A method and apparatus for manufacturing a combined polymeric structure are disclosed. The apparatus includes an extruder body (110), a die (120) configured to receive flowing polymeric material from the extruder body (110) and a motion unit. The die includes a hollow inner die (122), a protecting sleeve (124) located within the inner die (122) and an outer die (125) located at an exit (128) end of the hollow inner die (122). The motion unit is configured to cause bidirectional translational motion of the hollow inner die (122) relative to the outer die (125).

A three-dimensional (3D) drawing pen can include a housing that has a port that permits insertion of a strand of material into the housing. The strand can be moved through the housing toward a nozzle assembly configured to permit the strand to be extruded out of the 3D drawing pen in a form that retains its shape against gravity in free space to draw a 3D object.

A three-dimensional (3D) drawing pen can include a housing that has a port that permits insertion of a strand of material into the housing. The strand can be moved through the housing toward a nozzle assembly configured to permit the strand to be extruded out of the 3D drawing pen in a form that retains its shape against gravity in free space to draw a 3D object.

A compressible biomass carrier for use in fluid treatment systems is disclosed. The biomass carrier includes an extruded circumferential mesh-like structure and elongated elements positioned in a space confined by the circumferential mesh-like structure and at least some of the elongated elements are joined to an inner portion of the mesh-like structure.

The present disclosure provides a novel method of 3D printing using frontal polymerization chemistry. This method enables the printing of tough, high quality thermosets in a short time with the option of adding fiber reinforcement. As such, it facilitates fabrication of mechanically robust 3D-printed devices and structures.

The present disclosure provides a novel method of 3D printing using frontal polymerization chemistry. This method enables the printing of tough, high quality thermosets in a short time with the option of adding fiber reinforcement. As such, it facilitates fabrication of mechanically robust 3D-printed devices and structures.

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.

An apparatus comprising a three-dimensional (3D) drawing pen can permit a user to draw a 3D object in free space that retains its shape against gravity. The 3D drawing pen can include a body, a sensor supported by the body, a motor, and a nozzle assembly disposed at a distal end of the body. The motor can drive material toward the nozzle assembly upon actuation by the sensor. The nozzle assembly can include an extruder and an exit nozzle. The extruder can have a heating element for melting material and permitting the material to be extruded out of the exit nozzle in a solid form upon actuation of the motor by the sensor. The user can manipulate the 3D drawing pen to draw a 3D object that retains its shape against gravity.

An apparatus comprising a three-dimensional (3D) drawing pen can permit a user to draw a 3D object in free space that retains its shape against gravity. The 3D drawing pen can include a body, a sensor supported by the body, a motor, and a nozzle assembly disposed at a distal end of the body. The motor can drive material toward the nozzle assembly upon actuation by the sensor. The nozzle assembly can include an extruder and an exit nozzle. The extruder can have a heating element for melting material and permitting the material to be extruded out of the exit nozzle in a solid form upon actuation of the motor by the sensor. The user can manipulate the 3D drawing pen to draw a 3D object that retains its shape against gravity.

A sizer for cooling an extrudate, which includes a core and a housing. The core includes an extrusion channel which accommodates the extrudate, a core cooling channel, and a core vacuum channel in fluid communication with the extrusion channel. The housing includes a housing cooling channel and a housing vacuum channel. The core cooling channel is in fluid communication with the housing cooling channel, and the core vacuum channel is in fluid communication with the housing vacuum channel.