4 Essential Plastic Prototyping Techniques for Fabrication
Introduction to Plastic Prototyping
Prototyping is an essential activity in product development. It helps engineers and designers evaluate the feasibility of a project by creating a physical object that closely resembles the intended design. Building a prototype also allows them to test their design against certain requirements, make sure it works as intended, and identify any potential issues before entering mass production.
For plastic parts, a prototype can be created through a variety of processes, each with its advantages and disadvantages. Below are four of the most commonly used plastic prototyping techniques for fabrication: Stereolithography (SLA), Selective Laser Sintering (SLS), Fused Deposition Modeling (FDM), and CNC Machining.
Stereolithography (SLA)
Stereolithography (SLA) is an additive manufacturing process for producing parts from liquid photopolymer resins. SLA works by focusing a laser beam into a photopolymer resin, which hardens the material layer by layer until the entire part is built.
SLA is well-suited for producing detailed, accurate parts with complex geometries, as the laser accurately creates features with tight tolerances. In addition, parts produced with SLA can be ready in as little as one day, making it an ideal solution for those who need quick turnaround times.
On the downside, parts produced with SLA tend to be brittle and not as strong as parts made with other methods. Additionally, since the process is limited by the size of the build platform, larger parts may need to be split and glued together after printing.
Selective Laser Sintering (SLS)
Selective Laser Sintering (SLS) is similar to SLA, in that it is also an additive manufacturing process for producing parts from powdered materials. However, instead of a liquid photopolymer resin, SLS uses a thermally fusible powder such as nylon or polystyrene.
The powder is spread in thin layers on a build platform, and then a laser is used to selectively sinter the powder into solid parts layer by layer. SLS can produce parts with complex geometries and fine details, and parts made with SLS are generally more durable than those made with SLA.
However, SLS parts are prone to warping and shrinkage due to the heat generated by the laser, which can lead to dimensional accuracy issues. Additionally, the powder material can be difficult to remove from the build platform, and some materials can be quite expensive.
Fused Deposition Modeling (FDM)
Fused Deposition Modeling (FDM) is an extrusion-based additive manufacturing process for producing parts from thermoplastic materials. FDM works by heating and extruding thermoplastic material layer by layer onto a build platform.
FDM produces parts with good strength and durability, and parts can be printed in a wide range of materials, including ABS, polycarbonate, and nylon. FDM is also relatively fast and cost-effective, making it a popular choice for producing prototypes and low-volume production parts.
The downside of FDM is that parts tend to have a visible layer pattern, and complex geometries and fine details can be difficult to achieve. Additionally, some materials may require additional post-processing steps, such as sanding or acetone vapor smoothing, to achieve a smooth finish.
CNC Machining
CNC machining is a subtractive manufacturing process that uses computer-controlled cutting tools to shape a material into the desired shape. CNC machining can produce parts with high dimensional accuracy and surface finish and is well-suited for producing parts with complex geometries and intricate details.
CNC machining can be used to produce parts from various materials, including plastics, metals, and composites. The downside of CNC machining is that it can take longer to produce parts than other processes, and the setup cost can be quite high.
Conclusion
When it comes to creating plastic prototypes, there are many different processes available. Each process has its advantages and disadvantages, so it’s important to select the right process for your specific needs. The four most common plastic prototyping techniques for fabrication are Stereolithography (SLA), Selective Laser Sintering (SLS), Fused Deposition Modeling (FDM), and CNC Machining. Depending on the desired outcome, any of these methods can be used to create a successful prototype.