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).

A group of hollow modules through which the material to be extruded flows, is provided that includes at least: a rectangular heating-shaping module (6), in which the material undergoes a temperature increase and takes on the desired shape; and a tubular cooling-solidification module (8), in which the material, which has taken on the desired shape, changes from liquid to solid with said shape. A heating-reaction module (2) is provided upstream of module (6). The heating-reaction module (2) includes an interchangeable hollow tube (3) with an external heating system (4). The heating-shaping module (6) includes detachable parts (7) and includes another external heating system (4) based on the auto-acceleration of the curing reaction and of the heat supply from said system (4). The tubular portion between module (2) and module (6) includes a shaping coupling (5) equipped with a through-hole. The extrusion module includes a circuit through which the polymer flows into at least two push compartments (20).

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 plant for producing an extruded silicone intermediate has a mixer/extruder for mixing and subsequently extruding a silicone compound for producing a raw silicone extrudate. A heating apparatus of the plant serves for crosslinking the raw extrudate to give the crosslinked silicone intermediate. The result is a plant with which a silicone intermediate of this kind can be produced more economically.

A procedure for the devulcanization of scrap rubber and/or elastomers and apparatus therefor. The abstract of the disclosure is submitted herewith as required by 37 C.F.R. 1.72(b). As stated in 37 C.F.R. 1.72(b): A brief abstract of the technical disclosure in the specification must commence on a separate sheet, preferably following the claims, under the heading Abstract of the Disclosure. The purpose of the abstract is to enable the Patent and Trademark Office and the public generally to determine quickly from a cursory inspection the nature and gist of the technical disclosure. The abstract shall not be used for interpreting the scope of the claims. Therefore, any statements made relating to the abstract are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.

A method for performing an infrared treatment includes the steps of receiving an extruded product and feeding the extruded product to an oven including at least one lamp unit. The lamp unit includes a lamp, a reflective surface enclosing a first side of the lamp and positioned to direct radiation from the lamp, and a glass disposed between a second side of the lamp and an extruded product, wherein the glass separates the lamp and the extruded product. The method further includes the step of creating cross-linking between layers of the extruded product by directing the radiation at the extruded product. Still further, the method includes the steps of directing a first gas flow at a surface of the product and directing a second gas flow at the glass.

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 instant invention provides a polyethylene blend-composition suitable for blown films, and films made therefrom. The polyethylene blend-composition suitable for blown films according to the present invention comprises the melt blending product of: (a) from 0.5 to 4 percent by weight of a low density polyethylene having a density in the range of from 0.915 to 0.935 g/cm.sup.3, and a melt index (I.sub.2) in the range of from greater than 0.8 to less than or equal to 5 g/10 minutes, and a molecular weight distribution (M.sub.w/M.sub.n) in the range of from 6 to 10; (b) 90 percent or greater by weight of a linear low density polyethylene composition has a density in the range of 0.900 to 0.935 g/cm.sup.3, a molecular weight distribution (M.sub.w/M.sub.n) in the range of 1.5 to 4.5, a melt index (I.sub.2) in the range of 0.1 to 5 g/10 minutes, a molecular weight distribution (M.sub.z/M.sub.w) in the range of less than 3, vinyl unsaturation of less than 0.1 vinyls per one thousand carbon atoms present in the backbone of said composition, and a zero shear viscosity ratio (ZSVR) in the range from 1 to less than 2; (c) optionally a hydrotalcite based neutralizing agent; (d) optionally one or more nucleating agents; (e) and optionally one or more antioxidants.

The inner liner is composed of a polymer layer stack including a first layer containing an SIBS and a second layer containing at least one of an SIS and an SIB. At least one of the first layer and the second layer is a polymer composition containing one of a C4 polymer obtained by polymerizing a monomer unit having 4 carbon atoms, a layered clay mineral with an organic compound intercalated therein and at least one kind of rubber component selected from the group consisting of a natural rubber, an isoprene rubber and a butyl rubber. The second layer is arranged to come into contact with a rubber layer of the carcass ply. The inner liner has a thickness Ge at a shoulder position Pe exceeding 100% and being less than or equal to 500% of a thickness Gc at a crown central position Pc.

A paperboard substrate that can be used to provide a food packaging particle is provided having a water vapor barrier layer comprising HDPE in combination with a nucleating agent which is extruded on to a paperboard substrate. The resulting substrate has sufficiently good water vapor barrier when properties that dry foods such as cereals do not require a bag or inner liner as a separate moisture barrier.