Abstract: Emulsifier free fluoropolymer manufacturing method in which (a) a chain transfer agent, or a mixture of chain transfer agents are used wherein the chain transfer agents do not yield more than 0.4 weight % relative to the monomer feed of water soluble fluorinated compounds, or (b) a chain transfer agent or a mixture of chain transfer agents selected from alkanes, dialkyl ethers, hydrofluoroethers and/or hydrofluorocarbons.

Abstract: The present invention provides a method of bonding a fluoroelastomer layer to a silicone rubber layer, the method comprising the steps of: (i) providing a layer of a curable fluoropolymer composition comprising (a) a fluoropolymer capable of being dehydrofluorinated thereby forming reactive sites, (b) a dehydrofluorinating agent, (c) a curing agent capable of cross-linking said fluoropolymer through reaction with said reactive sites and (d) a peroxide; (ii) contacting said layer of said curable fluoropolymer composition with a curable silicone layer comprising a silicone resin and a peroxide; curing said layers while being in contact with each other at conditions sufficient to (a) cause dehydrofluorination of said fluoropolymer and cross-linking of said fluoropolymer layer and (b) cross-linking of said silicone resin, said curing being carried out in the presence of a bonding promoter selected from the group consisting of an organic compound having one or more nucleophilic groups capable of reacting with

Abstract: Provided is a process for making a copolymer of fluorinated olefin and hydrocarbon olefin selected from ethylene, propylene and mixtures thereof, the process comprising a substantially emulsifier free aqueous emulsion polymerization of said fluorinated olefin and said hydrocarbon olefin, optionally in the presence of fluoropolymer particles and/or fluorinated liquid in a form suitable to improve the copolymerization of fluorinated olefin and hydrocarbon olefin.

Abstract: A fluoropolymer having a melting point of at least 160° C. is provided wherein the fluoropolymer is derived from tetrafluoroethylene as the major component, one or more perfluoro vinyl ethers as the minor component, the perfluoro vinyl ether having the formula CF2?CFO(CF2)nORf wherein n is from 2 to 6 and Rf is a perfluoroalkyl group having 1 to 6 carbon atoms, and optionally a perfluoro alkyl vinyl ether having from 1 to 5 carbon atoms in the alkyl radical.

Abstract: The use of perfluorinated polymers and/or fluorinated ionomers as surfactant emulsifiers in emulsion polymerization of fluorinated monomers.

Abstract: The present invention provides a method of making an aqueous dispersion of non-melt processible polytetrafluoroethylene, the method comprising: (a) an aqueous emulsion polymerization of an amount of tetrafluoroethylene to produce a final amount of polytetrafluoroethylene solids and optionally up to 1% by weight based on the amount of tetrafluoroethylene of a perfluorinated comonomer, wherein said aqueous emulsion polymerization is initiated with a free radical initiator and the polymerization is carried out in the presence of a fluorinated surfactant, and wherein before completing the feeding of said amount of tetrafluoroethylene but after feeding at least 80% by weight of said amount of tetrafluoroethylene, free radicals capable of introducing ionic end groups or precursors thereof in the polytetrafluoroethylene polymer are caused to be formed at a rate that without counter measures would cause an increase in the polymerization rate of at least 20%; (b) reducing the amount of fluorinated surfactant in the th

Abstract: The present invention relates to imaging apparatus and method for detecting optical properties of transparent media. The present invention superimposes, either optically or electronically, at least two images of the transparent media in order to obtain the optical properties. By superimposing the images, the present invention is capable of detecting various optical properties of the transparent medium in a single configuration.

Abstract: The present invention provides a method of removing a fluorinated surfactant from waste water comprising fluoropolymer particles. The method comprises (i) adding a non-fluorinated surfactant to the waste water (ii) contacting the thus obtained waste water with adsorbent particles to adsorb at least a portion of the fluorinated surfactant to the adsorbent particles and (iii) separating the waste water and the adsorbent particles.

Abstract: A web positioning device includes one or more ports positioned in or adjacent at least one platen of a gap drying system, wherein upon generation of a vacuum force through each port, movement of a web of material conveyed through the gap drying system is arrested by drawing a first face of the web of material into contact with a portion of the web positioning device immediately surrounding each port. A method for controlling movement of a portion of a web of material using the web positioning device is also presented.

Abstract: A method and apparatus for producing microporous films. The method utilizes a casting surface and a condensing surface. The condensing surface is spaced from the casting surface to form a gap. The distance between the surfaces forming the gap is relatively small and is preferably less than 3 cm. A material, capable of forming microporous films through thermally induced phase separation processes, is cast onto the casting surface, preferably through conventional extrusion practices. The material contains at least one evaporative component that generally flashes off upon formation of the microporous material and condenses on the condensing surface.

