Parts made by additive manufacturing are often structural in nature, rather than having functional properties conveyed by a polymer or other component present therein. Printed parts having piezoelectric properties may be formed using compositions comprising a plurality of piezoelectric particles and a polymer material comprising at least one thermoplastic polymer and at least one thermally curable polymer precursor. At a sufficient temperature, the at least one thermally curable polymer precursor may undergo a reaction, optionally also undergoing a reaction with the piezoelectric particles, and form an at least partially cured printed part. The piezoelectric particles may be mixed with the polymer material and remain substantially non-agglomerated when combined with the polymer material. The compositions may define a form factor such as a composite filament, a composite pellet, or an extrudable composite paste, which may be utilized in forming printed part by extrusion, layer-by-layer deposition, and thermal curing.

Provided is a resin composition from which a three-dimensional molding can be produced at an appropriate speed and with high dimensional accuracy, wherein the obtained three-dimensional molding has high strength. This resin composition is used in a method for producing a three-dimensional molding composed of a cured product of a liquid resin composition by selectively irradiating the liquid resin composition with active energy rays. The resin composition includes at least: a first polymerizable compound, in a liquid state at room temperature, having radical polymerizability; a second polymerizable compound, in a liquid state at room temperature, having no radical polymerizability; and a filler, wherein the surface of the filler is covered with the second polymerizable compound.

A laser welding system is directed to simultaneously joining respective layers of a first bag and a second bag. The system includes a first film layer adjacent to a second film layer for forming the first bag, and a third film layer adjacent to a fourth film layer for forming the second bag, each layer of the plurality of film layers being made of a thermoplastic material that absorbs laser radiation having a wavelength of about 2 microns. A non-absorbing carrier film layer is positioned between the second film layer and the third film layer, the non-absorbing carrier film layer being made of a material that transmits substantially all energy of the laser radiation. A laser source applies the laser radiation toward portions of the plurality of film layers to be joined, forming the first bag generally simultaneously with the second bag.

A laser welding system is directed to simultaneously joining respective layers of a first bag and a second bag. The system includes a first film layer adjacent to a second film layer for forming the first bag, and a third film layer adjacent to a fourth film layer for forming the second bag, each layer of the plurality of film layers being made of a thermoplastic material that absorbs laser radiation having a wavelength of about 2 microns. A non-absorbing carrier film layer is positioned between the second film layer and the third film layer, the non-absorbing carrier film layer being made of a material that transmits substantially all energy of the laser radiation. A laser source applies the laser radiation toward portions of the plurality of film layers to be joined, forming the first bag generally simultaneously with the second bag.

A method for bonding thermoplastic fiber-composite parts comprises providing surface texture on one or both parts being bonded, and/or providing both parts with engagement features. Such surface textures and engagement features have a specific geometry and fiber alignment that facilitate fibrous interlock between the two parts at a bonding interface via in-situ consolidation.

A method for bonding thermoplastic fiber-composite parts comprises providing surface texture on one or both parts being bonded, and/or providing both parts with engagement features. Such surface textures and engagement features have a specific geometry and fiber alignment that facilitate fibrous interlock between the two parts at a bonding interface via in-situ consolidation.

A system for manufacturing a thermoplastic prepreg includes a double belt mechanism that is configured to compress a fiber mat, web, or mesh that is passed through the double belt mechanism, a resin applicator that is configured to apply monomers or oligomers to the fiber mat, web, or mesh, and a curing oven that is configured to effect polymerization of the monomers or oligomers and thereby form the thermoplastic polymer as the fiber mat, web, or mesh is moved through the curing oven. The double belt mechanism compresses the fiber mat, web, or mesh and the applied monomers or oligomers as the fiber mat, web, or mesh is passed through the curing oven so that the monomers or oligomers fully saturate the fiber mat, web, or mesh. Upon polymerization of the monomers or oligomers, the fiber mat, web, or mesh is fully impregnated with the thermoplastic polymer.

Provided herein, inter alia, are polymeric compositions and systems useful for maintaining particle dispersions for extended periods of time. Also provided are dry polymeric compositions and systems that are able to undergo fast hydration. Methods for using such compositions and systems are also provided.

The use of compatible, semi-miscible or miscible polymer compositions as support structures for the 3D printing of objects, including those made from polyether-block-amide copolymers such as PEBAX® block copolymers from Arkema, polyamides such as RILSAN® polyamides from Arkema, polyether ketone ketone such as KEPSTAN® PEKK from Arkema, and fluoropolymers, such a KYNAR® PVDF from Arkema, especially objects of polyvinylidene fluoride and its copolymers. One particularly useful miscible polymer is an acrylic polymer, which is miscible with the fluoropolymer in the melt. The support structure composition provides the needed adhesion to the build plate and to the printed object and support strength during the 3D printing process, yet it is removable after the fluoropolymer object has cooled. The support polymer composition is selected to be stiff and low warping, yet flexible enough to be formed into filaments.

A method of bonding a first object to a second object includes the steps of: providing the first object including thermoplastic material in a solid state, providing the second object including a proximal surface, applying a mechanical pressing force and a mechanical excitation capable to liquefy the thermoplastic material until a flow portion of the thermoplastic material is flowable and penetrates into structures of the second object, and stopping the mechanical excitation and letting the thermoplastic material resolidify to yield a positive-fit connection between the first and the second object. The second object has a region of low density, wherein the protrusion penetrates the region of low density at least partly before the thermoplastic material is made flowable, and wherein the first object includes a protruding portion after the step of letting the thermoplastic material resolidify, the protruding portion at least partly penetrates the region of low density.