Creating the perfect plastic prototype is super important.
- Avoiding costly design mistakes
- Testing your product’s performance
- Cutting overall project costs before investing in full-scale production
However, getting started can feel tricky.
Maybe you’re unsure about your design complexity, tolerances, size, or production volume. Maybe you’re stuck wondering which material or technique is right for your needs. Or maybe you’re just thinking, what the heck a plastic prototyping is?
Don’t stress, we’ll break it all down and explain four different plastic prototype fabrication techniques so you can figure out what works best.
What’s Plastic Prototyping?
A plastic prototype is a sample version of a product, used to test its design and function before mass production. Whether it’s a basic model to check size and shape or a detailed version to assess how it works, prototypes help fine-tune ideas, avoid errors, and get feedback from users and investors. This process ensures your product is ready for manufacturing and meets market needs.
Typically, there are two types of prototypes people need to make:
- Visual/tactile prototype: It just a simple model showing size and shape. It focuses on basic features without worring about functionality or detailed appearance. Techniques like SLA and FDM are cost-effective for rapid prototype development.
- Functional prototype: Also known as a working prototype, it includes key features, materials, and even graphics of the final product. This version lets businesses test or validate their design before moving to production.
Tip: For functional prototypes requiring certain physical properties like food safety (oral syringe), optical clarity or pressure retention, machining or casting may be necessary.
- High-resolution prototype: This type delivers a near-final look and feel, ideal for pitching to stakeholders, marketing, or evaluations. High-resolution 3D printing is a great option for creating these.
Plastic prototype manufacturing benefits various industries. For example, One startup produced 20 smartwatch casings with vacuum casting, slashing development time by 30% for their pre-launch. A medical firm used SLA 3D printing to quickly develop a precise surgical tool prototype for regulatory approval.
Why Building a Perfect Plastic Prototype Matters?
Wondering if plastic prototyping is worth the effort? The answer, definitely, is yes. Strong conceptual and prototype work lay the groundwork for success before entering EVT, DVT, and PVT stages. A high-quality prototype allows the design and development team to fully understand the product and address potential failures efficiently as production ramps up.
- EVT (Engineering validation test): Verifies that the engineering design meets functional requirements using the intended materials and manufacturing process.
- DVT (Design validation test): Confirms the product fulfills its functionality, performance goals, and complies with user expectations and regulatory standards.
- PVT (Production validation test): Assesses if the product is production-ready with consistent quality for high volume manufacturing.
These tests are just as valuable for other production development and manufacturing. Knowing the types of prototypes and testings helps you choose the rigtht prototyping fabrication method while considering lead time, part tolerances, resolution, and costs.
Prepare a CAD File Before Get Started
The first thing to reason before plastic prototype manufacturing is your CAD (Computer-Aided Design) model. The model is a digital representation of your intended product showing you and the manufacturer how the product should look. A CAD model also shows how the plastic parts fit together and the product’s functioning.
Some CAD software lets you annotate directly to 3D models, but not all manufacturers perfer this approach. a practical alternative is to create simplified 2D drawings with important specifiactions, and apply standard tolerances to the rest. Pay special attention to tolerances for features that are important to the product’s fit and function.
Besides, choose a trusted partner like RapidDirect for your prototype needs. We offer technical support, includidng DFM analysis, to minimize costly rework and keeps your project on track.
How to Get A Plastic Prototype Made?
Is there a technique for low volume plastic productions that are cost effective and still in the manufacturing? Yes. Here are 4 manufacturing methods you can follow to make plastic prototypes.
- 3D Printing
- Vacuum Casting
- Injection Molding
- CNC Plastic Machining
Based on the specifics of the part, determine the optimal manufacturing method for final production. Don’t get fixated on 3D printing, only to discover that injection molding is the best option when it comes to mass production.
3D Printing
When it comes to printing prototyping, three 3D printing methods stand out.
| Technology | Applications | Advantages | Limitations |
| FDM | Low-cost rapid design validation | Wide material selection, easy to use | Low surface precision, requires post-processing |
| SLA | High precision and detailed designs | Smoooth surface, suitable for visual prototypes | High-cost, limited applicability |
| SLS | Strength and functional testing | High strength and durability | Suitable for small batches, but relatively high cost |
Fused Deposition Modeling (FDM) – Low Cost
FDM 3D printing process uses extrusion for a layer-by-layer deposition of plastic materials until the final product is formed. When industrial-grade FDM printers are used, fabricators can make a plastic prototype with increased strength and resolution, depending on the materials involved. It is also a flexible procedure, compatible with several materials including PLA, ABS, Nylon, PETG, Polycarbonate, etc.
