Wisconsin Alumni Research Foundation

Makerbot Industries, LLC

Rauwendaal Extrusion Engineering, Inc.

Icipc-instituto De Capacitacion E Investigacion Del Plastico Y Del Caucho

The Madison Group: Polymer Processing Research Corp.

Tim Andreas Osswald

Michael Joseph Kobida

Charles John Haider

Cedric James Kovacs-Johnson

Taylor Michael Fahey

William Mauricio Aquite

Paul J Gramann

Nicola J Ferrier

Alberto Naranjo Carvajal

Chris J Rauwendaal

Maria Del Pilar Noriega Escobar

Alec James Redmann

Allen Jonathan Román

Martin Launhardt

Christian Schäfer

Bruce A Davis

Bruce Davis

Aspects of the disclosure are directed to methods and apparatus involving the extrusion of polymers or other materials. As may be implemented in accordance with various embodiments, a polymer is delivered into an inlet of a nozzle structure having the inlet and an outlet. The polymer is viscously heated and melted by rotating the nozzle structure about an axis extending through the inlet and the outlet, therein facilitating extrusion of the melted polymer through the nozzle structure outlet. A polymer supply may deliver the polymer into the nozzle structure inlet, and a coupler may facilitation rotation of the nozzle structure. A driver may further operate to control rotation of the nozzle structure relative to the coupler, for instance by generating a rotational output that causes rotation of the nozzle structure.

Rotating nozzle structure and method

Polymer pellets are formed using laminar gas flow within a downstream gas conduit, as may be implemented consistent with one or more embodiments herein. A gas channel directs gas to an outlet of a polymer extrusion mandrel via which a polymer melt is extruded. A downstream gas conduit extends away from the outlet of the polymer extrusion mandrel, and provides laminar gas flow along the polymer melt extending from the extrusion mandrel, and within the downstream gas conduit. Using this approach, laminar flow can be maintained along an initial portion of the polymer melt, and used to control the subsequent formation of pellets therefrom.

Pelletization gas guide

A filament for use with a printer head of a 3D printer includes an exterior surface and an interior surface having color selectively applied thereto, where the color of the interior surface is visible through the exterior surface, and where the color is applied only to the interior surface such that the color remains substantially isolated from components of the printer head when traveling therethrough.

Coloring filament for three-dimensionally printing colored objects

An assembly that is configured to be coupled to and communicate with a 3D printer having a printer head includes a color-application unit positioned upstream of the 3D printer. The color-application unit is configured to receive a filament and direct the filament to the printer head of the 3D printer. The assembly also includes a color applicator coupled to the color-application unit. The color applicator is operable to selectively apply color to an interior surface of the filament.

System for use with three-dimensional printer and method for using the same

A three-dimensional printer effects color changes in an extrudate using a color-application unit applying a colorant to the interior of a filament before it is melted within an extruder. Specifically, the color-application unit may receive a filament (or portions thereof) having an exposed interior surface, where color applicators are actuated to apply one or more colors to the interior surface of the filament in order to modify the extruded color. The filament may then be coupled, collapsed, or otherwise closed about the interior surface, e.g., by a mechanical coupler, to substantially enclose the interior surface of the filament, which is then fed to the extruder for fabricating a colored object in a three-dimensional fabrication process. By enclosing the colored surface within the filament before melting for extrusion, transition effects of a color change can be mitigated and transition time for a substantially complete change in color can be significantly reduced.

Three-dimensional printer with integrated coloring system

Polymer pellets are formed using air to influence the separation of polymer from a polymer melt. In accordance with one or more embodiments, a polymer material is extruded through a nozzle to form a polymer melt extending from the nozzle. A non-uniform thickness is generated in the polymer melt using a gas or gasses to apply a drag force to the polymer melt. This drag force reduces a thickness of a portion of the polymer melt adjacent the nozzle, and the polymer melt is fractured into discrete droplets at the reduced thickness. The discrete droplets are then solidified to form pellets.

Polymer pelletization via melt fracture

In a method and apparatus for micropelletization of a polymeric material, a melt thread of the polymeric material is formed by an extruder. A flowing gas is directed to the melt thread to form Rayleigh disturbances in the melt thread and break up the melt thread into discrete microdroplets. The discrete microdroplets are then solidified to form micropellets.

Method and apparatus for micropelletization

A device to visualize in-line the polymer melting in plasticating screw machines has an external metallic cylinder to be fixed in radial position regarding the barrel of the plasticating machine, a bushing with an optical window clear to the visible light spectrum resistant to pressure and temperature positioned in such a way that its external face is tangent to the internal surface of the barrel of the plasticating machine, and an internal metallic cylinder to guide the coolant gas and allow the use of an observation probe with operating temperature limits and an illumination system.

Device to visualize in-line and quantify the polymer melting in plasticating screw machines without significantly affecting its thermal regime

A screw extruder (10) having a barrel (18) which has a bore (26) defining an inner surface (44) and one or more extruder screws (28), positioned within the bore (26). The extruder screw or screws (28) include a central shaft (34) and one or more screw flights (30). The extruder screw or screws (28) farther including one or more dispersive mixing elements (204), (234), (308), (406), (508), (558), which interact with the inner surface of the barrel (44) to form one or more progressively narrowing passages (46) through which material is forced into multiple regions of high elongational and shear stress (480, (120), (214), (310), (410), (510), (564). A second preferred embodiment is a screw extruder (10) having a barrel (18) having a bore (26) defining an inner surface (44) and one or more extruder screws (600), (701), positioned within the bore (26). The extruder screw or screws (600), (701) include a central shaft (602), (706) and a number of dispersive mixing elements (604), (608), (714), which are configured and positioned to form a number of progressively narrowing passages (606), (716) through which material is forced into multiple regions of high elongational and shear stress (608), (718).

Screw extruder with improved dispersive mixing elements

A static mixer head that provides not only distributive mixing, but also dispersive mixing. Distributive mixing is accomplished by providing a series of baffles along the length of the mixing tube, each baffle being angled relative to the previous baffle. Dispersive mixing is accomplished by utilizing baffles that define a converging pathway for the mixing materials. The converging pathway promotes elongation and corresponding dispersion of the mixing materials. In one embodiment, the baffles are teardrop-shaped, and are arranged so that multiple baffles are generally parallel and adjacent to one another. Preferably, the baffles are oriented such that the mixing materials flow from the small tail portion of the baffles toward the larger head portion of the baffles, thereby encountering a gradual compressive force and corresponding elongation.

Growing community of inventors

Madison, WI, United States of America

Tim Andreas Osswald