Whether you are a medical device manufacturer, an automotive parts supplier, or an electronic device manufacturer, choosing the right silicone is important to your business.
Below, we will introduce silicone in detail to you to help you find suitable products for your business.
What is Silicone and Why is It So Widely Used?
Silicone is a synthetic polymer that consists of silicon, oxygen, carbon, and hydrogen. Besides, the multifunctionality and reliability of silicone are unmatched by most traditional materials, so it becomes an important material in various industries.
What are the Main Types of Silicone?
Silicone isn’t just one material—it comes in several main types, here are four types of materials:
Liquid Silicone Rubber (LSR)
LSR is a two-component platinum sulfide elastomer that has the features of low viscosity, good flowability, and high temperature rapid curing at high temperatures, so that it becomes an ideal choice for precision and complex design applications.
Advantages：
- LSR can maintain the integrity of its own structure, exhibit good temperature resistance, and remain stable in extremely high and low temperature environments.
- Because of its long polymer chains and elastic properties, it has good flexibility, elasticity, mechanical properties and inherent electrical insulation properties.
- LSR can resist various chemicals, oils, and water.
- The silicone has good resistance to ultraviolet radiation.
Disadvantages：
- Although the curing speed of LSR can be controlled by adjusting the formula or using catalysts, some types of LSR still need a longer time to cure.
- Due to the processing of LSR, you need to use specialized injection molding equipment; the manufacturing process may require high investment and technical requirements.
- Although LSR has good flexibility and high temperature resistance, if you want to make thermoplastic or certain polymers, its mechanical strength cannot compare to other materials.
Applications：
LSR is widely used in medical devices, automotive components, consumer goods, and electronic products, because LSR has many performances, such as good temperature resistance, good flexibility, elasticity, and mechanical properties, and so on.
So if you need to make seals, gaskets, pacifiers, and encapsulation molding components for electronic products, then choose it. But if your products need low investment and technical requirements, and you want to make thermoplastic or certain polymers, do not choose it.
High Consistency Rubber（HCR）
High-consistency rubber is made of high molecular weight polysiloxane chains; it can improve its hardness, heat resistance, and other properties by filling it with various fillers. At the same time, it can also be sulfurized by peroxide sulfurization systems or platinum catalyst formulations without producing chemical by-products.
Advantages：
- HCR has excellent heat resistance, and it can keep its integrity even at extreme temperatures.
- Because it consists of long-chain polymers and high molecular weight, it has good tensile strength and durability.
- This silicone can be mixed with various additives such as silicone oil and grease.
Disadvantages：
- HCR has poor fluidity that can make it difficult to fill small mold details.
- This silicone has a high viscosity, so it needs higher pressure or temperature control during processing.
Applications：
With excellent heat resistance, good tensile strength, and durability, HCR is widely used in making gaskets, seals, O-rings, and shock absorbers in the automotive industry.
So if you want to keep your products’ integrity at extreme temperatures and customize some performances, you can choose it, but if you want to use it to fill small mode details or need low pressure or temperature control in processing, do not choose it.
Room Temperature Vulcanizing Silicone (RTV)
Room temperature vulcanizing silicone is made of single-component or two-component materials.
Advantages：
- RTV can be applied and cured at room temperature.
- After being applied and cured, RTV has good flexibility and durability that allows it to adapt to various environmental conditions
- RTV can be resistant to chemical corrosion.
Disadvantages：
- The curing process of RTV usually depends on the humidity in the air.
- Although RTV has good elasticity, its tensile strength, wear resistance, and impact resistance are relatively lower.
Applications：
Because RTV has good flexibility, durability, and good corrosion resistance, it can be used to make seals, bonds, pots, or encapsulation in industries like electronics, automotive, aerospace, and construction.
So if you want to make these products, you can choose this silicone, but if you want your products to be used in environments with low humidity and endure significant mechanical stress, do not choose it.
Fluorosilicone Rubber (FSR)
Fluorosilicone rubber is a special elastomer that has the performance of silicone rubber and fluorocarbon materials.
