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).

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.

A method of monitoring stretchability of stretch films in a cast film method includes determining a position of a frost line of a film material, which is solidifying to form a film web, on a casting roller of a film machine, ascertaining a correlation of the determined position of the frost line with at least one target position, and comparing the ascertained correlation to at least one stretchability of the film material, which is assigned to the at least one target position.

A formulation includes a polymeric material and can be used to form an insulated container.

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 α.sub.rel of the rubber mixture in the frequency range of the ultrasound waves is determined, the standard deviation σ of the relative attenuation coefficient α.sub.rel is determined, and α.sub.rel and σ are used for detection of incipient crosslinking of the rubber mixture.

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).

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.

A method of monitoring stretchability of stretch films in a cast film method includes determining a position of a frost line of a film material, which is solidifying to form a film web, on a casting roller of a film machine, ascertaining a correlation of the determined position of the frost line with at least one target position, and comparing the ascertained correlation to at least one stretchability of the film material, which is assigned to the at least one target position.

A measurement system for monitoring an extruder or an injection moulding machine in operation, with a measurement device that generates a radar wave signal and emits it in the extruder or in the injection moulding machine, and detects a response signal corresponding to the emitted radar wave signal; and an evaluation device, that determines a run time t, phase shift and/or intensity change I of the radar wave signal on the basis of the detected response signal, and determines at least one operating parameter of the extruder or of the injection moulding machine on the basis of the determined run time t, phase shift and/or intensity change I of the radar wave signal, wherein the operating parameter points to a wear state of the extruder) or of the injection moulding machine. Further, a corresponding method and an extruder and an injection moulding machine with such a measurement system.