{"id":1286,"date":"2016-07-07T14:24:25","date_gmt":"2016-07-07T14:24:25","guid":{"rendered":"http:\/\/www.mark3d.de\/?p=1286"},"modified":"2017-09-06T19:58:39","modified_gmt":"2017-09-06T19:58:39","slug":"3d-druck-mit-isotropischer-faserausrichtung","status":"publish","type":"post","link":"https:\/\/www.mark3d.com\/de\/en\/tipps-zu-technik-und-design\/3d-druck-mit-isotropischer-faserausrichtung\/","title":{"rendered":"Part 1: 3D printing with isotropic fiber alignment"},"content":{"rendered":"
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Markforged\u2019s continuous strand composite 3D printers enable our customers to create industrial strength 3D printed parts, reinforced with composite fibers to produce properties similar to quasi-isotropic composite laminates, in a highly automated 3D printing system. Quasi-isotropic 3D printed parts have varying material characteristics along different axes, and by varying the fiber orientation in our Eiger slicing software, you can design strong parts to resist specific loading applications to which the part may be exposed.<\/p>\n
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A carbon fiber-reinforced chain link, finally failing at over 22,000 pounds of force<\/i><\/p>\n
High strength isotropic material* properties make engineering part design easy \u2013 if a material has the same properties in all directions, then making a part that is strong enough for an intended application is nothing more than a matter of geometry. In the case that material properties\u00a0will<\/i>\u00a0differ across different axes (as is the case in 3D printing), a quasi-isotropic* material is the next best option, since there is a strength difference along only one axis that must be taken into account and it will require much less time and design work to optimize for part strength than with a completely anisotropic* material. See the common terminology for composite material property orientation below for a deeper discussion of variations in material properties. Note that for convenience, and with the understanding that all 3D printed parts will have differing material properties in the Z direction (the axis normal to the printbed plane), Markforged has dropped the \u2018quasi-\u2018 from quasi-isotropic in describing our \u2018Isotropic Fiber\u2019 fill type.<\/p>\n
*Composite Terminology Glossary<\/i><\/p>\n Traditional thermoset composites (most consumer uses of carbon fiber employ this type of composite) are made from dozens to thousands of stacked layers of unidirectional composite material (often in the form of woven cloth or unidirectional tape) oriented in a pattern of different directions; composite designers employ a nomenclature structure in the form of an \u2018orientation code\u2019 to provide a simplified way of describing these repeating patterns. Each successive layer is generally rotated by some angle (often 45 degrees) relative to the layer below, and since the composite fibers making up the woven cloth in each layer are strongest in their tensile direction, rotating the cloth each layer produces a part with a much higher multi-directional bulk strength and stiffness than if the cloth had been laid up in the same direction on each layer.<\/p>\n Example carbon fiber layup composition \u2013 note the different angular fiber orientations in each layer (source:\u00a0Carbon Fiber Gear<\/a>)<\/i><\/p>\n A great primer on composite orientation codes can be found in this\u00a0presentation from the US Naval Academy<\/a>. A traditional orientation code is described by a series of angles bookended by square brackets and separated by forward slashes, to denote the various angles used in a particular composite layup strategy. For example, Eiger\u2019s default Isotropic Fiber fill pattern uses an orientation code of Unidirectional carbon fiber tape (as opposed to woven carbon fiber) produces the highest strength single direction composites (source:\u00a0Easy Composites<\/a>)<\/i><\/p>\n The\u00a0Mark Two<\/a>\u00a03D printer was designed to robustly produce high strength fiber-reinforced parts with 15x smaller geometries than the Mark One, but our upgraded software algorithms also give it significantly improved capabilities to create reinforced parts with high strength quasi-isotropic properties using our \u2018Isotropic Fiber\u2019 fill type.<\/p>\n Carbon fiber Isotropic fill is extremely robust and fully supported by the Mark Two\u2019s precision fiber extruder<\/i><\/p>\n You will note in the image above, from the external \u2018Part View\u2019 fiber configuration panel in Eiger, that there is an input box for \u2018Fiber Angles\u2019. This is a representation of the orientation code mentioned above and is one way to quickly control the high-level bulk material properties of a fiber-reinforced part in Eiger. The default [0\/45\/90\/135] code that Eiger uses will produce a transversely isotropic part (see the terminology box above) if you reinforce every layer of the part with the Isotropic Fiber fill. To input an orientation code in Eiger, simply type the angles of the various fiber orientations that you would like in your pattern into the \u2018Fiber Angle\u2019 box, separated by commas as in the image above.<\/p>\n The improved fiber routing algorithms also enable the Mark Two to print Isotropic Fiber fill using Markforged\u00a0carbon fiber filament<\/a>\u00a0as well as our new\u00a0High Strength, High Temperature (HSHT) Fiberglass<\/a>\u00a0filament \u2014 options that were not available with the Mark One due to technical limitations. The algorithm itself has been updated from its Mark One counterpart \u2014 if you use Eiger\u2019s 2D Internal View to view a layer with Isotropic Fiber fill sliced for the Mark Two, you will notice that the new algorithm enables a hybrid fill type, with concentric rings on the outside of the part and isotropic fill at the specified orientation angle filling in the internal area of the part. This produces a part with an improved external surface finish, while maintaining high overall strength and stiffness internally. \u00a0Using this strategy, the absolute strongest parts can be\u00a0achieved through carbon fiber 3D printing.<\/p>\n Notice as the angular fiber orientation rotates by 45 degrees every layer<\/i><\/p>\n The External View fiber parameters are good for fast reinforcement, but if you need more control over the strength of your parts, you can also edit the orientation codes of specific layer groups in the 3D Internal View of a part in Eiger. To start, select a part from your Eiger library, and enter the Internal View, which brings you to the 3D view by default.<\/p>\n Opening the internal view<\/i><\/p>\n Changing from 2D to 3D Internal View<\/i><\/p>\n Once inside the Internal 3D View, select a pre-existing fiber layer group in the layer bar by clicking on it.<\/p>\n Selecting a pre-existing layer group<\/i><\/p>\n To create a new group, click on the layer bar at the start or end point of your desired group and hold down the mouse button while dragging across the layers you want in the group. Then simply click \u2018Apply Changes\u2019 in the upper right layer control box to create the new group.<\/p>\n Creating a new layer group<\/i><\/p>\n If you aren\u2019t satisfied with the layers you chose for the group, you can always drag the triangular layer group delimiters to resize the layer. Once you\u2019ve selected a defined layer group that is configured to use Isotropic Fiber fill, you will notice that the \u2018Fiber Angles\u2019 field seen in the external Part View is also visible in the layer control box in the upper right. This parameter allows you the same level of control over fiber orientation codes that you had in the external Part View, except that rather than applying the orientation code globally across all fiber in the entire part, the Fiber Angles field in the 3D Internal View editor will allow you to modify the orientation code for just the selected layer group alone. This gives you the control to tailor high strength fiber placement to the specific geometry of your part.<\/p>\n Changing the Fiber Angles in a layer<\/i><\/p>\n And that\u2019s pretty much it \u2013 Eiger makes it incredibly simple to quickly configure the different layers of fiber reinforcement in a part!<\/p>\n\n
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<\/p>\nImproved Capabilities<\/i><\/h3>\n
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<\/p>\nFiner control for the strongest parts<\/i><\/h3>\n
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