Not only for plastic parts and products but plastic prototype is also used to test the design validity of metal and composite parts. Automotive, robotics, aerospace, toys, and other industries use these in their product development cycles.
Rapid prototype development using material gives cost-benefit in production allowing multiple iterations and a competitive edge in the market.
Furthermore, we will elaborate on concepts, methods, benefits, and material options for rapid plastic prototyping.
Why Use Plstic Prototypes?
Whenever a designer creates a new design of parts and products, they do not go directly into the production process. Instead, they are tested by making rapid prototypes and adjusted to achieve optimal performance and eliminate possible shortcomings.
Plastics are cost-effective materials for making prototypes; they can be shaped quickly into desired shapes using various techniques.
Rapid Prototype Development
Compared to traditional methods, rapid methods like 3D printing can make plastic prototypes in 1 day if you have your design ready.
Cost-Effectiveness
Quick production speed, low material cost, and manufacturability make rapid plastic prototyping cost-effective. It gives you the flexibility to perform many iterations to refine the design before final production for the market.
Material Flexibility
Nylong, PVC, polycarbonate, ABS, Polyethylene, Acrylic, and some thermosets can be used in rapid prototyping with both 3D printing and injection molding methods.
Complex Geometry and Intricate Features
Unlike traditional machining and other prototyping methods, rapid prototyping methods can make complex shapes and intricate contours.
Risk Mitigation
The cost and time benefit of rapid plastic prototyping allows for faster iterations and shorter product development cycles. It reduces the overall effort and timeline, mitigating the market risks.
Support for Innovations
The capability of making complex geometries gives designers more freedom. Additionally, the quick fostering of iteration allows for innovations by testing new concepts.
The Process of Plastic Prototyping
Creating plastic prototypes from scratch first requires a lot of analysis tasks and research to make a detailed design of the desired part or product you want to introduce into the market. Then, a few physical models of those designs are made with prototyping methods. Sometimes, these are used to test the structure and aesthetic, but most of the time, they are for functionality testing.
Rapid Prototyping steps
The series of testing and iterations helps to modify the design according to founded areas for improvement. It also gives ideas on how to enhance the performance of products and minimize the cost.
- Creating an engineering design based on product concepts, outlining all technical details.
- Choose a suitable plastic material and prototyping method
- According to the chosen material and method, convert your design(CAD) into compatible formats, e.g., STL or OBJ.
- Perform prototype manufacturing process with tight monitoring for quality control.
- If required, perform the necessary post-processing to correct the dimensions and surface quality.
- Test the prototype and go for iterations until you optimize your prototype for full-scale runs.
Rapid Prototyping Methods
Broadly, there are two categories of plastic prototyping and any other materials; Subtractive and Additive. Subtractive methods involve converting a raw block or bar of plastic into a prototype by removing material, such as CNC Milling and Turning. On the other hand, additives involve adding or fusing material to form shapes.
Let’s look at some of the key methods for plastic prototypes;
3D Printing
3D printed plastic prototypes
This additive manufacturing makes complex prototypes by building them layer by layer according to a 3D CAD model. It is highly beneficial in the production of complex shapes and intricate designs, which is quite challenging with conventional methods.
You can print thermoplastics such as PLA, ABS, PEEK, and even multi-material 3D printing with different materials at different sections.
Injection Molding
Injection molding prototypes
Injection molding is a method of shaping molten plastic in a mold cavity in a way that it cools and solidifies. Injection molding is perfect for most productions via large-volume runs. Furthermore, it provides better consistency and quality of surface finish. Although it costs a lot for the mold, the per-unit cost lowers significantly as the production volume increases.
CNC Machining
CNC machining plastic prototype
It is a subtractive method in which a solid block is shaped using computer-controlled tools. This method is preferable for prototypes requiring exceptional dimensional accuracy and excellent surface finishes. Moreover, CNC machining is compatible with a variety of plastics.
Material Options for Plastic Prototyping
Choosing the right plastic for the prototyping matters in testing the required performance criteria, whether you are using 3D printing, vacuum casting, injection molding, or any other method to build your prototype.
Consider desired mechanical and physical properties, material cost, compatibility with the chosen manufacturing method, and market availability in the selection process.
Let’s look at some common plastic options for prototyping projects;
- PLA: This biodegradable material is easy to 3D print and provides a smooth finish on 3D printed prototypes. You can use it for visual and concept models at the initial phase of prototyping.
- ABS: High-impact resistant plastic that is best for functional testing prototypes in automotive, electrical, robotics, and many other industries.
- Polycarbonate: A transparent thermoplastic with good impact strength, ideal for optical and transparent prototyping.
- Nylon: It has good mechanical strength and flexibility and is suitable for fittings, gears, bearings, sealing, etc.
- HDPE: It is a lightweight plastic that resists impact and humidity. You can use HDPE to make containers, pipes, toys, etc.
Conclusion
Overall, using plastic prototypes benefits you in terms of cost, manufacturing speed, and a high number of iterations. Utilizing fast rapid prototyping allows you to identify the errors and correct them before going into the market. However, choosing the right prototyping method and material is key to leveraging these advantages.
