Prototyping can be defined as the creation of the most tangible, primitive form of the product to be manufactured before it is manufactured . This shape is called the prototype of that product. The prototype comes after the design phase. Logically, prototyping is done before material selection . Thus, the materials to be selected are healthier and more accurately determined. in prototypeIncorrect geometries are corrected and intervened by returning to the design phase.
Prototypes are generally created with materials that can be painted and that will not cause problems in machining. Thus, there is no excess cost. The prototype can be built as a single piece, multiple piece, or mechanically movable assemblies. Each piece is painted with its own unique colors to make a difference between the pieces. This makes the appearance of the prototype more understandable. Prototypes can now be created with special prototype machines. These machines build the prototype from the core, layer by layer, to the surface. Since this process takes a very short time, its use in the industry is increasing rapidly.
Why is a prototype needed?
In the old manufacturing methods, there was little need for a prototype. The reason for this was that the product was already produced by gradually forming. With the development of computer aided design technologies, the production process has changed. It was possible to obtain products directly from the design. This paved the way for the necessity of creating a prototype of the product. After the design, the prototype of the product is created and the geometries are tested whether they are smooth and producible. If the designed product has geometries that cannot be produced, it is corrected. In addition, geometric lines that appear flexible in the computer environment may not seem that flexible in reality. A prototype is needed to predict this.
What are the Advantages of the Prototyping
The product to be manufactured by prototyping; it can be produced, of high quality, works, can be used, is designed in a safe and stylish way. Problems and troubles that are solved by the prototyping method, and no problems are encountered in the production stage or these problems are minimized.
What are the Disadvantages of the Prototyping?
While the product is still in the design phase, it becomes tangible and visible. As soon as the person who designed the product sees this product tangibly, subconsciously connects it to that product and limits the application of different ideas and geometries. A relationship is established between the other devices in the environment and the prototype. This causes the products to be similar to each other. There is a decrease in product variety and geometry differences.
Place of Prototyping in the Industry
With the use of computer aided drawings in every business, the need for prototypes began to increase. Some companies have filled this gap by providing prototyping tools within themselves. Organizations that were unable to fill this gap either continued their production without making prototypes or continued to work with companies that provided prototype service. Companies that do not attach importance to the prototype could not raise their success charts very high.
The need for special prototype machines arose. Businesses providing prototype services began to be established. With the development of prototyping applications, another concept that can be called antonym has emerged. That’s “reverse engineering” .
In short, prototyping had a special place in the manufacturing industry. Due to errors in production without prototypes, companies suffered material damage and could not provide continuity or had difficulty in providing, could not develop.
Virtual Prototyping
Virtual Prototyping provides the opportunity to examine the product with real image quality by using different design types developed in the computer environment. Different configurations desired on the product can be examined in one-to-one dimensions, with real-time real image quality, in 3D, and the most suitable product design can be put into production.
Rapid Prototyping
Rapid prototyping is a technology that allows us to obtain tangible physical models directly from three-dimensional CAD drawings prepared on the computer.
Rapid prototyping technologies provide solutions to problems experienced in product development processes. Before mass production of the designs drawn on the computer, samples must be prepared and these samples must pass various tests. This process can take days or even weeks when done with traditional methods. With rapid prototyping, this process is carried out within hours and the resulting outputs can be tested both visually and functionally.
Where Are the Produced Parts Used?
Visual design control of the product is made and possible form errors can be observed. Interlocking details of products containing more than one component and compatibility of parts can be checked. The operability of the mechanisms can be tested. A multi-part assembly can be produced and run in one go. It can be used as a master model in mold making. It can be used for precision casting process.
You can produce anything computer-drawn with rapid prototyping. The volume, wall thickness or form of the pieces do not constitute a limitation.
It is possible to produce different colors from different materials according to your material needs. You can produce flexible or rigid, transparent or matte parts.
The parts can be easily painted when desired and can be used on the same product. They can be cut, sanded and glued together. You can choose the one that suits your needs among the materials with variable heat resistance.
While many classifications can be made in rapid prototyping systems, the best one is the classification based on the initial state of the material used in prototype production. Accordingly, rapid prototyping systems;
- liquid based
- solid basis
- It can be divided into 3 groups as powder-based .
1. Liquid Based
- In liquid-based rapid prototyping systems, the material is initially in a liquid state.
- Through a curing/hardening process, commonly known as light, laser or heat, the liquid turns into a solid.
2. Solid Based
- It covers all forms of solid material except powder in solid-based rapid prototyping systems.
- In this context, solid can be in the form of wire (filament), roll, sheet and granule.
3. Powder Based
In powder-based rapid prototyping systems, the powder is usually in the solid state. However, due to the granular form of the powder, it has been studied in a different category from solid-based prototyping systems.
- In these systems, the bonding of powder particles to each other is achieved by melting the contact areas of the particles at the interface or by adding a binder or adhesive.
Rapid Prototyping Technologies
1) Mortar Masonry-Spraying (Polyjet-Object)
In this technique, the photopolymer raw material, which is liquid at room temperature, is sprayed from thousands of nozzles on eight injection heads to form layers (a method similar to that of plastic injection machines). The sprayed raw material is frozen and solidified at the same time by means of UltraViolet lamps. Layers with a thickness of 16 microns are formed one by one in this way and a prototype is obtained.
2) Mortar Masonry (FDM-Fused Deposition Modeling)
The solid raw material is heated and turned into a liquid. The liquid raw material is sprayed from a fine-tipped nozzle and plastered on the surface in a thin layer to form layers. The sprayed raw material then solidifies and forms the part. The physical model is obtained after the structure, which is built with support materials as in Polyjet technology, is separated from the support materials. In this technology, prototypes are built using ABS (acrylonitrile butadiene styrene) and PC (polycarbonate) materials. The physical and chemical properties of the parts produced by the Fused Deposition Modeling method are the same as the materials used in the products.
3) Powder Bonding-Heating (SLS-Selective Laser Sintering)
In the Selective Laser Sintering technique, a powdery building material that can be fused when heated is spread in a thin and uniform layer. Then, the selected areas on the surface are scanned with the laser beam, and the powder material melts with the heat generated at the points where the beam hits the surface and fuses with the other powder grains it is in contact with. Thus, it is produced by aggregation of powder layer by layer. After the production of the part is completed, the excess dust -which also functions as a support material- is cleaned from the part with the help of a brush.
4) Light Curing-Scanning (SLA-Stereolithography)
The photopolymer raw material, which is liquid at room temperature, has already filled the cube-shaped construction area. Light from a laser source is sent onto this liquid mass. The part is produced by ensuring that the desired areas are cured by scanning the material upwards, starting from the bottom of the light source. The solidified part is then removed from this liquid and, since it has not solidified yet, it is subjected to a secondary process and solidified under UltraViolet light. The materials used in stereolithography technology are photopolymer materials specific to this method. It is possible to obtain prototypes with different features according to the needs.
