Explore Silicone Injection Molding | Versatile and Durable

Table of Contents

Silicone injection molding machine
Silicone injection molding machine
Source: upload.wikimedia.org

1. Introduction

Silicone injection molding is in an entirely different world of its own when compared to other manufacturing methods. This world is characterized by dynamic possibilities spurred by precision, versatility, and durability. 

Essentially, silicone injection molding makes use of liquid silicone rubber materials to fashion some of the best plastic parts in the manufacturing world.

More importantly, just like other injection molding methods, silicone injection molding isn’t limited to an industry. Its quality precision-engineered products are applied across numerous industries. From medical tools to consumer products, you name it.

So, let’s take you on this manufacturing masterpiece course featuring this innovative technique and uncovering the steps that make the silicone injection molding method a remarkable one.

2. Understanding Silicone Injection Molding

You might have encountered silicone injection molded parts around you without ever noticing it. However, silicone injection molding accounts for numerous plastic parts in our daily lives. Thus, understanding how they are made is an important knowledge worth having.

In any case, highlighting a few of its benefits, especially in the high-quality mold manufacturing industry will give a basic understanding of its workings.

Firstly, silicone injection molding offers massive flexibility with its ability to turn liquid silicone rubber into specific custom designs. That is why it has wide application across several industries where bespoke components are their stock in trade. It is safe to say that complex geometries and intricate dimensions have nothing on this gem of plastic production technique.

Even if you are fabricating prototypes or moving on to mass production, silicone injection molding has got you covered.

Silicone injection molding
Silicone injection molding
Source: upload.wikimedia.org

3. Liquid Silicone Rubber (LSR) Materials and High Quality

A chef has recipes that make up a sumptuous meal. These recipes are a combination of different ingredients. Interestingly, so does high-quality silicone injection molded parts. Apart from high-quality mold manufacturing, the ingredients that make silicone injection molding a remarkable production method in plastic manufacturing are its materials.

Liquid silicone rubber (LSR) plays a significant role in ensuring silicone injection mold performs excellently well, hence, its employment for parts that can withstand the rigors of its applications. It is for this reason they are utilized in various industries.

In addition, a major feature of liquid silicone rubber is its adaptability to harsh conditions. It can endure severe heat as well as extreme cold temperatures and its structural properties stay intact.

For high-quality components that possess a long-lasting life span, liquid silicone rubber often provides the magic for this durability. Did we mention its biocompatibility qualities? Well, liquid silicone rubber is suitable for medical implants and other devices that require safety and compatibility with the human anatomy.

4. Silicone Injection Molding Process

Having scratched the surface of silicone injection molding, let’s dive deeper into the silicone injection molding process properly. 

For starters, the silicone injection molding process is one that requires proper control and monitoring to achieve perfection. These factors are necessary measures that ensure process streamlining and optimization.

The silicone rubber injection molding process commences with the proper mixture and measurement of the liquid silicone rubber in the mixing barrel. After mixing the materials to get a consistent mixture, injection begins via a cold-runner system into a hot mold. This is followed by curing the mix within the mold. This curing process is one of the most notable parts of the silicone rubber injection molding process considering that it is done in seconds.

Moreover, silicone injection molding also employs thermosetting plastic materials which means that once solidification occurs, the desired shape can then emerge. However, ensuring that there is a reduction in the lead time while making significant cost-savings is a function of how the cooling of this mix occurs. But more on that later. 

5. Versatility and Medical Grade Applications

Like a chameleon blending its skin to its environment, silicone injection molding has blended itself into the different industries where it is extensively applicable. 

Let’s start with the medical and healthcare industry. This is one of the highest end-users of silicone rubber products. With its biocompatible and durable qualities, silicone rubber materials make for a natural choice. Also, the versatility silicone injection molding offers allows for the meticulous crafting of medical instruments such as implants, surgical tools, and drug dispensing equipment. So, it could be for a heart pacemaker or a seal in a facemask, in any case, silicone rubber promotes reliability and safety.

Now, beyond the medical industry, silicone injection molding is also involved in the making of electronic devices that we use daily. Ranging from smartphones to earphones, all carry silicone rubber in one form or another. 

