Elastogran Maschinenbau Gmbh

Basf Aktiengesellschaft

Elastogran Maschinenbau Gmbh & Co.

Josef Wallner

Hans D Zettler

Heino Thiele

Bernhard Seid

Lothar Metzinger

Manfred Kelterbaum

Klaus Schlueter

Werner Weber

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.

Mixing head for producing a preferably chemically reactive mixture from

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. The flow restrictor can be pushed in an appropriate distance, making it possible to achieve a good restricting effect and therefore to exert a corresponding great influence on the mixing procedure or on the discharge characteristics.

Mixing head for mixing two or more plastics components which react to

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.

Split mold for multi-component plastics, especially polyurethanes

A mixing head for multicomponent plastics, especially polyurethane, in whose mixing chamber (2) a hollow piston (7) can be moved to and fro to control the component streams. The hollow piston contains an expulsion piston (8), which is movable independently of the hollow piston, and which can be passed through an outlet tube (3) which adjoins the outlet orifice (4). The end face (12) of the hollow piston forms, together with the mixing chamber wall (11) nearest the sprue, a shearing gap in which the components are mixed. As a result of the design and arrangement of the pistons (7) and (8), good mixing is achievable even under critical conditions, and the mixing chamber is also easily cleaned.

Mixing apparatus for multi-component plastics, especially polyurethane

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.

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Holzkirchen, Germany

Josef Wallner