Patent EP-1886793-A1 (EP)
Inventor: HEHL KARL
IPC: B29C67/00
Filed: 2007-08-10
Abstract: The production of three-dimensional object (6) from solidifiable material by sequential discharge of pressure drops, comprises plasticizing the solidifiable material in fluid phase by transferring the solidifiable material into the fluid phase by a plasticizing unit (1), feeding the fluid phase into a material storage device (2) with an intermittently operatable discharge or application unit (3), and discharging the drops through an outlet opening using the discharge or the application unit into a design space (7) for the three-dimensional object to be manufactured. The production of three-dimensional object (6) from solidifiable material by sequential discharge of pressure drops, comprises plasticizing the solidifiable material in fluid phase by transferring the solidifiable material into the fluid phase by a plasticizing unit (1), feeding the fluid phase into a material storage device with an intermittently operatable discharge or application unit, and discharging the drops through an outlet opening using the discharge or the application unit into a design space for the three-dimensional object to be manufactured. The design space and the outlet opening are moved relative to one another in the design space. The attachment of a plasticizing unit that is well-known in the injection molding technology to the material storage device that can be kept under pressure for feeding of the fluid phase into the material storage device. The pressure is applied on the fluid phase in the material storage device and produces a discontinuous trickle with a desired volume and a desired flight speed along the direction of the design space in direct relation to the intermittently operatable discharge or the application unit as a function of the pressure and temperature parameters in the material storage device and/or depending upon the opening time and geometry of the intermittently operatable discharge or the application unit. The plasticizing unit is directly attached to the material storage device and applies the pressure on the fluid phase that is homogenized by the treatment process. The fluid phase has a frontal laminar flow with flow speeds up to 10,000 m/s for the transition of the solidifiable material into the fluid phase. The dynamic viscosity number of the solidifiable material lies between 100-10,000 (Pas). The solidifiable material is a plastic or a resin that is common in the injection molding process. The desired volume of the droplet lies in the range of about 0.1 mm 3>. The opening time is lesser than or equal to 1 ms and/or the diameter of the outlet opening is 0.1 mm. For influencing the shape of the drops, sensors adjust the parameters of the plasticizing unit, pressure and/or temperature in the material storage, the discharge or the application unit and/or the closure unit through which the solidifiable material arrives at the outlet opening. The parameters comprise discharge velocity of the material from the plasticizing unit, pressure in the plasticizing unit, temperature in the plasticizing unit, temperature of the discharge or the application unit and/or the outlet opening, diameter and/or annular gap of the outlet opening in the region of the closure unit, length of the outlet opening, frequency and pitch of the closure unit, pressure of the carrier medium in the outlet unit, volumetric flow rate of the carrier medium and temperature of the material in the outlet unit. The parameters of the design space have the temperature, pressure and atmosphere of the design space. The sensors influence the speed and/or direction, with which the discharge or the application unit and/or the object carrier can be moved relative to one another. The parameters of the current application site comprise temperature and area of the current application site. The temperature of the object surface can be controlled by a temperature control unit for partially and completely dissolving the transitions between the individual drop-like parts. Several discharge or application units discharge different materials and/or apply the material at the same point in such a manner that the materials unite at the point. An independent claim is included for a device for the production of three-dimensional object from solidifiable material.