The automotive industry isn’t left out either. If you take out time to check your cars you’ll find that gaskets, spark plug boots, and connectors are all products made from silicone.

Furthermore, in the consumer goods industry, silicone has been a major player in manufacturing household products. if you doubt that, just take a stroll into your kitchen and you’ll find what you’re looking for in utensils and appliances. The ability of silicone to live with and around us cannot be quantified, just observe more and you’ll be amazed at your findings. 

6. High Purity Platinum Curing in Silicone Injection Molding 

Have you ever witnessed the sieving of wheat from the chaff? This is typically done to separate the unwanted particles from the useful substance. High-purity platinum curing agents are similar to these sieves. They allow the proper formation of the silicone parts being manufactured. 

During injection molding, platinum purifiers ensure the silicone molecules properly align. This eliminates any form of contaminants that may hinder the transformation of silicone parts from liquid to solid.

High-purity platinum curing assumes the role of a janitor in the curing process, mopping up all unwanted agents in the silicone. This fosters uniform and effective curing, which in turn promotes precision in the quality of the parts. 

Liquid silicone rubber injection molded parts can be prone to defects in their final products if not properly cured. For that reason, high-purity platinum curing becomes the essential element that saves the day.

However, for the sake of medical devices that make contact with the human body, the importance of high-purity platinum curing is vital. The stakes in ensuring the safety and reliability of medical tools are high. Hence, the stern expectations of medical device manufacturers to meet specified quality standards. Let’s take you a step further by comparing liquid injection molding to traditional methods. 

7. Liquid Injection Molding (LIM) vs. Traditional Molding

Comparing liquid injection molding (LIM) to traditional molding is like comparing the heights of the Great Eiffel Tower and that of the American white house. Even the blind can tell the difference. Likewise, liquid injection molding stands a crushing height taller than traditional molding, and that’s a fact.

Firstly, let’s consider material wastage. Much like highly precision manufacturing using 3D printing technology, liquid injection molding (LIM) is devoted to ensuring there is no excess. This precision beats that of the traditional molding method hands down. Traditional molding is known to waste excess materials by trimming away or discarding them. Nonetheless, liquid injection molding (LIM) does not permit that.

Up next, liquid injection molding maintains shorter cycle times in comparison to the cycle time in traditional molding. How does that happen? Liquid injection molding controls the injection and curing process. This speeds up the cycle time while sustaining quality. This is a crucial factor for brands aiming for a quick time-to-market window.

Additionally, liquid injection molding gives traditional molding a knockout punch by its ability to meet near-impossible designs. Traditional molding’s attempt at intricate dimensions will result in deformities and inconsistencies. 

What’s more, liquid injection molding possesses the capacity to churn out parts that are repeatedly identical. A feat traditional molding can only dream of. Need we say more?

8. Large Volume Production

If all we have been discussing is taken into account, it won’t be hard to deduce that silicone injection molding excels brilliantly in large-volume productions. Let’s show you why it is the most efficient and go-to method for manufacturers.

  • Short Cycle Time: The speed of parts manufacturing with silicone injection molding is unrivaled. Its automated and simplified process assists it in producing large volumes in no time. Its rapid production method ensures parts are constantly manufactured while maintaining consistency.
  • Precision: When large-volume production comes into the mix, consistency becomes a concern. But not with silicone injection molding as it raises the bar of efficiency by consistently churning out the best identical parts. With this understanding, the concerns about the disparity in quality, structural integrity, and performance go out the window.
  • Cost-effectiveness: Although the initial installation of tools can be on the high side, silicone injection molding efficiently makes up for this in the speed leading to short cycle times and precision in the part produced. As a result, the production of large volumes cancels out the initial cost of tooling.
medical use of silicone rubber
medical use of silicone rubber
Source: getarchive.net/

9. Specialized LSR Parts

The uniqueness of every part made of liquid silicone rubber is evident in its features. These features relate to the specific needs of each industry. let’s show you what we mean.