Stereolithography (SLA) – Functional Testing
FDM issues filaments, but SLA 3D printing employs plastic resin materials for creating prototypes. It involves using a high-powered laser which helps to solidify the model coming using a vat of resin. Manufacturers use this method for several purposes, including dental, medical, and general consumer components.
Selective Laser Sintering (SLS) – High-resolution
SLS technology also utilizes a high-powered laser. However, unlike SLA, it sinters powdered materials together to form a 3D model. This process features print quality that is superior to FDM’s. Plastic prototyping created via this method is more functional and has higher resolutions. They are generally more durable and flexible than FDM prints.
Benefits and Drawbacks of 3D Printing Plastic Prototypes
| Category | Details |
| Benefits | Creates prototypes faster and lowers manufacturing costs. |
| Direct CAD file upload enables smoother workflows. | |
| Offers flexible material choices for testing different prototype parts. | |
| Easy to update designs with CAD file changes for rapid iterations. | |
| Prototypes can be produced within 24 hours or less. | |
| Drawbacks | Limited durability, unsuitable for rigorous functional testing. |
| Layer lines and rough surfaces may require post-processing. | |
| Small inaccuracies can occur in large or complex designs. | |
| Time-consuming for printing complex or large parts. |
Vacuum Casting
Vacuum casting is an affordable method for producing 10 to 100 EVT units, and efficient solution for rapid vacuum cast prototype and early-stage production. It begins with a 3D printed master model, which is used to create a silicone mold. Raw materials are then injected into the mold cavity under vacuum pressure, producing accurate replicas in just 30 to 40 minutes. Each silicone mold can generate up to 25 parts. It supports a varietty of materials, from clear to opaque options.
Benefits and Drawbacks of Vacuum Cast Plastic Prototypes
| Category | Details |
| Benefits | Produces high-precision parts with fine details. |
| Silicone molds enable quick replication of identical prototypes. | |
| Ideal for creating parts with complex shapes. | |
| Yields prototypes of comparable quality to the final product when using proper mold materials. | |
| Compatible with a wide range of plastic materials with varied properties. | |
| Drawbacks | Limited mechanical and thermal resistance for real-world testing. |
| Struggles with extremely fine details or tight tolerances. | |
| Cost-efficient for small runs, but inefficient for large-scale production. | |
| Silicone molds degrade after 20-25 uses, requiring frequent replacements. |
CNC Machining
CNC machining is a fast and efficient way to fabrication plastic prototype for functional testing and validation. Unlike 3D printing, which builds layers, plastic CNC machining uses a subtractive process to carve designs from solid material blocks.
Modern digital milling machines, guided by computer automation and 3D inputs, boost accuracy and productivity. Since no molds are needed, CNC machining offers a cost-effective alternative for prototyping.
Benefits and Drawbacks of CNC Machined Plastic Prototypes
| Category | Details |
| Benefits | Tests fit, form, and function without injection mold tooling. |
| Offers tight tolerances, undercuts, threads, and size flexibility. | |
| Enables various surface finishes like polishing, painting, and powder coating. | |
| Provides fast turnaround times based on model complexity. | |
| Supports a wide range of materials for fabrication. | |
| Produces components with mechanical properties close to injection-molded parts. | |
| Drawbacks | Limited effectiveness for intricate designs or complex organic shapes. |
| Expensive for complex designs due to precision and time requirements. | |
| Less efficient for large-scale production compared to injection molding. |
Injection Molding
Injection molding isn’t usually the first choice for prototyping because it takes a long time and costs more. But when you’re making 100 or more plastic prototypes, quick-turn methods can make it worth considering. Using aluminum or 3D-printed molds with a standard mold base can cut down both time and costs without sacrificing quality.
That said, if 3D printing can get the job done, it’s still the better option. You avoid all the time spent designing, machining, and testing molds, which means faster iterations and quicker approvals.
Benefits and Drawbacks of Plastic Molded Prototypes
| Category | Details |
| Benefits | Enables fast, cost-effective testing without compromising quality. |
| Provides near-perfect replications for real-world operational insights. | |
| Suitable for fabricating complex parts with diverse shapes and weights. | |
| Ideal for industries requiring extensive testing and certifications, such as medical devices. | |
| Drawbacks | High tooling and mold costs make it impractical for small production runs. |
| Lengthy mold manufacturing and setup processes delay prototyping timelines. | |
| Expensive and time-consuming to implement design changes after mold creation. | |
| Consistent quality is harder to achieve in short production runs, leading to variances. |
Looking for plastic prototype manufacturing and fabrication services? Check out RapidDirect and upload your file to get an instant quote.
