Recently, we’re referring to a period of ten years now when liquid silicone, like wi, wildfire, has opted for production in numerous industries. At first, in the late 1900s, it was commonly used in medicines for implants. Fast-forward to today, there’s only an industry with the footprint of liquid silicone.
But what is liquid silicone? What advantages make it a material of choice for manufacturing? This article provides a detailed overview of liquid silicone, including its properties, types, and applications.
You know it’s good to educate ourselves on the materials surrounding us. How do they come into existence, and do you ever wonder if such materials are safe? Here’s an opportunity to learn about a special material: liquid silicone.
Understanding Liquid Silicone
For basic knowledge, liquid silicone is a silicon polymer composed of silicon, oxygen, hydrogen, and carbon. Going deeper, this silicon polymer comprises a silica and oxygen backbone to which other functional groups hang.
It’s one kind of silicon polymer that is highly valuable and versatile for manufacturing a wide spectrum of products across numerous industries. So far, you can explain to a layman, liquid silicone is a silicon polymer and like we put biscuits in boxes, it contains silicon, oxygen, hydrogen and carbon. Good!
Earlier, we said it is a silicon polymer, meaning it is produced from silicon. Silicon, on the other hand, is obtained from the sand(silica). In short, liquid silicone is a product obtained from sand after undergoing several processes.
Let’s proceed; liquid silicone consists of two-component systems where long polysiloxane chains are reinforced with specially treated silica. The components contain platinum catalysts and methyl hydrogen siloxane. It is considered the material of choice for industries such as automobiles or medical devices for which small and complex elastic parts need some to be produced at high speed.
Around us, we can find medical devices, household items, food contacts, kitchen items, high-precision industrial components, and cosmetic products, all made with liquid silicone. This points out properties and features that positioned it to be widely used in various goods and products. On this note, let’s dive into its properties.
Properties of Liquid Silicone
Chemically Resistant and Inert
For starters, they are chemically resistant and Inert. Liquid silicone is a chemically inert material that resists oxidation, making it hypoallergenic and not reacting with other chemicals. As a result, it is preferred for applications that require exposure to solvents and industrial chemicals like oil, acids, and bases. It is also suitable for use with products subjected to cleaning solutions.
Translucent and Clear Appearance
For clarity, translucent doesn’t mean fully transparent. It means semi-transparent, but clear means fully transparent. Depending on your preference, liquid silicone is translucent and clear.
Its translucent nature subtly blends with the surfaces you apply it to. For example, when you apply it to glass and ceramics, its presence gives a visual appeal, preserving the integrity and aesthetic quality of the materials.
Also, Liquid silicone is fully transparent, giving it a glass-like appearance, making it invisible when applied. In general, liquid silicone is a very good material when a discreet, effective, and undetectable seal is crucial.
Fast Curing Process
Liquid silicone takes 24 hours to cure, after which it can be safely exposed to water and moisture. Liquid silicone offers excellent and uniform deep curing.
Natural Electrical Insulator
Consistently exhibit dielectric or insulating properties even when subjected to different environmental changes. The environmental changes can be directly mixed with conductors.
For example, in the early 1940s, American electrical contractors used ceramics for insulating transmission lines. However, with the advent of polymers in the 1940s, they were no longer preferred. During testing, the contractors found insulators manufactured with liquid silicone stood out among other polymers as good insulators. It is an ideal material of choice for electrical applications, especially consumer electronics.
Water resistance
Liquid silicone is waterproof. It can withstand water for 20 years without losing its water-resistance abilities. It is often used for underwater projects, aquatic housing, and other projects with constant exposure to water and extreme weather conditions.
They are Tasteless and Odourless
Products manufactured with liquid silicone do not give off odor when used with other materials. For example, when used for cooking, the ingredients do not alter the recipe’s taste. You will get the right taste and odor, not a slight change.
Biocompatibility
Under excessive testing, liquid silicone consists of repeating units of inorganic silicon dioxide with methyl. These materials are very stable, biocompatible, and insoluble in body fluids. They occur naturally and abundantly in plants and within the earth’s crust.
We all consume plants every day. If silicone dioxide were incompatible with our bodies, we would have died, right? As a result, liquid silicone has demonstrated super compatibility with human tissue and body fluids.
