Making silicone molds for construction, industrial processes, personal care, and consumer goods has been increasing since a few years back. In 2020, the silicone market in the US was $3 billion. In 2021, silicone’s market value increased to $3.6 billion.
But you know what? That’s not it. From 2023 to 2030, an estimate explains a 5.6% increase in the silicone market.
Isn’t it huge and mouth-opening?
Whether it’s silicone or any other materials, molds have been used from the very early history of humanity. From engineers to chefs, everyone uses silicone molds for their tasks and products.
To participate in this huge industry, you must learn how to make a mold for silicone. This guide will explain to you every bit of silicone molding. Once you are through this guide, you will not need any further help.
Why Make Silicone Molds?
Making the mold of a material is dependent on how flexible it is. The high flexibility of the silicone material makes it easy to make molds and use them. How will the molded product come out of the mold if there isn’t flexibility in the mold material?
The flexibility of the silicone also makes it more lightweight than plastic molds. There are reduced chances of breaking the molded product when removing it from the silicone mold.
Most of the time, the required material is melted and then added to the mold for prototyping a product. If the mold material is not stable or high-temperature bearer, then the purpose of the mold will no longer be retained.
Silicone can deal with higher temperatures between -65 to 400 degree Celsius. Additionally, depending on the process used to make silicone molds increase, this temperature count even further.
Molds are not designed for one-time use; many batches can run through them. Manufacturing molds require time, effort, and money. So a mold must be durable to be used many times.
The more batches pass through a mold, the more it degrades, and the manufacturer will need new molds. Silicone is durable and it can last long; if taken care of properly. Best practices include cleaning the molds with soap and water. Then dry and store them in a flat place.
Here are some limitations you will have to deal with for silicone molds.
- On too much stretching, silicone mold can tear apart.
- Silicone is more expensive than many other molding materials, like organic rubber. You can consider the price of silicone to be twice high as latex.
- If purchased from a non-reputable company, you may buy low-quality silicone.
Common Applications for Silicone Molds
A wide range of industries requires extensive prototyping for their product parts before manufacturing the exact product. These industries include automotive, aerospace, food, and medical.
Different types of molds are used for the prototyping procedure; however, silicone molds are common.
Different prototyping procedures, like two-shot injection molding, are used in multiple industries. Of all other materials used for prototyping, silicone is preferred based on its flexibility, durability, and ease of use.
Silicone mold making is highly required and used in jewelry making and designing. Different designed silicone molds are used for making hand-carved jewelry.
The required labor and time for making this jewelry are reduced using silicone molds. Otherwise, many people will have to spend hours before making a single piece of jewelry.
Apart from full jewelry pieces, some parts are made using silicone molds, especially for bigger jewelry.
Different consumer goods utilize silicone molds to make perfectly shaped products. Like some, the companies make custom soaps and candles for their customers using silicone molds.
It helps them add different ingredients to the product per the customer’s demand. School supplies like rubber and sharpener are also designed with the help of silicone molds.
Small toys and crayons for kids also get shapes from silicone molds designed by manufacturers.
Food and Beverage
Chocolates, lollipops, and other food products are manufactured using silicone molds. These molds are mostly designed with food-grade silicone. It keeps the products safe and healthy to eat for the users. These molds are also used for cooking as silicone can withstand many temperatures.
They are safe to be used in the oven and microwave for making biscuits, muffins, or cupcakes.
Creative crafters often use silicone molds to make different products, and some businesses even use silicone to make custom silicone molds full.
For example, some companies offer you to have a foot replica of your baby’s foot to save as a memory. For this project, silicone is used to get the shape and size of the foot.
Even animal toys like dog treads are replicated using custom silicone molds.
Materials and Equipment Needed
1. Silicone Rubber
Silicone rubber is the main component in making silicone molds. RTV-2 silicone rubber is the raw material that is available in different types.
- Platinum cured silicone
- Tin cured silicone
They are usually divided into two parts and must be mixed before making the mold. It would only be possible to make the silicone mold by mixing these two types.
The mixture for making the molds is usually colorless or white. If you want to add color to your silicone molds, you must add silicone pigments. These special pigments will add a unique look to your molds.
Especially when making customized molds, it’s better to throw in a little die so it doesn’t look boring.
3. Mixing Cups and Stir Sticks
These are the basic and very important components when making a silicone mold. I prefer using a plastic container with measurements to make measuring easier. But make sure the plastic container is bigger than the master pattern so you can mix enough silicone for molding.
Wooden stir sticks are also required and easily available as disposable sticks in the market.
4. Mold Wall Materials
Mold boxes, or you may call them mold wall materials. They are important to provide a support structure where the mold material will be poured.
Different materials can be used for mold boxes, including:
- Corrugated sheet plastic
- Polycarbonate sheets
- Acrylic sheets
- Plexiglass sheets
5. Release Agent
Making silicone molds requires a releasing agent. It is important to apply a releasing agent to avoid sticking to the pattern and the mold.
Once the mold is formed, this releasing agent will make it easy to remove the pattern. Where two part mold is made, this releasing agent gets more important to avoid sticking the two halves.
6. Vacuum Chamber (Optional)
In some specific viscosities of the liquid silicone, like above 10000 CPS, there is a problem with bubbles in the final mold.
At the commercial level, these bubbles and entrapped air affect the sale of these silicone molds. That’s why a vacuum is applied to help release any bubbles.
How to Make the Masters for Silicone Molding
Master is the pattern you use to create the space or negative in your silicone mold. If you already have the product you want to replicate, you can directly use it as the master.
Ensure that your product is not delicate to get damaged with the silicone mold-making process.
In other cases where you do not have any already available product, you must make a prototype. For getting the prototype, there are three common methods used.
