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Compared with LSR designed primarily for injection molding, coating-grade LSR focuses on coating flow, substrate adhesion, flexibility, curing speed, temperature resistance and environmental durability.
Commercial coating-grade silicone products are available in different formulations and mixing ratios. For example, some products use a 1:1 mixing ratio, while other systems use different base-to-catalyst ratios depending on the formulation and application.
Typical commercial coating LSR products can cover a wide range of hardness and mechanical properties. Representative products have hardness values around 10–50 Shore A, tensile strength from approximately 3–8 MPa, and elongation from approximately 160% to 1500%.
Actual performance depends on the specific formulation and should always be confirmed using the manufacturer's technical data sheet (TDS).
Liquid Silicone Rubber for coating is a liquid silicone elastomer used to create a flexible silicone rubber coating on the surface of a substrate.
The material can be applied to substrates such as:
Polyester fabric
Polyamide or nylon fabric
Glass fiber fabric
Wires and cables
Technical textiles
Other industrial substrates
After application, the liquid silicone rubber is cured to form a continuous elastic coating.
Coating-grade LSR is commonly selected when the finished coating needs a combination of flexibility, temperature resistance, weather resistance, electrical insulation, chemical stability and long-term durability.
The main properties of coating-grade LSR include flexibility, high elongation, temperature resistance, weather resistance and adhesion to selected substrates.
| Property | Typical Characteristics |
|---|---|
| Material form | Liquid |
| Components | One-component or two-component |
| Hardness | Approximately 10–50 Shore A for representative products |
| Tensile strength | Approximately 3–8 MPa for representative products |
| Elongation | Approximately 160%–1500% for representative products |
| Curing | Heat curing or room-temperature curing, depending on formulation |
| Application methods | Knife coating, dip coating, metered coating and other methods |
| Common substrates | Fabrics, glass fiber, wires and technical materials |
| Key performance | Flexibility, adhesion, temperature and weather resistance |
These figures represent examples from commercial coating-grade silicone products rather than universal specifications for all LSR materials.
For example, Dow SILASTIC™ LC 1000 has a typical hardness of 10 Shore A, tensile strength of 3.5 MPa and elongation of 1500% under the specified test conditions.
Coating-grade liquid silicone rubber can be applied to polyester, polyamide, glass fiber and other technical substrates when the silicone formulation and surface treatment are compatible with the substrate.
Some LSR coating products are specifically designed for polyester and polyamide fabrics.
For example, Dow SILASTIC™ LCF 3600LV is designed for fabric and airbag coating and provides adhesion to selected polyamide and polyester fabrics without primer.
Liquid silicone rubber can also be used to coat glass fiber fabrics.
Typical applications include:
Heat-resistant sleeves
Insulation materials
Industrial fabrics
Expansion joints
Protective materials
Some silicone coating materials are designed for electrical wire sleeving and related insulation applications.
The required properties may include:
Electrical insulation
Flexibility
Temperature resistance
Environmental resistance
Substrate compatibility should always be confirmed through technical data and application testing.
Liquid silicone rubber can be applied by knife coating, dip coating, metered coating and other continuous coating processes, depending on the material viscosity, substrate and required coating thickness.
Knife coating uses a blade to control the amount of liquid silicone applied to the substrate surface.
The coated material is then passed through a heating system to cure the silicone layer.
Knife coating is widely used for technical textiles and fabric coating applications.
Dip coating applies silicone by immersing the substrate into liquid silicone rubber and then curing the material on the substrate surface.
Dip coating can be suitable for substrates that need relatively uniform coverage around their surface.
The final coating thickness depends on factors such as:
Material viscosity
Withdrawal speed
Substrate structure
Silicone formulation
Curing conditions
Metered coating uses controlled material delivery to regulate the amount of silicone applied to the substrate.
This method is useful when manufacturers need better control of coating weight or coating thickness.
The actual coating process should be optimized according to material viscosity, line speed, substrate structure and curing equipment.
Most industrial coating-grade LSR systems are cured by heat or another chemical curing mechanism, depending on the formulation.
A typical heat-curing process includes:
Material mixing → coating → heating → curing → cooling → inspection
For example, the technical information for Dow SILASTIC™ LC 1000 specifies a fabric coating condition of approximately 180°C for 1 minute, while the same product information indicates a minimum recommended temperature of approximately 150°C.
This demonstrates that LSR curing temperature and curing time are product-specific rather than universal values.
The actual curing conditions depend on:
Silicone formulation
Coating thickness
Substrate
Production line speed
Oven temperature
Required final properties
Manufacturers should follow the selected product's TDS and validate the curing process on the actual production line.
Commercial coating-grade LSR products can have significantly different hardness, tensile strength and elongation values.
| Example Product Type | Hardness | Tensile Strength | Elongation | Typical Application |
|---|---|---|---|---|
| Low-hardness fabric coating LSR | 10 Shore A | 3.5 MPa | 1500% | Fabric coating |
| Fabric and airbag coating LSR | 32 Shore A | 4.3 MPa | 331% | Airbag and fabric |
| Electrical/fabric coating LSR | 48 Shore A | 7.5 MPa | 160% | Wire sleeving and fabric |
| Electrical insulation coating LSR | 33 Shore A | 5 MPa | 450% | Electrical fabrics and sleeves |
These figures are representative commercial product data and should not be treated as specifications for all coating-grade LSR.
The large difference in elongation—from approximately 160% to 1500%—shows why material selection should be based on the actual application rather than hardness alone.
Liquid silicone rubber is suitable for fabric coating because it can form a flexible elastic layer while maintaining substantial elongation and resistance to environmental conditions.
