Getting your products out to light is not easy. But thankfully, technology is always developing to make our options a bit better. You’d relate if there was a time when you had an idea for a product, and found your back against the wall. At that time, you had one of two options. Either explain your product through abstract designs and hope it sells, or invest an upfront payment in mass production and cross your fingers that your product is perfect and doesn’t need any improvement. No need to mention, neither option was cost or quality efficient. The first option came with lack of an actual proof of concept, which made your chances of testing the market of getting an investment very slim. The second included taking risks which, more often than not, came back with the conclusion that your first prototype still needs a lot of development.

But then walked in the different techniques of rapid prototyping and they saved the day, alongside lots of millions of dollars. Out of every other rapid prototyping technique, the advancement in silicone molding and vacuum casting technology has started to catch quite the attention. Due to its cutting edge technology and cost and time efficiency, it’s proven to be a life saving technique.

We’ll discuss in more detail this technology, how it works, and the potential growth of its applications.

Rapid Prototyping Around the World

Rapid prototyping methods first came to light in the 1980’s. But unlike every other trend that calms down a while later, it’s been growing so fast. A recent forecast about the growth of the rapid prototyping industry around the world expects that, by 2026, the industry will expand at a CAGR of 12.91%. This forecasts the industry to reach up to US$ 6,513.9 million in the following 7 years. And while the growth of the rapid prototyping industry looks promising around the world, it’s especially interesting to delve into the scene of rapid prototyping in China.

The Advancement of Rapid Prototyping in China

China has become the world’s biggest exporter of manufactured products. So it was only expected that they would adopt the latest technologies in rapid prototyping, and even more, expand it on the biggest scale. Rapid prototyping has leveled up from being merely used for the visualization of the prototype and proof of concept, into actually manufacturing high-quality end products in small scale. Rapid prototyping is a big industry that includes many different technologies, it’s also involved in almost every end use industry. You might be most familiar with 3D Printing (also known as FDM), Stereolithography (aka. SLA), and Computer Numerical Control (CNC) Machining.

These techniques are some examples of the technology used in additive and subtractive materials, but there are other less widespread technologies that use injection molding of polymerized materials. Injection molding is more commonly known in case of mass production, that’s why it would come as a surprise to know that you can use this technology in small-scale production. In that case, Silicone Molding and Vacuum Casting is the best technology you can adopt.

Silicone Molding and Vacuum Casting

When it comes to manufacturing a prototype for testing the market, you want to produce enough items but not too much, a process known as Low Volume Production. This makes silicone molding and vacuum casting in China your best bet, as, globally, China is the leading country in using the technology with all of its advancement. Low volume production enables you to conceptualize your product idea and produce the first batch of prototypes for testing. And to carry out this process, you can use Silicone Molding and Vacuum Casting technology to cut down costs, time, and efforts, while producing very high quality and diverse end products.

So what is Silicone Molding and Vacuum Casting?

3D Printing, Silicone Molding, and Vacuum Casting: Three Techniques Combined. While 3D printing on its own can be used to create a few items of the prototype, it still has its own limitations. For instance, it wouldn’t really be cost or time efficient to start a low volume production using 3D Printing technology. It is, however, a great option to be incorporated as the first step in the silicone molding and vacuum casting technique.

Silicone molding and vacuum casting is a rapid prototyping technology that can be used for low volume production, and it combines two ancient methods: Using silicone to create the molds, and injecting the substance into the silicone mold using vacuum to remove any bubbles. This technique has started to gain quite the attention, because it opens a very wide door of possibilities that could change the face of production in the next few years.

Applications of Silicone Molding and Vacuum Casting Technology
It can be difficult to imagine the promise that this technology offers in the production scene, but in all honesty, it’s amazing. The technology can be adopted in almost every field of industry, no matter the simplicity or complexity. It can also be used in achieving different milestones in the production process, such as:

Testing of the products in the pre-launching phase.
Conceptualization of prototypes and providing a proof of concept.
Marketing or products in the pre-production phase
Thermal and air flow testing
Assembly line trials
Testing of functionality and durability

So far, silicone molding and vacuum casting has been used, and its use is progressively expanding, in many industries such as:

Automotives
Aerospace & Defense
Consumer Goods and Electronics
Home Decor and Appliances
Prosthetic and Medical Equipment
Product Marketing

How the Process Works

The process of low volume production using silicone molding and vacuum casting technology can be divided into four main phases:

1 – Creating the Master Pattern

In this phase, the 3D Printing technology is called upon to create the first piece, also called the Master Pattern, which is the product that we want to replicate in low volume. The creation of the masterpiece can be carried out using 3D Printing technology, or FDM to be exact. The master pattern can also be created using SLA technology, which is another additive manufacturing technology. No matter the method used, the masterpiece is first designed using a Computer AIded Design (CAD) program, from which the 3 dimensional design of the product becomes ready to be printed. The files are then printed using the digital fabrication technology of choice, and the master pattern is now ready to be duplicated. As this is the main copy which is going to be duplicated, it is essential that the design, pattern, and finishing be as accurate and precise as possible.

