3D PRINTING IN TEXTILES

M Aditya (40)Megha R (29)

Programming Component

STLSTL is also known as Standard Tessellation Language. This file format is supported by many other software packages. It is widely used for rapid prototyping and computer aided manufacturing. The STL format specifies both ASCII and binary representations. Binary files are more common, since they are more compact.An STL file describes a raw unstructured triangulated surface by the unit normal and vertices of the triangles using a three-dimensional Carteisan coordinate system . STL coordinates must be positive numbers, there is no scale information, and the units are arbitrary.

Rhinoceros (abbreviated Rhino) is a stand-alone, commercial 3D modeling software application developed by Robert McNeel & Associates. The software is based on a mathematical model called NURBS (non uniform rational B-spline ), which is adept at producing curves and surfaces in computer graphics. Non-uniform rational basis spline (NURBS) is a mathematical model commonly used in computer graphics for generating and representing curves and surfaces. It offers great flexibility and precision for handling both analytic and modelated shapes.

Rhinoceros 3D

This is an algorithm for a typical STL program

The coloring option is not provided in the basic STL

header file. STL allows the programmer to choose different shades of the three basic colors –red , green and blue by changing the number associated with each color within the range

Grasshopper 3D

Grasshopper is a visual programming language developed by David Rutten at Robert McNeel & Associates. Grasshopper runs within the Rhinoceros CAD application. Programs are created by dragging components onto a canvas. The outputs to these components are then connected to the inputs of subsequent components. Grasshopper is used mainly to build generative algorithms. Many of Grasshopper's components create 3D geometry. Programs may also contain other types of algorithms including numeric, textual, audio-visual and hepatic applications.

A user requires absolutely no knowledge of programming to make designs using Grasshopper.

Mechanical Component

• PA12 or Nylon 121. Flexible material. Hence can be used to

make springs that allow bending of fabrics2. Used to make rigid support fabrics

• CosyflexResembles knitted fabrics. Used for making hygiene textiles.1. High elasticity2. Waterproof and breathable3. Made of rubber latex and viscose fibres4. Fully biodegradable

• TPU 92A (Thermoplastic Polyurethane)

1. Developed specifically for textile 3D printing

2. Durable elasticity3. High tear resistance4. High resistance to load5. Good temperature range

MATERIALS

Mechanical Processes

Selective Laser Sintering (SLS)The machine uses a computer-controlled laser to draw the bottom cross section onto the surface of a bed coated with a powdered polymer that melts and fuses where struck by the laser. It consists of two pistons and a roller. The build piston moves upwards and the roller pushes the polymeric powder onto the build piston.The build piston is then lowered to a depth corresponding to the section's thickness. The feed piston moves up again and the roller pushes some more material. And the next cross section is then drawn directly on top of the previous one. This is repeated until the part is finished.

There are two techniques used-Selective laser sintering-Fusion deposition modeling

Fusion Deposition Modeling (FDM)The FDM technology works using a plastic filament or metal wire which is unwound from a coil and supplies material to an heated extrusion nozzle which can move in all directions.The molten polymeric material is dropped in the form of beads. It instantly solidifies when it exits nozzle forming one layer.

Electronics Component

Electronics Component

LasersA laser oscillator comprises of an optical resonator in which light can circulate e.g. between two mirrors. Within the resonator is a gain medium which amplifies the light. Without the gain medium, the circulating light would become weaker and weaker in each resonator round trip, because it experiences losses upon reflection at mirrors. To amplify light, the gain medium requires external supply of energy – it needs to be “pumped”, e.g. by injecting an electric current.

Electronics Component1. CO2 lasersContinuous wave diode i.e. output power is constant over time.Lasing medium is a mixture of CO2, nitrogen, hydrogen and helium.Excited nitrogen molecules collide with C02 molecules. Thus excited CO2 molecules release photons.Thus population inversion is caused due to collision due to nitrogen molecules. Helium helps in removing heat.Infra-red light produced.

P-n junction or p-i-n junction acts as lasing medium.Similar to an LED where recombination of holes and electrons produces photons.Photon emission can be stimulated and hence amplification can be achieved.

2.Laser diodes

Electronics Component• Heating elements1. Power resistors 2. Ceramic heating cartridge – joule heating element consisting of nichrome wire

wound on a ceramic core.3. Power MOSFET –metal–oxide–semiconductor field-effect transistor used in linear

region/ ohmic region. Used instead of BJT as they do not suffer from thermal runaway. Ohmic mode is achieved when VGS > Vth and VDS < ( VGS – Vth )

Diagrammatic representation of mosfetCeramic heating cartridgePower resistor

Mathematics component

Mathematics Component

Math plays an important role in designing 3D printed textiles. Of course the final modeling is done using software on computers but the basic principle involved is derived from mathematics.

Coordinate Systems-A coordinate is a series of numbers that describes the location in the given space. -3D graphics system operates in a mathematical space. The space used in most of the 3D graphics is called 3D Cartesian coordinate.

-The Cartesian coordinate system uses a series of intersecting line segments to describe a location with respect to the origin.

Constructive Solid Geometry

Simple solid objects used for representation are called primitives. They can be cubes, cuboids, cones, spheres, cylinders, etc.A complex object can be constructed from primitives by means of operations, which are typically Boolean operations on sets i.e. union, intersection and difference.

Union Difference Intersection

ScalingAn object can be scaled to make it proportionally bigger or smaller by a factor of k. If the same scale is applied in all the directions, then the scaling is being performed in a uniform scale. Thus, the object is dilated about the origin. Uniform scaling preserves the angles and proportions. If all the lengths in uniform scaling increase or decrease by a factor of k, then the areas change by a factor of k^2and the volumes (in 3D) by a factor of k^3.

Bibliography

• Silicon graphics international corp. (SGI) official website• Blogs by Solid Concepts®• www.3ders.org• www.thre3d.com• www.tamicare.com

Thank You