherein the adhesive consist essentially of perfluoroalkoxyethylene (PFA).

Item 42. The composite diaphragm according to any one of items 35 through 41, wherein the skived polytetrafluoroethylene (PTFE) or skived modified polytetrafluoroethylene (mPTFE) of the first layer or the second layer further comprises at least one filler.

Item 44. The composite diaphragm according to item 43, wherein the at least one filler is present in an amount of at least about 1% by volume, such as at least about 2% by volume, at least about 3% by volume, at least about 5% by volume, at least about 7% by volume, at least about 10% by volume, at least about 12% by volume, at least about 15% by volume, at least about 17% by volume, or at least about 20% by volume.

Item 45. A diaphragm membrane, the diaphragm membrane comprising:

a laminate, wherein the laminate includesa first layer of a first fluoropolymer,a second layer of at least one ply of a fluoropolymer fabric overlying the first layer, anda third layer of a second fluoropolymer overlying the second layer opposite to the first layer, wherein the laminate has a strain of not more than 50% at a stress of 15 MPa as measured by DIN EN ISO 527 with a sample width of about 1 inch, at a clamp distance of about 50 mm, and a speed of about 50 mm/min; and

a backing, the backing having a connector for a piston or a spring.

Item 46. A diaphragm pump comprising the diaphragm membrane according to item 45.

Item 47. A solenoid valve comprising the diaphragm membrane according to item 45.

Item 48. A conveyor belt, the conveyor belt comprising

a laminate, the laminate comprising a first end and a second end, wherein the laminate includesa first layer of a first fluoropolymer,a second layer of at least one ply of a fluoropolymer fabric overlying the first layer, anda third layer of a second fluoropolymer overlying the second layer opposite to the first layer, wherein the laminate has a strain of not more than 50% at a stress of 15 MPa as measured by DIN EN ISO 527 with a sample width of about 1 inch, at a clamp distance of about 50 mm, and a speed of about 50 mm/min; and

a seam connecting the first with the second end.

Item 49. A bearing comprising

a laminate, wherein the laminate includesa first layer of a first fluoropolymer,a second layer of at least one ply of a fluoropolymer fabric overlying the first layer, anda third layer of a second fluoropolymer overlying the second layer opposite to the first layer, wherein the laminate has a strain of not more than 50% at a stress of 15 MPa as measured by DIN EN ISO 527 with a sample width of about 1 inch, at a clamp distance of about 50 mm, and a speed of about 50 mm/min; and

a substrate, the substrate overlying and in direct contact with the third layer.

Item 50. A method of manufacturing a laminate, the method comprising:

providing a first layer of a first fluoropolymer;

overlying a second layer of at least one ply of a fluoropolymer fabric onto the first layer;

overlying a third layer of a second fluoropolymer onto the second layer opposite to the first layer to form a stack;

compressing the stack at a pressure of at least 1.5 MPa; and

heating the stack to a temperature of at least the glass transition temperature Tgof the fluoropolymer fabric for a first duration of at least 100 seconds.

Item 51. A method of manufacturing a laminate, the method comprising:

providing a first layer of a first fluoropolymer;

applying a first adhesive onto the first layer

overlying a second layer of at least one ply of a fluoropolymer fabric onto the first adhesive;

applying a second adhesive;

overlying a third layer of a second fluoropolymer onto the second adhesive to form a stack;

compressing the stack at a pressure of at least about 1.5 MPa; and

heating the stack to a first temperature of at least the melting temperature Tmof the first adhesive or the second adhesive for a first duration of at least 100 seconds.

Item 52. The method according to items 50 or 51, further comprising, after the heating, cooling the stack to a second temperature at a cooling rate of at least 0.0001° C./s and not greater than 2° C./s.

Item 53. The method according to any one of the items 50 through 52, wherein the pressure is at least about 1.6 MPa, such as at least about 1.7 MPa, at least about 1.8 MPa, at least about 1.9 MPa, at least about 2.0 MPa, at least about 2.05 MPa, at least about 2.10 MPa, or at least about 2.15 MPa.

Item 54. The method according to any one of the items 50 through 53, wherein the pressure is not greater than about 4.0 MPa, such as not greater than about 3.5 MPa, not greater than about 3.0 MPa, not greater than about 2.5 MPa, not greater than about 2.4 MPa, not greater than about 2.35 MPa, not greater than about 2.30 MPa, not greater than about 2.25 MPa, or not greater than about 2.20 MPa.