2 – Making the Silicone Mold

The process of duplication then starts with creating the mold which encompasses a design typical to that of the master pattern. This can be done through several steps:

The master model is placed inside a frame made from ABS or rigid paper, and this is where the casting of the silicone will be made.
Next is setting the partition line that indicates the two halves of the silicone mold.
The special silicone rubber is then poured, in two consecutive phases, in the frame and surrounding the master pattern.
After pouring of the first half, the silicone mold is inserted into a vacuum machine and oven to be cured of the bubbles, after which the second half is poured and then cured too.
The mold is left to harden, and then is separated into two halves.
The master pattern is removed, and the silicone mold is now ready to duplicate the master pattern.

3 – Vacuum Casting of Polyurethane

Now that the silicone mold is ready, it’s time to duplicate the master pattern. This is done through injecting a certain substance (usually polyurethane) into the silicone mold, and by the pressure of vacuum, the substance fills the mold and takes the exact shape of the original piece. The polyurethane resin can be treated as need be to give the exact color, texture, flexibility, or rigidity of the substance to be duplicated. As for the curing time, it’s differs depending on the substance used. On average, it takes around 40 to 90 minutes for the curing process to be done and for the duplicated product to be ready for extraction.

4 – Post-Processing and Finishing

The last step is to open the silicone mold and extract the duplicated product. In this step, any excess substance is removed, and the product is post-processed to the end-use design and finish needed. It can be sprayed, painted, or added in to other different parts depending on the end use.

Advantages, Features, and Limitations

This technology, although not very widespread yet, has contributed to the production process with a lot of solutions with extremely high-quality end results. However, it definitely has its own limitations. Let’s take a quick overview of its advantages, end materials properties, limitations, and its convenience in comparison with different production techniques.

1 – Advantages

As we’ve previously mentioned, silicone molding and vacuum casting technology has found its way into many industries and for different purposes. That’s because the technology comes with a lot of advantages, such as:

Short period of time needed to create the silicone mold, which can take 3-5 working days.
The low costs needed to create the silicone mold is very appealing in comparison with the investment you’d need to create same-quality products using steel molds.
The end products come with an extremely high quality that competes with the durability and functionality of injection molded parts.
It speeds up the production process and the testing phase, which gets the product in to the market quickly.

2 – Properties of End Materials

Another advantage of this technology is the diversity with which the end materials can be. The polyurethane resin used can be treated to simulate a wide variety of materials, such as ABS, POM, Elastomers, Nylon, and Polypropylene. They also possess a strong collection of features, such as:

Heat resistance
Can be treated to give different colors, tints, or to be transparent
Fire retardant substances
Flexibility and rigidity can be manipulated
Stable against UV rays
Can be post-processed in diverse finishes: sparkling texture, matt, satin, or even glossy finishes.

3 – Comparison to other Rapid Prototyping Technologies

It’s important to note that while silicone molding and vacuum casting can be used in low volume production and rapid prototyping, its role falls under a different category than the rest of the CNC rapid prototyping technologies. Rapid prototyping includes different digital fabrication technologies, such as Stereolithography (SLA), 3D Printing or FDM, CNC Machining, Laser Sintering, and others. Some of these techniques are additive and others are subtractive, but one thing they all have in common is that they’re all manufactured from a CAD design. That is, the digital design is converted into a live physical object using the technology of choice. Meanwhile, silicone molding and vacuum casting depends on the presence of a master pattern even before the molding process, which is created using one of the aforementioned rapid prototyping technologies.

As such, both kinds of technologies are complementary. It’s not an “either, or” situation, it depends on your own end purpose and desire. Are you trying to test a CAD design and inspect its functionality? In this case, you might only need one item to test your design with a visual proof. Perhaps you want more than one item. As long as it’s a few number of items , usually up to 10, 3D printing or SLA can take care of the process just great.

However, in case you want to launch a testing batch of your product, then you’ll need more than 10 pieces. You want enough items to be able to get back accurate reports, but at the same time you don’t thousands of mass-produced pieces, in case you needed to modify the next batch. In this case, using silicone molding and vacuum casting is the perfect technology to produce anywhere between 10 to 500 pieces, all while ensuring the least costs and maximum efficiency in time and quality.

4 – Limitations

There are mainly two limitations to this technology, which is the limited lifetime of the silicone mold, and the need of a master pattern to start the process. Although it’s easy to create, doesn’t take a lot of time, and gives rise to extremely accurate duplicates, the silicone mold has a limited life. After duplicating a few dozen parts, the silicone mold will need to be replaced with a new one. The need for a master pattern is another limitation, as this requires an initial investment at first. However, the ability to create low volume production will soon compensate for the costs.

Silicone Molding and Vacuum Casting Changing The Production Game

As the end user market keeps on growing, the growth in the production scene still stays ahead of the game. It’s 2019 and technology always manages to take our breath away, but the advancement in rapid prototyping technologies is taking it to a whole new level. Instead of spending months in the conceptualization phase or spending thousands in the first commercialization, the advancement in silicone molding and vacuum casting technology in China has made it possible to get the highest quality products, in the shortest time and with the least costs. And yet, it’s only getting started!

The Advancement of Silicone Molding and Vacuum Casting Technology