Invented by Travis Alexander Busbee, Avin Dhoble, Noah Tremblay, Clara H. Rhee, Sean Christopher Troiano, Kornit Digital Technologies Ltd
The Kornit Digital Technologies Ltd invention works as followsThe present invention relates in general to the methods of printing articles, such as three-dimensional printing, and to the articles that are formed using these techniques. This includes printing footwear articles containing particles. Certain embodiments are directed towards composites that contain particles (e.g. reinforcing particle), such as rubber particles. These particles can be used to improve slip resistance or abrasion. Polyurethanes and other compounds may be added to the composites, for example, in order to make fabrication easier, such as by using 3D printing or other printing techniques. Some embodiments relate to the methods for making or using these articles. In some embodiments, for example, a composite can be made by mixing particles, e.g. reinforcing powder, with a first fluid, and a second liquid within a nozzle such as a microfluidic print nozzle that may be used to direct a product onto a surface.
Background for 3D-printed articles of footwear with particle technology
The manufacture of composites can involve expensive and hazardous materials. Composites can also be difficult to control. “We need to improve the manufacturing methods for composites.
The present invention relates in general to methods for printing articles with three-dimensional prints and other techniques of printing, as well as to articles made from these techniques, such the printing of articles containing particles. The present invention can include interrelated products, alternative approaches to a problem or a variety of uses for one or more articles and/or systems.
In one aspect, this invention is directed at an article. In one embodiment, the article is 3D-printed for use in footwear. The article may include a 3D printed article that has a gradient between a first and second portion.
In some embodiments, an article used in footwear is the subject. In certain embodiments, an article may include a 3D printed composite that includes particles (e.g. reinforcing particle) with a numerical average size greater than 10 microns but less than 400 microns.
In some embodiments, an article may comprise a polymeric material. The article can include particles (e.g. reinforcing particle) distributed within the polymeric structures to form a gradient in weight percent. In certain embodiments, the polymeric structure is adhered with a textile.
In some embodiments the article consists of a polymeric material and a chemical blowing agent that is not expanded in at least one portion of the polymeric material. In some embodiments, the polymeric material is covered with a textile.
In a second aspect, the invention is directed generally to a process. In some cases the method is a printing method, such as 3D-printing. In one embodiment, the method comprises flowing a fluid (e.g. reinforcing particle) through a first inlet and a second through a secondary inlet.
The method in another set embodiments includes flowing a liquid into a microfluidic print nozzle. It also involves flowing particles into the nozzle (e.g. reinforcing particle), mixing the fluid with the particles using an impeller, and then printing the mixture on a substrate.
In one set of embodiments the method involves flowing a fluid into a microfluidic nozzle through two inlets, a fluid that contains a foam-forming agent and another fluid that contains a cell-forming substance. The first fluid is mixed with the second fluid in a homogenous manner to create a mixture and then printed onto a substrate.
The method in another set embodiments includes flowing fluid into a microfluidic print nozzle, mixing fluid and gas inside the microfluidic print nozzle with an impeller, forming a froth containing bubbles of gas dispersed throughout the fluid, then printing the froth on a substrate.
The method includes the steps of mixing the first fluid with the second fluid to form foam precursor in a mixing chamber, transferring the foam and cell-forming agents into a microfluidic print nozzle, rotating the impeller inside the microfluidic print nozzle to create a mixture between the foam and cell-forming agents, and printing this mixture onto a surface.
In a further set of embodiments “the method” comprises flowing at least 2 inputs into a mixer nozzle to create a mixture containing a blowing agent. It is possible that the method further comprises flowing at least 2 inputs through a mixing nozzle in order to create a second mix. The first mixture can be deposited in a first region to create a first polymer. A second region containing the second mixture can be deposited to produce a second rubber. The first region of an article can be heated up to a temperature that is greater or equal to the activation temperatures of the blowing agents. In certain embodiments, heating the first area of the article can cause differential expansion between the region and the second of the item and physical deformation.
In a second aspect, the invention is directed generally to a device. In some embodiments the device is for printing, such as 3D-printing. According to a set of embodiments the device comprises: “a first microfluidic print nozzle having a mixing chamber with a first impeller, a microfluidic second printing nozzle having a mixing chamber with a mixing impeller, a microfluidic second printing nozzle having a mixing chamber with a mixing impeller, and an independent controller arranged and configured to control the rotation of the first and second impeller.
The device can also include a microfluidic print nozzle with a mixing chamber, an impeller, and either a heating source or cooling source that is in thermal contact with the nozzle. It may also contain a controller designed to control the rotation of the impeller.
