Davis-standard Corporation

John P Christiano

Michael R Thompson

Thomas J Oravits

John Radovich

Edward J Smith

Andrew A Merckel

Jason Baird

Norton Wheeler

Robert F Moeller

Saulius Tomas Eiva

Frederick C Suppon

Chad Allen Biron

Joseph A Wnuk

Hassan Helmy

Alexandre MacGregor

Christopher Rosivach

Tyler Robert McKenna

Alexandre Macgregor

Saulius T Eiva

Tyler Robert Mckenna

T Eiva Saulius

Biron Chad Allen

A tube forming apparatus for forming polymeric tubing includes a housing between rear and discharge ends. The tube forming apparatus includes a core tube assembly with an exterior core tube and an inner core tube positioned partially therein and in an interior area of the housing. The tube forming apparatus includes a die that has an inner die-surface. A diverter tip is mounted in and extends from the inner core tube into the die forming a die opening between the die and the diverter tip. The tube forming apparatus includes a core tube adjustment system mounted proximate the rear end which includes an axial displacement device configured to axially position the core tube assembly for modulating wall thickness of the tube and/or an angular displacement device configured to modulate the inner core tube for modulating concentricity of the tube.

Polymeric tube forming apparatus with a multi-dimensional control system

An extrusion apparatus includes a diagnostic system with a material processing section and an extruder screw disposed for rotation in a barrel and surrounded by a shroud assembly. The apparatus includes a temperature control system with heater sand cooler. The apparatus includes a speed control apparatus that has a drive unit and a speed variation device that is coupled to the extruder screw. The apparatus includes a diagnostic system in communication with the material processing section and/or the speed control apparatus. The diagnostic system includes a sensor system in communication with the material processing section and/or the speed control apparatus; and a computer processor in communication with the sensor system and a computer. The computer processor includes a computer readable medium that employs one or more algorithms and that are executable by the computer to generate signals characterizing performance of the material processing section and/or the speed control apparatus.

Diagnostic troubleshooting system for an extrusion system

A screw for a plasticating apparatus has one or more helical flights. A portion of the screw has a plurality of advancing grooves arranged in a noncontinuous helix cut in the screw. The advancing grooves are dimensioned to receive material therein as the material is conveyed through the barrel. The screw has a plurality of noncontinuous cross-cut grooves traversing one or more of the advancing grooves. The cross-cut grooves have a second helix angle greater than the first helix angle and less than ninety degrees; and/or one or more of the cross-cut grooves have a third helix angle of about ninety degrees.

Plasticating apparatus screw having grooves of varying angles and depths

A casting apparatus for manufacturing polymer film includes a die for discharging a molten polymer and having discharge direction oriented at a discharge angle offset from horizontal. The apparatus includes a first chill roll having a first diameter and a second chill roll having a second greater diameter. There is a first gap between the first chill roll and the second chill roll. The discharge angle is of a predetermined magnitude to gravity assist delivery of the molten polymer to the first gap. The second chill roll is positioned to gravity support the film exiting the first gap along a first length of a first side of the film. A first polishing roll is positioned downstream first and second chill rolls. The first polishing roll engages and cools a second length of a second opposite side of the film. The first length is substantially equal to the second length.

Casting apparatus for manufacturing polymer film

A film casting apparatus includes a die which has a non-zero angled discharge direction relative to a horizontal plane. A chill roll is positioned downstream of the die. A film displacement device is positioned proximate to the chill roll and is configured to position the molten polymer on the chill roll and establish the thickness of the film. The non-zero discharge angle is of a predetermined magnitude to gravity assist delivery of the molten polymer to the chill roll. The chill roll is positioned to gravity support the polymer film along a first length of a first side of the polymer film. A first polishing roll is positioned downstream of the chill roll and engages and cools a second length of a second side of the polymer film which is opposite the first side. The first length is substantially equal to the second length.