Item 55. The method according to any one of items 50 through 54, wherein the first duration is at least 110 seconds, such as at least 120 seconds, at least 130 seconds, at least 140 seconds, or at least 145 seconds.

Item 56. The method according to any one of items 50 through 55, wherein the first duration is not greater than 250 seconds, such as not greater than 220 seconds, not greater than 200 seconds, not greater than 180 seconds, not greater than 170 seconds, not greater than 160 seconds, or not greater than 150 seconds.

Item 57. The method according to any one of items 52 through 56, wherein the cooling rate is not greater than 1.8° C./s, such as not greater than 1.6° C./s, not greater than 1.4° C./s, not greater than 1.2° C./s, not greater than 1.0° C./s, not greater than 0.8° C./s, not greater than 0.6° C./s, not greater than 0.5° C./s, not greater than 0.4° C./s, not greater than 0.3° C./s, not greater than 0.2° C./s, or not greater than 0.1° C./s.

Item 58. The method according to any one items 51 through 57, wherein the first adhesive or the second adhesive are the same or different and are selected from the group consisting of tetrafluoroethylene-hexafluoropropylene (FEP), modified tetrafluoroethylene-hexafluoropropylene (mFEP), perfluoroalkoxyethylene (PFA), modified perfluoroalkoxyethylene (mPFA), polyimide (PI), polyamidimide (PAI), polyphenylene sulfide (PPS), polyphenylene sulfone (PPSO2), liquid crystal polymers (LCP), polyether ether ketones (PEEK), aromatic polyesters (Ekonol), ethylene-tetrafluoroethylene (ETFE), tetrafluoro-ethylene-perfluoro (methyl vinyl ether) (MFA), modified polytetrafluoroethylene (mPTFE), polyvinylidene fluoride (PVDF), ethylene-chlorotrifluoroethylene (ECTFE), polyethersulfone (PES), polyetherketone (PEK), and any combination thereof.

Item 59. The method according to item 58, wherein the first adhesive and the second adhesive comprises perfluoroalkoxyethylene (PFA).

Item 60. The method according to item 59, wherein the first adhesive and the second adhesive consist essentially of perfluoroalkoxyethylene (PFA).

Item 61. The method according to any one items 50 through 60, wherein the first fluoropolymer and the second fluoropolymer are the same or different and are selected from the group consisting of polytetrafluoroethylene (PTFE), modified polytetrafluoroethylene (mPTFE), ethylene-tetrafluoroethylene (ETFE), perfluoroalkoxyethylene (PFA), tetrafluoroethylene-hexafluoropropylene (FEP), tetrafluoro-ethylene-perfluoro (methyl vinyl ether) (MFA), polyvinylidene fluoride (PVDF), ethylene-chlorotrifluoroethylene (ECTFE), and any combination thereof.

Item 62. The method according to item 61, wherein the first fluoropolymer comprises polytetrafluoroethylene (PTFE) or modified polytetrafluoroethylene (mPTFE).

Item 63. The method according to item 62, wherein the first fluoropolymer consists essentially of polytetrafluoroethylene (PTFE) or modified polytetrafluoroethylene (mPTFE).

Item 64. The method according to item 63, wherein the second fluoropolymer comprises polytetrafluoroethylene (PTFE) or modified polytetrafluoroethylene (mPTFE).

Item 65. The method according to item 64, wherein the second fluoropolymer consists essentially of polytetrafluoroethylene (PTFE) or modified polytetrafluoroethylene (mPTFE).

Item 66. The method according to any one of items 50 through 65, wherein the first fluoropolymer or the second fluoropolymer further comprises at least one filler.

Item 68. The method according to item 66, wherein the at least one filler is present in an amount of at least about 1% by volume, such as at least about 2% by volume, at least about 3% by volume, at least about 5% by volume, at least about 7% by volume, at least about 10% by volume, at least about 12% by volume, at least about 15% by volume, at least about 17% by volume, or at least about 20% by volume.

Item 69. The method according to item 66, wherein the at least one filler is present in an amount of at not greater than about 40% by volume, such as not greater than about 35% by volume, not greater than about 30% by volume, not greater than about 27% by volume, not greater than about 25% by volume, not greater than about 22% by volume, not greater than about 20% by volume, not greater than about 17% by volume, or not greater than about 15% by volume.

