Abstract: A method for preparing a gas sensor includes forming a mixture containing an aqueous buffer solution including a dissolved dye, a polymeric precursor of a cross-linked polymeric material, and a cross-linking agent and reacting the polymeric precursor and the cross-linking agent in the mixture to form a gas sensor including micro-compartments of the aqueous buffer solution dispersed in the cross-linked polymeric material.

Abstract: Water absorbent, water insoluble, cross linked polymer fibre or film can be made by dry extrusion of a solution of a substantially linear polymer formed from a water soluble blend of monoethylenically unsaturated monomers comprising a plasticizing monomer, evaporating the solvent and forming polymeric fibre or film plasticized by an external plasticizer, stretching the fibre or film while the external plasticizer remains in the fibre or film, and then cross linking the polymer.

Abstract: A method for the grafting of at least two different monomers onto molten hydrocarbon polymer, in which the monomers are capable of undergoing thermally induced copolymerization, is disclosed. The method involves contacting one of said monomers with the other of said monomers in the presence of molten polymer and under admixing conditions such that the monomers and polymer are rapidly admixed. In preferred embodiments, the process is operated in the absence of initiator for the grafting reaction and in the substantial absence of antioxidant in the polymer. Preferably, one of the grafting monomers is selected from the group consisting of styrene, 2-methyl styrene, 4-methyl styrene, alpha-methyl styrene, beta-methyl styrene, 4-vinyl anisole, stilbene and indene, and mixtures thereof, and the other of the grafting monomers is selected from the group consisting of maleic anhydride, itaconic anhdride, citraconic anhydride, maleimide and N-phenylmaleimide, and mixtures thereof.

Abstract: Method of and apparatus for making a shaped crosslinked extruded polymeric product by extruding compacted, melted polymer, e.g., polyethylene, into a mixer formed on or fitted to the discharge end of an extruder, injecting proportionate amounts of a mixture of compounding ingredients including olefinically unsaturated hydrolyzable silane, free-radical generator and, preferably, a silanol condensation catalyst into the compacted, melted polymer. The polymer and compounding ingredients are blended in the mixer until the silane is grafted to said polymer, and the resulting grafted polymer mixed with the silanol condensation catalyst is extruded thruugh a die to form the product of the required final shape. The resulting product is subjected to the action of H.sub.2 O until the grafted polymer is crosslinked.

Abstract: The invention relates to a copolyamide for application in films with improved barrier properties. The copolyamide containing tetramethyleneadipamide and tetramethylene-isophtalamide in a ratio between 9:1 and 1:9 and a relative viscosity of at least 2.0, and a process for the production of the copolyamide. Preferably the copolyamide contains a small amount of a compound that induces the formation of networks between the polyamide chains.

Abstract: The present invention provides a fiberglass composite which possesses outstanding armor properties. This ballistic resistant composite material employs a high strength magnesia aluminosilicate glass fabric and a prescribed phenol formaldehyde condensation product as the matrix resin. The composite is produced from a prepreg by molding under controlled conditions and the prepreg material is formed with a controlled heating cycle.

Abstract: Articles from filaments of thermotropic liquid crystal polymers are formed by pultrusion without use of extraneous binder, wherein the filaments formed in a bundle are essentially parallel to permit the greatest surface contact between adjacent filaments.

Abstract: In order to apply pressure and heat to a sheet material as required in the manufacture of a laminated sheet material, the sheet material is conveyed in through an entrance opening of a pressure vessel, along through an interior space thereof, and out through an exit opening thereof, substantially filled with a pressure medium which is maintained at a temperature above its melting point in the interior space of the pressure vessel, but is maintained at a temperature below its melting point in the entrance and exit openings of the pressure vessel, so as to accomplish sealing in such zones by solidification of the pressure medium, whereby enabling continuously to treat a long sheet material under constant application of pressure and heat over a relatively long time period in which respective portions of the sheet material traverse the pressure vessel.

Abstract: In the production of a thread-reinforced hose from polymeric material, the still formable material, a mold core, and the reinforcing thread or threads are fed continuously into a shear head and united. This takes place while utilizing the rotary movement of the shear mandrel contained in the shear head such that each thread used is passed axially through the shear mandrel and is wound around the mold core after emerging from an opening at the end. The embedding of the thread into the material and its winding about the mold core take place simultaneously. After the finished hose emerges from the nozzle of the shear head the material solidifies and the mold core is removed.

