Abstract: The polygon effect in a double belt conveyor for the continuous production of laminates having a foam core foamed in situ between covering layers is avoided in that the slat belts are provided with guiding rails in the deflection areas, and in that the slat belts are driven by rotating pulling elements. The driving elements of the pulling elements engage on catches which are arranged along the slat belts, only in the sections of straight-line motion of the slat belts.

Abstract: The device of the present invention is used for the production of a reaction mixture. The device has a housing with a guide bore provided therein for an injection piston. Feed lines with entry openings and recirculation lines are provided. The device is also provided with a rotary slide valve which contains a mixing chamber through which the ejection piston can pass. The slide valve is movable to a position that frees the entry openings to the mixture chamber and to a position that connects the entry openings (through flow channels provided in the rotary slide valve) with the recirculation lines.

Abstract: The present invention is directed to a process and apparatus for introducing gas into one of at least two free-flowing components which are subsequently mixed to provide a foam-forming free-flowing mixture by transferring the component to have gas dispersed therein from a supply container to a gas loading area, loading the component with gas and returning the component to the supply area, wherein the gas used in the gas loading area is obtained from a gas cushion maintained in the supply container and wherein the gas is compressed to a pressure higher than the pressure in the gas loading area before it is dispersed into the free-flowing component.

Abstract: The invention relates to a nozzle for mixing at least two flowable (and in particular foam-forming) reaction components comprising a housing; component supply pipes leading into the housing; a housing bore arranged in the housing having a coaxial outlet channel in its end face; at least one needle casing arranged coaxially in the housing bore; an injection needle guided coaxially in the needle casing; a first chamber arranged between the wall of the housing bore and the needle casing with one of the component supply pipes opening into said first chamber; a second chamber arranged between the needle casing and the injection needle, with another component supply pipe opening into said second chamber; wherein in the closed state, said injection needle forms a tight fit with the internal end face of the needle casing, and the external end face of said needle casing forms a tight fit with the internal end face of the housing bore; and wherein in the open state, said injection needle frees a coaxial nozzle opening

Abstract: Closure units for molding tools, in particular those for the production of polyurethane moldings comprising long lifting cylinders arranged between an upper cross head and a movable cross head for lowering and raising the upper half of a molding tool, the movable cross head being mounted on columns connecting the fixed cross head to a base by means of short lifting cylinders having arrestable drag pistons arranged therein, were found to offer advantages in terms of economy of design and operation.

Abstract: A nozzle is used to mix two or more flowable reaction components which nozzle has a force controlled injection needle (7) and a force controlled needle casing (12) guided in a guiding bore (12). One component emerges centrally into an outlet channel (3) while the opening (25,26) of at least one further supply pipe (23,24) lies in the area of a sealing surface (4) which limits one side of the guide bore (2) and which forms a tight fit (18) with an outer sealing surface (17) thereof when the needle casing (12) is in a closed position.

Abstract: The instant invention is directed to a process for filling a cavity with a flowable reaction mixture through an inlet opening located at the bottom of the cavity. The process broadly comprises injecting a relatively small amount of reaction mixture into the cavity to cover the inlet opening with reaction mixture. The injection process is then briefly interrupted. Thereafter, the remaining amount of reaction mixture is injected into the cavity. The invention also relates to apparatus useful in performing the above-described process.

Abstract: In the continuous production of block-foam from liquid reaction components, the danger of over-rolling exists in installations having low throughputs and in installations having high throughputs, which over-rolling results in faults in the finished block. These over-rolling phenomena are avoided by providing a conveyor belt in the mixture charging zone which belt transports on its conveying surface a foil which has trough-shaped indentations which can correspond to trough-shaped indentations in the conveying surface. The reaction mixture is portioned into the indentations of the foil. These portions are only spread out once the reaction mixture has reached the creamy phase.

Abstract: The present invention is directed to an apparatus for producing a reaction mixture from at least two fluid components comprising: (A) a storage container for each component; (B) feed pipes leading from each storage container via metering pumps to injection nozzles; (C) return pipes leading from each injection nozzle to the storage containers; (D) the injection nozzles opening into the mixing chamber of a mixhead, the mixhead having an outlet opening downstream of the injection nozzles, each injection nozzle comprising (i) a housing, (ii) a bore arranged in the housing, the bore connected to a feed pipe and a return pipe, (iii) a nozzle needle within the bore, the nozzle needle being provided with (a) an annular groove for connecting the feed pipe and the return pipe, (b) a sealing surface, and (c) a needle spindle, (iv) a sealing surface in the housing, the sealing surface adapted to contact the sealing surface of the nozzle needle, and (v) a central nozzle bore located in the sealing surface (vi) wherein the

Abstract: A process and a mixing head for the production of a reaction mixture comprising at least two reaction components, with a high degree of mixing. By this process, reaction components are introduced, at a high pressure into one end of the mixing chamber of the mixing head, these components being deflected by the front of the discharge piston which forms the opposite end of the chamber, a counterflow forming intensive turbulences on the wall of the mixing chamber and on the boundary surface with the incoming flow before this counterflow exits the mixing chamber at the same end through which it entered the chamber, substantially as a radially-directed, laminar flow.