Item 70. The method according to any one of items 50 through 69, wherein the fluoropolymer fabric is selected from the group consisting of polytetrafluoroethylene (PTFE), modified polytetrafluoroethylene (mPTFE), ethylene-tetrafluoroethylene (ETFE), perfluoroalkoxyethylene (PFA), tetrafluoroethylene-hexafluoropropylene (FEP), tetrafluoro-ethylene-perfluoro (methyl vinyl ether) (MFA), polyvinylidene fluoride (PVDF), ethylene-chlorotrifluoroethylene (ECTFE), and any combination thereof.

Item 71. The method according to item 70, wherein the fluoropolymer fabric comprises polytetrafluoroethylene (PTFE) or modified polytetrafluoroethylene (mPTFE).

Item 72. The method according to item 70, wherein the fluoropolymer fabric consists essentially of polytetrafluoroethylene (PTFE).

Item 73. The method according to any one of items 50 through 72, wherein the first or the third layer have a thickness of at least about 0.05 mm, such as of at least about 0.1 mm, at least about 0.15 mm, at least about 0.2 mm, at least about 0.25 mm, at least about 0.3 mm, at least about 0.35 mm, at least about 0.4 mm, or at least about 0.45 mm.

Item 74. The method according to any one of items 50 through 73, wherein the first or the third layer have a thickness of not greater than about 2 mm, such as not greater than about 1.8 mm, not greater than about 1.6 mm, not greater than about 1.4 mm, not greater than about 1.2 mm, not greater than about 1 mm, not greater than about 0.95 mm, not greater than about 0.9 mm, not greater than about 0.85 mm, not greater than about 0.8 mm, not greater than about 0.75 mm, not greater than about 0.7 mm, not greater than about 0.65 mm, not greater than about 0.6 mm, not greater than about 0.55 mm, not greater than about 0.5 mm, not greater than about 0.4 mm, or not greater than about 0.3 mm.

Item 75. The method according to any one of items 50 through 74, wherein the at least one ply of fluoropolymer fabric has a thickness of at least about 0.04 mm, such as of at least about 0.08 mm, at least about 0.12 mm, at least about 0.16 mm, at least about 0.20 mm, at least about 0.24 mm, at least about 0.28 mm, at least about 0.32 mm, or at least about 0.36 mm.

Item 76. The method according to any one of items 50 through 75, wherein the at least one ply of fluoropolymer fabric has a thickness of not greater than about 1 mm, such as not greater than about 0.8 mm, not greater than about 0.6 mm, not greater than about 0.55 mm, not greater than about 0.5 mm, not greater than about 0.45 mm, not greater than about 0.4 mm, not greater than about 0.38 mm, not greater than about 0.34 mm, not greater than about 0.3 mm, not greater than about 0.26 mm, or not greater than about 0.22 mm.

Item 77. The method according to any one of items 50 through 76, further comprising chemically etching the fluoropolymer fabric prior the overlying of the second layer.

Item 78. The method according to item 77, wherein the chemically etching includes soaking the fluoropolymer fabric in ammonia.

EXAMPLES

General

In the following examples, a fluoropolymer layer was overlaid with a fluoropolymer fabric. A second fluoropolymer layer was overlaid onto the polymer fabric to form a fluoropolymer/fluoropolymer fabric/fluoropolymer assembly. Fluoropolymer layers were selected from skived PTFE, skived mPTFE. The fluoropolymer fabric was selected from two types of PTFE fabric, namely Gore-Rastex® CCC 216 (37/37 threads/cm; twill 3/1) or Teflon-Gewebe TC 117 (24/22 threads/cm). Optionally, an adhesive was placed between one fluoropolymer layer and the fluoropolymer fabric. In the examples, PFA was selected as an adhesive. The assemblies were laminated at pressures between 0.3 MPa to 0.5 MPa and a temperature between 400° C. and 410° C., in most experiments 405° C., for 100 to 200 seconds, in most experiments 150 seconds. Afterwards, the laminates were quickly cooled with water to 40° C. Cooling time took up to 500 seconds. In all experiments, the fluoropolymer fabric is an internal layer of the laminate. The laminate cross-section can be symmetric with the fluoropolymer fabric being the central layer. Alternatively, the laminate can be asymmetric, where the numbers of layers overlying one major surface of the fabric is different from the numbers of layers overlying a second major surface.