Abstract: In a method of manufacturing an extruded product of a fire-retardant crosslinked polyolefin composition, including the steps of mixing 10 to 200 parts by weight of at least one material selected from the group consisting of an inorganic fire retardant, an organic fire retardant, and an inorganic filler to 100 parts by weight of polyolefin, adding predetermined amounts of an unsaturated alkoxysilane and a radical polymerization initiator to the resultant mixture to cause silicone grafting, and bringing a reacted mixture into contact with water in the presence of a silanol condensation catalyst, a cooling zone is formed between an extruder and a crosshead to set a uniform temperature of a molten resin composition and to cool the composition temperature to a desired temperature.

Abstract: The invention relates to a process for the manufacture of hollow articles, in which a photocurable resin is introduced into a mold which transmits light, the mold is irradiated until the resin has polymerized to the desired depth, the remaining resin is allowed to run out and the partially polymerized layer is then fully cured. The hollow articles may be used in particular as expendable cores in the manufacture of plastics containers by the winding process.

Abstract: A process for preparing collagen tubes includes extruding an aqueous gel containing about 1.5% native collagen through a cylindrical spinneret equipped with a central concentric tube designed to receive a part of a coagulation bath, followed by coagulation of the internal and external walls of the tube, leaving the spinneret in a coagulation bath constituted by about 70% acetone and 30% ammonia, followed by drying. Following drying, the collagen tube may be subjected to reticulation by dehydration carried out at about 80.degree. C. under a pressure of about 0.1 mm of Hg (vacuum) for about 24 hours. The reticulated collagen tube may eventually be subjected to a treatment which permits the introduction of azide groups onto the molecule without requiring that the collagen be coupled to any external molecule.

Abstract: An analytical technique for controlling the curing process of fiber-reinforced composite materials that are formed using thermosetting resins. The technique is the percent gel method and involves development of a time-to-gel equation as a function of temperature. From this equation a rate-of-gel equation is then determined, and a percent gel is calculated which is the product of rate-of-gel times time. Percent gel accounting is used to control the proper pressure application point in an autoclave cure process to achieve desired properties in a production composite part.

Abstract: Method and apparatus are disclosed for inducing dimensional stability in cured composite structures using acoustic emission analysis to identify the appropriate level and extent of coincident thermal conditioning. Temperature of the composite structure is lowered at a bounded rate to a minimum temperature typical of the intended operating environment. Passive stress wave acoustic emissions of the composite are analyzed to generate a signature of stress relaxation events over time. When the rate of stress relaxation events decreases below a predetermined percentage of the maximum rate, and remains below that level for a period of time sufficient to predict operational stability, thermal conditioning is terminated.

Abstract: Acrylic resin sheets having an excellent heat moldability and solvent resistance are prepared by:(1) preparing a syrup of methyl methacrylate or a monomer mixture comprising at least 60 weight % of methyl methacrylate and not more than 40 weight % of an acrylic acid ester by partially polymerizing the monomer or monomers in the presence of 0.01 to 2.0 weight %, based on the monomer or monomers, of a chain transfer agent, as well as a polymerization initiator; and(2) incorporating the thus-prepared syrup with 0.02 to 1.0 weight %, based on the syrup, of a cross-linking agent, and subjecting the resulting mixture of cast polymerization under such conditions that if the crosslinking agent is not present, the intrinsic viscosity of the completely polymerized sheet is in the range of 0.05 to 0.12 l/g.

Abstract: EPDM roof sheeting is prepared by ionizing radiation curing of a sheet calendered from 100 parts uncured EPDM elastomer, 40-150 parts carbon black, 30-100 parts process oil and an ionizing radiation crosslinking promoter. Preferably, the promoter is dicumyl peroxide, .alpha.,.alpha.'bis (t-butylperoxy) diisopropylbenzene, liquid high vinyl 1,2-polybutadiene resin or ethylene glycol dimethacrylate and an average dose of ionizing radiation of about 15 to about 35 megarads is used to produce sheeting meeting RMA (Rubber Manufacturers Association) Roofing Council tensile strength and elongation requirements for non-reinforced black EPDM rubber sheeting used in roofing applications.

