Plastic products are in our lives everywhere. During the plastic products development process, Plastic prototype verification before mass production is very common. But do you know how to make the plastic prototypes? Today we will explore different rapid prototyping methods for creating plastics Prototype.
What is Plastic Prototyping？
Plastic prototyping is the first step for a product to create a preliminary version of the plastic product. It’s a way to assess or test the product before going to mass production. Depending on the purpose, a plastic prototype can be created with different prototyping methods and materials.
Why Plastic Prototypes Are Important
Creating a plastic prototype is a valuable step for businesses, especially when it fits with three main testing stages: Engineering Validation Test (EVT), Design Validation Test (DVT), and Production Validation Test (PVT). These stages are essential for making sure the product is perfect before mass production.
- Engineering validation testing (EVT): A plastic prototype helps check the technical design. It ensures the product works as planned and meets engineering requirements.
- Design validation testing (DVT): This stage focuses on the look and feel. Testing here ensures the product’s appearance, durability, and user experience are just right.
- Production validation testing (PVT): Finally, the prototype is used to confirm that the product can be produced in large quantities without losing quality.
Prototypes also help present ideas to investors and stakeholders. Having a physical model lets them see and touch the product, making it easier for them to understand its value. For market testing, plastic prototypes can be shared with potential customers, gathering their reactions and feedback before the product is officially launched.
Overall, this process helps designers and prototyping companies make important adjustments. It ensures that both the manufacturer and the user get a high-quality, market-ready product, supporting quick testing and improvement.
What are some common materials for a plastic prototype?
Thermoplastics
Thermoplastics are the most common material used in plastic prototypes. These plastics are solid (often in colored pipes) that can be melted, molded, and then cooled into different shapes. Thermoplastics are popular because they’re easy to recycle and reshape, and they work well for creating strong, functional prototype parts. In manufacturing, they’re often melted and injected into molds. Thermoplastics such as Acrylic, ABS, and Polycarbonate are widely used for creating plastic prototypes, especially ABS material is the most used material for various kinds of ABS prototypes.
Resins
Resins are synthetic materials that come from natural sources and are very flexible. They can be liquid or solid and are often mixed with other chemicals to harden or soften them. Resins are commonly used for making items like jewelry, home decor, coasters, and furniture tops.
Elastomers
Elastomers are stretchy, rubber-like materials known for their flexibility and durability. They can be stretched and will return to their original shape, making them perfect for parts that need flexibility. They’re commonly made from synthetic rubber or silicone and are widely used in medical, consumer, and aerospace products. Elastomers are often molded into shape using methods like injection molding.
Four Rapid Plastic Prototyping process
There are four main methods to create a plastic prototype including CNC machining, 3D Printing, Urethane casting, and Prototype injection molding. Let us check these plastic prototyping processes as below.
CNC machining
CNC machining is an effective method for creating plastic prototypes with high precision and accuracy. With computer-controlled cutting tools, a CNC machine can cut a solid block into a functional prototype. CNC machining offers lots of advantages for plastic prototyping, including fast turnaround times, high precision, and high-quality surfaces especially for the optic clear prototypes.
Steps for creating a plastic prototype with CNC machining
Step 1: Plastic Prototypes CAD design.
due to the limitations of the CNC machining process, the Prototype designer will design the product that could fit the machines, a Complex structure of plastic products will be split piece by piece.
Step 2: Machining on CNC machines.
Once the designer finishes the design, the CAM software with Generate the CNC program by translating the CAD design into machine-readable code, also called G-code and M-code. This involves specifying the tool paths, cutting depths, feed rates, and any other machining instructions necessary to produce the desired prototype.
Step 3: Bonding.
After all the pieces are prepared, use adhesive bonding techniques to securely join them together. this is to get the complete prototype with good strength.
Step 4: Grinding and polishing.
Sanding the surface of the prototype to remove any rough edges, burrs, or imperfections, ensuring a smooth surface, and then Apply polishing methods to further enhance the surface finish of the prototype. use specialized tools, compounds, and buffing techniques to achieve the desired level of smoothness and glossy of the prototype surface.
Step 5: Surface finishing.
this depends on the end user’s requirement to apply different aesthetic effects on the surface of plastic prototypes. the main surface finishing methods include dyeing, Painting colors, Vacuum Metallization, Matte Finish, Laser Engraving, Screen printing, and Brushing.
3D Printing
3D printing is an additive manufacturing process. it creates the plastic prototype by depositing melted plastic material layer-by-layer based on a digital design file. in this way, 3D printing can manufacture prototypes with remarkable complexity and short lead time at low cost. it is the cheapest and fastest way to make a plastic prototype. there are different 3D printing technologies including FDM 3D printing, SLA 3D printing, SLS 3D printing, and DLP 3D printing.
