Abstract: A heat exchanger comprising plates of thermoplastic tubes arranged in a way which minimizes the thermal resistance at the outer surface of the tubes preferably to not more than 5 times the resistance to heat transfer at the inside of the tubes. The tubes are arranged in the tube plates in groups that can be flat or slightly wavy, such as undulating in a periodic manner, or offset with open spaces facing groups of tubes in alternating rows. This is done in a way that maximizes turbulence outside the tubes and minimizes vortices which can trap coolant in the interstices between tubes.

Abstract: An apparatus and method for making thermotropic liquid crystalline polymer films with improved transverse direction properties comprises two preferably embossed rollers which oscillate oppositely with respect to each along their respective rotational axes. Film made by passing a liquid crystalline polymer between such rolls has improved transverse direction properties. Such films are useful in multilayer containers and for circuit boards.

Abstract: A method for bonding a tube into a device each of which is formed from a thermoplastic polymer. The device has first and second solid members in spaced apart relationship to form a hollow cavity therebetween. At least one linear channel extends through each of said solid members in an aligned relationship, such that a tube may be passed through in sliding engagement, including through the hollow cavity. Molten polymeric composition is injected into the hollow cavity at a temperature lower than the melting point of the thermoplastic polymer so as to bond to the thermoplastic polymer and to the tube to form fluid-tight bonds therewith.

Abstract: A process and the product thereof, wherein thermoplastic tubing for use in a heat exchanger is extruded with a multifilament yarn inside to act as a turbulator. The extrusion is started with a small rod or a lead-in wire pushing the end of the yarn through the die into the tubing to a place where it adheres to the inner wall of the tubing as it is cooling, then the yarn is pulled into the tubing as it is extruded. The part of the tubing with the lead-in wire is cut off, leaving tubing with efficient turbulation.

Abstract: A method for making thermotropic liquid crystalline polymer films with improved transverse direction properties comprises two preferably embossed rollers which oscillate oppositely with respect to each along their respective rotational axes. Film made by passing a liquid crystalline polymer between such rolls has improved transverse direction properties. Such films are useful in multilayer containers and for circuit boards.

Abstract: Plastic tube-type heat exchanger structures are made with partially crystallized partially aromatic polyamides of high glass transition temperature. The structures are then annealed to further crystallize the polyamides, causing shrinkage and building up residual tensile stresses. These stresses counteract the swelling caused by water absorption and temperature rise during use of the heat exchanger and keep the structures dimensionally stable.

Abstract: A method for bonding tubes into an article, each of which is formed from a thermoplastic polymer, especially an aliphatic polyamide. The article has a plurality of channels into which tubes are placed in sliding engagement. The article is moved towards a heating block having pins, such that a pin is inserted into each tube. The article and heating block are brought into a juxtaposed position such that the polymer of the tubes melts and forms a coating on said article. The method is particularly useful in the formation of tubed heat exchangers, for example with 100-300 or more tubes, in one cycle.

Abstract: A process for coating a metal surface with a fluororesin, using a primer comprising fluororesin, aluminum flake and more polyether sulfone than polyamideimides.

Abstract: Mixtures of PVF, bis-phenol-epichlorohydrin copolymer, hindered phenol, phosphite and mercaptoarylimidazole permit formation of thick PVF articles.

Abstract: A coating composition of a perfluorocarbon resin and an electroconductive double shell pigment comprising inner shells of amorphous silica or a silica-containing material and outer shells of antimony-containing tin oxide is useful on a copy roller or belt.

Abstract: Laminar structures of PVF and substantially amorphous resin such as PEKK, backfilled with injection molding resin, exhibit an excellent combination of physical and aesthetic properties.

Abstract: Metal cookware coated with a multilayer system including a primer with more Al.sub.2 O.sub.3 and a blend of PTFE and PFA or FEP, a midcoat with less Al.sub.2 O.sub.3, and a topcoat with PTFE, and processes for preparing such coating systems.

Abstract: A panel is disclosed that is formed from a planar, substantially inflexible cellulosic substrate having a rough or uneven surface, at least one layer of paper or veneer and a layer of an electrically conductive wire mesh or metal foil interposed between the substrate and the layer of paper or veneer. The substrate and the layers are bonded together with a layer of a polyolefin that has been grafted with an ethylenically unsaturated carboxylic acid or anhydride. The polyolefin is a homopolymer of ethylene or copolymer of ethylene and a higher hydrocarbon alpha-olefin. Processes for the manufacture of the panel are also disclosed. The panel may be used in the construction industry, especially as electrical shielding or for the removal of stray electrical currents from electrical or other equipment.

Abstract: Improved non-stick coating systems can be applied to untreated smooth substrate with a primer of polytetrafluoroethylene and a perfluorinated copolymer of tetrafluoroethylene and perfluoro vinyl ether to give a concentration gradient.

Abstract: Improved non-stick coating systems can be applied to untreated smooth substrate with a primer of polytetrafluoroethylene and a perfluorinated copolymer of tetrafluoroethylene and hexafluoropropylene to give a concentration gradient.

Abstract: Improved non-stick coating systems can be applied to untreated smooth substrate with a primer of a first polytetrafluoroethylene having a melt viscosity over 10.sup.10 poises plus a second polytetrafluoroethylene having a melt viscosity in the range of 10.sup.4 to 10.sup.8 poises to give a concentration gradient.

Abstract: A panel, especially a construction panel, formed from a substantially inflexible cellulosic substrate having a rough or uneven surface is disclosed. The substrate is coated with a layer of a grafted polyolefin and a layer of kraft paper or veneer. The polyolefin is a homopolymer of ethylene or copolymer of ethylene and at least one C.sub.4 -C.sub.10 hydrocarbon alpha-olefin having a melt index of less than 20 dg/min that has been grafted with at least 9 ppm of an ethylenically unsaturated carboxylic acid or anhydride. One-step and multi-step processes for the manufacture of the panels are disclosed. The panels may be painted or coated by other means, and are useful in the construction industry, especially for interior surfaces of buildings. The panels may be formed from cellulosic substrates that may not otherwise be useful for the end-uses of the panels.

Abstract: Improved non-stick coating systems can be applied to untreated smooth substrate with a primer of a first polytetrafluoroethylene having a melt viscosity over 10.sup.10 poises plus a second polytetrafluoroethylene having a melt viscosity in the range of 10.sup.3 to 10.sup.8 poises to give a concentration gradient.

Abstract: Improved non-stick coating systems can be applied to untreated smooth substrate with a primer of polytetrafluoroethylene of two types, having higher and lower melt viscosities, to give a concentration gradient.