Rapid Prototyping Zarith Zahran Bin Zaidi (57274113098) Prepared by: Zarith Zahran Bin Zaidi (57274113098) Muhammad Jazli Jasri (57274113o42) Muhammad Faez bin Othman (57274113066) Nurul Fazlina binti Mohamad Zulfazlee(57274212089)

What is Rapid Prototyping? a group of techniques used to quickly fabricate a scale model of a part or assembly using three-dimensional computer aided design (CAD) data. Construction of the part or assembly is usually done using 3D printing or "additive layer manufacturing" technology. Used in a wide range of industries, Rapid prototyping allows companies to turn innovative ideas into successful end products rapidly and efficiently.

Type of Rapid Prototyping Stereolithography Selective Laser Sintering Laminated Object Manufacturing Fused Deposition Modelling Solid Ground Curing Ink Jet printing techniques

Stereolithography Stereolithography (SLA), the first Rapid Prototyping process, was developed by 3D Systems of Valencia, California, USA, founded in 1986. A vat of photosensitive resin contains a vertically-moving platform. The part under construction is supported by the platform that moves downward by a layer thickness (typically about 0.1 mm / 0.004 inches) for each layer. A laser beam traces out the shape of each layer and hardens the photosensitive resin.

Highlights of Stereolithography The first Rapid Prototyping technique and still the most widely used. Inexpensive compared to other techniques. Uses a light-sensitive liquid polymer. Requires post-curing since laser is not of high enough power to completely cure. Long-term curing can lead to warping. Parts are quite brittle and have a tacky surface. No milling step so accuracy in z can suffer. Support structures are typically required. Process is simple: There are no milling or masking steps required. Uncured material can be toxic. Ventilation is a must.

Selective Laser Sintering Selective Laser Sintering (SLS®, registered trademark by DTM™ of Austin, Texas, USA) is a process that was patented in 1989 by Carl Deckard, a University of Texas graduate student. Its chief advantages over Stereolithography (SLA) revolve around material properties. Many varying materials are possible and these materials can approximate the properties of thermoplastics such as polycarbonate, nylon, or glass-filled nylon.

Highlights of Selective Laser Sintering Patented in 1989. Considerably stronger than SLA; sometimes structurally functional parts are possible. Laser beam selectively fuses powder materials: nylon, elastomer, and soon metal Advantage over SLA: Variety of materials and ability to approximate common engineering plastic materials. No milling step so accuracy in z can suffer. Process is simple: There are no milling or masking steps required. Living hinges are possible with the thermoplastic-like materials. Powdery, porous surface unless sealant is used. Sealant also strengthens part. Uncured material is easily removed after a build by brushing or blowing it off.

Laminated Object Manufacturing The figure below shows the general arrangement of a Laminated Object Manufacturing (LOM™, registered trademark by Helisys of Torrance, California, USA) cell: Material is usually a sheet laminated with adhesive on one side, but plastic and metal laminates are appearinpaper g.

Highlights of Laminated Object Manufacturing Layers of glue-backed paper form the model. Low cost: Raw material is readily available. Large parts: Because there is no chemical reaction involved, parts can be made quite large. Accuracy in z is less than that for SLA and SLS®. No milling step. Outside of model, cross-hatching removes material Models should be sealed in order to prohibit moisture. Before sealing, models have a wood-like texture. Not as prevalent as SLA and SLS®.

Fused Deposition Modelling Stratasys of Eden Prairie, MN makes Fused Deposition Modeling (FDM) machines. The FDM process was developed by Scott Crump in 1988. The fundamental process involves heating a filament of thermoplastic polymer and squeezing it out like toothpaste from a tube to form the RP layers. The machines range from fast concept modelers to slower, high-precision machines. The materials include polyester, ABS, elastomers, and investment casting wax. The overall arrangement is illustrated below:

Highlights of Fused Deposition Modelling Standard engineering thermoplastics, such as ABS, can be used to produce structurally functional models. Two build materials can be used, and latticework interiors are an option. Parts up to 600 × 600 × 500 mm (24 × 24 × 20 inches) can be produced. Filament of heated thermoplastic polymer is squeezed out like toothpaste from a tube. Thermoplastic is cooled rapidly since the platform is maintained at a lower temperature. Milling step not included and layer deposition is sometimes non-uniform so "plane" can become skewed. Not as prevalent as SLA and SLS®, but gaining ground because of the desirable material properties.

Solid Ground Curing Solid Ground Curing, also known as the Solider Process, is a process that was invented and developed by Cubital Inc. of Israel. The SGC process uses photosensitive resin hardened in layers as with the Stereolithography (SLA) process. However, in contrast to SLA, the SGC process is considered a high- throughput production process.

Highlights of Solid Ground Curing Large parts, 500 × 500 × 350 mm (20 × 20 × 14 in), can be fabricated quickly. High speed allows production-like fabrication of many parts or large parts. Masks are created w/ laser printing-like process, then full layer exposed at once. No post-cure required. Milling step ensures flatness for subsequent layer Wax supports model: no extra supports needed. Creates a lot of waste. Not as prevalent as SLA and SLS, but gaining ground because of the high throughput and large parts.

Ink Jet Printing Techniques Ink jet printing comes from the printer and plotter industry where the technique involves shooting tiny droplets of ink on paper to produce graphic images. RP ink jet techniques utilize ink jet technology to shoot droplets of liquid-to-solid compound and form a layer of an RP model. Common ink jet printing techniques: Sanders Model Maker™ Multi-Jet Modelling™ Z402 Ink Jet System™ Three-Dimensional Printing

Sanders Model Maker Exceptional accuracy allows use in the jewelery industry. Accuracy is partly enabled by a milling step after each layer deposition. Plotting system is a liquid-to-solid inkjet which dispenses both thermoplastic and wax materials. Compared to SLS® and SLA, not as established. Multi-Jet Modelling Fast. Office-friendly: non-toxic materials, small footprint, low odor. Simple operation: operates as a network printer in an office environment. Models are primarily for appearance use.

Z402 Ink Jet System Fast: one to two vertical inches per hour, depending on layer density. Office-friendly: non-toxic materials, small footprint, low odor. Simple operation. Compared to SLA and SLS®, not as established. Three-Dimensional Printing Binder is "printed" on unbound powder layer. Without milling step, work plane can become successively skewed. Not as established as SLA and SLS®.

Why Rapid Prototyping? To increase effective communication. To decrease development time. To decrease costly mistakes. To minimize sustaining engineering changes. To extend product lifetime by adding necessary features and eliminating redundant features early in the design.

Benefits of Rapid Prototyping Fast and effective communication of design ideas Effective validation of design fit, form, and function Greater design flexibility, with the ability to run quickly through multiple design iterations Fewer production design flaws and better end- products