The present invention lies in the field of 3D printing methods. In particular, the invention relates to 3D printing methods for the production of a 3D part in a layer-by-layer manner, wherein the printable composition is a pasty polyurethane composition comprising at least one polyisocyanate resin, at least one monomer and/or prepolymer that is polymerizable by exposure to radiation and at least one photoinitiator, wherein the pasty polyurethane composition has a viscosity factor (1.5/15) of at least 2 at application temperature.

A tool provided that individually creates three-dimensional structural elements which are sequentially positioned into formation of a shaped object.

Embodiments in accordance with the present invention encompass compositions encompassing a latent organo-ruthenium compound, a pyridine compound, a photosensitizer and an ultra violet light blocking compound along with one or more monomers which undergo ring open metathesis polymerization (ROMP) when said composition is exposed to suitable actinic radiation to form a substantially transparent film or a three dimensional object. Surprisingly, the compositions are very stable at ambient conditions to temperatures up to 80° C. for several days and undergo mass polymerization only when subjected to actinic radiation under inert atmosphere such as for example a blanket of nitrogen. Accordingly, compositions of this invention are useful in various opto-electronic applications, including as 3D printing materials, coatings, encapsulants, fillers, leveling agents, among others.

The present disclosure concerns a digital fabricating method for constructing 3D structures, comprising the following steps: (a) precursor consist of monomers and photo-initiator is introduced into reaction cell; (b) exposing the precursor to the DLP projector for several times to gain an inhomogeneous sheet; (c) swelling the sheet in solvent to gain 3D structure. The disclosure provides a simple and easy way to produce precise 3D structure.

A method for manufacturing a silicone hydrogel contact lens is described that comprises curing a polymerizable composition comprising at least one siloxane monomer and at least one hydrophilic vinyl-containing monomer in a contact lens mold comprising a molding surface having a coating comprising a hydrophilic polymer. The hydrophilic coating is not solubilized by the polymerizable composition during the curing step. The resulting polymeric lens body is removed from the mold, washed to remove any of the hydrophilic polymer that may have transferred from the mold surface to the lens during the curing or lens removal process, and packaged to provide a silicone hydrogel contact lens having a contact angle that is lower than what it would otherwise be had the lens been cured in the same contact lens mold lacking the hydrophilic coating.

Methods, systems, and apparatus include computer programs encoded on a computer-readable storage medium, including a system for reducing adhesion during cure processing for a stereolithographic 3D printed object. The system includes resin tank for maintaining a liquid photopolymer resin. The system further includes a light source. The system further includes controller for selectively exposing the liquid photopolymer resin to form a solid object in the resin tank. The resin tank is constructed of a rigid material that has an oxygen permeability that is above a first threshold so as to reduce a separation force required to remove the solid object from the resin tank after curing.

A pattern is formed on a substrate with a layer of a curable composition (A1) containing a component (a1) serving as a polymerizable compound on a surface of the substrate, then dispensing droplets of a curable composition (A2) containing at least a component (a2) serving as a polymerizable compound and a component (b2) serving as a photopolymerization initiator dropwise discretely onto the curable composition (A1) layer to lay the droplets, subsequently sandwiching a mixture layer of the curable composition (A1) and the curable composition (A2) between a mold having a pattern and the substrate, then irradiating the mixture layer with light to cure the layer, and releasing the mold from the mixture layer after the curing, a Distance in Hansen space Ra((a1)−(A2)) between the component (a1) serving as a polymerizable compound in the curable composition (A1) and the curable composition (A2) being 6 or less.

A large area patterned film includes a first patterned area; a second patterned area; and a seam joining the first patterned area and the second patterned area, wherein the seam has a width less than about 20 micrometers. A method for tiling patterned areas includes depositing a predetermined thickness of a curable material; contacting a first portion of the curable material with a mold; curing the first portion of the curable material; removing the mold from the cured first portion of the curable material; contacting a second portion of the curable material with the mold, such that the mold contacts a portion of the cured first portion of the curable material; curing the second portion of the curable material; and removing the mold to yield a seam between the cured first portion of the curable material and the cured second portion of the curable material, wherein the seam has a dimension less than about 20 micrometers.

A method of fabricating a polishing layer of a polishing pad includes successively depositing a plurality of layers with a 3D printer, each layer of the plurality of polishing layers deposited by ejecting a pad material precursor from a nozzle and solidifying the pad material precursor to form a solidified pad material.

Provided is a three-dimensional object formation method including: a first step of forming a film by delivering a first liquid containing at least water and a hydrogel precursor: and a second step of curing the film formed in the first step, wherein the first step and the second step are repeated a plurality of times.