Systems and methods for making it easier to remove support structures printed in conjunction with printing an object using stereolithographic additive manufacturing are disclosed. In some exemplary embodiments, one or more interfaces between the printed object and the support structures are modulated to allow for easy separation between them, in some instances even when the object and support structures are made from the same material. Various modulation techniques are disclosed, including adjusting an intensity of exposure to light at interfaces between the object and support structures, and using two materials where one material cures at two wavelength ranges and the other material only cures at one of the two wavelength ranges. Other systems and methods that allow for easy separation of part and support structure are also described.

This invention relates to a high molecular weight nylon powder composition for 3D printing, its preparation method and use. The composition comprises: 100 parts by weight of high-viscosity nylon powder, 1-5 parts by weight of a flow agent, and 0.1-1 parts by weight of an antioxidant; the high-viscosity nylon powder is one or more selected from nylon 6, nylon 66, nylon 11, nylon 12, nylon 612 and nylon 610; or the powder composition is obtained via polymerization reaction of the raw materials comprising the following components, based on the weight parts of lactam monomers or amide monomers: 100 parts by weight of lactam monomers or amide monomers, 0.005-1 parts by weight of a catalyst, and 0.1-1 parts by weight of an antioxidant. The high molecular weight nylon powder composition prepared in the present invention has a particle diameter in the range of 20-100 micrometers, good powder spreading performance, and is suitable for the 3D printing process, and the product of the high molecular weight nylon powder composition has good mechanical properties, good dimensional stability and low manufacturing cost.

An actinic ray-curable-type inkjet ink composition for 3D printing includes an acrylate monomer A capable of forming a homopolymer having a glass transition temperature of from 25° C. to 120° C.; an acrylate monomer B capable of forming a homopolymer having a glass transition temperature of −60° or higher and lower than 25° C.; a bifunctional acrylate oligomer C having a weight-average molecular weight of from 2,000 to 20,000; and an acylphosphine oxide compound, in which the mass content of bifunctional or higher-functional acrylate compounds is 15% by mass or less.

A process for making a molded flexible foam. The processes includes: (a) depositing a foam-forming reaction mixture onto a surface of a mold cavity, and (b) allowing the foam-forming reaction mixture to react in the mold cavity. The foam-forming reaction mixture includes: (1) a polyisocyanate present in an amount of less than 45% by weight, based on the total weight of the reaction mixture; (2) an isocyanate-reactive composition; (3) a blowing agent; and (4) a catalyst. The isocyanate-reactive composition includes: (i) at least 50% by weight, based on the total weight of polyol in the isocyanate-reactive composition, of a polyether polyol having a functionality of greater than 2, an oxyethylene content of 0 to 50% by weight, based on the total weight of the polyether polyol, more than 50 mol % of primary OH groups and an OH number of 8 to 112 mg KOH/g; and (ii) a component comprising: (A) an amine-initiated polyether polyol (II), wherein amine-initiated polyether polyol (II) has an OH number of at least 500 mg KOH/g and a functionality of 2.5 to 4, and wherein amine-initiated polyether polyol (II) is present in an amount of greater than 0 and no more than 10% by weight, based on the total weight of polyol in the isocyanate-reactive composition; (B) a CO.sub.2-producing carbamic acid which is present in an amount of greater than 0 and no more than 10% by weight, based on the total weight of polyol in the isocyanate-reactive composition; or (C) both (A) and (B).

In one aspect, inks for use with a three-dimensional (3D) printing system are described herein. In some embodiments, an ink described herein comprise 10-70 wt. % or 20-40 wt. % of a cyclopolymerizable monomer, based on the total weight of the ink. The cyclopolymerizable monomer comprises an acrylate moiety and an ethenyl or ethynyl moiety, and the α-carbon of the acrylate moiety and the α-carbon of the ethenyl or ethynyl moiety may have a 1,5-, 1,6-, 1,7-, or 1,8-relationship. Additionally, an ink described herein can have a viscosity of 1600 centipoise (cP) or less at 30° C., or of 500 cP or less at 30° C. and can be used to print a desired 3D article having mechanical properties similar to those of articles formed from thermoplastic materials.

Liquid radiation curable compositions are disclosed which are suitable for hybrid (i.e. cationic and free-radical) polymerization when processed via additive fabrication equipment utilizing sources of actinic radiation with peak spectral intensities in the UV/vis region. Also disclosed are methods of creating three-dimensional parts via additive fabrication processes utilizing sources of actinic radiation with peak spectral intensities in the UV/vis region employing liquid radiation curable compositions suitable for hybrid polymerization, and the parts cured therefrom.

A system for producing foams for prosthetics and orthotics include a heated housing that stores monomer containers, temperature-controlled hoses separately coupled with the containers and configured to receive monomers from the containers, a dispensing gun assembly fluidly coupled with the containers by the hoses, and a computer controller configured to control a dispensing time period during which the monomers are dispensed from the containers and through the hoses to the dispensing gun assembly and dispensed out of the dispensing gun assembly as a polymer foam. The controller is configured to stop dispensing of the polymer foam out of the dispensing gun assembly upon expiration of the dispensing time period.

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 method of forming a three-dimensional object, which may include the steps of: (a) providing a carrier and an optically transparent member having a build surface, the carrier and the build surface defining a build region therebetween; (b) filling the build region with a polymerizable liquid that comprises a reactive blocked monomer and/or prepolymer comprising a self-polymerizing monomer and/or prepolymer blocked with a light-polymerizable blocking group; (c) irradiating the build region with light through said optically transparent member to form a solid polymer scaffold from the reactive blocked monomer and/or prepolymer and also advancing the carrier away from the build surface to form a three-dimensional intermediate; and then (d) heating and/or microwave irradiating, the three-dimensional intermediate sufficiently to degrade the scaffold and regenerate the monomer and/or prepolymer in de-blocked form, which monomer and/or prepolymer in turn self-polymerize, to form said three-dimensional object.

Embodiments of the microfluidic device may include of an array of microfluidic cell capture chambers, each functionalized with a different antibody to recognize a target antigen, and a network of code-multiplexed Coulter counters placed at strategic nodes across the device to quantify the fraction of cell population captured in each microfluidic chamber. For example, an apparatus may comprise a fluid inlet port divided into a plurality of separate microfluidic paths, each separate microfluidic path configured to transport a plurality of cells, the plurality of separate microfluidic paths, each comprising a plurality of microfluidic cell capture chambers, an outlet port to discharge a merged output of cells from the plurality of microfluidic cell capture chambers, and a plurality of sensors to detect cells passing into or out of a microfluidic cell capture chamber.