Station (7) and method of curing for a tread strip (2); provided are: a flat curing mold (9) which is composed of a lower shell (10) and an upper cover (11); and an extractor element (17) which is suitable for extracting the cured tread strip (2) from the lower shell (10) after the curing operation; the cured tread strip (2) has a first wall (13), which has a relief design and is in contact with the lower shell (10), and a second wall (14) which is opposite the first wall (13), and is in contact with the upper cover (11); the extractor element (17) is suitable for adhering to the second wall (14) of the tread strip (2) along the entire length of the second wall (14) itself; and the extractor element (17) is movable perpendicularly with respect to the second wall (14) of the tread strip (2) in order to simultaneously raise the whole tread strip (2) from the lower shell (10).

The coextrusion installation is intended to generate a profiled element for a tire tread by extruding a sublayer made of first elastomeric compound, an overlayer made of second elastomeric compound for forming the tread pattern blocks, and inserts made of third elastomeric compound. The installation includes pre-scrapers followed by scrapers for deepening the embedding trenches, injectors for injecting an insert at the bottom of each embedding trench, and then a covering wall which allows the streams of the second elastomeric compound to meet by filling the embedding trench in question and by covering the corresponding insert so as to embed the said insert at a predetermined embedding depth.

The invention relates to a multiple extrusion press head for producing tread profiles of tyres, comprising: a base body (12) having a first supply opening (22) for connecting a first extruder, a second supply opening (24) for connecting a second extruder, a third supply opening (26) for connecting a third extruder, and a fourth supply opening for connecting a fourth extruder; a first head part (14) which is mounted such that it can swivel in relation to the base body, and which has a receiving means (32) that is open in the direction of the base body (12); a second head part that is mounted such that it can swivel in relation to the base body (12); at least one flow channel insert (18, 20) that is mounted such that it can swivel in relation to the base body (12), wherein the first head part (14) and the second head part (16) can be brought into a closed state, in which the head parts (14, 16) are connected to one another in a pressure-tight manner, and a first flow channel (34), a second flow channel (36), a third flow channel (38) and a fourth flow channel (40) are formed in the multiple extrusion press head (10), wherein every flow channel is connected to a supply opening. According to the invention, the base body (12) has a fifth supply opening (30) for connecting a fifth extruder, and the multiple extrusion press head (10) has a second flow channel insert (20), which, independently of the first flow channel insert (18), is mounted such that it can swivel in relation to the base body (12), and borders a fifth flow channel (42) that is connected to the fifth supply opening (30).

Aspects of the present invention relate to methods for characterizing a multi-layered tire tread. In one example, a method comprises providing a first rubber composition having a first refractive index and providing a second rubber composition having a second refractive index. The method further comprises determining a difference between the first refractive index and the second refractive index and comparing the difference to a threshold refractive index. In addition, the method comprises adding a refractive index modifier to the first rubber composition and/or second rubber composition in case the comparison provides that the difference is lower than the threshold refractive index, so that the difference is greater than, or equal to, the threshold refractive index.

The present disclosure is directed to actinic radiation curable polymeric mixtures, cured polymeric mixtures, tires and tire components made from the foregoing, and related processes.

The invention includes methods and apparatus for demolding a tread from a mold. In particular embodiments, such methods include a step of demolding a first end of a tread from a mold to form a demolded portion of the tread, the tread extending lengthwise from the first end to a second end. A further step includes folding the tread such that at least a portion of the demolded portion is arranged overtop a portion of the tread remaining within the mold. Yet a further step includes applying lubricant to the tread to thereby lubricate relative translation between folded portions of the tread. A further step includes demolding additional portions of the tread by sliding at least a portion of the demolded portion along the portion of the tread remaining in the mold with the lubricant arranged between the demolded portion and the portion of the tread remaining within the mold.

In an embodiment, the present invention provides an extrusion device for producing a profile from plasticizable material, including at least one extruder head, in which the plasticized material can be supplied to a gap which is delimited by at least one roller and at least one bar that bears against a bearing surface in a predefined position via a fixing element in an operating position of the extrusion device. The fixing element includes a flat pressure-transmitting element which, in the operating position, can be placed against a pressure surface of the bar that is opposite the bearing surface, the pressure-transmitting element including a double-armed lever, which is pivotable about at least one axis, in order to compensate for a possible deviation from the predefined parallel orientation of the pressure-transmitting element with respect to the pressure surface of the bar.

A rubber article mold capable of discharging air from a molding-surface side to a back-surface side during curing while suppressing the entry of rubber into an air vent hole and a method for producing such a rubber article mold are provided. The rubber article mold includes air discharge means for discharging air from a molding-surface side for molding a rubber article to a back-surface side. The air discharge means is formed as an annular hollow penetrating from a molding surface to a back surface of the rubber article mold. The annular hollow has an inflow area where the air on the molding-surface side flows in, a discharge area for discharging the air having flowed in from the inflow area to the back-surface side, and an intermediate area communicating with the inflow area and the discharge area and smaller or larger in diameter than the inflow area and the discharge area.

A tire tread may be formed by simultaneously extruding a tread cap formed of a first material and a tread base formed of a second material having a substantially different stiffness property than the first material. One tread element may have a strip of the second material extending from the tread base into the tread cap and, a second tread element may also have a strip of the second material extending from the tread base into the tread cap.

A preformer (1) is designed to extrude jointly a plurality of elastomer mixes in a direction of flow (X1), in order to form a profiled element, the preformer comprising for this purpose, superimposed in a direction of stacking (Z1), transverse to the direction of flow (X1), a first channel (11), a second channel (12) which is separated from the first channel (11) by a first partition (15), then a third channel (13), separated from the second channel (12) by a second partition (16), the preformer also comprising a stiffener (20) formed integrally with the first partition (15) and the second partition (16), and extends through the second channel (12), having a leading edge (21) which splits the flow of elastomer material following the second channel (12).