Key Considerations for Plastic Rapid Prototyping
This section delves into the key considerations that designers and engineers must account for when navigating the complex landscape of plastic prototyping.
1. What’s Your Application?
The application of your prototype should be your first consideration. These prototypes find their utility across diverse industries and serve various purposes. For instance, they might be designed for non-functional testing in marketing or sales contexts. Alternatively, it could be aimed at functional testing with target users. Selecting a manufacturing method that accurately replicates the final product’s color, shape, and surface texture is critical to ensure the prototype meets its specific objectives.
2. How Complex Is Your Prototype?
Does your design include tight tolerances or complex internal features? The answer to this question will help you choose the correct plastic prototyping technique. Some manufacturing options are limited when it comes to the geometry of designs. Some of them may require high-level design for manufacturing (DFM) optimization before they can be economical or cost-effective. Technologies that can effectively comply with the intended geometry of your plastic part are the best choices.
3. How Quickly You Need the Prototype?
How quickly you need the prototype will also affect your choice of technique. CNC machining use sophisticated tooling coupled with automation to create prototypes within 24 hours. However, tooling and setups for injection molding could push lead times up to weeks. If you need testing done very quickly, you should choose methods that produce parts rapidly.
4. Which Material Suitable for Your Porject?
“How can I prototype a part to test if a particular resin will work effectively?” To pick the right material, consider the stresses and conditions your part will face. Balance factors like cost, appearance, and functionality while comparing the benefits of various manufacturing methods.
Refer to the accompanying table for a comparison of common plastics and their suitability with different prototyping techniques.
| Vacuum Casting | 3D Printing | CNC Machining | Injection Molding | |
| ABS | Good | Excellent | Excellent | Excellent |
| Polycarbonate (PC) | Excellent | Good | Good | Excellent |
| Polypropylene (PP) | Fair | Good | Fair | Excellent |
| Nylon | Good | Excellent | Excellent | Good |
| Acrylic (PMMA) | Excellent | Excellent | Good | Good |
| Polyethylene (PE) | Fair | Good | Fair | Excellent |
| Polylactic Acid (PLA) | Fair | Fair | Excellent | Fair |
| Thermoplastic Polyurethane (TPU) | Good | Good | Excellent | Good |
| Polyether Ether Ketone (PEEK) | Fair | Excellent | Good | Excellent |
| Acetal (POM) | Good | Excellent | Fair | Excellent |
| Polyethylene Terephthalate (PET) | Fair | Good | Good | Excellent |
| Polyvinyl Chloride (PVC) | Good | Good | Fair | Excellent |
Keep in mind that performance can vary even with the same material. For example, a machined plastic prototype won’t fully replicate the function or durability of a molded part due to differences in material properties.
Finally, align your prototype design with the testing phase and its specific goals so you can gather the insights you need.
5. What’s Your Budget?
Several factors affect the cost of plastic prototypes. These factors include the materials used, the part’s complexity, and the technique used. However, 3D printing is generally less expensive than CNC machining. Injection molding is somewhat more costly than the initially mentioned processes due to mold milling costs.
The low fixed costs of 3D printing ensure zero economies of scale. That is, the first copy has the same cost as the last. The fixed costs of CNC machining are also low, with total costs rising at a steady rate. So, you’d expect the cost of each part to be a little higher than similar parts produced with 3D printing.
For prototype plastic injection molding cost, is relatively high for the first few parts. However, the price steeps lower as the volume increases. It is clear that the plastic prototype cost is relative and depends largely on the method used and the volume required.
| Technology | Initial Cost | Per-Unit Cost | Production Time | Ideal Scale |
| CNC Machining | Medium | Medium | 1-3 days | Single prototypes |
| 3D Printing | Low | High | A few hours | Single or small batches |
| Vacuum Casting | Medium | Low | 7-10 days | Small batches |
| Injection Molding | High | Low | 2-6 weeks | Large-scale production |
Work with RapidDirect Plastic Prototyping Services
At RapidDirect, we help turn your ideas into reality, whether you’re creating a single prototype or gearing up for full production. Our team of skilled engineers and designers knows the ins and outs of CNC machining, 3D printing, injection molding, and vacuum casting. We’re not just here to make parts—we’re here to help you succeed.
Here’s what sets us apart: we care about getting it right. We’ll give you personalized advice to optimize your project and make sure it’s top quality at every step. Need just a few parts? No problem—we have no minimum order requirements. With our strong industry connections, we’ll get you the most efficient and innovative solutions out there.
Ready to bring your project to life? Contact RapidDirect today! Upload your CAD file and embark on a journey to turn your innovative ideas into tangible, successful products. Let’s build the future together!
