Plastic Prototyping

Designing a new part is not an easy process, people have to overcome many design issues. It is necessary to have a prototype stage that can help get a good design. Therefore, it is important to know the manufacturing process if you are a designer or a buyer who wants to get a quality manufacturing service.

Today in this article below, we take our ten years’ manufacturing experience to work out a comprehensive guide for this. I suggest you keep reading, it will help you to be an expert.

What Are The Benefits Of A Plastic Prototype?

In summary, plastic prototyping has the following advantages.

1. Verify The Appearance And Industry Design
Industrial design is the first step for a product design. To make a good industrial product, the most important thing is to make sure the appearance is exquisite. As the prototype is a physical object which can intuitively reflect the designer’s creativity, so it is easy for us to verify whether the design matches the design trend.

2. Finalize The Structure Design
By having a prototype sample on hand, it can help structure engineers to check out the design defect and improve structure design accordingly.

3. Verify Function
Once we build up the sample and power it up, we can check the whole function and operation. Therefore, it can verify if we can find out an improved room for function.

4. Avoid The Risk Of Tooling Modification
Once we have a plastic prototype, we can check out all potential design problems before tooling. By doing this, we can reduce the risk of tool modification.

5. Help With The Exhibition
As the plastic prototype is similar to a real product, so we can get a prototype at a quick timetable for an exhibition. At the same time, we can use it to make a product catalog and sales ads for marketing work.

6. Direct Sales With Plastic Prototype Parts
As for some industries such as medical instruments and equipment products, we can make the prototype product to be the same as the tooled product. Thus, we can put the prototype directly into the market in a short time, this can take up the market for you quickly.

What Are The Types Of Plastic Prototypes?

There are many types of plastic prototypes.

Defining it by material, there are acrylic, polycarbonate, acrylonitrile-butadiene-styrene (ABS), polyethylene, nylon prototyping, and more.

Defining by machining method, there are CNC plastic machining, 3D printing, vacuum casting prototype, and more.

What Is The Difference Between Plastic Injection Parts And Plastic Prototype Parts?

We can talk about the difference between the three parts: quality, cost, and lead time.

The first part is quality. 

If we use the CNC machining way to make a prototype, then there is not much difference. Both ways can produce high-quality parts.

The other two parts are cost and lead time. 

It needs plastic injection molding to make plastic injection parts, this will cost high at more than $3000. What is more, the tool manufacturing progress is complicated, it normally takes more than 4weeks to finish it. Thus, plastic injection molding is a high-cost manufacturing way with a long lead time. This way is only good for a high volume order.

The rapid plastic prototype, on the other hand, refers to no tool. It only takes material costs and labor costs. Therefore, this way is the best option for a low volume order.

What Is The Manufacturing Progress To Build A Plastic Prototype At RapidDone?

Let us take the CNC machining process as an example:

First, the programmer engineer analyzes the 3D drawing. In this progress, they work out the programming language that controls the CNC machining machine.

Secondly, the operator runs the CNC programming code into the machine to cut material. After this step, we can get the original shape of a plastic prototyping part.

At this stage, as the previous plastic prototype has a lot of marks and burrs on the surface, we need to send it to the hand-made department for polishing.

Next, we need to go to the painting department for surface treatments.

At last, we have a QA check for our rapid prototype product. Both fits and appearance need to be checked carefully. Once the test result is good,  then we can pack and ship it out to customers.

What Are The Common Plastic Materials For Prototype Manufacturing?

A lot of plastic material can be used and there are mainly below types:

1. ABS Material

ABS is the most common plastic material for a plastic prototype. It has good impact resistance and temperature resistance. As it is good for glue, so it is very convenient if you want to assembly one ABS part to another plastic part with glue.

2. Polycarbonate Material

This is a clear material with high transparency, but it also has good impact resistance and high-temperature resistance. Thus, Polycarbonate is the first option for a clear plastic prototype project.

3. Acrylic Material 

This material is also called plexiglass, it is a little easy to crack under big force impact, but it has the highest transparency. Due to this advantage, it is the best option for optical prototype building.