Abstract: A part made of a resin-containing composite material, also having at least one insert made of a different material, is hardened by electron beam radiation in zones having a surface mass at the most equal to 4 g/cm.sup.2 and by X-radiation in zones having a surface mass above 4 g/cm.sup.2. The X-radiation, in doses up to 10 Mrad, is produced by action of the electron beam on a target placed between the part and the electron beam.

Abstract: Extruded articles such as filaments and films are fabricated by blending the components of a curable liquid silicone rubber composition at temperatures of from -60.degree. to +5.degree. C. and then extruding the composition into water maintained at a temperature of at least +25.degree. C. to cure said composition. The water bath preferably contains a surfactant to facilitate processing of the extruded article. The present method provides uniformly cured articles that are almost bubble-free and have low shrinkage ratios.

Abstract: For the continuous pressing of sheet material in a reaction zone between two endless, heated press belts of a double band press at increased process temperatures, the capability for operating at process temperatures which are higher than critical, permissible operating temperatures of the double band press is achieved by heating the press belts in such a way that they have the highest temperature at their outsides facing the sheet material with heat flow through the press belt being effected from the hot outer side to the opposite inner side of the press belt. The heat flow direction in the reaction zone which otherwise leads from a pressure plate to the press belt outer side is thus reversed and, heating members are arranged in the vicinity of the press belt on the outer side thereof shortly before the reaction zone.

Abstract: A process for producing a microcellular cast resin product, by casting a water-in-oil emulsion of polymerizable components which will gel and partially polymerize by an exothermic reaction, and placing the partially polymerized casting in a fluid medium maintained at a temperature and pressure such that evaporation of water and monomers is inhibited but sufficient to promote complete polymerization while retaining dispersed water within a microcellular structure. The water content of the emulsion can range from about 1% to about 90% by weight, and the microcellular structure may be either the open cell or the closed cell type.

Abstract: A method of manufacturing an electro-conductive elastomeric material comprises mixing together silicone polymer gum, graphitic carbon particles, curing and cross-linking agents in the presence of an oil having a carbon chain length of at least 16 and having a high degree of mesogenicity, together with a volatile additive in which the oil and gum dissolve and/or disperse miscibly. The volatile additive may be Toluene, Chloroform, Tetrahydrofuran, n-Hexane or SBP3.

Abstract: There is provided a process for the manufacture of molded bodies of polyurethane integral foam, such as body parts for the automotive industry, in which the first step of the process, the polyol component is prepared and in the second step of the process the polyol component is reacted with the isocyanate component according to the reaction injection molding method. In the mold and/or after removal from the mold, the molded bodies are subjected to thermal aftertreatment within the framework of a third process step for thirty minutes to three hours at 120.degree. to 180.degree. C. Also, the polyol component may contain nucleating agents, so that the nucleated molded bodies may or may not need be thermally aftertreated.

Abstract: A method of continuous molding a rod-like product includes forming an uncured rod-like molding by passing reinforcing fibers impregnated with uncured thermosetting resin through a squeezing die having a predetermined shape. Molten thermoplastic fluororesin is extruded in a ring shape to enclose the rod-like molding. A sheathing layer of the thermoplastic resin is formed by causing the thermoplastic resin to come into contact with the outer periphery of the uncured rod-like molding and by cooling and solidifying the thermoplastic resin. The uncured rod-like molding and the sheathing layer are introduced into a heated tank thereby hardening the thermosetting resin. The sheathing layer is stripped from the molding to form a rod-like product having a surface of fiber reinforced thermosetting resin.

Abstract: The invention relates to highly filterable polyvinyl polypyrrolidone particles and to the process for improving filterability of standard polyvinyl polypyrrolidone granules, wet cakes and slurries which comprises heating granular polyvinyl polypyrrolidone, containing a minor amount of non-crosslinked and/or unsaturated sites while maintaining between 1 wt. % and 20 wt. % moisture at a temperature of between about 50.degree. C. and about 250.degree. C. under a pressure of from about 5 psig. to about 200 psig. and collecting product having an average particle size distribution between about 40 and 400 mesh, a non-volatile water solubles (NVWS) content less than 2% and a filter flow rate greater than 95.

