Abstract: The apparatus for mixing multicomponent plastics, in particular polyurethane, has a steadying attachment 1 which is arranged at the outlet orifice 12 of a mixing head 10. The steadying attachment is equipped with a plurality of lamellae 3 which are movable in the region of the emerging mixture of components and run in the direction of flow of the said mixture. Advantageously, the lamellae can be moved forward and back in a guide housing which has webs 2 which occupy the space between the lamellae and thus ensure cleaning. Steadying is achieved by greater friction with the wall and an increase in the outflow cross-section.

Abstract: The test apparatus is equipped with two valves, of which the valve arranged in the test line 3 which branches off from the return line 1 is a seat valve 7 whose outlet aperture 13 forms the end of the test line, so that the amount of component emerging through the outlet aperture passes directly into the test beaker 6. The other valve, which is preferably a sliding valve 9, is designed and arranged so that one valve opens only when the other valve is closed, so that undefined flow through both lines 1 and 3 is avoided. The test apparatus permits error-free determination of the test amount per unit time. No residues remain in the apparatus, and the individual parameters which are important for the test result can be determined exactly and simply.

Abstract: In a mixing head, a housing (1) has a bore (2) in which a control piston (7) can be moved to and fro. One portion of the bore constitutes the mixing chamber (4), which is bounded by the end face of the control piston and by a plurality of restrictors (9) and (10) which are arranged in a row one next to the other and/or one behind the other, and can be slid into the bore. The restrictors are preferably introduced into the bore (2) from diametrically opposite sides, forming a cascade-like structure. Inlet orifices (5) and (6) for each plastic component enter the mixing chamber. As it flows, the mixture of plastic components is divided, by the cascade-like structure, into a plurality of part-streams and thereby subjected to additional mixing, and passes, with sufficiently laminar flow, into a mold.

Abstract: To control the intermittent movement of a conveyor belt or carousel, fitted with molds, in a unit for the manufacture of moldings from multi-component plastics, an intended/actual value comparison of the speed of the conveyor belt or carousel as a function of the distance of the molds from fixed devices for filling, demolding and similar operations of the molds is carried out so as to provide control signals for the electric motor. The actual value is determined from a signal voltage generated in correspondence with the rotary movement of the electric motor. The signal voltage is additionally, and in parallel to the speed regulation, converted to electric pulses which are summed in their time sequence, as a function of the movement steps of the conveyor belt or carousel, and are compared with a predetermined master function which can be varied.

Abstract: The apparatus for the production of moldings, preferably of polyurethane, possesses a conveyor, which is preferably a continuous conveyor in the form of a rotary table (2), on which exchangeable molds (3) to be filled are arranged. A mixing apparatus having a mixing head (8) is provided for filling the molds, and a mold release station (5) is also present. Each mold (3) has a plug (10) which connects it to the program control unit (1) and whose contacts are set so that they select, by means of an appropriate code, the program assigned to this code. A decoder (6) translates this code and determines the corresponding program. This avoids incorrect operation as a result of incorrect program selection. Each mold determines its program itself by means of the coding at the contacts of its plug.

Abstract: The mixing head is provided with a flow restrictor 5 which can be driven into the mixing chamber 2 downstream of the inlet orifices 3, and whose front face (for 6) is matched to the contour of the mixing chamber to avoid leaving any space here which cannot be purged by the purging plunger. When the flow restrictor is pushed forward into its working or restricting position, it is simultaneously rotated, the extent of rotation being no more than 90.degree. by the time the restricting position has been reached. This makes it possible to drive the flow restrictor much further into the mixing chamber than when no rotation is effected. The tongues or projections 6 produced as a result of matching the front face to the contour of the mixing chamber only come into contact with the sections of the mixing chamber wall which are opposite the flow restrictor.

Abstract: A mixing head essentially comprises a housing with a mixing chamber which has inlet orifices for the individual plastics components and an outlet orifice for the plastics component mixture. In the mixing chamber is located an expulsion plunger of identical cross-section, which plunger is connected to a working piston which can be actuated by a pressure medium, the plunger being movable to and fro between a mixing position, which leaves the inlet orifices open, and a position in the region of the front outlet orifice, in which it seals the inlet orifices from the mixing chamber. The mixing head moreover has a restrictor which can be pushed into and out of the mixing chamber by a pressure medium.

Abstract: A split mold for multi-component plastics, especially polyurethanes, with venting channels has heating devices in the zone of the said channels to prevent plastic from entering the channels and thus forming flash on the moldings.

