In the realm of advanced polymer materials, Liquid Silicone Rubber (LSR) has become indispensable in high-end manufacturing sectors such as medical devices, smart wearables, AR/VR, electronic encapsulation, and automotive components. This is due to its excellent flowability, fast curing speed, safety, and environmental friendliness.
Liquid silicone breathable strap | Picture from the Internet
As a critical reinforcing filler in LSR, the quality of precipitated silica directly determines the performance of the final product.
Leveraging over 20 years of technical expertise in functional silica, JSJ has developed a specialized series of precipitated silica products tailored for LSR, precisely meeting the stringent performance requirements of various applications.
Figure | JSJ’s Silica for Liquid Silicone Rubber
Figure | JSJ’s silica products
Figure | JSJ’s silica products
In this article, we’ll explore the background and advantages of LSR, explain how JSJ’s specialized precipitated silica enhances LSR performance, and demonstrate how our professional solutions empower customers to boost product competitiveness.
Background and Advantages of Liquid Silicone Rubber
From Traditional Silicone to Liquid Silicone
The development of Liquid Silicone Rubber (LSR) is closely tied to the study of silicon. The discovery of the silicon element in the 19th century laid its chemical foundation. By the mid-20th century, the application of silicone materials accumulated valuable technical experience. In the 1970s, limitations in solid silicone rubber processes, such as low molding efficiency, spurred the development of LSR. Industrial production began in the late 1980s, with China entering the industrialization phase in the early 21st century.
Liquid Silicone Rubber (LSR) is a liquid elastomer material composed of high-molecular-weight polysiloxane as the base polymer, combined with reinforcing fillers, cross-linking agents, and other additives. It boasts high transparency, excellent resistance to extreme temperatures (-60°C to over 200°C), anti-aging properties, superior biocompatibility, and no byproducts during curing. Through injection molding, LSR can be rapidly formed into precise, complex-shaped products.
Today, LSR is widely used in medical devices, food-contact materials, automotive parts, electronics, electrical applications, and aerospace.
Xiaomi’s 2024 first OWS open-ear earphones use skin-friendly LSR for the ear-hook component. | Image sourced from the internet
Liquid silicone phone cases. | Image sourced from the internet
Various LSR products. | Image sourced from the internet
How Precipitated Silica Impacts LSR Performance
Key Parameters and Their Effects
The specific surface area, oil absorption value, average particle size, and dispersibility of precipitated silica significantly influence the mechanical properties, processability, and appearance of LSR. JSJ ensures high performance and stability by precisely controlling these parameters.
Specific Surface Area
Specific surface area is a critical factor affecting silicone rubber performance. A surface area that is too low results in insufficient reinforcement, while one that is too high increases system viscosity, hindering processability. JSJ’s specialized precipitated silica for LSR precisely balances surface area to deliver excellent reinforcement while maintaining optimal flowability.
Oil Absorption Value
The oil absorption value directly impacts the mechanical properties and processing characteristics of silicone rubber. Higher oil absorption enhances intermolecular forces, improving tensile and tear strength. JSJ’s precipitated silica offers stable, adjustable oil absorption, ensuring LSR maintains high strength alongside excellent mold release and surface finish.
Average Particle Size
Large particle sizes cause significant light scattering, reducing transparency, while overly small particles may aggregate, affecting dispersion uniformity. JSJ tightly controls process parameters to manage the secondary structure and particle size distribution of precipitated silica, optimizing both light transmission and uniform reinforcement.
Dispersibility
High-dispersibility precipitated silica, as a reinforcing filler in LSR, distributes evenly within the system. The hydroxyl groups on the silica surface form physical or chemical interactions with silicone rubber molecular chains, significantly enhancing tensile strength, tear strength, and hardness. Additionally, high dispersibility allows the silica structure to break down easily during mixing and shearing, improving dispersion and further boosting mechanical properties.
JSJ’s precipitated silica stands out due to advanced production processes and stringent quality control. With narrow particle size distribution and regular particle morphology, our products disperse quickly and uniformly in LSR systems, providing reliable reinforcement and elevating product performance.
These parameters are interconnected and require systematic evaluation. For more product details and specifications, feel free to contact us directly.
Parameterized Customization
Accelerating Product Development
JSJ’s technical team, drawing on deep expertise and extensive experimental data, has established a comprehensive precipitated silica selection system. By providing your target silicone rubber performance requirements and process conditions, we can quickly recommend the most suitable precipitated silica model and offer detailed formulation adjustments.
This parameterized customization service has helped numerous clients overcome performance challenges, significantly shortening product development cycles. Regardless of your application, JSJ’s precise control over key silica parameters delivers tailored reinforcement solutions. Our technical team, backed by rich application data, recommends the optimal precipitated silica product based on your specific formulation and process conditions, helping you balance performance and cost to enhance market competitiveness.
For more information or to discuss your needs, contact us today!
