For decades, mold releases have been serving a crucial role in the molding industry. Initially, sticky parts were the norm in this industry, especially during the infancy stages. Even with the introduction of technology, material advancement, and evolution in mold designs, mold releases have remained essential. They play an important role in ousting sticky parts and increasing cycle times.
During the lifespan of the mold, especially when they age, they may exhibit minor issues. While these defects don’t affect the quality or finish of parts, they become a setback during part ejection. As a result, the cycle times slow. But thanks to the mold release, you can extend your mold’s lifespan and efficiency when in use. And in this text, we’ll look into two primary mold release agents, silicone and non-silicone mold release agents. Let’s start:
What is Silicone Mold Release Agent?
For starters, silicone, or polysiloxane refers to siloxane compounds, polyorganosiloxane, silicon resin, and silicone oil. It has many industrial applications and in this case, it’s an excellent mold release agent. Thanks to its remarkable durability, less pollution, and great isolation, silicone is the best release agent. Speaking of molding, it applies to butyl rubber, plastic, and rubber materials.
Difference between Silicone and Non-Silicone Mold Release Agent
While silicone and non-silicone mold release agents play a staple role in the field of molding, they possess unique differences. And it’s these differences that make one better than the other. For starters, we’ll look into the pros and cons of both. This info will help you know what to expect when using either of them:
Silicone Release Agent
- Stands out as the best option.
- Very slippery but durable
- Longer lifespan between re-applications
- Great for food-linked molding
- More cycles per application
- None paintable
- Not suitable for electrical components
- Not suitable for parts that will undergo secondary operations such as:
- Ultrasonic welding
- Hot stamping
- Pad Printing
Non-silicone Release agent
- Suitable for electrical components
- Certain formulations are fit for food-linked molding
- suitable for parts still undergoing secondary molding
- Not as great as silicone in lubrication
- Not long-lasting as silicone
- Frequent re-application after a few cycles
- Dosage form and form
When it comes to non-silicon release agents, they are simple in form and dosage. And a perfect example is fatty acid and paraffin. On the other hand, silicone release agents come in diverse forms as well as the dosage form. As a result, they are perfect for versatile applications.
- Working temperature
Silicone structural integrity depends on the silicon-oxygen bond. And this is a strong bond that can withstand extreme temperatures well. What’s more, its melting point is more than that of rubber, thus assuring safety and success when using it. This means carbonization and decomposition of the release agent are out of the picture. On the other hand, you can’t claim the same with non-silicone release agents.
Safety is paramount in any industrial process. And when it comes to silicone and non-silicone release agents, the two exhibit different safety levels. For starters, these two release agents are both synthetics with similar temperature limits. However, if you exceed organic fluoropolymers’ optimum surface temperature, it becomes toxic.
This release agent begins to emit toxic fumes. On the other hand, silicone materials can withstand extreme temperatures. Further, they’re still safe and non-toxic when under extreme temperature that exceeds their maximum limit.
- Peeling Force
Unlike non-silicone release agents, silicone has the least peeling force. And this is because it has the least surface energy. Therefore, when you use silicone, releasing parts from the mold is the easiest.
Thanks to the excellent heat resistance of the silicone release agent, it has a longer lifespan. That means when you apply it once, it can handle multiple cycles before you re-apply it. This is especially true for silicone release agents formulated using silicone resin. They come with high tolerance to extreme temperature with excellent stability.
As a result, they exhibit the longest service life. On the other hand, non-silicone release agents have the least service life. Due to their unstable nature and low tolerance to extreme temperature, you may have to re-apply it frequently.
Silicone has more industrial applications than non-silicone release agents. For instance, you can use it in plastics and rubber molds. Also, it’s reliable in injection and extrusion processing. But most importantly, it’s economical since it requires less labor and speeds up production. Lastly, Silicone ensures all your products come out with excellent quality.
Silicone mold release agent is better
Undoubtedly, both silicone and non-silicone release agents are resourceful in industrial applications. But even so, certain key features make one better than the other. In this case, Silicon takes the lead when you weigh between their pros and cons.
For more insight why silicone mold release agent is better, here are some remarkable benefits it comes with:
- More convenient
- Excellent Heat Resistance
- Versatile application
- Mild surface tension
- Provides good gloss on products
- Creates a uniform film
- Zero affinity to resin
- Longer life in service
- It’s the mainstream mold release agent
Silicone mold release agent features
You can use silicone mold release in various applications, which includes plastics, foods, metals, and rubbers.
- Chemical Stability
Since they are chemically dormant, they are the best choice when it comes to mold release agents. Thanks to their stability, they do not deform, swell or corrode the mold when in use.
- Reliable on Intricate Molds
Thanks to the low-surface tension nature of silicone release agents, they provide excellent lubrication on intricate molds. This means you can release with ease complex items from this mold.
- Cold and Heat Resistance
They exhibit strong resistance to extreme temperatures. That means, they can withstand both cold and heat and still guarantee efficient production.
- Mold release-ability
Owing to their incompatibility with organic materials, they provide remarkable mold-release performance.
- Comes in various forms
Silicone mold release agents can be available in various forms, which makes them flexible for various applications. In this case, we’ll look at some basic forms. First is the silicone aerosol and oil type. Of all the types of silicone mold release, they’re the most convenient options. You only need to spray them on the mold surface to create a working film.
