A production method for a resin molding includes: preparing fiber-reinforced resin by continuously feeding a long roving containing a reinforcing fiber, with its length unchanged, into base resin that has been heated to be plasticized; forming a resin molding using the fiber-reinforced resin; and heating the formed resin molding in a non-oxidizing atmosphere.

The sheet-like rubber forming device has a die body which has an opening having a predetermined cross sectional shape, and a variable die lip which is arranged in a front side of the die body and can change the height of the opening. The variable die lip is constructed by a first movable body and a second movable body. The die lip control unit controls the variable die lip so as to drive the first movable body in an opening direction from a state in which the first movable body and the second movable body are closed when the forming is started, hold the positions of the first movable body and the second movable body after reaching a predetermined height, and drive the second movable body in a closing direction when the forming is finished.

The extrusion apparatus includes a screw in a fixed barrel. The barrel has a feed inlet and an outlet with an extrusion nozzle which discharges into the nip between first and second rotary rolls that can rotate in opposite directions. The apparatus also has a first means for rotating and a first control means that are able to synchronize the speed of rotation of the first roll and the screw and has a second means that is able to rotate the second screw at a different speed of rotation than the first roll. The first control means can regulate the speed of rotation of the screw depending on the width of the strip, and a second control means can regulate the speed of rotation of the second roll depending on the thickness of the strip.

A method for controlling the thickness of a continuous elongated element made of elastomeric material, applied according to coils wound on a forming support, includes: advancing a head end of the continuous elongated element toward the forming support; subjecting, during the advancement, the continuous elongated element to a first stretching with a first stretch coefficient before applying on the forming support; and subjecting, during the advancement, the continuous elongated element to a second stretching with a second stretch coefficient during the application on the forming support. During the first stretching, a span of the continuous elongated element adjacent to the head end is stretched with a supplementary stretch coefficient greater than the first stretch coefficient, in a manner so as to confer, also to the span adjacent to the head end, a stretch and a section similar or substantially equivalent to those of the rest of the continuous elongated element.

A system and a method for controlling an extrusion line of mixed plastics, wherein a temperature of one or more heaters of the extrusion line is measured by one or more first sensors; a temperature and pressure of an extruder head is measured by one or more pairs of second sensors; a coolant temperature of a set of dies is measured by one or more third sensors; an amperage of an extruder motor is measured by an ammeter; a pulling speed of a pulling unit is measured by a tester; and wherein a computing device configured to receive the measurement data from the one or more first sensors, from the one or more pairs of the second sensors, from the one or more third sensors, from the ammeter, from the tester.

Disclosed are techniques for mitigating vent flow into a vent attachment on an extruder vent of an extruder. The vent attachment has a vent attachment port configured to release gases from the extruder vent. The techniques include monitoring temperature via a temperature probe mounted at least partly inside an interior opening of the vent attachment. The temperature probe is communicatively coupled to a programmable logic controller (PLC). A region of the vent attachment adjacent the temperature probe is cooled so as to reduce an operating temperature of the region and of the temperature probe. Vent flow is detected in response to the PLC determining a rate of temperature change of the temperature probe exceeding a predetermined threshold rate and thereby indicating presence of the material in the vent attachment port.

A method for controlling the thickness of a continuous elongated element made of elastomeric material, applied according to coils wound on a forming support, includes: advancing a head end of the continuous elongated element toward the forming support; subjecting, during the advancement, the continuous elongated element to a first stretching with a first stretch coefficient before applying on the forming support; and subjecting, during the advancement, the continuous elongated element to a second stretching with a second stretch coefficient during the application on the forming support. During the first stretching, a span of the continuous elongated element adjacent to the head end is stretched with a supplementary stretch coefficient greater than the first stretch coefficient, in a manner so as to confer, also to the span adjacent to the head end, a stretch and a section similar or substantially equivalent to those of the rest of the continuous elongated element.

A method for controlling the thickness of a continuous elongated element made of elastomeric material, applied according to coils wound on a forming support, includes: advancing a head end of the continuous elongated element toward the forming support; subjecting, during the advancement, the continuous elongated element to a first stretching with a first stretch coefficient before applying on the forming support; and subjecting, during the advancement, the continuous elongated element to a second stretching with a second stretch coefficient during the application on the forming support. During the first stretching, a span of the continuous elongated element adjacent to the head end is stretched with a supplementary stretch coefficient greater than the first stretch coefficient, in a manner so as to confer, also to the span adjacent to the head end, a stretch and a section similar or substantially equivalent to those of the rest of the continuous elongated element.

The invention relates an extrusion device (100) for extruding a semi-finished product made of elastomeric material, comprising an extrusion body (10) extending along a feeding direction (A) and a pump (20) arranged downstream of the extrusion body (10) along said feeding direction (A). The extrusion body (10) comprises a hopper (30) for loading an elastomeric material and an extrusion screw (50) extending along said feeding direction (A) and having an inlet portion (50a) arranged close to the hopper (30) and an exit portion (50b) arranged close to the pump (20). The extrusion body (10) also comprises a motorised roller (40) arranged at the inlet portion (50a) of the extrusion screw (50) and configured to receive the elastomeric material from the hopper (30) and feed it to the extrusion screw (30). The extrusion screw (50) has a length and a diameter such that the ratio between length and diameter is comprised between 4 mm and 8 mm. The invention also relates to an extrusion process carried out through the aforementioned extrusion device (100).

An extrusion apparatus intended for the manufacture of a coextruded profiled element P for tyres, produced from rubber compounds of various compositions, comprises a profiling device (30) arranged at the outlet of at least two flow channels (34, 35) for rubbery compounds of different composition. The said channels receive the compounds from positive-displacement contrarotating twin-screw extruders (10, 20), the screw flights interpenetrating and having conjugated profiles.