Frenkel C-d Aktiengesellschaft

A-z Formen-und Maschinenbau Gmbh

Firma A2-formen-und Maschinenbau Gmbh

Paul Meyer

An extrusion device for tires has a heatable extruder for extruding and supplying an elastomer to a prepared and rotatably supported carcass being rotated in a direction of rotation for entraining the extruded elastomer. The extruder has at least one die mouth facing a carcass sidewall. The mouth is a slot having a width and a length. The width extends in a direction of rotation of the carcass and is delimited by an upper and a lower edge. The length extends radially across the carcass sidewall. The slot has an outlet opening defining an area whose normal is slanted toward the carcass sidewall such that in the direction of rotation the upper edge of the slot is closer to the carcass sidewall than the lower edge of the slot.

Extrusion device for retreading tires

A tire retreading device has a tread feeding device for feeding the tread to a tire casing and an extruder for extruding a cushion gum layer onto the tire casing. The extruder has a first and a second lip defining the extrusion die. The first lip, positioned behind the second lip in the direction of rotation of the tire casing, projects in a direction toward the tire casing relative to the second lip. The first lip is an applicator shoe that is pressed under prestress against the tire casing so as to deform the tire casing. With the retreading device a cushion gum layer is applied to the tire casing and during the application the applicator shoe is pressed against the tire casing with such a pressing force that a radius of curvature of the tire casing conforms to a radius of curvature of the applicator shoe. With this measure, depressions in the surface of the tire casing are filled with excess cushion gum.

Direct extrusion cushion-gumming and skive-filling of tire casings for

A plasticizing unit is provided for palsticizing material which is subsequently supplied to an injection molding press. The unit includes a screw disposed in a barrel which has an inlet, an outlet, a reservoir zone portion, and a plasticizing zone portion. The plasticizing zone portion of the barrel and the screw each have a continuous helical groove of opposite hand as the other groove and the grooves transfer material therebetween to effect plasticizing of the material. The reservoir zone portion of the barrel receives a shot volume of material which has been plasticized during passage through the helical grooves of the barrel and the screw. A volume displacement member which is axially movably disposed in a bore of the screw is movable within the reservoir zone portion to selectively control the shot volume of plasticized material received in the reservoir zone portion.

Plasticising unit for a screw injection moulding machine having improved

A Transfermix cold feed extruder having a plasticizing section that includes a plurality of screw flights therein in a transfer zone that is formed over a common length of the screw and barrel of the extruder. In the transfer zone, a helical groove in the screw varies in cross section from a full area to a zero area, and a helical groove of opposite hand in the barrel correspondingly varies in cross section from a zero area to a full area. The extruder is provided with a set of flow deflectors in a cut in the screw positioned immediately upstream of the plasticizing section. By the coaction of the flow deflectors with the plurality of screw flights, an increase of throughput for difficult-to-extrude compounds, with an improvement in the quality of the extrudate, is obtained in a surprising manner.

Plasticizing sections of cold feed rubber extruders

A single-rotor cold feed extruder having a barrel and a screw and incorporating a transfermix plasticizing/mixing section is disclosed. The extruder is provided with a fixed set of flow-interrupters/deflectors carried by the barrel and positioned in a circumferential cut in the screw downstream of the transfermix section. The extruder is characterized by radially movable throttle members which are located around the flow interrupters/deflectors so as to provide an increase of throughput for and improved quality of difficult-to-extrude compounds.

A binding rubber extruder for retreading tires is provided with an extruder head, an axis of which extends essentially vertically to a surface of a carcass. The revolving speed of the rotatably drivable carcass and the extrusion speed are adjusted relative to one another. The extruder head is provided with a nozzle, that has a radius of curvature that corresponds at least to a greatest radius of the carcass whereby the nozzle is pressable against the carcass surface with a gentle, elastic force.

Binding rubber extruder

The increasingly high standards of consistency and uniformity demanded of cold feed rubber extruders are met by providing notches in the flights of the screw at least in the feed-inlet of the extruder. The notches are at a lead-angle greater than that of the extruder screw flights, so to pull the rubber and advance it positively. Throttling means are used to adjust the amount of squash-back and there is an independently variable-speed drive for a feed roller in the feed inlet.

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Ascona, Switzerland

Paul Meyer