Abstract: Plastic resinous tubes, particularly for medical use is improved in blood compatibility when brought into contact with blood, by applying a low-temperature plasma treatment to inner surfaces of the tubes, which plasma is produced through electrodeless electric discharges by the effect of microwave to make it possible to prevent the tube from being heated in such a treatment. The inner surfaces of the tubes thus activated may be further subjected to an inner surface graft copolymerization treatment to enhance blood compatibility.

Abstract: A method of producing a plastic leaf spring for motor vehicles comprising forming a plurality of cured duromeric plastic strips reinforced with high strength fibers aligned substantially in the direction of the maximum elongation or compression of the fibers occurring under spring load at least in essential resilient regions of the spring, the said resilient regions being said strips bonded together by an adhesive and eventually also being bonded to a second, more resilient element and/or to another element and a process for its preparation.

Abstract: A method for producing nonspherical particles including those of prolate spheroidal, oblate spheroidal, and ellipsoidal shape is described. A microparticulate latex can be produced wherein the microparticles in the latex are substantially identical in all dimensions. The overall shape, volume, and aspect ratio or aspect ratios of the particles can be systematically controlled. Non-spherical particles ranging in sizes from about 0.01 microns to about 100 microns can be produced from a variety of polymeric materials. Such particles can be used as model particles for a variety of scientific studies, calibration standards for electron microscopes, and in a variety of optical, thermal, electrical, and biomedical applications.

Abstract: A polycarbosilastyrene copolymer which comprises recurring carbosilane units of the formula I: ##STR1## and recurring silastyrene units of the formula II: ##STR2## is useful for producing a shaped sintered silicon carbide article by shaping the polycarbosilastyrene copolymer to a desired form, by applying an ultra-violet ray treatment or heat treatment to the shaped article, and by sintering the resultant cross-linked, non-fusible shaped article at an elevated temperature.

Abstract: A process and apparatus for molding a plurality of articles of hardenable material such as plastic which requires each article to be maintained under heat and pressure for a cure interval. A molding press is utilized wherein there is placed a first open mold assembly having spaced die halves between supporting mold platens. At least one of the die halves has a resilient pressure pad between the die and the mold platen supporting the die half. The press is closed to maintain the mold platens in a first force applying position having a slight gap between the die halves and locking the platens in the first position. The mold assembly is removed while in its first locked position from the press and gas from the curing material is evacuated through the gap between the die halves while heating the material.

Abstract: A method is shown for forming a spark plug boot having at least one internal shoulder. An outer tube is first formed of an elastomeric material having an internal bore and a selected length. An inner tube, also formed of an elastomeric material, is inserted within the bore of the outer tube. The inner tube has an external diameter selected to allow it to be slideably received within the bore of the outer tube and has a length which is less than the length of the outer tube. The inner and outer tubes thus assembled are then exposed to electromagnetic radiation for a time sufficient to bond the external diameter of the inner tube to the internal bore of the outer tube.

Abstract: Clamps mounted on a reciprocal frame grip a web of connected molded fibrous articles and move toward a cutter a distance equal to one article length, thereby presenting to the cutter the connecting portion between adjacent articles and also pulling the next portion of uncured fibrous material into the mold press for shaping and curing. After the cutting operation the clamps open and move toward the mold into position to again grip and feed the web toward the cutter. Connected rows of webs can also be handled by slitting the rows as they move toward the cutter. The articles, which can be quite deep compared to the thickness of the connecting portions between articles, are supported during travel and while stationary by support plates separate from the reciprocal frame. The various components which contact or cause movement or cycling of the apparatus can be adjusted to permit handling of articles and webs of different dimensions.

Abstract: A latent curing fibre is produced by coating a glass fibre with an (optional) thermoplastic (polyamide) adhesion-promoting layer, a (preferably brittle) curing agent layer (e.g. styrene/maleic anhydride), and a flexible curable layer of epoxy plus curable polyester. Composites of this fibre with non-reactive glass braids consolidate and cure exceptionally well under a heat-shrink sleeve to provide Class F electrical insulation.

Abstract: A composite ribbon suitable for winding into coils, comprising an acrylate resin film destined to be used as an intermediate layer in safety glass panels, interposed between two thin protective films, is produced by means of a continuous process of polymerization induced by light radiation, using the two protective films themselves as a polymerization cell.