In addition, there are different types of liquid silicone. Let’s examine the different types.
Types of Liquid Silicone Rubber
General purpose LSR
This type of liquid silicone is widely used for producing adult products, sheaths, lap joints in metals, bending panels, gap filling, and pipes, etc. General-purpose liquid silicone rubber is employed due to its short curing time, good mechanical properties, high transparency, etc.
High-Temperature LSR
This product covers various pressures, temperatures, and process streams. It can withstand extreme heat up to 1350 F without degrading or compromising its quality. It is specially produced for use in extreme temperature conditions. It can be in the form of sealants for high temperatures, gaskets( for example, gaskets in aircraft cockpits), etc.
Medical Grade LSR
They are formulated to meet strict biocompatibility and safety requirements for medical and healthcare products. Medical-grade silicone is strong while appearing flexible and soft to the touch. It is sterilizable and capable of withstanding shock and vibrations.
A major factor considered in adopting medical products is the aspect of immunological reactions to tissues in the human body. A suitable medical product must not trigger tissue reactions in the human body. Before the approval of medical-grade LSR products, they were tested and proven safe with no potential to trigger tissue reactions in humans.
The contract between the human body and medical-grade LSR can be likened to an agreement between an employee and an employer. The employer sets strict rules and disallows small talk or any reaction from the employee; you do your job, while the employee promises to abide by the rules.
Food-grade liquid Silicone rubber
Food-grade LSR is similar to medical-grade LSR. These are the only grades of LSR that can come into contact with the human body after being proven to meet strict requirements laid by regulatory bodies like the FDA.
Food-grade LSR comes into contact with food and beverages, baby products, baking molds, and kitchen utensils. They are non-toxic and odorless, generally able to withstand 250 F and 450 F in short exposure. In real-time, they are used to make kitchen and bakeware.
Electrical Conductive Liquid Silicone
These types of silicone products are specially designed to conduct electricity. This is due to the fact that silicone is naturally an insulator. So, converting silicone to a conductive material entails compounding it with carbon and other conductive substrates. Examples of conductive silicones include heaters, cable connectors, electro conductive boards and EMI gaskets etc.
Optical Clear LSR
Almost as transparent as the best glass, they are significantly lighter than glass and offer higher resistance. They do not discolor or lose transparency due to age or exposure to heat or Ultraviolet rays. They are scratch and crack resistant. Suitable for making products like lenses of all types, wet environment outdoor and indoor light fixtures, light pipes, low and high-heat environment impact parts and so on.
Now, how do we apply the different types of liquid silicone into producing goods, parts and accessories. Keep reading to easily find out all the answers.
Application of Liquid Silicone
Automobile industry
Medical Industry
Medical components and assemblies are produced with liquid silicone. They include balloon catheters, tubing for feeding and drainage compression bars, electro surgical handpieces, airways etc. They are also used in skin medication to aid absorption and functionality.
Liquid silicone rubber are used for producing sensitive medical surgical instruments like respirators, diaphragms, drug delivery and health-monitoring devices.
Consumer Products
Liquid silicone rubber has dominated the consumer market with extensive manufacturing of wearable technologies (fitbit, jawbone) Headphones, hearing aids, water tighteners, kitchen goods, protective gloves with liquid silicone.
Nothing in this world is 100%, there has to be at least 0.00001% shortfall, well does that apply to liquid silicone? Even so, you can be rest assured its advantages outweighs its limitations. So, what are they?
Limitations of Liquid Silicone
Generate excess waste
The process of producing liquid silicone generate excess waste than other rubber materials due to the need for accurate mixing and curing requirements.
Less Tear Strength
Although liquid silicone are elastic, however, when compared to other elastic materials like latex it has a less tear strength.
Costly
Products made with liquid silicone are expensive compared to other raw materials like latex, iron, aluminum etc. This is due to the rigorous process involved in producing liquid silicone to attain its great physical features.
Final Thoughts…
Well, liquid silicone is a special material that gets all the scores a judge can award when it comes to the properties of an efficient and powerful material. Scientists are still conducting research on areas where liquid silicone can be improved and on the potential risks it can impose. For now, thousands and millions of tonnes are being consumed yearly by different industries for production.