Abstract: A liquid coating is formed on a substrate by electrostatically spraying drops of the liquid onto a liquid-wetted conductive transfer surface and transferring a portion of the thus-applied liquid from the transfer surface to the substrate. Optionally, one or more nip rolls force the substrate against the transfer surface, thereby decreasing the time required for the drops to spread and coalesce into the coating. Preferably, the coating is passed through an improvement station comprising two or more pick-and-place devices that improve the uniformity of the coating. The coating can be transferred from the conductive transfer surface to a second transfer surface and thence to the substrate. Insulative substrates such as plastic films can be coated without requiring substrate pre-charging or post-coating neutralization. Porous substrates such as woven and nonwoven webs can be coated without substantial penetration of the coating into or through the substrate pores.

Abstract: A spatial notch filter is described that adapts in accordance with changes to an angular velocity of a rotating component within a manufacturing system. In a manufacturing system, noise may appear in feedback signals due to spatially distributed physical features in the system, such as imperfections in the components or sensors. This noise may be concentrated in a frequency band that changes as the angular velocity of rotating system components changes. The invention provides techniques for filtering this noise with one or more notch filters, and for adapting the center frequency of the notch filter as a function of angular velocity. The center frequency of the notch filter tracks the noise when the noise frequency changes.

Abstract: An imaging device for sequentially imaging a portion of a continuously moving web to provide a digital data stream which is then analyzed by a single computer without the used of dedicated signal processing hardware. Techniques for operating on the data stream from an imaging device are disclosed, particularly including operations based on blob information stored in terms of starting position and segment run lengths in a crossweb direction. These allow definitions of blobs to be accumulated in a line-by-line fashion, and allow classes of defects commonly found in continuous web manufacturing to be identified with far less computing power than was previously required. In particular, in the challenging application of inspecting flexible circuits, data rates in excess of 10 mega-pixels/second are achieved and successfully processed.

Abstract: A curable fluoroelastomer composition for preparing a perfluoroelastomer. The composition includes; (1) a perfluoropolymer having one or more cure-sites selected from a halogen capable of participating in peroxide cure reaction and/or nitrile groups; (2) an organic peroxide and/or a compound capable of effecting curing of the perfluoropolymer through said nitrile groups; and (3) optionally a polyunsaturated coagent. The perfluoropolymer in the composition is essentially free of ionic end groups and the total amount of metal cations in the composition is not more than 10 ?g/g perfluoropolymer. The perfluoroelastomers may be obtained from curing the composition in a sufficiently low amount of metal cations so as to make the fluoroelastomer suitable for use in the semi-conductor industry.

Abstract: High purity fluoropolymers are obtained by the emulsion polymerization process, removing essentially all ions and coagulating the polymer essentially without adding ions. These polymers are useful in the field of electronic devices.

Abstract: The present invention provides a fluoropolymer that is melt-processible and thermoplastic and that has a melting point between 100° C. and 320° C. The fluoropolymer is derived from (a) one or more gaseous fluorinated monomers, (b) one or more modifiers selected from (i) olefins having a bromine or iodine atom bonded to a carbon of the double bond of the olefin, (ii) olefins corresponding to formula (I): Xa2C?CXa—Rf—Br??(I) wherein each Xa independently represents hydrogen, fluorine, bromine, chlorine or iodine, Rf is a perfluoroalkylene group, typically having 1 to 8 carbon atoms, a perfluorooxyalkylene group or a perfluoropolyether group and (iii) mixtures thereof; and (c) optionally one or more comonomers selected from non-gaseous fluorinated monomers and non-fluorinated monomers. The resulting fluoropolymer has long chain branches. The invention further provides a method for making these polymers.

Abstract: A process for manufacturing fluoroolefins comprising perfluorinating a starting material comprising at least one carbon-bonded hydrogen by electrochemical fluorination, dissociating this separated effluent in a pyrolysis, quenching and separating the effluent to yield tetrafluoroethylene and/or hexafluoropropylene.

Abstract: A composition and method for making a fluoroelastomer is disclosed. The composition comprises a fluoroelastomer containing chlorine and an organic compound containing at least an hydride function. The hydride function has the formula MH where M is Si, Ge, Sn or Pb.

Abstract: Continuous void-free uniform coatings are formed on substrates of limited length. The substrate is wrapped around a mounting roll and nipped between the mounting roll and one or more pick-and-place contacting rolls. Coating liquid is applied to the substrate or to a pick-and-place roll, preferably as a pattern of stripes. The mounting roll, substrate and pick-and-place rolls are caused to rotate for a plurality of revolutions. Wetted surface portions of the pick-and-place roll repeatedly contact the substrate, the coating is repeatedly picked up from and placed onto the substrate, and the coating becomes more uniform. Extremely uniform and extremely thin coatings can be quickly and easily obtained, with easy adjustment of the final coating thickness.

Abstract: A fluoropolymer suitable for the preparation of a fluoroelastomer. The fluoropolymer generally includes repeating units derived from the monomers tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, chlorotrifluoroethylene and optionally one or more repeating units from fluorinated monomers other than tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride and chlorotrifluoroethylene.