Steps for creating a plastic prototype with 3D Printing
Step 1: Prepare The 3D Printer.
Set up the 3D printer, ensuring it is properly calibrated and the printing bed is clean and level. Install the correct printing material and ensure the printer settings match the desired specifications.
Step 2: Slice The 3D Model and Start The Printing.
Use slicing software to convert the 3D model into instructions which is called G-code. Adjust settings such as layer height, infill density, and speed, Load the G-code file onto the 3D printer initiate the printing process, and then wait for the printer to run.
Step 3: Grinding and polishing.
once the printing process is finished. make the same grinding and polishing process with CNC machining above.
Step 4: Surface finishing.
this is the same process as CNC machining above.
Urethane Casting
Urethane casting, also known as silicone molding or vacuum casting, is a cost-effective method for producing plastic prototypes with low-volume manufacturing of less than 100 pieces. This process has something similar to traditional injection molding, it uses a silicone mold to cast Liquid urethane resin to create urethane casting prototypes.
Steps for creating a plastic prototype with Urethane Casting
Step 1: Create The Master Pattern.
Master Pattern is used for making silicone mold. it can be created by CNC machining and 3D Printing.
Step 2: Making The Silicone Mold.
Use the master pattern to Make a silicon mold for casting. Pouring Liquid silicone to be around the master and remove all air to form the silicone mold.
Step 3: Casting prototype.
Pour the mixed urethane resin into the silicone mold, Cure the liquid urethane resin in the mold and After the resin has fully cured, open the mold and take out the plastic part.
Step 4: Surface finishing.
this is the same process as CNC machining above
Prototype injection molding
Injection molding can be used for creating plastic prototypes even this process is mainly used for mass production. injection molding prototyping uses soft steel for tooling material and a more simple tooling constructor to inject low-volume plastic prototypes. this process is usually required to make the plastic prototype with the same material with mass production.
Steps of creating a plastic prototype with injection molding
Step 1: Mold design.
Design the rapid mold with simple construction to lower the cost.
Step 2: CNC machining the soft steel mold.
CNC machines mill the steel and make the mold according to the mold design.
Step 3: injection molding.
Inject the plastic material into the mold to form the plastic parts.
Step 4: surface finishing.
This could be the same process as other plastic prototyping methods.
Considerations Before Making a Plastic Prototype
Before creating a plastic prototype, it’s important to choose the right type based on your needs. If you only need to showcase the product’s design without full functionality, visual prototyping is a great option. This type focuses on the appearance of the product, and 3D printing and urethane casting are commonly used to create these prototypes.
If you need the prototype to closely resemble how the final product will function, functional prototyping is the way to go. This type is crucial for testing and refining the product’s performance and how users interact with it. CNC machining is the right choice for this type of prototype.
For a prototype that is almost identical to the finished product, high-resolution prototyping is the best choice. This type is used for final evaluations, marketing, and stakeholder presentations, as it shows the product’s quality and finish in great detail. Injection molding will be a good option for these prototypes.
Comparison of Plastic Prototyping Methods
Different plastic prototyping methods use different plastic materials and with different timing and cost. we introduce a comparison for you when you need to choose for making a plastic prototype.
| Processing Methods | Materials | Application | lead time | cost |
|---|---|---|---|---|
| CNC machining | thermoplastic sheets such as Acrylic sheets, Polycarbonate sheets, POM sheets, ABS sheets, Nylon sheets, etc. | For those plastic prototypes with high precision and strength for function prototypes. | 3 to 7 days | Moderate |
| 3D printing | Photopolymers for SLA, and Plastic Filaments for FDM and SLS. | Use for just looks-like plastic prototypes. | 1 to 3 days | low |
| Urethane Casting | Riding Urethane Resins and rubber-like Urethane Resins are used for casting, a similar performance to engineering plastics. | Use for looks-like plastic prototypes with small quantities from 5 to 100 pieces. | 3 to 7 days | low for each piece |
| Injection molding | thermoplastic materials such as Acrylic, ABS, Polycarbonate, etc. | Use for function prototypes that have the same material performance as mass production | 15 to 20 days | High |
How can I get a plastic prototype made?
There are many factors you need to consider before creating the perfect plastic prototype such as materials, budget, and timing. KUSLA’s rapid prototyping service can help you make plastic prototype parts faster, easier, and more efficient. We support all of the above plastic prototyping methods with very high-quality standards.
FAQs
How Much Does a Plastic Prototype Cost?
the cost of a prototype depends on the prototyping process and the complexity of the parts. generally, A plastic prototype part can cost from $10 to $200, and for a complex prototype assemble can cost from $1000 to $10000 and even more.
How to make a plastic prototype at home?
With a desktop 3D printer, you can make a plastic prototype at home. just finish your design in the CAD software and load it into the 3D printer, then you can print the prototype with the materials prepared.
