Thermoformed polymeric foam articles and methods of forming the same are described. In some embodiments, thermoformed articles are produced from multi-layer foamed sheet where the formed article has a density equal to or less than the precursor multi-layer sheet. One of the layers of the thermoformed article may be a polymer foam layer having a density reduction between 5% and 50% as compared to the solid polymer. Such polymer foam layers can be referred to as medium density or high density foams. Advantageously, the methods described herein are practical for commercial use and, for example, can be used to produce a variety of thermoformed articles suitable for use in many different applications.

Apparatus for injection of fluid into an extruder is provided, including a static mixer section with a pipe assembly coupled with the static mixer outlet and leading to the extruder barrel; the pipe assembly outlet and barrel injection opening have diameters less than the maximum internal diameter of the static mixer casing. The invention greatly simplifies the fluid injection apparatus used with extruders, while giving more efficient absorption of thermal energy with a minimum of environmental contamination, and the ability to inject multiple streams into the extruder.

Apparatus for injection of fluid into an extruder is provided, including a static mixer section with a pipe assembly coupled with the static mixer outlet and leading to the extruder barrel; the pipe assembly outlet and barrel injection opening have diameters less than the maximum internal diameter of the static mixer casing. The invention greatly simplifies the fluid injection apparatus used with extruders, while giving more efficient absorption of thermal energy with a minimum of environmental contamination, and the ability to inject multiple streams into the extruder.

A system for halogenating olefinic-based elastomer, the system comprising a first extruder, a first kneader vessel downstream of said first extruder and in fluid communication with said first extruder, a second extruder downstream of said first kneader vessel and in fluid communication with said first kneader vessel, a second kneader vessel downstream of said second extruder and in fluid communication with said second extruder; and a third extruder downstream of said second kneader vessel and in fluid communication with said second kneader vessel.

Apparatus (20) for injection of fluid into extrusion system components such as a preconditioner (24) or extruder (100) is provided, preferably as a composite assembly including a fluid injection valve (52) and an interconnected static mixer section (54). Alternately, use may be made of the fluid injection valve (52) or static mixer section (54) alone. The invention greatly simplifies the fluid injection apparatus used in extrusion systems, while giving more efficient absorption of thermal energy with a minimum of environmental contamination, and the ability to inject multiple streams into the extrusion systems.

The extrusion device of a solid film comprises a cell provided with an input opening of a material designed to form the solid film, and an output opening of the solid film from the cell. The device comprises a first heat exchanger for applying a first temperature to the output opening and a second heat exchanger for applying a second temperature in a first zone of the cell distinct from the output opening and a control circuit imposing first and second sets of first and second temperatures. The first set enables a volume of the material in solid phase to be formed. The second set enables a temperature gradient to be generated in the volume so as to generate a pressure forcing extrusion of the solid film via the output opening.

An extruder (100) for comestible material comprises a tubular barrel (104) and one or more elongated, axially rotatable, helically flighted screws (120, 122) within the barrel (104), where the barrel (104) has a delivery opening (114a). The extruder barrel (104) is equipped with an assembly (22) for delivery of fluid to the interior thereof, including a static mixing section (54) operable to blend the steam and water to create a blended mixture; the blended mixture is delivered to the barrel opening (114a) by means of a conveying assembly (84, 86) having a pipe assembly (86) with an outlet in communication with the barrel opening (114a); the pipe assembly (86) and opening (114a) have diameters less than maximum internal diameter of the static mixer casing (72).

A method for extruding a comestible material comprises the steps of passing comestible material into an extruder (100) with rotation of the extruder screw(s) (120, 122) and delivery of fluid comprising steam and water into an opening (114a) of the extruder barrel (104). The fluid delivery step comprises separately directing individual quantities of steam and water into the casing (72) of a static mixing section (54), and blending the steam and water to create a blended mixture, and then delivering the blended mixture into the barrel (114a). The blended mixture is delivered to the barrel opening (114a) by means of a conveying assembly (84, 86) having a pipe assembly (86) with an outlet in communication with the barrel opening (114a); the pipe assembly (86) and opening (114a) have diameters less than maximum internal diameter of the static mixer casing (72).

Apparatus (20) for injection of fluid into extrusion system components such as a preconditioner (24) or extruder (100) is provided, preferably as a composite assembly including a fluid injection valve (52) and an interconnected static mixer section (54). Alternately, use may be made of the fluid injection valve (52) or static mixer section (54) alone. The invention greatly simplifies the fluid injection apparatus used in extrusion systems, while giving more efficient absorption of thermal energy with a minimum of environmental contamination, and the ability to inject multiple streams into the extrusion systems.

A method for extruding a comestible material comprises the steps of passing comestible material into an extruder (100) with rotation of the extruder screw(s) (120, 122) and delivery of fluid comprising steam and water into an opening (114a) of the extruder barrel (104). The fluid delivery step comprises separately directing individual quantities of steam and water into the casing (72) of a static mixing section (54), and blending the steam and water to create a blended mixture, and then delivering the blended mixture into the barrel (114a). The blended mixture is delivered to the barrel opening (114a) by a conveying assembly (84, 86) having a pipe assembly (86) with an outlet in communication with the barrel opening (114a); the pipe assembly (86) and opening (114a) have diameters less than maximum internal diameter of the static mixer casing (72).