What Is LSR Injection Molding
Injection molding of Liquid Silicone Rubber (LSR) is a highly efficient process for producing pliable, durable silicone products in high volumes. This technology is widely used in the manufacturing of components for medical, electrical, and consumer applications, thanks to both the inherent properties of silicone and the precise parameters of the injection molding process.
This advanced method allows us to produce a wide variety of silicone products, such as gaskets, kitchen utensils, and overmolded components, to meet the diverse needs of our customers. By optimizing the process parameters, we ensure that every silicone product we manufacture meets the highest standards of durability and performance, making it ideal for applications that demand both resilience and precision.
Special Considerations for Liquid Silicone Injection Molding
Part Design
Liquid silicone injection molding presents unique design considerations compared to thermoplastic injection molding, though the requirements are generally less stringent for silicone products. The flexibility of silicone allows for easy removal from metal molds, eliminating the need for ejector pins and enabling a more relaxed approach to draft angles. The shear-thinning property of liquid silicone facilitates smooth flow into all areas of the mold, reducing the necessity for consistent wall thickness. Additionally, silicone parts can be designed thicker than their thermoplastic counterparts, offering greater design freedom.
A significant advantage of liquid silicone injection molding is the ability to incorporate protruding undercut sections. Due to the material's softness and pliability, these irregular features can often be removed from the mold without requiring side actions.
However, one limitation of liquid silicone injection molding is its tendency to cause flash, as the low viscosity of the liquid allows it to seep through the parting line. Ensuring that the tooling is properly sealed is essential to minimize this issue.
Key design guidelines include:
- Keeping parting lines short to reduce flash.
- No draft required for very shallow parts; otherwise, apply one degree per 2.5 cm.
- Position gates on the underside or in non-visible areas.
Metering and Mixing
Unlike thermoplastic injection molding, liquid silicone injection molding involves metering two components of the silicone mixture—one of which contains the platinum catalyst—in a precise ratio using a metering unit. These components are then combined through a static or dynamic mixer before injection.
Temperature Control
The process of liquid silicone injection molding operates differently from thermoplastic injection molding. While thermoplastics are melted into a liquid before being cooled into a solid, liquid silicone starts as a liquid at room temperature. After injection into the mold, the mold is heated to accelerate curing. To prevent premature curing, manufacturers may use a cooled runner and sprue system to manage the flow of the silicone.
Although customers may not need to delve deeply into these technical details, it is crucial to recognize that experienced silicone molding providers—distinct from thermoplastic specialists—are better equipped to manage the intricacies of the process and mitigate issues such as flash.
By understanding these special considerations, manufacturers can optimize the production of high-quality silicone products, ensuring both design flexibility and operational efficiency.
Why Choose Neosilicone for Your LSR Injection Molding Services
Rapid Prototyping & Production
Neosilicone offers swift turnaround times, delivering prototypes in as fast as 15 days. This accelerated process is ideal for testing the functionality and manufacturability of your silicone products before committing to full-scale production.
Expert Engineering Team
With extensive experience across thousands of projects, our skilled mold engineers possess the expertise to optimize parameters for any type of part. This ensures that your silicone products are produced to the highest standards, regardless of complexity.
State-of-the-Art Facilities
We leverage both imported and top-tier local injection molds to deliver precise and high-quality silicone products. Our advanced facilities enable us to minimize both time and cost, ensuring you receive the best value for your investment.
Scalable Production Capacity
Our expansive network of partner facilities allows us to seamlessly scale production to meet your needs. With injection machines ranging from 10 to 1000 tons, we are equipped to handle orders of any size, from small batches to mass production.
Cost-Effective Durability
Whether you require rapid tooling, mass production molds, or end-use silicone products, we provide solutions that balance affordability with tight tolerances and long-lasting durability.
Fast Global Delivery
Neosilicone’s global logistics network ensures that you receive high-quality silicone products and exceptional customer service within as little as 15 days, all while maintaining competitive pricing.
Advantages of Liquid Silicone Injection Molding
Liquid silicone injection molding offers a unique blend of benefits, combining the efficiency and high-volume production capabilities of traditional injection molding with the superior material properties of liquid silicone rubber. This process is particularly advantageous for producing high-quality silicone products at scale.
Efficiency
The liquid silicone injection molding process is highly efficient, making it ideal for the rapid production of large quantities of silicone products. This efficiency is driven by the ability to quickly and accurately inject silicone into molds, ensuring consistent and repeatable results.
Precision & Detail
The high pressure used in injection molding ensures that liquid silicone fully penetrates every detail of the mold before curing. This results in silicone products with intricate features and superior surface finishes, outperforming those made from melted thermoplastics in terms of detail accuracy.
Enhanced Design Flexibility
Silicone products benefit from increased design freedom, as they do not require uniform cooling and can be easily removed from metal molds. This flexibility allows for more complex and innovative designs without compromising the quality or performance of the final product.
Exceptional Material Properties
Silicone products produced through this method exhibit excellent thermal, chemical, and electrical resistance. Additionally, they have a low compression set, maintaining their shape and performance under stress, making them ideal for a wide range of demanding applications.
Cost-Effectiveness
Liquid silicone injection molding is a cost-effective solution for producing high-quality silicone products. The process is particularly economical when using low-cost aluminum molds, which further reduces the overall cost per part, especially in large production runs.
High-Volume Production
This method excels in high-volume production, capable of producing millions of silicone products with consistent quality and precision, making it an ideal choice for large-scale manufacturing.
Applications of Liquid Silicone Injection Molding
Automotive Industry
Liquid silicone injection molding is widely used in the automotive industry, primarily due to silicone's exceptional temperature resistance. This property allows silicone products to perform reliably near engines and other high-heat areas. Common automotive components made from silicone include single-wire, radial, and flange seals, connectors, assemblies, electronic covers, and A/C vent cushions. A more visible application is the soft edge of windshield wiper blades. Silicone is an ideal material because it doesn’t scratch the windshield and lasts longer than traditional rubber, even with prolonged exposure to sunlight.
Medical Applications
In the medical field, liquid silicone injection molding is invaluable for producing silicone products due to the material’s outstanding biocompatibility. Silicone is safe for prolonged contact with human skin and offers the necessary softness and flexibility required for many medical devices. Injection molded medical components include drug delivery systems, fluid management systems, biotechnology parts, seals, catheters, respiratory masks, lenses, and covers for electronic medical devices.
Industrial Applications
The industrial sector benefits significantly from the durability and resilience of injection molded silicone products. Silicone parts like seals, gaskets, strain relief devices, and grommets are popular in various industrial applications. These molded silicone products offer excellent UV resistance, chemical resistance, and temperature resistance, making them ideal for harsh industrial environments.
Consumer Products
Liquid silicone injection molding is also extensively used in manufacturing consumer silicone products. Items such as kitchenware, wristwatches, wearable technology, toys, pacifiers, and baby bottles are commonly produced using this process. The flexibility, durability, and safety of silicone make it an excellent material choice for these everyday products.