Second, we’ve got an ointment-type silicone release. It’s more complex than the previous, but reliable once it cures and forms the working surface. Silicone ointment is perfect for rough surface products. Further, it’s sustainable and can handle more cycles.
Lastly, on this point, you’ve got water-emulsion silicone release. It doesn’t rely on solvents like the rest, thus causing no environmental pollution. However, the mold release force is bigger than the rest. Also, the number of cycles after each application is fewer.
Silicone mold release agent types
There are two major ways to classify silicone release agents. First, you can classify it according to form and product composition. Secondly, you can classify it according to its lifespan in service.
Form and Product Composition
- Silicone Resin
The ground material when it comes to silicone resin release agents is methyl phenyl and methyl silicone resin. However, other curable and cross-linkable silicone polymers can also play a part.
Oftentimes, they’re dissolved in gasoline, toluene, or ethanol, among other organic solvents to create a solution of silicone resin. When it comes to application, you can either dip or spray it on the mold surface. And finally, you can cure it by heating it to make it ready for production.
- Silicone Rubber
Silicone rubber in liquid form can work directly as a mold release agent. However, for more applications, you’ll have to mix it with organic solvents to create a silicone rubber solution. Thereafter, add catalysts and cross-linking agents, and some auxiliary components. Once the solution is ready, apply it to the mold surface to create a hydrophobic working film (silicone rubber).
- Silicone Emulsion
The base material for silicone emulsion is either silicone resin or silicon oil. And thereafter, you can add water and an emulsifier to create silicon emulsion. However, it only becomes a working film on the mold after water vaporizes.
- Silicone Oil
This release agent is derived from organosilicon polymer, known to be high molecular and inert. It includes the likes of methyl phenyl silicone oil, and methyl silicone oil, among other modified silicone oils.
With that said, silicone oil serves as the primary release agent with the addition of gasoline or toluene as solvents. If you need a semi-solid release agent derived from silicone oil, add mica powder, diatomite, and silica and kneed them.
- Silicone Aerosol
Now, the based material here is silicone oil. But it only becomes a silicone aerosol release agent after adding butane or Freon among other propellants. After mixing, they’re packaged in a spray container. During application, the propellant serves as the carrier of the release agent. And once it’s on the mold surface, the propellant volatilizes leaving behind the mold release agent as the working film.
In this case, the release agent is derived from organoalkxysilane or organochlorosilane. However, it’s important to note that using organosilane directly comes with limitations. And they include organochlorosilane, which has an affinity for water.
Therefore, it absorbs it from the air when curing on the mold surface leading to hydrolysis. Unfortunately, the resulting product (hydrogen chloride) is corrosive making organosilane applicable to corrosion-resistant molds (ceramics and glass) only.
- Other types
Finally, on the types of silicone mold release agents, there are elastic molds crafted from silicone rubber. Such molds exhibit good heat tolerance and anti-bonding properties of a release agent. As such, they’re great for de-molding. Thanks to these properties, they’re reliable when dealing with intricately shaped items.
According to the service life of silicone mold release agents, there are two categories. They include:
During the production process, some of the release agents are consumed or fused with the product. As a result, the release agent has limited uses or is used once after each coat. With that said, temporary silicone mold release agents are those derived from inert silicone oils.
When it comes to semi-permanent silicone mold release agents, the situation is different. The release agent is firmly attached to the mold. Therefore, none of it transfers to the product during production. That means the semi-permanent silicone release agent is indigestible firmly remains on the mold surface after curing.
How to choose silicone mold release agent
Consider the following key factors when choosing a silicone mold release agent:
- Contamination or Transfer
You can choose a silicone release agent based on the rate of transfer. For instance, if you need products with the least or no traces of transfer, then consider using semi-permanent silicone mold release. It forms a firm working surface on the mold and it’s indigestible. Therefore, none of the material transfers to the products. However, if transfer or contamination is not an issue, then you can work with any silicone release agent.
There are two major types of silicone release agents. And they are classified according to service life or form and product composition. Therefore, if you are not sure about the type of release agent that will work best on your product, this will help. Consider revisiting the information on types of silicone mold for more insight in this text.
While all the types of silicone agents serve to help release the product from the mold, their cost differs. Also, the brand and quality of the release agent plays part in the cost of the product. First, set a budget, and then compare it with various offers available online to see what price range fits it.
- Molding cycles per application
Silicone mold release agent happens to have the most cycle per application than their counterparts. But when it comes to various types of silicone mold release, you’ll also realize that the molding cycles also differ. Depending on the profitability you’re targeting, it’s worth considering release agents with most cycles. It will not only improve the rate of production but also reduce the running cost of operation.
- Mold fouling
A higher rate of mold fouling can hike the production cost in your facility. Therefore, if you want to maintain a low cost of production, consider working with silicone release agents with the highest lifespan per application.
- Environmental Impact
All silicone mold release agents mixed with solvents have a given degree of environmental impact. However, if you want to exert zero pollution on the environment consider using silicone water emulsion.
Lastly, both silicone and none-silicone release agents are essential in the molding industry. While both have advantages as well as shortcomings, silicone release agent seems to take the day. It’s a reliable option that guarantees more profitability when you use it in an industrial setup. Thanks to the more cycles per application, it guarantees the highest production efficiency. And being a mainstream release agent, rest assured you’re working with the best product in the market.