A device for processing thermoplastic plastic includes a storage container for receiving pieces of plastic particles or a conveying line for conveying the pieces of plastic particles, and a conveying screw following the storage container/the conveying line at a transfer opening. The device also includes an extruder following the conveying screw and an air outlet arranged opposite the transfer opening and directed at this opening. In a method for operating the device, an air stream is aligned with the transfer opening. The strength and/or the direction of the air stream is adjusted or controlled as a function of a load on the extruder.

Methods for extrusion of polyolefins (112) that control specific energy input to the extruder (102) for gel reduction. Disclosed herein is an example method for forming plastic products (120, 208) with reduced gels, comprising: melting a polyolefin resin (112) in extruder (102) to form a melt; adjusting specific energy input in the extruder (102) to reduce gels in the melt; and forming the melt into a polyolefin product (120, 208). Disclosed herein is also an example method for forming plastic products (120, 20) with reduced gels, comprising: melting a polyolefin resin in extruder (102) to form a melt; selecting a throttle valve (104) position for gel reduction; setting the throttle valve (104) at the selected throttle valve (104) position to restrict flow of the melt out of the extruder (102); and forming the melt into a polyolefin product (120, 208).

Methods for extrusion of polyolefins (110) that utilize melt temperature to control molecular weight and also reduce gels. Disclosed herein is an example method for controlling polymer chain scission in an extrusion system (100), comprising: melting a polyolefin resin (110) in extruder (102) at a first melt temperature to form a first melt (112); passing the first melt (112) through a screen pack (106); forming the first melt 112) into a first polyolefin product (116, 118); melting additional polyolefin resin (110) of the same grade in the extruder (102) at a second melt temperature to form a second melt (112), wherein the second melt temperature differs from the first melt temperature by 5 C. or more to control chain scission in the extruder (102); passing the second melt (112) through the screen pack (106); and forming the second melt (112) into a second polyolefin product (116, 118).

The invention relates to a method for the online monitoring of film quality during a production process for a plastic film, in particular a blown film or a continuously cast film, in which method the film material (1) is fed out of an outlet device (40) that is designed as a melt lug (4) by a transport device (10). The film material (1) cools on or in front of the transport device (10) and the film material (1) solidifies in front of or on the transport device (10).

A device (1a . . . 1i) for processing thermoplastic plastic is described, comprising a storage container (2) for receiving pieces of plastic particles or a conveying line (14) for conveying the pieces of plastic particles, and a conveying screw (3) following the storage container (2)/the conveying line (14) at a transfer opening (A). The device (1a . . . 1i) also comprises an extruder (4) following the conveying screw (3) and an air outlet (7) arranged opposite the transfer opening (A) and directed at this opening. A method for operating the device (1a . . . 1i) is also described, in which an air stream is aligned with the transfer opening (A). The strength and/or the direction of the air stream is adjusted or controlled as a function of a load on the extruder (4).

An apparatus (1) for optical inspection of a mass of polymeric material (2) passing through an extruder (3) having a hollow extrusion cylinder (4) extending elongately in a longitudinal direction comprises an optical sensor (8) which can be operatively coupled to the extrusion cylinder (4) and having an infrared light emitter (8a) and a receiver (8b) configured to measure a measurement parameter representing an optical property of the polymeric material (2) inside the extrusion cylinder (4) and is characterized in that it comprises a plurality of the optical sensors (8) which can be operatively coupled to the extrusion cylinder (4) in a plurality of measurement sites located in succession and spaced from each other along the longitudinal direction and a processor (9) programmed to acquire a plurality of measurement signals containing the measurement parameters measured by the corresponding optical sensors (8) and programmed to process the plurality of measurement signals in order to calculate a corresponding plurality of values of a control parameter indicating a physical state of the polymeric material (2) as a function of a longitudinal position.

The invention relates to a method for checking the silanization of pale-colored fillers, where a mixture comprising at least one silanized pale-colored filler, preferably silanized silica, and comprising at least one rubber is irradiated with ultrasound waves in a frequency range of 4 to 10 MHz, preferably of 5 to 7 MHz, and the signal strength of the ultrasound waves is determined after transmission through the rubber mixture, where the relative attenuation coefficient .sub.rel of the rubber mixture in the frequency range of the ultrasound waves is determined, the standard deviation of the relative attenuation coefficient .sub.rel is determined, and .sub.rel and are used for detection of incipient crosslinking of the rubber mixture.

A method for measuring a degree of cross-linking of a component of elastomeric material obtained as a result of a hot-forming process, includes a preliminary calibration step in which a plurality of samples are provided, made of the same material as the component. The samples have different degrees of cross-linking following respective hot-forming processes conducted for different periods of time. The preliminary calibration step includes providing a measuring device having an electrical circuit, in which a voltage generator is arranged in series with metal contacts configured to selectively receive a sample, and an ammeter, positioning a sample between said metal contacts, providing a predetermined voltage value, and detecting the corresponding current value by means of said ammeter. The aforesaid steps are repeated for each sample so as to obtain a calibration map that associates a given degree of cross-linking of the material constituting said component with each determined value of electrical conductivity.