Abstract: The present invention relates to an apparatus for the production of a flowable reaction mixture of at least two flowable components which mixture forms a foam or solid material, comprising:(a) storage means for said components;(b) supply lines leading from the storage means via metering pumps to a mixing head;(c) said mixing head having a mixing chamber;(d) injection openings connected to said supply lines and opening into said mixing chamber;(e) said mixing chamber having an outlet opening downstream of said injection openings;(f) said outlet opening having an elastic outlet tube whose throughflow cross section may be varied connected thereto; said apparatus further characterized in that:(g) the outlet tube has at least one means associated therewith for deflecting said outlet tube;(h) an ejection piston is associated with said outlet tube, which piston is capable of filling the outlet tube; the contour of the inside wall of said outlet tube corresponding to the external contour of said ejection piston.

Abstract: Hydraulically coupled injection nozzles (5,28) and return nozzles (15,38) are used in an apparatus for producing a reaction mixture of fluid components forming foam or a solid material. These nozzles (5,15,28,38) comprise control pins (11,20,34,43) which are designed to be inserted into the openings (6,17,29,40) of the nozzles (5,15,28,38). The ratio between the distances which the control pins (11,20,34,43) travel outside and inside the orifices (6,17,29,40) is adjusted in such a way that, when the nozzles (5,15,28,38) are switched from "mixing" to "circulation" or vice versa, there is a time interval during which all the nozzles (5,15,28,38) are closed.

Abstract: The invention relates to a method and a device for producing a solid-forming or foam-forming flowable reaction mixture by metered injection of flowable reaction components into a mixing zone from which the finished reaction mixture is discharged.

Abstract: The instant invention is directed to a process for filling a cavity with a flowable reaction mixture through an inlet opening located at the bottom of the cavity. The process broadly comprises injecting a relatively small amount of reaction mixture into the cavity to cover the inlet opening with reaction mixture. The injection process is then briefly interrupted. Thereafter, the remaining amount of reaction mixture is injected into the cavity. The invention also relates to apparatus useful in performing the above-described process.

Abstract: The invention is directed to a device for the discontinuous production of block foam comprising a mixing unit, a means for moving the unit approximately vertically into and/or out of a mold with the unit having reaction component feed lines, a stirring means, and a mixing container having a plate with feed openings for the reaction components characterized in that(A) a distributing device is arranged below the feed opening for one of the components and(B) the mixing container comprises a bottomless cylindrical shell, the lower rim of which can be placed on the bottom of the mold.

Abstract: The instant invention broadly relates to a process and apparatus for filling a cavity with a reactive mixture. More particularly, the invention relates to a process for filling cavities, particularly mold cavities, with a reactive, flowable mixture which preferably forms foam, wherein at least two reaction components are brought into a mixing zone, where they are mixed and then brought into the cavity, the improvement wherein at the beginning of the filling process, during a limited time interval, the reaction mixture is fed into the cavity under low flow velocity until the mixture has reached a certain level in the cavity, and subsequently the remaining mixture to be injected, is fed in under increased flow velocity.

Abstract: The instant invention is directed to a process for the continuous production of block-shaped foam and to the equipment used therefore. The process of the invention broadly involves the heating of the bottom film prior to application of the foamable mixture. In this way, the undesirable crust generally formed on the bottom of the foam blocks is substantially reduced and/or eliminated.

Abstract: Continuous foam blocks with rectangular cross-section are produced on a side-limited conveyor band by feeding a foamable mixture to a cover foil travelling with said conveyor band and covering the free surface of the mixture with a bearing layer not earlier than immediately after the supply of the mixture and not later than before the zone in which a skin would be formed on the free surface of the block.

Abstract: The instant invention is directed to an improved device for the continuous production of foam blocks of rectangular cross-section, comprising an endless conveyor belt with side walls, means for supplying a covering sheet to the upper surface of the upper rim of the conveyor belt and the side walls, a charging device for supplying a foamable reaction mixture to the upstream end of the said upper rim of the conveyor belt, and a plurality of mold covers which are placed along the foaming area and each of which is suspended from a guiding device, the improvement wherein each guiding device comprises first and second links secured to mounting means, a diagonally extending rod pivotally connected at its lower end to the mold cover, a first lever pivotally connected at one end to the first link and pivotally connected at its opposite end to a point on the rod intermediate its ends, and a second lever pivotally connected at one end to the second link downstream of the pivotal connection between the first lever and th

Abstract: The instant invention relates to an apparatus for the continuous production of foam plastic blocks of a rectangular cross-section, in particular based on polyurethane. The apparatus generally comprises an endless conveyor belt whose upper run is provided with side walls, an unwinding device for a bottom and side sheet to cover the upper run of the belt and the side walls, a levelling device in the form of a roller or a doctor, which extends transversely in relation to the conveyor, a mixture application device and an unwinding device for a sheet to cover the mixture applied.