If your design is simple, it can create the pattern of your desired product. You can try it yourself if you have a talent for sculpting. However, if that’s not the case, you can hire a sculptor to get your pattern.
Wood carving is another option that you can use for making your pattern or master. Carving is better than sculpting as wood can withstand more heat and all the processes in making a silicone mold.
3: 3D Printing
Professionals also use 3D print patterns for making patterns. Desktop 3D printers are used most commonly because of their benefits, and you get higher accuracy, flexibility, and ease of prototyping.
Constructing The Frame
A: Focus On The Frame
Your frame should be able to enclose the object you want to duplicate. It would be better if the frame is tight, leaving out no extra space in between. For the base plate, it should be smooth enough but do not use glass.
The reason is that silicone rubber is attachable to the glass. Removing the mold from the frame will become difficult when the mold is fully formed. Of course, it will be a nuisance after putting too much effort into the process.
That is why it is sometimes preferred to use wood as the base plate because it is repellent to silicone rubber.
B: Smooth Side Walls For Base Plate
We told you to use wood as a base plate, but do you know what you should use for the side walls? For the sidewalls, planed wood or MDF boards are most suitable. These should be big enough to store the silicone mold without pouring the silicone rubber outside the walls.
According to a general rule, you can keep the walls 10 mm above the length of your object. These extra 10 millimeters will help the cooling process of the silicone molds.
Remember to seal the mold joints of the walls as much as possible. If there is any leakage, your silicone rubber will pour out, making a mess. An ideal sealer is molding clay, as it will leave no open space behind.
Later on, a cotton swab and toothpick can be used to make the joints smooth enough, adding an alignment to the walls.
C: Placing The Object In The Mold
This is a very important step because you need to correctly place the object in the mold to get an accurate mold. You must place the object in the frame with its main side facing upward.
Don’t leave the object between the frame; fix it with the floor using hot glue or other reliable material. For example, you can use double-sided adhesive tape.
If the object slips from its position, your mold will not be perfect in its shape.
Mixing the Silicone
A: Measure The Two Types of Raw Rubber
With a ratio of 1:1, mix up both components in a plastic cup for measuring. You can use a separate measuring plastic cup or mix both components in your preferred cup. Use a wooden stick for mixing, but avoid spilling the silicone outside.
B: Mix Small Portions
Mixing smaller portions is easy and does not add too many bubbles to the silicone. As liquid silicone is somewhat hard, mixing larger amounts at a time will be difficult. You can divide the total amount into several cups and mix it easily.
C: Tap The Bottom of Cups
Now it’s time to release the air bubbles after the mixing process. Tap each cup on the multiple tabletop types to help release bubbles. Now let the cups sit for a while on the table before pouring the silicone into the frame.
Pouring The Silicone
A: Spray With Release Agent
Before pouring the silicone, spray the release agent on all the walls of the frame. Alternatively, you can paint the walls with oil to prevent the silicone from sticking. This process will make it easier for you to take out the silicone mold.
B: Pour Silicone Mass
Now start pouring the silicone mass into the frame. Starting with a thin layer in the corners and angles is better if your frame has different corners. Then you can start pouring throughout the frame.
Frames with lesser corners and edges are easier because you can directly pour the silicone mass without worrying about filling the corners. When pouring the silicone mass, be careful to cover the entire object with silicone.
C: Fill Up To Five Millimeters Above From The Blank
Wait to pour the mass till the height of the object. Instead, continue pouring until you reach above five mm from the object height. Once you fill the frame, tap on each side of the frame using your fingers, and it will release any air bubbles formed during the pouring process.
Finishing the Mold
A. Trimming and Cleaning the Mold
Once the mold is solidified, you can remove it from the box. You will see some extra silicone on the sides of the mold that needs to be trimmed. Use sharp scissors to trim the extra sides of the mold.
B. Apply The Talcum Powder
Now apply the talcum powder to the silicone mold, as it will help keep the silicone supple.
Tips and Tricks
1. Using a Vacuum Chamber
Using a vacuum chamber to make silicone molds is the wisest thing to do. Although it’s not compulsory, if you can afford it, you should do it to avoid any kinds of bubbles inside your silicone mold.
If you are a manufacturer, it is for sure that you want to sell your molds to people who want to make some products.
A mold with bubbles and trapped air inside might not be catchy for a customer, affecting your sales.
2. Mixing and Pouring Techniques
Using accurate mixing and pouring techniques while making silicone molds is very important. You can affect the durability and flexibility of the silicone molds if you need to know the ratio of materials required.
Also, inappropriate mixing techniques can trap air inside the silicone, damaging the mold.
3. Choosing the Right Release Agent
With a release agent or make the silicone mold, you might save time and money. The releasing agent must remove the mode from the mold box. It’s similar to oiling the tray before adding the cake batter because it helps take out the cake easily without affecting its shape.
You can research the market regarding what release agents are available.
Silicone molds are used for various functions, like plastic injection molding. Different methods can be used for making silicone molds depending on the manufacturer’s preferences.
Each process brings its pros and cons. Depending on your requirements, you can select any procedure you want.
There is no one certified method or way to make silicone molds. You can use different methods to achieve the desired results.
Kemal: Your Leading Mold Manufacturing Supplier
If you are looking for the best mold manufacturing supplier, then Kemal is the best choice. Having customers in 60+ countries and years of experience, we have robust capabilities.
We are not only your mold manufacturers. Instead, you can trust us to design your molds.
Many of our customers bring mold ideas to us with uncertainty. The mold designing professionals at Kemal help such customers finalize their design thoughts.
Once you are satisfied with the design, we can start manufacturing the silicone molds for your business. Check out our website and get your quote for manufacturing silicone molds of the best quality and price.