The present application relates to components, such as dental apparatuses, having geometrical features to facilitate post-fabrication cleaning, including methods of fabricating the same. In one embodiment, a dental apparatus, such as a retainer, an aligner, or a dental attachment placement appliance, comprises one or more concave surfaces for which one or more apertures is formed therethrough at or near a maximum depth of a given concave surface.

A method is provided for dyeing a molded part produced in a 3D printing process with a polymer. The method includes a dyeing step for dyeing the surface of the molded part with a dye, and a first post-treatment step for fixing the dye which has penetrated the surface of the molded part. Optionally, a second post-treatment step can be carried out in order to achieve even better fixing of the dye which has penetrated the surface of the molded part.

The present disclosure relates to a process for dyeing a hydrolysis-resistant polyester film. The process comprises dyeing of a hydrolysis resistant polyester film in a dye bath comprising at least one coloring agent (dye), at least one polyhydric alcohol, and optionally at least one UV absorber to obtain a dyed film. The dyed film is subjected to quenching followed by cleaning and drying to obtain a dyed hydrolysis-resistant polyester film. The process of the present disclosure is simple, economical, improve hydrolysis resistance, and also retains the mechanical properties of the film when exposed to harsh environmental conditions.

The present invention provides a process for modifying the surface of a polyvinyl alcohol film or fabric by applying heat and pressure to the film or fabric to increase the moisture on the surface which is held by the fabric and to coalesce the surface fibers and reduce the porosity of the surface.

A system for producing three-dimensional objects forms fluid paths within the support structure to facilitate the removal of the support structure following manufacture of the object. The system includes a first ejector configured to eject a first material towards a platen to form an object, a second ejector configured to eject a second material towards the platen to form support for portions of the object, at least one portion of the support having a body with at least one fluid path that connects at least one opening in the body to at least one other opening in the body, and a fluid source that connects to the at least one fluid path of the support to enable fluid to flow through the at least one fluid path to remove at least an inner portion of the support from the object.

The invention provides method for producing a 3D item (1) by means of fused deposition modelling, the method comprising: —a 3D printing stage comprising layer-wise depositing an extrudate (321) comprising 3D printable material (201), wherein during at least part of the 3D printing stage the extrudate (321) comprises a core-shell extrudate (1321) comprising a core (2321) comprising a core material (2011), and a shell (2322) comprising a shell material (2012), to provide the 3D item (1) comprising 3D printed material (202), wherein the 3D item (1) comprises a plurality of layers (322) of 3D printed material (202), wherein one or more of layers (322) comprises one or more core-shell layer parts (3322), wherein each of the core-shell layer parts (3322) comprises a layer core (3321) comprising the core material (2011), and a layer shell (3322) comprising the shell material (2012), wherein the 3D item (1) has an item surface (252) defined by at least part of the 3D printed material (202); —an exposure stage comprising exposing at least part of the item surface (252) to a liquid (402), wherein the core material (2011) has core material solubility SC1 for the liquid (402) and wherein the shell material (2012) has a shell material solubility SS1 for the liquid (402), wherein SC1<SS2.

A surface finishing apparatus and method for smoothing and coloring parts made by additive-manufacturing technologies is disclosed. The surface finishing apparatus includes a tank or chamber into which a part is placed. A colorant is added. The part is both colored and smoothed until the part is at a desired smoothness and color. The part may be smoothed by different suitable smoothing technologies, including abrading with solid media, spraying with a liquid fluid, spraying with solid particles entrained in a liquid fluid, or submersing in a liquid vortex. Also disclosed is a composition for a colorant for a finishing process that smooths a surface of an additively manufactured part while coloring the additively manufactured part.

The present invention relates to a method for predicting the shape of a three-dimensional object which has been subjected to a diffusion process for a predetermined duration. The prediction method uses a law of vertical morphing and a law of lateral morphing. The law of lateral morphing applies to a description of the contours of different slices of a sample at standardised heights. The description of the contour of a slice is obtained by a curvilinear Fourier transform of the contour or by a two-dimensional spatial Fourier transform of a contour line approximating said contour. The present invention also relates to the manufacture of a three-dimensional object of a given material and a given nominal shape.

A method for treatment of polymer elements obtained by an additive manufacturing process comprises applying to the polymer element a treating liquid in liquid form.

The disclosure relates to smoothing of a surface of models made by additive manufacturing process utilizing melted polymer layers, by condensation of solvent vapors thereon. A method for solvent vapor smoothing of a surface of a plastic product by: placing the plastic product to be smoothed in a closed chamber (110) having heated walls (112-116) and a heated evaporator (111) for solvent; determining process parameters; heating (503) at least one wall (112-116) of the chamber (110) to a first temperature and heating the evaporator (111) to a second temperature; introducing (504) a solvent to the evaporator (111); allowing (506) the solvent vapors to condense on the outer surface of the product; and collecting solvent vapors from the chamber (110).