A heater-cooler system includes a plurality of heaters in thermal communication with a barrel of an extruder. The heater-cooler system includes a plurality of shroud assemblies that each define a cavity between a shroud assemblies and one of the heaters. Each heater is enclosed by one of the shroud assemblies. Each of the shroud assemblies has an intake port and an exhaust port. The heater-cooler system includes a blower connected to the intake port. The blower delivers air to the cavity. A portion of the each of the shroud assemblies at the exhaust port defines a flap moveably integrated therewith. The flap is opened by an increase in pressure in the cavity caused by operation of the blower. The flap seals the cavity in a closed position upon termination of blower operation. The flap is configured as a poppet valve.

Heater-cooler system for a barrel of an extruder and a method of using the same

A heater-cooler system includes a plurality of heaters in thermal communication with a barrel of an extruder. The heater-cooler system includes a plurality of shroud assemblies that each define a cavity between a shroud assemblies and one of the heaters. Each heater is enclosed by one of the shroud assemblies. Each of the shroud assemblies has an intake port and an exhaust port. The heater-cooler system includes a blower connected to the intake port. The blower delivers air to the cavity. A portion of the each of the shroud assemblies at the exhaust port defines a flap moveably integrated therewith. The flap is opened by an increase in pressure in the cavity caused by operation of the blower. The flap seals the cavity in a closed position upon termination of blower operation.

A method for maximizing a width of a pre-stretch film includes providing polymer being suitable for producing the pre-stretch film. A pre-stretch film having strips of increased thickness is produced. The method includes coordinating a thickness of the strips of increased thickness with a formation of edge thickening caused by neck-in during stretching of the pre-stretch film.

Apparatus for manufacturing and processing pre-stretch films having strips of increased thickness

An axially elongated extruder screw includes a screw body having an axially extending extruding portion defined by a feed section at an inlet end of the screw, a metering section at an outlet end of the screw and a barrier section between the feed and metering sections. At least one helical primary flight extends about and is coaxial with the screw body. The primary flight and the screw body cooperate to form a channel in the feed section for conveying resinous material to the barrier section. The barrier section includes at least one helical secondary flight extending from the primary flight about the screw body which in turn defines a first surface of revolution between the primary and secondary flights. At least one helical tertiary flight is positioned between the primary and secondary flights and also extends about the screw body which defines a second helical surface of revolution between the secondary and tertiary flights. A third surface of revolution is formed between the primary and tertiary flights and extends axially along the barrier section. A series of circumaxially contiguous cam-like forms are created by a second and third surfaces of revolution, each cam-like form being defined by a segment of the screw having a root, a crest, a first surface portion extending radially outwardly from the root to the crest in the direction of screw rotation, and a second surface portion extending radially inwardly from the crest to the root.

Extruder screw

An axially elongated extruder screw includes a screw body having an axially extending extruding portion defined by a feed section at an inlet end of the screw, a metering section at an outlet end of the screw and a barrier section between the feed and metering sections. At least one helical primary flight extends about and is coaxial with the screw body. The primary flight and the screw body cooperate to form a channel in the feed section for conveying resinous material to the barrier section. The barrier section includes at least one helical secondary flight extending from the primary flight about the screw body which in turn defines a first surface of revolution between the primary and secondary flights. At least one helical tertiary flight is positioned between the primary and secondary flights and also extends about the screw body which defines a second helical surface of revolution between the secondary and tertiary flights. A third surface of revolution is formed between the primary and tertiary flights and extends axially along the barrier section. A series of circumaxially contiguous cam-like forms are created by a respective one of the second or the third surfaces of revolution, each being defined by a segment of the screw having a root, a crest, a first surface portion extending radially outwardly from the root to the crest in the direction of screw rotation, and a second surface portion extending radially inwardly from the crest to the root.

An axially elongated extruder screw includes a screw body having an axially extending extruding portion defined by a feed section at an inlet end of the screw, a metering section at an outlet end of the screw and a barrier section between the feed and metering sections. A first helical primary flight extends continuously about and is coaxial with the screw body substantially along the entire length of the extruder screw. A second helical primary flight extends continuously at least part-way along the feed section to the outlet end of the extruder screw. The barrier section of the extruder screw defines first and second barrier flights positioned between the primary flights and cooperating therewith to form first and second melt and solids channels that extend along the barrier section of the extruder screw.

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Old Lyme, CT, United States of America

John P Christiano