Abstract: Provided is a method of 3D printing with the use of a heater-free, hand-held 3D printing device such as a 3D printing pen. The method consists of adjusting the extrusion feed rate of the substance through the orifice with the use of a substance feed mechanism to provide curing conditions at which the extruded substance maintains a shape-sustaining state; extruding the substance; and curing the extruded substance to the shape-sustaining state by irradiating the extruded substance outside the device with light-radiation elements such as LEDs. The feed rate of the extrusion is carried out once, experimentally, before multiple practical use of the heater-free 3D printing device. The extrudable substance is a photopolymerizable polymer composition that has kinematic viscosity in the range of 7.00 to 10.00 MM2/C when measured at room temperature by the capillarity method.

Abstract: The present invention relates to polymer compositions suitable for 3D printing. The composition comprises 60 to 80 mass % of oligoester acrylate; 10 to 30 mass % of a liquid polyethylene glycol; 7 to 9 mass % of a non-liquid polyethylene glycol; and 0.1 to 1 mass % of a system of photopolymerization initiators. A distinguishing feature of the composition is that after being extruded at an environment temperature of 22° C. with the extrusion rate of 2.5 to 3.5 cm/sec through a nozzle of a hand-held 3D printing device having an output orifice with a diameter in the range of 0.6 to 1.5 mm and after being irradiated after extrusion with a light having a wavelength in the range of 390 to 410 nm by LEDs having a total power of 2 Wt, the composition maintained its shape without a support.

Abstract: A 3D printing pen for extruding and curing a radiation-curable pasty polymer composition has a housing that contains a disposable cartridge filled with the composition. The cartridge also contains a piston that is slidable in the cartridge due to engagement of the nut secured in the piston with a lead screw that is located in the cartridge and driven from a motor so that displacement of the piston inside the cartridge expels the composition from the pen through an orifice at the end of the cartridge opposite the motor. The front end of the housing also contains LEDs that emit light onto the thread of composition on exit of the composition from the device. The mode of operation of the 3D printing pen and viscosity of the composition are selected so that after curing the extruded thread maintains its shape without supports.