An mPTFE skived layer having a thickness of 0.42 mm was overlaid with a PTFE polymer fabric (Gore-Rastex® CCC 216; 37/37 threads/cm; twill 3/1) having a thickness of 0.25 mm. A second mPTFE skived layer with a thickness of 0.42 mm was overlaid onto the polymer fabric to form an mPTFE/PTFE fabric/mPTFE assembly. The assembly was laminated according to procedure described above.

A PTFE skived layer having a thickness of 0.5 mm was overlaid with a PTFE polymer fabric (Gore-Rastex® CCC 216; 37/37 threads/cm; twill 3/1) having a thickness of 0.25 mm. A second PTFE skived layer with a thickness of 0.5 mm was overlaid onto the polymer fabric to form a PTFE/PTFE fabric/PTFE assembly. The assembly was laminated according to procedure described above.

An mPTFE skived layer having a thickness of 0.42 mm was overlaid with about 0.025 mm of PFA film. The PFA film was overlaid with a PTFE polymer fabric (Gore-Rastex® CCC 216; 37/37 threads/cm; twill 3/1) having a thickness of 0.25 mm. The PTFE fabric was overlaid with another 0.025 mm of PFA film. A second mPTFE skived layer with a thickness of 0.42 mm was overlaid onto the PFA film to form a mPTFE/PFA/PTFE fabric/PFA/mPTFE assembly. The assembly was laminated according to procedure described above.

A PTFE skived layer having a thickness of 0.5 mm was overlaid with about 0.025 mm of PFA film. The PFA film was overlaid with a PTFE polymer fabric (Gore-Rastex® CCC 216; 37/37 threads/cm; twill 3/1) having a thickness of 0.25 mm. The PTFE fabric was overlaid with another 0.025 mm of PFA film. A second PTFE skived layer with a thickness of 0.5 mm was overlaid onto the PFA film to form a PTFE/PFA/PTFE fabric/PFA/PTFE assembly. The assembly was laminated according to procedure described above.

A PTFE skived layer having a thickness of 0.4 mm was overlaid with about 0.050 mm of PFA film. The PFA film was overlaid with a PTFE polymer fabric (Gore-Rastex® CCC 216; 37/37 threads/cm; twill 3/1) having a thickness of 0.25 mm. The PTFE fabric was overlaid with another 0.050 mm of PFA film. A second PTFE skived layer with a thickness of 0.4 mm was overlaid onto the PFA film to form a PTFE/PFA/PTFE fabric/PFA/PTFE assembly. The assembly was laminated according to procedure described above.

An mPTFE skived layer having a thickness of 0.42 mm was overlaid with about 0.025 mm of PFA film. The PFA film was overlaid with a PTFE polymer fabric (Gore-Rastex® CCC 216; 37/37 threads/cm; twill 3/1) having a thickness of 0.25 mm. A second mPTFE skived layer with a thickness of 0.42 mm was placed onto the fabric to form a mPTFE/PFA/PTFE fabric/mPTFE assembly. The assembly was laminated according to procedure described above.

A PTFE skived layer having a thickness of 0.5 mm was overlaid with about 0.025 mm of PFA film. The PFA film was overlaid with a PTFE polymer fabric (Gore-Rastex® CCC 216; 37/37 threads/cm; twill 3/1) having a thickness of 0.25 mm. A second PTFE skived layer with a thickness of 0.5 mm was placed onto the fabric to form a PTFE/PFA/PTFE fabric/PTFE assembly. The assembly was laminated according to procedure described above.

An mPTFE skived layer having a thickness of 0.42 mm was overlaid with a PTFE skived layer having a thickness of 0.1 mm. A PTFE polymer fabric (Gore-Rastex® CCC 216; 37/37 threads/cm; twill 3/1) having a thickness of 0.25 mm was laid over the PTFE skived layer. A second PTFE skived layer having a thickness of 0.1 mm was laid onto the polymer fabric and a second mPTFE skived layer with a thickness of 0.42 mm was laid over the second PTFE skived layer to form a mPTFE/PTFE/PTFE fabric/PTFE/mPTFE assembly. The assembly was laminated according to procedure described above.

