What is 3D Printing?
3D printing (also known as additive manufacturing) is a parallel design and manufacturing technology that integrates materials, structures, and functions. It has wide applications in industry, medicine, and education. Although 3D printing can be used to make customized items with complicated structures, the commonly used basic 3D printing can only make objects from one material. The object is designed as a three-dimensional model with specific measurements using 3D printing software. 3D printing is an efficient process that builds up custom objects while lowering production and
manufacturing costs.
How Does 3D Printing Work?
First, a model of the object is designed to create a 3D printing file. This file is stored and is eventually transferred to a 3D printer using 3D printing software. The 3D printer reads the design and begins to print thin layers of material to create
the object. During the 3D printing process, the 3D printer remains paired with the 3D modelling software on a computer to direct and monitor the 3D printing process.
Steps Involved in 3D printing:
1. A 3D Model is designed with the help of 3D modelling Software.
2. Use 3D printing software to slice the model into sections so the 3D printer knows how much 3D printing material is needed.
3. STL file from Slicer software is saved into a memory card of the 3D Printer and Printing of the model is started
4. Post-processing is done i.e. (sanding, colouring, polishing, etc)
FDM
This FDM technology is most common and is also known as Fused Deposition Modelling. FDM 3D printing is a technology that works both horizontally and vertically, where an extrusion nozzle moves over a build platform. The process involves the use of thermoplastic material that reaches a melting point and is then forced out, to create a 3D object layer by layer. As the design takes shape, it is clear to see each layer as a horizontal cross-section. Following the completion of one layer, the nozzle of the printer is lowered in order for the next layer of plastic to be added to the design. Once the object has been created, the materials that are used to support the object can then be removed. Many businesses use FDM 3D printing technology as it allows the creation of detailed and intricate objects. Therefore, engineers are using it to allow them to test parts for fit and form. It is a technology that is now assisting the creation of small parts and specialized tools that would once take a lot longer to produce.
How Does FDM 3D Printing Work?
In the same way as other forms of 3D printing, FDM uses a digital design that is uploaded to the 3D printer. There are a lot of different polymers used, such as ABS, PLA, PVC, TPU & Composites. These take the shape of plastic threads that are fed from a coil and through a nozzle. The filaments are melted and fed onto the base, known as a build platform or table with the base and the nozzle, both of which are controlled by a computer. As the nozzle moves across the base, the plastic cools and becomes solid, forming a hard bond with the previous layer. At this point the printhead goes up in order for the next layer of plastic to be laid. As always, 3D printing is efficient and fast but the time it takes to create an object does depend on its size. Smaller objects that are around several cubic inches can be created quickly but larger, more complex object will take longer.
Advantages of FDM:
- Easy handling
- Cost efficient
- Flexibility in material choice
- Less post-processing
Stereolithography (SLA)
Stereolithography (SLA) is an additive manufacturing process that belongs to the vat photopolymerization family. Also known as resin 3D printing. SLA is one of the most widely used vat photopolymerization technologies. It is used to create objects by selectively curing a polymer resin, layer by layer, using an ultraviolet (UV) laser beam. The materials used in SLA are photosensitive thermoset polymers that come in a liquid form.
SLA is still the most cost-effective 3D printing technology available when parts of very high accuracy or smooth surface finish are needed. Best results are achieved when the designer takes advantage of the benefits and limitations of the manufacturing process
How does SLA 3D printing work?
1. SLA 3D printing works by first positioning the build platform in the tank of liquid
photopolymer, at a distance of one layer height for the surface of the liquid.
2. A UV laser creates the next layer by selectively curing and solidifying the
photopolymer resin.
3. During the solidification part of the photopolymerization process, the monomer
carbon chains that compose the liquid resin are activated by the light of the UV laser
and become solid, creating strong unbreakable bonds between each other.
4. The laser beam is focused in a predetermined path using a set of mirrors, called
galvos. The whole cross-sectional area of the model is scanned, so the produced part
is fully solid.
5. After printing, the part is in a not-fully-cured state. It requires further post-processing
under UV light if very high mechanical and thermal properties are required
Advantages of SLA 3D Printing:
- SLA can produce parts with very high dimensional accuracy and with intricate details.
- SLA parts have a very smooth surface finish, making them ideal for visual prototypes.
- Speciality SLA materials are available, such as clear, flexible, and castable resins.
Vaccum Casting
Vacuum Casting is a casting process in which a liquid material is drawn into a silicone mold using a vacuum to create complex components. The liquid materials used for vacuum casting are elastomers such as plastic and rubber. Vacuum casting is sometimes referred to as polyurethane casting or urethane casting as polyurethane resin, a type of elastomer, is used as the casting material. Vacuum casting is an economical alternative to injection molding for making plastic components as the production cost of vacuum casting is comparatively lower. Vacuum casting is an excellent production process for batch production and other lowvolume production jobs. Vacuum casting is heavily used in the FMCG and consumer product manufacturing as well as industrial electronics production.
How does Vacuum Casting work?
Vacuum casting is very similar to injection molding, where the cast material is injected into molds for creating products. The difference between vacuum casting and injection molding is in the types of molds used. In injection molding, molds are made of aluminum, steel, etc. On the other hand in vacuum casting, silicone molds are used. This greatly reduces the cost of mold making, as silicone is cheaper and it also possesses good durability. The casting material most commonly used in this process is polyurethane. Different polyurethanes have different properties, such as good structural rigidity, elasticity, flexibility, shock and temperature resistance and so on. Thus depending on the type of product being manufactured, different polyurethanes can be used. The vacuum casting process can be broken down into the following 5 steps:
1. 3D Model of component
2. Creating Master Pattern of the Mold
3. Making Silicone Molds
4. Preparing POLYURETHANE Resin
5. Curing And Demolding
Advantages of Vacuum Casting:
- Multiple components can be used from the master pattern within 24hrs which would
reduce the product design prototyping stage cutting time and cost on new product
development - Vacuum casting can be used to create small batches of high-quality injection
moulding type parts for prototypes or low volume end-use parts for low stress,
relatively benign environments - A wide range of vacuum casting resins are available to suit various applications such
as clear, rubbery, flame retardant, food-grade and coloured to suit - Resin type can be changed easily without the need to retool to test various material
types for a given application or part Complex shapes and features can be
accommodated by using multi-segment moulds & cores.
