Improvements in the extrusion of thermohardenable materials are achieved by cooling the material in the initial zone of the extruder and reducing residence time by use of a prescribed length to diameter ratio and screw speed, particularly useful for intermittent application during robotically controlled mass production.

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 floor or wall panel and to a method of producing such panel. The panel comprise at least one core layer comprising at least one composite material, said composite material comprising at least one mineral filler, and at least one thermoplastic binder, which are present in a preferred ratio and composition such that a relatively light weight and rigid panel is obtained.

A system for producing a homogenous extrudate powder coating composition having predetermined properties, the system comprising a color library database that is configured to store one or more input formulation data objects capable of use in controlling the inputs and operation of an electronically controlled homogenous extrudate mixer.

The present invention relates to a processing technology for manufacturing seepage irrigation pipe with alternating effluent sections and non-effluent sections, and in particular, to the field of underground seepage irrigation in agriculture and forestry. The processing technology combines the production unit for water-effluent pipes with the production unit for non-effluent pipes, and produces the seepage irrigation pipeline by adjusting the raw material ratios, controlling the spindle speed, spindle acceleration time, and spindle deceleration time of the two pipeline production units, to generate a seepage irrigation pipe with alternating effluent sections and non-effluent sections. The lengths of the effluent sections and non-effluent sections can be adjusted, the pipe wall thickness can also be adjusted by adjusting the inner and outer diameter of the internal mold of the pipe forming unit, a seepage irrigation pipe with alternating effluent sections and non-effluent sections is environment-friendly, efficient, water-saving, and useful for underground irrigation.

An electrical connector with thin interior walls is made by extruding a polymer or polymer composite into a sheet of approximately 0.25 mm to 0.5 mm thickness. The sheet is then calendered to a thickness of about 0.05 mm to 0.3 mm. The calendered sheet is cut into notched sections. The notched sections are assembled and placed into an injection molded housing of a connector. The sections are secured in place by using an adhesive, force fit, snap fit, or welding process to form the thin interior walls of the connector.

The invention generally relates to a method of making a plastic aggregate, and its use to make concrete products. The aggregate is formed by providing a granulated waste plastic material, introducing the granulated waste plastic material into an extruder having a die, the die having a ratio of die nozzle open area to die land area of about 1:10 to about 1:40, and extruding the granulated waste plastic material through the extruder to generate an extruded plastic aggregate. The method can include the presence of controlled cooling, the addition of additives and treatment of the surface of the aggregate to produce a desired aggregate that can be used to make a concrete product with desired properties, such as compressive strength and weight.

A method of extruding filament comprises the steps of cutting a bulk source material into pieces having size S.sub.1, performing a first extrusion pass comprising the steps of melting the pieces in an extruding device at a temperature T.sub.1 and extruding a first filament at an extrusion speed V.sub.1, and performing at least one additional extrusion pass k comprising the steps of cutting the first filament into pieces having size S.sub.k, melting the pieces in an extruding device at temperature T.sub.k, and extruding a final filament at an extrusion speed V.sub.k. A system for extruding filament is also described.

Described is a system for transferring a dose of polymeric material comprising a head for supplying the polymeric material and at least one conveying device, provided with a conveying wall, which is configured for advancing along a path through the supplying head for transferring to the conveying wall a dose obtained from the polymeric material supplied from the supplying head; and wherein the supplying head comprises a duct which is provided with a straight outfeed region extending along an axis which is configured to supply the polymeric material to a supplying outfeed. The outfeed region comprises at least a first zone and a second zone facing each other, the supplying head having at least one variation configuration in which the first zone and the second zone are asymmetrical to disturb a flow of polymeric material in the outfeed region in such a way as to control the supplying direction of the polymeric material, supplied from the supplying outfeed and to transfer to the conveying wall. A method is also proposed for transferring the dose of polymeric material from the supplying head to the conveying device and a method for supplying the dose.