Abstract: An apparatus comprising a housing with a guide bore in which an expulsion plunger can move to and fro, a portion of the guide bore constituting a mixing chamber which is bounded by the end face of the free end of the plunger and by two nozzle bodies which can be slidingly introduced into the guide bore. The plastics components flow, via inlet channels, through the nozzle bodies into the mixing chamber, the corresponding inlet orifices in the nozzle bodies being exposed during the stroke of these bodies. The end faces of the nozzle bodies constitute a restrictor in the form of an adjustable gap, which gap represents the outlet orifice of the mixing chamber and causes additional mixing of the plastics components. Using the apparatus, constant and good intensity of mixing is attainable, over the entire injection cycle, when processing two reactive plastics components.

Abstract: To mix two or more fluid plastic components, which react with one another, intimately and abruptly, the components are injected under high pressure and at high velocity into a mixing chamber. To provide greater control of the type of mixing, i.e. to allow control of the spread of the jet and/or the jet volume and the jet energy losses, the components are guided so that they impinge on one another at an angle, preferably an angle which can be varied. To achieve this, and in particular to allow the point of impingement of the jets to be varied, the injection nozzles can be slid or pivoted at right angles to the lengthwise axis of the mixing chamber, and may also be adjustable in the direction of the said axis, and in respect of their distance from the axis.

Abstract: A mixing apparatus for mixing components that interact chemically, preferably polyurethane-forming components, the apparatus including a control plunger disposed within a housing and movable along a mixing chamber between opposing inlet and return ports, the control plunger having along its wall surface return grooves for connecting the inlet ports to the return ports when the plunger is in a position blocking communication between the inlet ports and the mixing chamber wherein a wall surface portion of the control plunger which in the closing position of the plunger is disposed intermediate the return ports is provided with discrete recesses which mutually overlap in the direction of movement of the control plunger.

Abstract: A high pressure injection mixing head for mixing and ejecting plastic materials consisting of more than one component. The mixing apparatus includes at least two mixing assemblies connected at their outlet ports to a transfer cylinder of a larger diameter. The components are being mixed in the mixing assemblies and then transferred into the transfer cylinder from which the mixture is injected into a mold. The mixing chambers of the mixing assemblies and the cavity of the transfer cylinder are automatically purged when the mixing head ejects material. An entry port for additional material may be located on the transfer cylinder.

Abstract: Method and apparatus for preparing multi-component plastic materials wherein at least one of the components is compounded with admixed solid materials or is highly viscous, the various components are continuously recycled and are metered separately by associated continuously operating feed pumps, and a mixing operation is effected in a mixing chamber served by a control piston. In the circuit for the compounded or viscous component a transmitter device is connected in a position downstream of the respective continuously operating feed pump and upstream of the associated mixing chamber inlet port. This transmitter device operates in a manner similar to a piston pump and increases the delivery pressure of the compounded or viscous component upon discharge into the mixing chamber whereby the operation of the transmitter is operatively coupled to the operation of the control piston at the mixing chamber. The component circuit may furthermore include a filling pump and a check valve.

Abstract: A mixing and proportioning apparatus for multi-component plastics materials such as polyurethane comprises a number of tanks, a mixing chamber and a separate pipe connecting each tank to the mixing chamber. The tanks are provided with pressurizing means for causing the components to flow through the pipes and each pipe is provided with a metering mechanism to control the flow of the component through it. The metering mechanisms of the different pipes are all positively coupled to each other so that the rates of flow of the components through the pipes are all kept in constant proportions.

Abstract: A mixing device for mixing together multi-component plastics materials, for example polyurethane, comprises a mixing chamber into which supply ducts for the components lead and in which a piston is reciprocable between a retracted position in which the supply ducts are in communication with the mixing chamber and a forward position in which the supply ducts are shut off from the mixing chamber. The piston is provided with an axial bore through it connected to a supply of air under pressure to enable air to be supplied into the mixing chamber together with the components for producing plastic foam such as foamed polyurethane.

Abstract: A mold including a blind channel connected to the sprue runner so that the first material entering the mold will be trapped in the blind channel.

Abstract: A mixing apparatus including a mixing chamber with a reciprocating valve piston and a separate "recycle" chamber with a reciprocating grooved plunger. Piston and plunger are controlled in unison by a piston and cylinder assembly. In the "open" position of the valve piston pressurized components supplied through inlet conduits may enter the mixing chamber. In the "closing" position of the valve piston, the components supplied are by-passed across the grooved plunger back to their respective reservoirs.