Abstract: A component-feed nozzle for a reaction-mixing head of a reaction injection device includes a housing having a component inlet and a component outlet. Received in the housing is a closing and flow restriction member which is movable by a linear drive between at least two positions. In a first position, the closing and flow restriction member closes the component outlet, and in a second position clears the component outlet, thereby establishing a flow communication between the component inlet and the component outlet. The closing and flow restriction member has at least a first area and a second area, which generate forces in opposite directions, when the component pressure is applied, wherein the areas are sized in such a way that the opposing forces substantially offset one another.

Abstract: The present invention relates to a mould, in which a completely closed cavity can be formed in one operating state, comprising an injector (10) which is at least partially accommodated in the mould (14) and the discharge opening of which opens into the closed cavity. According to the invention, the injector is designed with a material feed duct (30) and a material return duct (34), wherein the two ducts (30, 34) open into a connecting chamber (32) in the region of the tip of the injector (10) and are flow-connected to one another via said connecting chamber (32). In this case, an injector needle (36) can be switched into at least two operating positions, wherein, in one moved-forward operating position, the discharge opening is closed by means of the tip (38) of the injector needle (36) and, in the other, pulled-back operating position, the discharge opening is flow-connected to the connecting chamber, and the injector (10) is therefore open.

Abstract: The present invention relates to a mould, in which a completely closed cavity can be formed in one operating state, comprising an injector (10) which is at least partially accommodated in the mould (14) and the discharge opening of which opens into the closed cavity. According to the invention, the injector is designed with a material feed duct (30) and a material return duct (34), wherein the two ducts (30, 34) open into a connecting chamber (32) in the region of the tip of the injector (10) and are flow-connected to one another via said connecting chamber (32). In this case, an injector needle (36) can be switched into at least two operating positions, wherein, in one moved-forward operating position, the discharge opening is closed by means of the tip (38) of the injector needle (36) and, in the other, pulled-back operating position, the discharge opening is flow-connected to the connecting chamber, and the injector (10) is therefore open.

Abstract: A component-feed nozzle for a reaction-mixing head of a reaction injection device includes a housing having a component inlet and a component outlet. Received in the housing is a closing and flow restriction member which is movable by a linear drive between at least two positions. In a first position, the closing and flow restriction member closes the component outlet, and in a second position clears the component outlet, thereby establishing a flow communication between the component inlet and the component outlet. The closing and flow restriction member has at least a first area and a second area, which generate forces in opposite directions, when the component pressure is applied, wherein the areas are sized in such a way that the opposing forces substantially offset one another.

Abstract: A mixing head includes an integrated shot counting apparatus. The shot counting apparatus is hereby implemented as an integrated circuit with a detector for ascertaining an operating parameter of the mixing head, and an electric acquisition and storage unit operatively connected to the detector and having a counter and a non-volatile memory device which is operatively connected to the counter.

Abstract: An injection nozzle for mixing heads of reaction molding machines is disclosed which comprises a housing in which a adjustment assembly is provided for slidably moving between two adjustable stops, wherein the adjustment assembly is configured as a control sleeve which includes a pressure chamber with a movable control piston disposed therein and the pressure chamber can be impinged upon by a pressure medium, for example hydraulic fluid and wherein a first stop is provided for the control sleeve and a second stop is provided for the control plunger thereby permitting an adjustment of two operating points that are exactly reproducible, so as to prevent disturbances during operation of the molding process.

Abstract: Integrated in the mixing head of a polyurethane apparatus for producing a mixture stream of chemically reactive plastic components, is a cutting arrangement by which natural fibers or fiber strands of soft-elastic and tough consistency can be drawn from a continuous strand and, after cutting into fiber pieces of given length, can be introduced into the mixture stream. The cutting arrangement includes an inner guide tube which receives a fiber strand, drawn from a continuous fiber strand by two feed rollers, and fed via the guide tube and an outer support tube to rotating knife elements. By subjecting the guide tube to a vacuum and applying a compressed gas stream to the end of the outer support tube, the soft-elastic fiber strand is held straight in a manner which is optimal for the cutting process. The cut fiber pieces are introduced together with the gas stream into the mixture stream of chemically reactive plastic components.

Abstract: Integrated in the mixing head of a polyurethane apparatus for producing a mixture stream of chemically reactive plastic components, is a cutting arrangement by which natural fibers or fiber strands of soft-elastic and tough consistency can be drawn from a continuous strand and, after cutting into fiber pieces of given length, can be introduced into the mixture stream. The cutting arrangement includes an inner guide tube which receives a fiber strand, drawn from a continuous fiber strand by two feed rollers, and fed via the guide tube and an outer support tube to rotating knife elements. By subjecting the guide tube to a vacuum and applying a compressed gas stream to the end of the outer support tube, the soft-elastic fiber strand is held straight in a manner which is optimal for the cutting process. The cut fiber pieces are introduced together with the gas stream into the mixture stream of chemically reactive plastic components.

Abstract: An injection nozzle for mixing heads of reaction molding machines is disclosed which comprises a housing in which a adjustment assembly is provided for slidably moving between two adjustable stops, wherein the adjustment assembly is configured as a control sleeve which includes a pressure chamber with a movable control piston disposed therein and the pressure chamber can be impinged upon by a pressure medium, for example hydraulic fluid and wherein a first stop is provided for the control sleeve and a second stop is provided for the control plunger thereby permitting an adjustment of two operating points that are exactly reproducible, so as to prevent disturbances during operation of the molding process.

Abstract: Integrated in the mixing head of a polyurethane apparatus for producing a mixture stream of chemically reactive plastic components, is a cutting arrangement by which natural fibers or fiber strands of soft-elastic and tough consistency can be drawn from a continuous strand and, after cutting into fiber pieces of given length, can be introduced into the mixture stream. The cutting arrangement includes an inner guide tube which receives a fiber strand, drawn from a continuous fiber strand by two feed rollers, and fed via the guide tube and an outer support tube to rotating knife elements. By subjecting the guide tube to a vacuum and applying a compressed gas stream to the end of the outer support tube, the soft-elastic fiber strand is held straight in a manner which is optimal for the cutting process. The cut fiber pieces are introduced together with the gas stream into the mixture stream of chemically reactive plastic components.

Abstract: An apparatus for producing a fiber reinforced synthetic resin provides a fiber feed passage through an outer chamber to which the synthetic resin for feed. A feed passage for the fiber extends concentrically in this chamber and has a tubular formation of a diameter less than that of a cleaning piston which is displaceable in the annular space between this tubular formation and the inner wall of the chamber.

Abstract: A method of and apparatus for the measurement of the degree of charging of a liquid synthetic resin component with a gas in which the flushing of the measuring column and the detection of the hydrostatic pressure are effected solely by control of the intake valve to the measuring chamber, a discharge valve at the bottom of an overflow chamber connected to the measuring chamber, and a three position valve connected to the top of the overflow chamber. In one position of this latter valve, a pressurized gas is applied to the overflow chamber to drive overflow liquid component back to the tank: in another position of this valve the column can be equilibrated with atmospheric pressure: in a third position this valve is closed.