An mPTFE skived layer having a thickness of 0.42 mm was overlaid with a PTFE skived layer having a thickness of 0.1 mm. The PTFE skived layer was overlaid with about 0.025 mm of PFA film. A PTFE polymer fabric (Gore-Rastex® CCC 216; 37/37 threads/cm; twill 3/1) having a thickness of 0.25 mm was laid over the PFA film. A second PFA film having a thickness of about 0.025 mm was layered over the polymer fabric. A second PTFE skived layer having a thickness of 0.1 mm was laid onto the PFA film and a second mPTFE skived layer with a thickness of 0.42 mm was laid over the second PTFE skived layer to form a mPTFE/PTFE/PFA/PTFE fabric/PFA/PTFE/mPTFE assembly. The assembly was laminated according to procedure described above.

An mPTFE skived layer having a thickness of 0.42 mm was overlaid with a PTFE polymer fabric (Teflon-Gewebe TC 117; 24/22 threads/cm) having a thickness of 0.27 mm. A second mPTFE skived layer with a thickness of 0.42 mm was overlaid onto the polymer fabric to form an mPTFE/PTFE fabric/mPTFE assembly. The assembly was laminated according to procedure described above.

A PTFE skived layer having a thickness of 0.5 mm was overlaid with about 0.025 mm of PFA film. The PFA film was overlaid with an PTFE polymer fabric (Teflon-Gewebe TC 117; 24/22 threads/cm) having a thickness of 0.25 mm. The PTFE fabric was overlaid with another 0.025 mm of PFA film. A second PTFE skived layer with a thickness of 0.5 mm was overlaid onto the PFA film to form a PTFE/PFA/PTFE fabric/PFA/PTFE assembly. The assembly was laminated according to procedure described above.

High Frequency Flexlife Test

A sample was prepared according to Example 3. From the sample, a disc having a diameter of 125 mm was cut out and a concentric hole having a diameter of 18 mm was cut into the disc to form Sample 1. The flexlife test sample 1 was placed in the test set up as described inFIG. 4D. The test sample was cycled through to 15 mm amplitudes and the cycles were counted. A Comparison Sample 1 made of quenched mPTFE was prepared and subjected to the same test. Table 1 shows the results of the test.

Tensile Strength Testing

Stress-strain testing was conducted of samples having a sample width of 1 inch with a clamp distance 50 mm and a speed 50 mm/min. Sample 2 was prepared according to Example 3. Comparison Sample 2 comprised of quenched mPTFE, Comparison Samples 3 and 4 comprised of PTFE and mPTFE, respectively; and Comparison Sample 5 comprises of a laminate including mPTFE/PFA/mPTFE.FIG. 6depicts the stress-strain curves of the samples.

Deformation Under Load

A sample of the laminate having a thickness of about 1 mm was loaded under a compression die (area 3 cm2) for 24 hours at a load of 25 MPa. The thickness was measured 15 minutes after release of the load. The difference of original thickness and thickness after load is the Deformation under Load following ASTM D621. Results for some Examples are summarized in Table 2.

Water Vapor Transmission Rate measurements of sample sheets having a thickness of about 1 mm were measured at 38° C. using a MOCON Aquatran Water Vapor Analyzer with test conditions at a humidity of 100% and a carrier gas flow rate of 20 sccm. The test area is 50 cm2and the exam cycle takes 480 minutes. Results for some Examples are summarized in Table 2.

Oxygen Transmission Rate measurements of sample sheets having a thickness of about 1 mm were measured at 25° C. using a MOCON OxTran 2/21 oxygen permeation analyzer with test conditions at a humidity of 0% and 100% oxygen carrier gas at a flow rate of 20 sccm. The test area is 50 cm2and the exam cycle takes 60 minutes. Results for some Examples are summarized in Table 2.

As can be seen from Table 2, the Deformation under Load of the Examples improves over the Deformation under Load of PTFE and mPTFE while maintaining water vapor and oxygen permeabilities in a range that suffices certain standards for an application, such as diaphragms for diaphragm pumps. In one embodiment, a Deformation under Load is not greater than 150 μm and the water vapor permeability is not greater than 0.085 g*mm/m2*d. In one embodiment, a Deformation under Load is not greater than 150 μm and the oxygen vapor permeability is not greater than cc(O2)*mm/m2*d*atm.