Disclosed in the present application are: a pen-type structure for mixing and discharging a bio-ink or a hydrogel: and a bio-ink or hydrogel printing method using same. The pen-type structure comprises: a cylindrical first barrel for housing a first screw; a cylindrical second barrel for housing a second screw, which is longer than the first screw and has a structure parallel with the first screw; a controller connected to a gear of the first screw and a gear of the second screw so as to drive the first screw and the second screw; two or more supply units formed in the first barrier and supplying a bio-ink or hydrogel material into the first barrel; and a bio-ink or hydrogel discharge unit which extends from the end portion of the second barrel on the opposite side of the controller, and which discharges bio-ink or hydrogel.

The process includes a non-crosslinked self-sealing composition which is introduced into an extrusion means, the geometric and thermodynamic characteristics of which have been specially adapted. The speed and temperature conditions of the extrusion means are adjusted so that, at an application nozzle forming the outlet die of the extrusion means, the self-sealing composition is crosslinked. The application nozzle is brought close to the internal surface of the casing previously set in relative motion with respect to the application nozzle, and an extruded and crosslinked bead that has a given width and profile is deposited directly on the internal surface of the casing.

Puck and collar alignment device embodiments facilitate simultaneous insertion of free end portions of screw shafts into open end portions of complementary drive couplings. The embodiments have alignment keys that correct deviations in alignment and rotation introduced while moving the screw shafts though a barrel of an extruder. Tapered front faces of the alignment keys incrementally adjust coaxial alignment, and tapered side faces of the alignment keys incrementally adjust rotational position cooperatively between the alignment devices and drive couplings. The coaxial and rotational position adjustments cooperate to simultaneously guide multiple alignment keys to fit within corresponding keyway sections while providing alignment of external splines on the screw shafts to interlock in a timed relationship with internal splines on the drive couplings during the simultaneous insertion.

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.

An extruder according to an embodiment includes: a screw configured to rotate around a rotation axis extending in one direction; a cylindrical cylinder extending in the one direction, the cylinder being configured to house the screw; a drive unit disposed at one end of the cylinder, the drive unit being configured to rotate the screw; a die disposed at the other end of the cylinder, the die being configured to discharge a raw material kneaded by the rotation of the screw as a strand; an adjustment unit disposed between the cylinder and the die, the adjustment unit being configured to adjust a flow-velocity distribution of the raw material flowing into the die; and a detection unit configured to detect a discharge amount of the strand discharged from the die.

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 twin-screw extrusion device is disclosed, which includes a barrel and a twin-screw mechanism, the twin-screw mechanism includes a first screw, a second screw and a drive assembly, the drive assembly includes a plurality of idler gears and two mutually engaged elliptical gears, one of the elliptical gears is fixedly connected to the first screw, the other elliptical gear synchronously rotates with one of the idler gears, the last idler gear is fixedly connected to the second screw, a rotation speed of the first screw is .sub.1=N, an eccentricity of each of the elliptical gears is k, 0<k<0.8, an included angle between a connecting line of the first screw and the second screw and a long axis of each of the elliptical gears is , and a rotation speed of the second screw is .sub.2, satisfying

[00001]${}_2=\frac{\left(1-k^2\right)N}{1-2k\cos +k^2}.$

A twin-screw extrusion device is disclosed, which includes a barrel and a twin-screw mechanism, the twin-screw mechanism includes a first screw, a second screw and a drive assembly, the drive assembly includes a plurality of idler gears and two mutually engaged elliptical gears, one of the elliptical gears is fixedly connected to the first screw, the other elliptical gear synchronously rotates with one of the idler gears, the last idler gear is fixedly connected to the second screw, a rotation speed of the first screw is .sub.1=N, an eccentricity of each of the elliptical gears is k, 0<k<0.8, an included angle between a connecting line of the first screw and the second screw and a long axis of each of the elliptical gears is , and a rotation speed of the second screw is .sub.2, satisfying ${}_2=\frac{\left(1-k^2\right)N}{1-2k\cos +k^2}.$

The invention provides an appartus for adjusting the thickness of a resin film exiting an extrusion lip of a blown film extruder, the apparatus comprising: a gear motor configured to provide a rotational movement in any one of two directions; an actuation unit connected with a first side to the gear motor and with a second side to the extrusion lip, wherein the actuation unit is configured to convert the rotational movement of the gear motor into an axial movement, and wherein the actuation unit is further configured to adjust a local width of the extrusion lip by the axial movement for adjusting the thickness of the resin film exiting the extrusion lip of the blown film extruder.