Advantages：
- This silicone can resist the erosion of corrosive chemicals and oils.
- FSR has a strong molecular structure and relatively long polymer chains.
Disadvantages：
- Although FSR has good chemical resistance and high temperature resistance, it has poor tensile strength and wear resistance.
- FSR can not be used under extremely low temperatures or for a long time, because fluorosilicone rubber may experience a decrease in flexibility, brittleness, or cracking in this environment.
Applications：
FSR has good chemical corrosion resistance, so it can be used in automotive, aerospace, and oil and gas industries to make seals, gaskets, and O-rings.
And if you want your products to be used for a long time, you can choose this silicone, but if you need your products to have good tensile strength, wear resistance, and to be used under extremely low temperatures, do not choose FSR.
How to Choose the Right Silicone Type for Your Applications？
Firstly, you should know what performances you need(such as temperature resistance, chemical resistance, mechanical strength, etc.), so if you are in high temperature or chemical environments, you can choose fluorosilicone rubber; if you need high-precision manufacturing, you can choose LSR, but if you only need a general seal and bond, you can choose RTV.
Secondly, if you want the silicone to make molds, you can choose LSR, and if you need silicone that can be rapidly cured, you should choose RTV.
Besides, when you choose silicone, you still need to consider factors such as UV radiation, moisture, high and low temperatures, as well as cost performance matching, to ensure silicone complies with relevant industry standards or regulations (such as FDA certification).
FAQ
How Long Does Silicone Last in Different Applications?
Generally speaking, silicone can last for 5 to 20 years in medical devices and electronic packaging, up to 10 to 20 years in automotive seals and building sealants, and typically has a useful life of 5 to 10 years in food storage containers and kitchen supplies.
Besides, silicone can typically last for 5 to 15 years in outdoor equipment and outdoor in the air open applications, so you can choose the right one according to your needs.
Can Silicone be Recycled, and How is it Disposed of Properly?
The silicone can be recycled, but because it’s a thermosetting polymer, it’s not easily reprocessed like common plastics, which makes the recycling process more complex.
If silicone cannot be recycled, you can handle it by landfilling because it is non-toxic, but its durability may make it exist in the environment for a long time.
In addition, do not burn silicone because it may release harmful gases during the burning process. If you want to deal with silicone, you can contact local recycling centers or manufacturers to learn about the correct disposal methods.
What Certifications Should Silicone Products Have?
Silicone products according to their application fields need conform to different certifications, including FDA Food Grade Certification EU, LF (food, ISO 134 (medical devices), USP Class VI (biocompatibility), CE certification (medical products), RoHS and REACH certification (environmental requirements), ISO 9001(quality management), and UL certification (high temperature resistance).
Besides, antibacterial and biocompatibility certification can also be suitable for medical and food fields to ensure the safety and compliance with industry standards of silicone products.
Which Silicone is Best for Molds?
Because the LSR has good flexibility, low shrinkage, and precision, it’s very suitable to make high-quality and durable molds. And, additive-cured silicone (platinum catalyzed) has good durability, so it can be used to make artworks, jewelry, and industrial parts molds.
Besides, if you are producing on a small scale, you can choose RTV silicone because it is easy to operate and is an ideal choice for making simple molds.
How to Care for Silicone?
You can lengthen the useful life of silicone and keep its good condition by the following methods:
- If you want to nurse silicone products, you should use warm water, mild detergent, and avoid contact with strong acids, alkalis, and sharp objects.
- After washing, you should make silicone products completely dry, but do not expose them to high temperatures or strong ultraviolet radiation, otherwise they may be damaged.
- When you store silicone products, you should place them in a dry and cool place to avoid them coming into contact with chemicals.
- You should check it for cracks or deformations regularly, and try to avoid oil residue as much as possible. And if there is an odor, you can wash it with white vinegar or water with baking soda.
Final Thoughts
The right silicone will add bricks and tiles to your business, so what are you waiting for? Whatever your business needs, Contact Legensilicone, and we will provide products that are suitable for your business.
