Abstract: The present invention relates to a method for producing foam plastics and a device for effecting same. The method resides in foaming with continuous and proportioned injection of all components successively in two stages, mixing water, resin and a foaming agent under pressure with compressed air to obtain homogenized foam with a foam coefficient of 15 to 20, with subsequent injection thereinto of a curing catalyst together with compressed air. The device for carrying out the proposed method comprises proportioners the inlets whereof are connected to tanks each being intended for a respective component, as well as curing and foaming chambers communicating through two closely adjacent coaxially arranged pipes forming an annulus, the outer pipe being provided with diametrically oposite connections for letting into the annulus the catalyst and compressed air.

Abstract: A feeder for apparatus for ejecting a mixture of liquids, e.g. urethane foam, comprises a pair of swash plate proportioning pumps one individual to each of the liquids, e.g. resin and isocyanate, each proportioning pump being fed by a gear pump from a supply of the respective liquid. Seepage along the drive shafts of the isocyanate pumps is continuously removed by bathing them in a recirculating stream of flushing agent. The swash plate and gear pumps and flushing agent pump are all driven by a single motor from a common chain drive. The liquids are heated during passage through separate hoses to a common dispensing head or gun, by immersed coil electric resistance heaters extending lengthwise freely within the hoses. A novel control system is provided for the hose heater circuit, the adequacy of the liquid supply and other operating conditions.

Abstract: A process and apparatus for the polymerization of ethylene in at least one multizone reactor at a pressure of 300 to 2500 bars and at a temperature of 150 to 350.degree. C. The reaction mixture is passed from the reactor to a separator at a pressure of 50 to 500 bars in which the polymer separates from the gas. The polymer is then passed to a hopper at a pressure of 1 to 20 bars in which the major part of the gas remaining dissolved in the polymer is removed. The gas from the separator is recompressed and is returned only to the first zone of the reactor.

Abstract: In a preferred embodiment, minute bubbles of a suitable gas are rapidly entrained in a liquid chemical constituent of a reaction injection molding system (e.g., polyurethane) to reduce the viscosity of the constituent and the density of parts molded therefrom. A small portion of the constituent is continuously withdrawn from and returned to a main holding tank via a recirculation line wherein minute gas bubbles are dispersed from a microporous stone into the flowing portion of the constituent. The recirculating and gas entraining processes are continued until a predetermined quantity of the gas is dispersed in the molding constituent.

Abstract: This invention relates to methods and apparatus for successively dispensing predetermined quantities of urea formaldehyde foamed resin mixture having as constituents a resin component and a hardener component in which a prefoamed one of said components and the other component are independently fed under pressure to a mixing chamber where they are mixed and from which, they are dispensed, any residue of the urea formaldehyde foamed resin mixture left in the mixing chamber after said predetermined quantity has been dispensed therefrom being swept and removed prior to the mixing chamber being supplied with the next batch of said components.The present invention is particularly useful for filling pre-cast cavity building blocks with insulating foamed material.

Abstract: Insulating foam producing and delivering apparatus includes foaming agent and resin supplies, means for delivering the foaming agent and resin and also air under pressure and a foam gun for generating the foam and mixing the foam with the resin. The foam gun includes a foaming chamber in which foaming agent and air are discharged in jets so as to impact against blades of a free spinning propeller which is turned by jets to create a mixing turbulence and thereby whips the foaming agent and air into the desired froth or foam. The foam is combined with the resin through an extended resin discharge nozzle located downstream of the foaming chamber so as to confine the resin mixing essentially to the output applicator or dispenser hose and thereby to minimize clogging due to hardened resin residue. Transparent air, foaming agent and resin supply lines enable constant monitoring of the ingredients and facilitate the maintenance of the desired foam density and other desired conditions of the foam.

Abstract: A nozzle for the injection of urea-formaldehyde foam insulation in a building includes a two-stage foaming chamber in the foam chemical line which includes a plurality of jets for effecting bubbling of the foaming chemical and a bubble-sizing, apertured plate positioned downstream of the jets to further enhance the foaming action of the chamber. The nozzle further includes a body into which the foaming agent is coaxially delivered with respect to an axailly extending resin injector. The end of the resin injector extends from the body of the nozzle and a flexible injection hose is removably attached to the end of the nozzle such that the resin and foaming agent mix in the flexible hose.

Abstract: The instant invention relates to a process and apparatus for the preparation of a reaction mixture for the production of foam materials from at least two components, wherein one of the components, before it is mixed with the remaining components to form the reaction mixture, is passed through a constriction at a predetermined flowrate. The constriction produces a zone of reduced pressure and a gas is fed into the reduced pressure zone.

Abstract: Very compact resin mixing and delivery device for use in mixing and delivering such resin as urea formaldehyde with foaming agents or the like and for delivering such mixtures to a delivery conduit which is adapted for applying the resin and foaming agent in place so that it may develop into a cured cellular foam like hard filler or body for use in various applications such as building insulation, wall reinforcing and filling various voids or cavities in a great variety of structures.

Abstract: Polyester foam is formed by simultaneously cross-linking an unsaturated polyester resin and generating carbon dioxide as a blowing agent. The foam-forming components are divided into two equal volume parts which are metered together to effect the simultaneous reactions and form the foam. Apparatus is described for effecting the foam-forming method.

Abstract: Stable foams of reaction resins and/or condensation resins can be obtained by adding a blowing agent which is gaseous under normal conditions to the resin under pressure, the gas liquid interface being enlarged while dispensing with moving equipment, allowing the mixture to expand and to cure.

Abstract: The invention relates to a frothing method for mixing a liquid propellant having a low boiling point with further components for the production of foamed material, more particularly polyurethane. The invention also relates to an apparatus for carrying out the method with a mixing head for high pressure mixing of the main components in a mixing chamber. The foam production is carried out in two stages involving a first chamber for receiving and premixing reactive polymeric components, and a second chamber intersected by the first into which the mix components are advanced while the frothing propellant is injected at the intersection. The frothed reactive polymeric mix is then discharged from the second chamber into a suitable mold for forming the finished polymerized product.

Abstract: A high pressure mixing head is disclosed for combining a plurality of reactive fluid polymeric components to form a mixture thereof for molding purposes. The mixing head incorporates an expulsion plunger operating in a mixing chamber into which the several components are admitted through individual inlet openings which are covered and uncovered by reciprocation of the plunger. The mixing head further incorporates inlet valves and valve chambers located respectively upstream of the several inlet openings and so arranged that the inlet valves prevent admission of the individual components into the mixing chamber, irrespective of the plunger position, unless a predetermined pressure of the respective components is attained. Each valve chamber is connected to component feed and return lines forming part of the respective component circulating systems so that component flow at relatively low pressure takes place at all times between mixing/molding periods of operation.