Abstract: This invention provides novel thermosetting preform having superior transparency which is composed of the resin produced by partially polymerizing the mixture of (A) 4 to 30 wt % of at least one vinyl monomer containing carboxyl group, (B) 4 to 96 wt % of at least one vinyl monomer containing glycidyl group, and (C) up to 92 wt % of at least one copolymerizable monomer, said preform being characterized in that the amount of unreacted monomer remaining therein is less than 20 wt % and the glass transition temperature range is 120.degree. C. or lower. This invention also provides a method of production of a highly transparent molded article with high productivity which is superior in heat resistance and in chemical resistance by heating and molding said preform.

Abstract: A continuous vulcanized assembly process for producing an anti-fouling material comprises cleaning the surface of a sheet of copper alloy anti-fouling material by shotblasting, use of a rotary abrasive member or by a chemical treatment. A layer of elastomeric material is extruded onto the metallic material and the elastomeric material is then cured at an elevated temperature using a rotary press. The material thus produced can be stored on reels for subsequent attachmnent to appropriate structures.

Abstract: A method of forming a fiber reinforced synthetic resin rod-like molding including a rod-like core portion having at least in the outer portion thereof a reinforcing fiber bundle integrally adhered together by a thermosetting resin and a thermoplastic resin layer coating the core portion is disclosed. The outer surface portion of the core portion and the inner surface portion of the thermoplastic resin layer are integrally adhered together due to an anchor effect generated by contacting between the thermosetting resin and the thermoplastic resin in a semifluid state under pressure.

Abstract: A method for bonding silicone rubber to a metal member is shown in which the metal member is first treated by heating the metal member to a temperature and for a time sufficient to form an oxide layer on the outer surface of the metal member. The treated metal member is then contacted with an uncured silicone rubber composition, and the silicone rubber composition is cured to bond the treated metal member to the silicone rubber composition.

Abstract: A process and apparatus for producing a cross-linked, extruded or sprayed product.

Abstract: Synthetic resin plates having an irregular flow pattern of different colors are prepared by continuously polymerizing polymerizable materials in a polymerization zone defined by confronting surfaces of two confronting and running endless belts and gaskets held between the confronting surfaces of the belts. Polymerizable materials of different colors are supplied in the polymerizable material supply region close to the upstream end of the polymerization zone by a plurality of supply means, each of which includes at least one polymerizable material supply opening to the polymerizable material supply region. The supply means are arranged in such a manner that they are spaced from one another in the direction of travel of the belts.

Abstract: A method of manufacturing fiber reinforced silicone elastomer hoses and the hoses (25) resulting from the method are disclosed. The method comprises the step of extruding an unreinforced silicone elastomer inner tube (13) containing two vulcanizing agents having different activation temperatures. The extruded inner tube (13) is partially cured by heating the tube to the activation temperature of the lower temperture vulcanizing agent. The partially cured inner tube (13) is mounted on a mandrel (19) and wrapped with a fabric reinforced, calendered sheet (21) of uncured silicone elastomer containing a vulcanizing agent. External pressure is applied to the wrapped tube while the wrapped tube is heated to activate the second vulcanizing agent of the inner tube (13) and the vulcanizing agent of the wrapping sheet (21).

Abstract: A method for continuously vulcanizing hoses which comprises two steps: microwave vulcanization; and conventional vulcanization by heat conduction through a heating medium. A layer of heat-resistant synthetic resin which has a melting point higher than the vulcanizing temperature is provided over the outer periphery of a rubber hose in a uniform thickness. This layer is in close contact with the hose but not adherent thereto. After the resin layer is cooled and hardened, the rubber hose is heated and cured in a microwave vulcanizing tank before being subjected to vulcanization by heat conduction through a heating medium in an ordinary vulcanizing tank. After completion of vulcanization, the layer of synthetic resin is peeled off and removed.

Abstract: Polyimide film prepared from a precursor solutions of polyamic acid in a solvent can be dried during or following the thermal or chemical conversion step, which produces a polyimide, by adding to the solution a small amount of an alkyl ester of phthalic, terephthalic, or isophthalic acid, casting the solution on a flat surface and heating the solution on the flat surface at about 100.degree.-200.degree. C.; then, removing the resulting partially converted film from the flat surface and heating it, under restraint, to about 200.degree.-375.degree. C., to bring about complete conversion and remove virtually all of the solvent. Polyimide films are useful in various applications where high temperature resistance is required, including composites for aerospace applications and for circuit boards for electronic equipment.