For example, Dow SILASTIC™ LC 1000 has a reported elongation of 1500% and a hardness of 10 Shore A under specified test conditions.
This combination of low hardness and high elongation can be useful for applications where the coated fabric needs to remain flexible.
Potential fabric coating applications include:
Technical textiles
Protective fabrics
Airbags
Industrial fabrics
Flexible insulation materials
Fiberglass fabrics
Liquid silicone rubber coating is used in automotive, electrical, industrial textile and other applications where a flexible protective or functional coating is required.
Silicone-coated fabrics are widely used in automotive airbag applications because the coating can provide a flexible barrier layer on the fabric.
Coating-grade silicone products are available specifically for airbag applications and can be designed for adhesion to selected polyester and polyamide fabrics.
Liquid silicone rubber can be used for:
Conveyor belts
Protective clothing
Technical textiles
Expansion joints
Tent materials
Fiberglass fabrics
Heat-resistant materials
The required silicone formulation depends on the operating temperature, mechanical stress and environmental exposure of the finished product.
Silicone-coated glass fiber fabrics can be used in heat-resistant and industrial applications.
Typical applications include:
Fiberglass sleeves
Thermal insulation
Flexible expansion joints
Heat-resistant fabrics
Industrial protective materials
The silicone formulation should be selected according to the required temperature resistance, flexibility and adhesion.
Certain coating-grade silicone materials are designed for electrical wire sleeving and insulation applications.
Important properties may include:
Dielectric strength
Volume resistivity
Temperature resistance
Flexibility
Resistance to environmental aging
For example, commercial silicone products for electrical applications can provide dielectric strength in the range of several tens of V/mil, depending on the formulation and test method.
The correct coating-grade LSR should be selected based on the substrate, coating process, viscosity, adhesion, hardness, elongation, curing conditions and final operating environment.
The following seven factors should be evaluated:
Identify the substrate first:
Polyester
Polyamide / Nylon
Glass fiber
Wire
Cable
Metal
Other technical materials
Viscosity affects:
Flow behavior
Coating uniformity
Penetration
Coating thickness
Production speed
Select the Shore A hardness according to the flexibility and mechanical requirements of the finished coating.
If the coated substrate will be repeatedly stretched, bent or folded, elongation is an important selection criterion.
Commercial coating-grade silicone products can have elongation values ranging from approximately 160% to 1500%.
The silicone must have sufficient adhesion to the selected substrate.
Some commercial products provide primerless adhesion to specific polyester or polyamide fabrics, but this performance should not be assumed for every silicone formulation or substrate.
Check:
Curing temperature
Curing time
Production line speed
Oven configuration
Substrate temperature resistance
Consider the finished product's exposure to:
High and low temperatures
Humidity
UV radiation
Ozone
Chemicals
Water
Mechanical stress
Electrical loads
Not always. Whether a primer is required depends on the silicone formulation and substrate.
Some coating-grade LSR products are specifically formulated to provide primerless adhesion to selected polyester or polyamide fabrics.
However, primerless adhesion to one substrate does not mean that the same silicone will adhere without primer to every material.
For this reason, manufacturers should conduct adhesion testing on the actual substrate before mass production.
LSR coating and RTV silicone coating are different material systems and should not be selected solely according to the word "silicone."
| Feature | LSR Coating | RTV Silicone Coating |
|---|---|---|
| Material form | Liquid silicone | Liquid/paste silicone |
| Components | Often 2K | 1K or 2K |
| Typical curing | Often heat curing | Often room-temperature curing |
| Production | Suitable for continuous industrial processing | Suitable for various coating/sealing applications |
| Processing speed | Can support high-speed production | Depends on formulation |
| Typical applications | Fabrics, airbags, wire sleeving, technical textiles | Coating, sealing, bonding and protection |
| Key selection factors | Viscosity, adhesion, cure speed, coating process | Cure mechanism, adhesion, working time and application method |
The correct material should be selected according to the manufacturing process and final application rather than the generic term "silicone coating."
Liquid silicone rubber coating is a liquid silicone material applied to a substrate and cured to form a flexible silicone rubber layer.
Yes. Certain LSR products are specifically formulated for polyester, polyamide and other technical fabric coating applications.
Yes. Certain coating-grade LSR products are specifically developed for automotive airbag fabrics.
Yes. Certain silicone rubber coating systems are designed for glass fiber fabrics and fiberglass sleeves.
Yes. Some liquid silicone rubber products are specifically designed for electrical wire sleeving and insulation applications.
Representative commercial coating-grade LSR products can range from approximately 10 to 50 Shore A, although the available range depends on the manufacturer and formulation.
Commercial coating-grade LSR can have elongation values ranging from approximately 160% to 1500% or more, depending on the formulation.
Many industrial LSR coating systems use heat curing, but the required curing method depends on the formulation.
There is no single universal curing temperature for LSR coating. Representative commercial products may use temperatures around 150–180°C or higher, depending on the formulation, substrate and production process.
Not necessarily. Some LSR products provide primerless adhesion to specific substrates, while other applications may require a primer or surface treatment.
Select the material based on the substrate, coating method, viscosity, adhesion, hardness, elongation, curing conditions and final operating environment.
Liquid Silicone Rubber for coating is a versatile material for fabric, glass fiber, electrical and technical textile applications because it can form flexible silicone layers with controlled mechanical and environmental properties.
The most important factors when selecting coating-grade LSR are:
Substrate → Viscosity → Coating Method → Adhesion → Hardness → Elongation → Curing Conditions → Final Application
There is no single LSR formulation suitable for every coating application. The final material should be selected according to the substrate, production process and required performance, with TDS data and application testing used to confirm suitability before mass production.
