摘要:
A method and composition for forming investment casting patterns wherein thermally-collapsible microspheres are incorporated into the pattern composition. The patterns can be made either by conventional pattern forming techniques or by solid imaging techniques. After investing the microsphere containing pattern in the ceramic shell, the pattern and shell are heated, causing a collapse of the microspheres and thereby preventing cracking of the shell. The shell is then heated to burn-out the remaining pattern material and fire the shell, thereby creating a mold.
摘要:
A method and apparatus, where high viscosity liquids, including pseudoplastic, plastic flow, and thixotropic liquids, as well as gels, semi-solid, and solid materials are viscosity reduced during coating and allowed to increase in viscosity during imaging steps, for use in Solid Imaging applications. Use of these materials and the apparatus improves coating uniformity and final object tolerances.
摘要:
An apparatus and method for fabricating integral three-dimensional objects from successive layers of photoformable compositions by exposing the layers of the composition through a detachable flexible transparent film, one side of the film being in contact with the composition and the other side of the film with a rigid transparent plate, which guides and supports the film.
摘要:
This invention discloses compositions adapted to produce, through solid imaging means, excellent quality objects having material properties that simulate the look and feel of polypropylene articles.
摘要:
Solid objects are formed in an imagewise layering process in which components of a dispersion are homogenized to form an alloy. Imagewise exposure of the layers to radiation to form an alloy permits separation of the exposed, homogenized regions from non-exposed, non-homogenized regions. As each layer is formed and imagewise homogenized, contiguous layer regions are bonded together to form a homogenized, three-dimensional object which may be separated from surrounding dispersion.
摘要:
An imaging method and apparatus produces an integral three-dimensional object from a multiplicity of cross sectional portions of the object. The cross sectional portions correspond to photohardened portions of contiguous photoformed precursor sheets of a photohardenable liquid composition.
摘要:
A computer-implemented method is provided for generating the estimation of current position, velocity and acceleration state vectors and associated uncertainty estimation (covariance) of a boosting ballistic missile. The method includes constructing a state tensor of the projectile from a plurality of sensor measurements in Earth-Centered, Earth-Fixed (ECEF) coordinates; translating the state tensor to Cartesian coordinates as a transform state; determining a covariance matrix from the transform state; updating the transformed state as an updated transform state; and updating the covariance matrix as an updated covariance. The process can further include adjusting the covariance matrix by an approximate transition matrix and a process noise matrix. The noise matrix can be translated from a local noise matrix based on a propagation time-step, a scaling parameter, and a bias process noise level. A time-of-flight in the state tensor can be updated by smoothing from a launch event.
摘要:
An apparatus for fabricating integral three-dimensional objects from successive layers of photoformable compositions by exposing the layers of the composition through a semi-permeable film that allows creation of release coatings on the side of the film facing the composition.
摘要:
In a solid imaging system, the beam of a relatively high-powered beam radiation source, and more particularly a laser, is modulated in accordance with its varying vector sweep speed so that substantially constant layer depth is maintained at all scanner speeds in a strip of photohardenable composition as it hardens and solidifies in response to the source's irradiation.
摘要:
The invention relates to a radiation curable composition comprising relative to the total weight of the composition (A) 0–29 wt % of a cationically curable component having a linking aliphatic ester group, (B) 10–85 wt % of an epoxygroup containing component other than A, (C) 1–50 wt % of an oxetanegroup containing component, (D) 1–25 wt % of a multifunctional acrylate and a radical photoinitiator and a cationic photoinitiator.