4. TPE And TPU Material

It is a soft material and the hardness range from 30 degrees to 90 degrees. Therefore, it is good to be used for remote control and other rubber pads samples.

5. POM Material

This material has high hardness and high density, so it is good for making a gear prototype.

6. PPS And PEEK Material

The advantage is that they can stand high temperature at about 200 degrees. Thus, they are suitable to build some coffee machines or water heaters prototype. However, they are very expensive, the price is about 50 times higher than the normal ABS material. Therefore, it is not as popular as other plastic materials.

7. Nylon Material

This material has high strength and good abrasion resistance material, it is good for gear prototyping. But the disadvantage is that it is not easy to be fixed by glue, so we have to be careful during the big size prototype manufacturing.

What Is The Common Plastic Prototyping Methods?

To build a plastic prototype, there are a lot of manufacturing technologies. However, the best four ways are CNC machining, 3D printing, vacuum casting, and rapid injection molding. 

1.  CNC Machining

CNC machining is the most common way for plastic manufacturing. It uses a variety of different sized tools to carve out a 3D model from a solid block of plastic material by a lathe machine or a milling machine.

The main materials for this processing are ABS, PC, PMMA, PA, POM, PA + fiberglass, and POM. Among them, ABS is the most common plastic material. However, the density of ABS raw materials in a plastic sample is lower than the one used for injection-molded products ABS. Besides, Polycarbonate and Acrylic are used for processing transparent parts.

Compared with 3D printing parts, CNC machined parts are stronger. Therefore, this method is good for some structures that are relatively simple, strong.

2. Vacuum Casting

Vacuum casting is also called silicon casting.

Below is the normal manufacturing procedure, it takes three steps.

First, we need to build a silicon mold by using the original sample.

Secondly, we fill the liquid plastic material into the silicone mold we made in the last step.

Lastly, we bake them into a backing machine at temperature 60 ℃-80 ℃ for several hours. After that, we can get the plastic part which is the same as the original one.

As for materials, vacuum casting is good for an array of materials. It is a liquid PU material with the name of ABS-like or Polycarbonate (PC)-like….and more.
It covers from opaque to transparent, as well as many colors.

As you know, undercut is a big issue for plastic injection, but we can easily fix this problem with vacuum casting. Thus, this processing technology is more suitable for products with more complex structures, smaller sizes, and fewer quantities.

Each mold can produce around 25 prototypes, and the turnaround time is as fast as one week. 

In a word, it is a good way to build plastic prototype order for the quantity from 10sets to 100 sets.

3.  3D Printing

3D printing is an additive manufacturing technology.

There are three most popular options for producing prototype plastic parts: Fused Deposition Modeling (FDM), Stereolithography (SLA), and Selective Laser Sintering (SLS).

√ FDM

FDM 3D printing is a technology by using an extrusion process to deposit plastic material in a layer-by-layer fashion. It is the most widely used form of 3D printing, a lot of people even create FDM 3D-printers at home for personal use. 

Overall, FDM is a cheap way but not so good for surface finish quality. Thus, it will need more post-processing if aesthetics is important.

√ SLS 

This is a technology by using a high-powered laser to sinter powder together into a 3D model. The most common material is Nylon. Compared with FDM, the quality is much better. 

This type of plastic prototyping is more flexible and durable.

√ SLA

Instead of using filament, SLA 3D printing utilizes plastic resin materials to make plastic prototypes. This process is widely used for various prototyping purposes, especially within the medical, dental, and consumer goods space. 

Its advantage is that it can print complex parts at a fast speed. However, the disadvantage is that the printed material is relatively fragile. 

Therefore, it is good for a cosmetic check but not a good option for a functional plastic part.

4. Rapid Injection Molding

Rapid Injection molding refers to a faster and more cost-effective tooling compared to traditional steel molds. The molded parts are low-volume injection molded parts, it is ideal for the precision plastic prototype with Quality for around a 10K shot life.

How To Handle Large Size Prototyping Plastic Parts?