The device includes, in another set of embodiments: a microfluidic print nozzle with a mixing chamber, an impeller therein and a controller designed and arranged for lateral movement of the impeller inside the microfluidic printer nozzle.
The nozzle can be controlled by a computer, or another controller, to control the deposition onto the substrate.” Gases or other materials can be added to the product in the nozzle. For example, to create foam.
The following detailed description will reveal other advantages and novel features when viewed in conjunction with the accompanying illustrations.
The present invention relates in general to the printing materials using 3D printing or other printing techniques and to articles made from these techniques. In certain embodiments, articles can be used in footwear. Certain embodiments are directed towards composites that contain particles (e.g. reinforcing particle), such as rubber particles. These particles can be used to improve slip resistance or abrasion. Polyurethanes and other compounds may be added to the composites, for example, in order to make fabrication easier, such as by using 3D printing or other printing techniques. Some embodiments relate to the methods for making or using these articles. In some embodiments, for example, a composite can be made by mixing particles, e.g. reinforcing powders, with at least one first fluid and one second fluid in a nozzle such as a microfluidic print nozzle that is used to direct the product onto a surface.
In some embodiments, a printed article (e.g. 3D-printed articles) can include a composite. In certain embodiments, the composite can be made up of a matrix, and a number of particles, such as reinforcing ones. The matrix can include polyurethane and other polymers that are suitable for manufacturing articles. Below are some examples of polyurethanes or other suitable polymers. The composite can be made of foam in some embodiments. However, this is not required for all embodiments. In some cases, the particles (e.g. reinforcing particle) may increase slip resistance due to friction. The particles can provide an increased resistance to abrasion or toughness, for example, on a surface. In some cases, the particles can be used to create texture. For example, they could produce a rougher or bumpier surface texture on an article or give it a particular appearance. The surface of the article can be given a certain appearance or?sheen? Rubber particles can be used in some embodiments. Rubber can be sourced from any source and recycled or virgin rubber is also acceptable. Rubber can be made from natural rubber or synthetic rubber. Rubber examples include but are not restricted to recycled tire rubber or ground tire rubber. Rubber particles can be made from a wide range of polymers including, but not limited, to natural rubber, styrene-butadiene, polyacrylics (PVA), PVC, polychloroprene, polyurethanes (neoprene), butyl rubbers and polyurethanes. In some cases, combinations of these rubbers and/or others may be used. In some cases, it is not known the exact compositions of polymers within rubber particles. Rubber can be derived from various natural sources, and thus may contain a wide variety of polymers. It may also have been recycled (e.g. tires, pencil erasers or other rubber products, footwear etc.). In one embodiment, for example, recycled rubber from sources like discarded tires can be made into particles by using techniques such a mechanical grinding, cryogenic milling, cutting and shredding.
In other embodiments, rubber particles may also be reinforced with other materials, such as glass fiber, calcium carbonates, or gypsum. Examples include silica particles, fumed silicon, silicon carbide and titanium dioxide. Other examples are fibers, carbon fibre, gypsum fiber, glass fiber, calcium oxides, nanorods or microrods made of carbon fibers. In some embodiments, the particles may comprise silicone particles, wax particles, or polytetrafluoroethylene particles, or combinations thereof. In some embodiments the particles (e.g. reinforcing particle) can be a thermoplastic urethane with a blowing agents inside, which has not yet been expanded, or a expanded thermoplastic urethane. In some embodiments the particles (e.g. reinforcing particle) are a blowing agents that decomposes into gas above a temperature of activation. In some embodiments, the particles comprise azodicarbonamide particles, sodium bicarbonate particles, hydrazine particles, toluenesulfonylhydrazine particles, or oxybisbenzenesulfonylhydrazine particles, or combinations thereof. Reinforcing particles can be hollow or solid spheres in some embodiments. As non-limiting examples of such spheres, they can be made from glass or polyurethane. The spheres can be hollow polyurethane or elastomer ones.
In some embodiments the particles (e.g. reinforcing particle) can have a maximum numerical average size of at most 1000 microns. In certain embodiments the particles (e.g. reinforcing particle) may have an average numerical dimension of up to 1000 microns. The above ranges can be combined (e.g. at least 10 microns with at most 1000 microns or at minimum 50 microns with at most 400 microns or at minimally 50 microns but at maximum 250 microns). Particles can be spherical or non-spherical. The particles can be of different sizes or shapes in some cases (e.g. in crumb rubber, ground tire rubber, etc.).
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