Abstract: Indefinite length tubular and sheeting products can be fabricated using either a continuous or step-wise method which uses a two-stage curing sequence. In the first curing stage, the center portion of a thermosetting web is fully cured leaving the lateral edges of the web in an uncured state. The uncured lateral edges are then spliced, either directly to one another, or spliced with a similar web having uncured edges to form either a flat sheet or a tubular preform having longitudinal uncured spliced seams. In the second curing stage, these uncured longitudinal splices are fully cured to form either tubular articles or flat sheeting having completely uniform physical properties throughout.

Abstract: A method of forming simulated marble articles from materials polymerizable within a cell or mould characterized in that the mould is filled under conditions in which the polymerizable materials are introduced as streams following the flow path into the cell or mould and the contents are polymerized with the cell or mould disposed so that the flow lines are on a height gradient relative to each other. Limited intermixing of the compositions during the initial stages of the curing process produce an attractive simulated marble effect. The mould may be filled so that the flow lines are disposed in a near vertical position and then rotated so that they are in a near horizontal position with adjacent flow lines on a near vertical height gradient.

Abstract: A shear head in which an extruded vulcanizable composition meets preheated reinforcing strands has a compartment adjacent a mouth of the head which is evacuated to reduce the danger of gases affecting adhesion of the strands to the composition.

Abstract: Method of and apparatus for controlling the liquid-steam interface in a continuous vulcanization system which includes the steps of selecting a preferred water-steam interface position within a curing tube, detecting the elevation of water in the tube by a water sensitive sensing means, converting the detected elevation data into a signal, and controlling the position of the interface according to the signal.

Abstract: A novel process is provided for producing prefoam type cellular concrete articles, which uses a foamed slurry (E) consisting essentially of an aqueous slurry (A) of a calcium silicate-based cement compound, an aqueous slurry (B) of a calcium aluminate-based cement compound, a specific setting retarder (C), and an aqueous foamed liquid (D). The process is further characterized in that: (i) the foamed slurry (E) is cast and provided with hardened strength sufficient for demolding in 20 to 120 minutes after it has been poured into a mold; (ii) the demolded article is subjected to precuring under specific conditions of humidity, temperature and precuring time; and (iii) the molded article is then subjected to hydrothermal curing under high pressure.

Abstract: The compression molding of sections (15), bars, molded articles, or similar, consisting of vegetable particles mixed with binding media was uneconomical, because the relatively short molding time was overlapped by the disproportionate curing time. In order to considerably improve upon this deficiency, the inventor proposes to feed the molded section (15), or similar, along its longitudinal axis into a curing unit, while the sections (15) between the molding jaws (3 through 6) should remain in clamped position. The molding jaws (3 through 6), together with the cured section (15), are then returned through the press and the section is ejected after the unlocking of the molding jaws (3 through 6). Within the framework of the cyclic work, the individual operating processes can be adjusted to one another.

Abstract: A synthetic resin plate having at least two different colors is prepared by a process having the steps of supplying at least two polymerizable liquid materials differing in the color from at least two inlets, passing them through at least two groups of flow paths alternately arranged, extruding and injecting the polymerizable liquid materials into a polymerization apparatus, polymerizing the liquid materials, and withdrawing a plate-shaped product having a striped pattern extending from the surface to the interior or a plate-shaped product having said striped pattern in which the boundary area between the adjacent stripe lines of different colors is gradated.

Abstract: An apparatus is disclosed for forming elongate structures of composite materials. The apparatus includes a plurality of forming dies for preheating, heating and then cooling an elongate portion of composite material while shaping the material within an internal passage. A pulling device is utilized to continuously draw elongate strips of composite material through the forming dies. The pulling device includes two opposed endless track devices. One of the endless track devices serves to mount a plurality of engagement dogs, each having a substantially flat surface for engagement of the elongate portion of composite material. The other endless track device serves to mount a plurality of pivoting engagement dogs, each having a curvilinear surface wherein increased resistance by said elongate strip of composite material will pivot the curved surface into closer alignment with a corresponding flat surface, thereby tightening the grip of the pulling device on the elongate strip of composite material.