An extrusion head arrangement has a plurality of extrusion heads arranged next to one another along a transverse axis. Each extrusion head has a housing with at least one flow channel for forming a strand of extrudable plastic in the direction of a longitudinal axis. The housing has an outer housing part extending along the longitudinal axis with an outer circumferential surface. A longitudinal bore parallel to the longitudinal axis is arranged in the outer housing part. The outer circumferential surface of the outer housing part has an oval cross-section with a largest diameter and a smallest diameter. The extrusion heads are arranged next to each other with the smallest diameters parallel to the transverse axis. The longitudinal bores are each arranged on a diameter deviating from the smallest diameter.

A production device for melt-blown non-woven fabric, with which a high molecular weight polymer can be reduced in molecular weight by applying a shear force to the high molecular weight polymer without adding an additive such as a peroxide that promotes thermal decomposition reaction, and a low molecular weight polymer can be efficiently produced. The low molecular weight polymer and the melt-blown non-woven fabric are produced using a continuous high shearing device that applies a shear force to the high molecular weight polymer serving as a raw material by rotation of a screw body 37 to reduce the molecular weight of the high molecular weight polymer so as to obtain a low molecular weight polymer, and cools the low molecular weight polymer by passing the low molecular weight polymer through a passage 88 arranged in the axial direction inside the screw body 37.

A 3D printing system includes a first cartridge container for reversibly receiving a first cartridge which stores printing fluid for 3D printing, and a print head with an outflow opening. The 3D printing system further has a first fluid line, which connects the first cartridge container to the print head to supply printing fluid to the print head. In addition, the 3D printing system has a first temperature-control channel, which encases the first cartridge container and the first fluid line externally, and which is passed through, in the intended state of use, by a temperature-control medium.

A nozzle includes a tubular, temperature-controlled outer casing, centered on an axis. For a more compact and efficient design, the nozzle also includes an inner member coaxially arranged inside the outer casing and mounted rotatably about the axis relative to the outer casing, such that a downstream portion of the inner member extends outside the outer casing and engages with a drive motor to rotate about the axis, and such that a channel having an annular cross section and centered on the axis is defined between the outer casing and the inner member. The channel has an upstream end and a downstream end between which the material flows into the channel when it is pushed through the nozzle such that, when the material is pushed through the nozzle, the material moves through the channel from the upstream end to the downstream end whereby the material axially exits the channel.

A heat bolt unit according to one embodiment includes a plurality of heat bolts disposed in parallel to one another, and a holding portion that holds the plurality of heat bolts. The holding portion holds a base end portion of each of the plurality of heat bolts disposed in parallel to one another. In other words, the holding portion holds the plurality of heat bolts disposed in parallel to one another in a cantilever manner.

A performance of a die is improved. An injection hole IH, a nozzle NZa and a nozzle NZb are formed in a center member DIa of a die DI to extend from an extrusion surface ES to an injection surface IS. A heat source HT and a plurality of heat insulating layers HI1 are arranged inside the center member DIa. One of the plurality of heat insulating layers HI1 is adjacent to the nozzle Nzb and is closer to the extrusion surface ES than the heat source HT. The other of the plurality of heat insulating layers HI1 extends in a direction from the extrusion surface ES toward the injection surface IS at a position being farther from the nozzle NZb than the heat source HT.

A performance of a die is improved. An injection hole IH, a nozzle NZa and a nozzle NZb are formed in a center member DIa of a die DI to extend from an extrusion surface ES to an injection surface IS. A heat source HT and a plurality of heat insulating layers HI1 are arranged inside the center member DIa. One of the plurality of heat insulating layers HI1 is adjacent to the nozzle Nzb and is closer to the extrusion surface ES than the heat source HT. The other of the plurality of heat insulating layers HI1 extends in a direction from the extrusion surface ES toward the injection surface IS at a position being farther from the nozzle NZb than the heat source HT.

An illustrative example embodiment of a method of making a concrete expansion joint insert includes moving a material including a resin having a melt temperature through a die having a flow passage that ends in an exit having a selected geometry, increasing a temperature of only a segment of the die near the exit to an elevated temperature that is at least 1.5 times the melt temperature, and increasing the temperature of a portion of the material to an increased temperature above the melt temperature through contact with the segment having the elevated temperature.

A system for optimizing the multi-extruder deposition process in a 3D printer including multiple extruders requires each extruder to have a body including an outer thermal insulation shell; the shell allowing the inlet/outlet of a fluid for the active and controlled refrigeration of the extruder. A method for optimizing the multi-extruder deposition process in a 3D printer with multiple extruders involves managing the temperature of each extruder using active refrigeration sized so as to have a sudden control of the cooling ramp and to manage the viscosity of the material in the event of extruder change. For the entire duration of the printing with another extruder, the unused extruder nozzle remains in a limited range around the extrusion temperature, thus eliminating downtime, while the solidified filament from the sudden forced cooling is pulled back into a low temperature nozzle area where it does not degrade during non-use.

A nozzle module and a three-dimensional printer are provided. The nozzle module includes a heat dissipation assembly, a locking assembly, and a nozzle assembly. The rotary member can rotate relative to the clamping ring, and a width of the opening is selectively reduced or increased when the rotary member rotates relative to the clamping ring, thereby enabling the clamping ring to clamp or release the nozzle assembly. Quick assembly and quick disassembly can be achieved, the assembly and the disassembly are convenient, and the assembly efficiency and the disassembly efficiency are improved.