For most of the plastic prototype parts, the size is small. When dimensions do not exceed the machine processing stroke, it is very easy to handle.

However, we sometimes encounter some large-scale plastic prototypes. The size is too large that we can’t run them into the machine. 

For such big size plastic parts, we normally consider two manufacturing ways: 3D printing and CNC machining. Compared with CNC machining, most of the 3D printer has shorter proceeding strokes and higher machining costs. Therefore, the best option will be CNC machining , we normally have two handling ways for it.

First, we should consider one whole piece of processing. By doing this, we need to make sure we have a large CNC machining with a big machining stroke. Our CNC machining strokes at RapidDone can reach 2000mm, our experienced operators can easily make larger prototypes.

If we do not have such a big machine, then we will have to consider to disassemble the plastic parts into pieces. After that, we need to splice the parts back together. But this will lower the strength of the part, and the performance may not be as good as one full piece. 

If we choose this option, it is necessary to pay attention to the selection of materials, and we should choose the one with good glue performance such as ABS plastic material. 

Do not worry about the cosmetic of splicing location, as that area can be polished and fully be covered by painting.

RapidDone has a lot of experience for big size project. If you have a similar project and look for a trusted supplier, contact us so we could discuss further info and offer the best service we could.

How Much Does It Cost To Make A Plastic Rapid Prototype?

This depends on some basic parameters such as MOQ and manufacturing way and design, so it is difficult to suggest an exact price.

Normally, we can consider using 3d printing for a small size plastic part with a simple feature. The price can be very cheap for just under $15, but it might increase to be $30-$50 if we change to use CNC machining.

However, there is some on-line quotation system like xometry, you can upload your 3D drawing and get your quotation out in one minute.
You can also send a mail to your quoation team, RapidDone can come back to you quickly.

Can I Make A Plastic Prototype By Myself?

Yes, you can.

The best way is to use a 3D printer. To do this, there are three steps.

The first step, work out your design sketch on paper with a detailed requirement.

The next step, create a 3D drawing by using 3d design software such as SolidWorks or ProE. Once the 3d drawing is done, export it to be .stl-format to get ready for printing.

At last, you can print it with a 3D printer if you have one. If not, you can get one one-line 3d printer shop near you. This can be very fast and only take a couple of days.

What Are The Plastic Prototype Finishes?

The finish is the last step for a plastic prototype part. There are three common types below.

1. Polishing

Polishing is the most important process for plastic prototyping manufacturing. This process can help you remove the spur and have a smooth surface, that is to say, polishing is the key to get good cosmetic prototype plastic parts.

2. Painting

Painting is a most common finish. However, customers are required to provide a Pantone number or a color sample for this job.

3. UV Coating

The UV coating is also an important finish. During this progress, a worker sprays a layer of transparent oil on the surface of the prototype part and bake it with ultraviolet light. Eventually, it adds an additional protective layer to the painting layer.

How Long It Takes To Build A Plastic Prototype?

Well, it depends.

But it is usually a short lead time counting by days. For example, we can typically get it done within 5 days for simple parts. However, it might take some more days if you have a high requirement for the surface. 

No matter what, take it with less than 10days for most of the plastic part orders.

Which Types Of CAD Files Do RapidDone Accepts For The Sample Build?

The best file format we accept is .stl format, this can be run into the machines directly.

However, we have an experienced team and we can convert all your file formats, all we need is your original design file.

How Does RapidDone Control Quality For Our Plastic Prototypes?

At RapidDone, we have an experienced team for the quality monitor from material to the final finished parts.

First, we have an IQC team to check all the raw plastic material from the outside material supplier.

During our manufacturing progress, we have a production QC team. They follow up and inspect the parts at the production line.

At last, after the prototyping parts are fully done, our QA team have a full quality check before we pack them up.

In Conclusion

In short, know about the whole manufacturing progress and find the right manufacturing technology is important to the success of your plastic prototype. I hope the above can help you.

Talk to us if you have any query for a plastic project or other rapid prototyping services, our team can come back to you with a professional solution.