  • Medical-Grade Implants: As earlier mentioned, liquid silicone rubber is spectacular at making medical and healthcare devices. Ranging from implants to prosthetics, its biocompatibility properties are second to none. Furthermore, it meets the specified standard regulations for medical equipment. In manufacturing medical-grade implants, precision, durability, and body fluid resistance are the key factors in applying liquid silicone rubber injection molding.
  • Electrical Insulators: Specialized liquid silicone rubber parts in creating electrical insulators rely on the technique’s ability to ensure safety. Essentially, parts such as gaskets, and protective electrical covers are manufactured by employing LSR injection molding. And the results speak for itself.
  • Automotive and Aerospace Parts: The longevity of an automobile or airline is hinged on the quality of its parts. That same quality is what liquid silicone rubber offers when applied to making specialized parts. The capacity to withstand extreme heat and exposure to chemical components are essential properties required of these parts. LSR never disappoints with that, and that is why it is trusted to cover your automotive and aerospace needs.
  • Consumer Goods: The majority of kitchen wares and infant products are made by utilizing LSR. The color schemes it permits, the aesthetic features, and the performance capabilities make it the ideal method for such consumer goods amongst many others.

10. Quality Control and ISO 9001 Certification

What keeps the trust of consumers in a particular brand or product? Many will say it is their apt attention to detail. And they would be right for saying that. Nevertheless, the contributing factor to achieving a detailed product is precision. previously, computer-based manufacturing like high-quality CNC machining is how is precision attained. But now, with a robust quality control standard in play, much can be done to ensure product quality.

The place of quality control cannot be replaced. Quality control is the behind-the-scene operative that guarantees a product’s reliability and functionality. The same can be said of liquid silicone rubber injection molding. A step-by-step quality marker is set up to maintain accuracy, excellent performance, and consistency.

On that premise, ISO 9001 is the highest stamp of quality a manufacturer can have to attest to its compliance with standard guidelines. It is a certification that is recognized all over the world, stating its trust and reliance on the product. A brand or manufacturer with this certification has passed in flying colors the quality control test. The certification of quality assurance is a seal that implies consistent and constant delivery of remarkable products.

Consequently, before this certification can be issued, every step of the liquid injection molding must be tested via various methods. They are not limited to but include, material inspection, dimensional accuracy, visual observations, and other process optimization standards. So, get tested and get certified.

Automotive silicone products
Automotive silicone products
Source: pxfuel.com

11. Applications Beyond Medical

For the umpteenth time, silicone injection molding is applicable in various ways beyond medical application. Even though medical application takes the top position in its beneficiary ranks, there exists many other applications silicone injection molding fits into.

Fabrication of automotive products is one such application. In the auto industry, silicone injection molding is hugely in demand to manufacture auto parts that are resistant to UV exposure among others. Chemical and heat resistance are other properties expected of an LSR injection molded part.

Consumer products that include baby products are made employing silicone injection molding. For instance, pacifiers, bottle suckers, and personal care items are all functionally satisfying due to their soft feel, color appeal, and compatibility with the human body. You should begin to look out for other consumer products to understand the awesomeness of such crafts that might not have been possible save for this technique.

Electronic devices are not forgotten. For safety all around us, electrical cables are covered with silicone-based materials. These coverings are immune to chemical exposures and moisture. This in turn helps the electrical coverings last longer.

Industrial equipment also benefits from silicone injection molding in helping craft machine pumps and valves. These heavy-duty tools endure the rigors of their applications without losing their structural compositions. 


In summary, silicone injection molding exists as a revolutionary method of manufacturing. It stands on its pedestal ranking above traditional techniques in various ways. One such way is minimal wastage of material. Another is shorter cycle time, to mention a few.

Its processes kick start by mixing and measuring the silicone materials in a barrel, before injecting them into the mold where curing, cooling, and solidification occur. It is equally noteworthy to mention the application of high-purity platinum curing to the process. This allows the silicone material to be cured effectively and rapidly.

However, an important characteristic is its versatility which remains unmatched in the medical field and in every other field where applicable. What more can we say?

Ultimately, all silicone injection molding isn’t complete and effective without a strong quality control unit to certify the quality and functionality standards of silicone injection molded parts. 


Gary Liao

Gary Liao

Gary Liao is the Engineering Manager of TDL Company and has more than 20 years of mold design experience.

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