The present disclosure relates a method of chemical polishing a 3D printed object. The method comprises treating a 3D printed object with solvent to reduce the surface roughness of the 3D printed object, and controlling the Youngs modulus of the 3D printed object within a target value by selectively removing at least part of the solvent from the 3D printed object.

A process for continuous production of partly crystalline polycondensate pellet material which comprises the step of crystallizing the pellet material in a second treatment space (6a) under fixed bed conditions by supply of energy from the exterior by means of a process gas, wherein the process gas has a temperature (T.sub.Gas), which is higher than the sum of the pellet temperature (T.sub.GR) and the temperature increase (T.sub.KR) which occurs due to heat of crystallization released hi the second treatment space (6a), i.e., (T.sub.Gas>(T.sub.GR+T.sub.KR)). The pellets at the exit from the second treatment space (6a) have an average temperature (T.sub.PH), which is 10 to 90 C. higher than the sum of the temperature of the pellets (T.sub.GR) and the temperature increase (T.sub.KR) which occurs due to heat of crystallization released in the second treatment space (6a), i.e., (T.sub.GR+T.sub.KR+90 C.)T.sub.PH(T.sub.GR+T.sub.KR+10).

Aspects of the disclosure include a fabrication platform for supporting a bioprinted fiber structures during printing, patterning, and/or processing, comprising a frame with a plurality of posts for securing a cross-linkable fiber during printing thereof, and where a continuous length of the cross-linkable fiber is printed around a plurality of posts during the 3D bioprinting process. The fabrication platform enables the cross-linkable fiber to be suspended during one or more of printing, patterning, and/or processing. In this way, the bioprinted fiber structure comprises a uniform outer surface, and can be easily modified and/or further processed after printing and patterning are completed.

A decorative concrete with a very uniform finish surface and a method of fabricating the same is disclosed. A concrete mixture is poured over a subgrade which defines an exposed surface. The exposed surface is finished with any of several techniques, and the surface is then worked with an abrasive material, and additional techniques are used to color and seal the concrete.

Roof shingles and methods of production thereof are provided. The roof shingles may include ethylene-propylene-diene terpolymer (EPDM). The EPDM may include an outward-facing surface and a substrate-facing surface. The outward-facing surface may include a reveal and a conceal. The reveal may be visible when the roof shingle is installed and the conceal may be covered by an upslope adjacent roof shingle when the roof shingle is installed. The roof shingle may include a reinforcement core. The reinforcement core may include galvanized steel. The reinforcement core may be embedded within the EPDM. The roof shingles may include adhesive sealant. The adhesive sealant may be applied to the substrate-facing surface for binding the roof shingle to a downslope adjacent roof shingle or a substrate. The roof shingles may include a plurality of EPDM granules being located on at least a portion of the surface of the reveal.

A method and apparatus are set forth for volumetric additive manufacturing (VAM) wherein light rays that are used to determine tomographic projections are modelled using ray tracing, in order to account for projector non-telecentricity and etendue in all three dimensions. The path of rays from each light source (e.g. pixel) are computed as they propagate through the VAM system. Optical effects such as refraction, transmission loss, absorption, etendue, and non-telecentricity are intrinsically accounted for via ray tracing. Using these rays, the required dose to solidify the photosensitive resin is computed.

Systems, methods, and devices for additive manufacturing are provided. In some embodiments, a method includes: coupling a plurality of build platforms to a carrier; forming a plurality of 3D objects on the plurality of build platforms using an additive manufacturing process, where each build platform receives at least one 3D object thereon; removing the plurality of build platforms from the carrier; performing post-processing of the plurality of 3D objects while the 3D objects remain on the respective build platforms; and separating the plurality of 3D objects from the respective build platforms.

A process can be used for the surface treatment of three-dimensional objects which have been produced in additive manufacturing processes from at least one polymer. The process involves a) immersing the three-dimensional object in a substance mixture A, b) leaving the three-dimensional object in the substance mixture A for a time, and c) removing the three-dimensional object from the substance mixture A. The process then involves d) immersing the three-dimensional object in a substance mixture B, e) leaving the three-dimensional object in the substance mixture B for a time, and f) removing the three-dimensional object from the substance mixture B. The substance mixture A has a temperature (process temperature A) which is above the melting point of the polymer, and the substance mixture B has a temperature (process temperature B) which is below the melting point of the polymer.

Provided is a method of manufacturing a brush, such as a wafer cleaning brush. The method includes providing a polyvinyl alcohol (PVA) solution, forming an insoluble polyvinyl fluoride (PVF) by adding formaldehyde to the PVA solution, adding a water-soluble inorganic compound including a plurality of particles to the insoluble PVF, and mixing the insoluble PVF with the water-soluble inorganic compound to form a mixture of the water-soluble inorganic compound and the insoluble PVF, forming a brush by inserting the mixture of the water-soluble inorganic compound and the insoluble PVF into a mold and heat-treating the mixture, removing the wafer cleaning brush from the mold; and washing the wafer cleaning brush to remove the plurality of particles of the water-soluble inorganic compound from the wafer cleaning brush.

Disclosed is a method for treating objects produced by an additive manufacturing process which have at least one surface formed from a polymer with a glass transition temperature of at least 120 C., and preferably are formed from such a polymer, and in which the surface of the object is brought into contact with an organic or inorganic solvent. By such a treatment, the surface of the objects can be smoothed and relevant mechanical properties can be improved. Further disclosed are three-dimensional objects produced according to such a method and to the use of organic or inorganic solvents to reduce the surface roughness and/or to improve the mechanical properties and/or the chemical resistance.