Liquid Silicone Rubber Injection Molding Services
Fecision provides custom liquid silicone rubber injection molding for precision parts. We develop the mold and process around the required surface quality and dimensions, then use inspection results to prepare for repeat production.
- ISO 9001 Certified
- ISO 13485 Certified
- Tolerances tight to +/- 0.02 mm
Custom Liquid Silicone Rubber Molding Built for Production
Fecision develops custom LSR parts around your assembly. We select the grade for the required function, with hardness options from 10 to 80 Shore A. The mold then defines the geometry and finish needed to reproduce the approved design.
Our custom LSR injection molding process delivers consistent quality and tight tolerances you can rely on. Hundreds of clients around the world already trust us, and together we have developed and shipped millions of custom silicone rubber parts.
LSR Molding Materials
We select the LSR grade for the conditions the part will face. A food-contact seal needs different evidence from an optical component, and heat or repeated movement can place further demands on the material. These requirements are reviewed before mold design and sampling.
Standard LSR
A versatile liquid silicone rubber grade suited for durable molded parts, stable processing, and repeatable production across general industrial and consumer applications.
Medical-grade LSR
Formulated for biocompatibility, cleanliness, and process control in medical and healthcare products that require reliable validation and traceable quality systems.
Optical-grade LSR
Designed for high light transmission, visual clarity, and stable optical properties in components used for lenses, lighting, and transparent silicone rubber features.
Food-grade LSR
A food-contact silicone rubber option selected for taste neutrality, safe repeated use, and dependable performance in beverage, infant, and kitchen-related applications.
Fecision works with established silicone suppliers, including Wacker, Dow, Momentive, and Shin-Etsu. Where a standard grade does not meet the application, we can work with a material partner on a custom formulation. Development focuses on the required performance and how reliably the compound can be molded.
LSR Injection Molding Capabilities
Use these LSR injection molding capabilities to align part size, tolerance, tooling strategy, and production expectations before quoting or mold build.
| Standard | Description |
|---|---|
| Size | 300 x 200 x 100 mm |
| Tolerance | Mold tolerance: +/- 0.01 mm, Parts tolerance: +/- 0.05 mm |
| Part to Part Repeatability | +/- 0.1 mm |
| Mold Cavities | Single cavity molds, multi-cavity molds |
| Mold Cavity Life | 3 million to 5 million shots for production tooling |
| Mold Material | Tool steel: P20, H13 Stainless steel: 420 |
| Available Mold Types | Prototype tooling, production tooling |
Secondary Operations
Many LSR parts need more than molding. In-house finishing keeps post-curing, marking, trimming, bonding, assembly, and inspection connected to the same production quality system.
LSR Injection Molding Case Studies
See how Fecision turns drawings, material targets, and production constraints into practical LSR molding programs with controlled tooling, validation, and inspection.
"The valve looked simple, but small changes in slit geometry created real leakage and feeding problems. Fecision helped us stabilize the opening pressure, improve durability, and remove odor concerns for a premium baby feeding line."
Stabilizing a Silicone Rubber Duckbill Valve for Baby Feeding Products
A leading baby feeding product manufacturer needed more consistent LSR duckbill valve performance for bottle and breast-pump assemblies, with better opening pressure control, fatigue resistance, and odor performance.
Fecision reviewed food-grade LSR selection, slit cutting tolerance, wall thickness, and fit geometry together, helping the program improve leakage control and move toward stable production quality.
Full Case StudyLSR Parts Fecision Has Produced
Explore examples of molded LSR parts produced for sealing, healthcare, food-contact, electronics, and custom industrial applications.
Silicone Rubber Sealing Components
Duckbill Valve
LSR Injection Molding Processes
A reliable LSR molding process starts before injection. We review the part, build the mold strategy, control mixing and curing, then inspect finished parts before shipment.
Design & Communication
Review your drawings, material requirements, and application needs. Complete DFM analysis and confirm tooling, tolerance, and production specifications before manufacturing begins.
How Does Liquid Silicone Rubber Injection Molding Work?
Liquid Silicone Rubber (LSR) injection molding is a common process for producing silicone rubber components. Although it follows the same basic principle as plastic injection molding, LSR requires a dedicated injection molding system. During production, Part A and Part B are metered at a 1:1 ratio and blended in a static mixer. If required, pigments or additives are introduced during this stage.
The mixed LSR is then injected through a cooled injection unit into a heated mold using a cold runner system. While the injection unit remains cool to prevent premature curing, the heated mold vulcanizes the material into its final shape. After the curing cycle is complete, the mold opens, the finished part is ejected, and the process repeats.
LSR Injection Molding Design Guidelines
Good LSR part design improves mold flow, demolding, tolerance control, and production yield. Use these guidelines as a starting point before DFM review.
| Design Rules | Guidelines |
|---|---|
| Wall Thickness | Minimum: 0.2 - 0.25 mm
Recommended: 1.5 - 3.0 mm |
| Draft Angle | General features: 0° - 2°, commonly 2°. |
| Corner Radius | Inside corner radius is roughly equal to Wall thickness. Inside radius should be at least 0.5 mm, outside radius around 1.5 mm. |
| Tolerance | Standard tolerance: +/- 0.1 to +/ 0.2 mm Precision tolerance: +/- 0.05 mm |
| Mold Temperature | 130°C - 200°C or 320°F - 450°F |
| Shrinkage | Compensate for 2.5% - 3.5% silicone shrinkage during mold design. |
Applications of Liquid Silicone Rubber Injection Molding
LSR injection molding is widely used where soft-touch performance, sealing, biocompatibility, heat resistance, and repeatable precision matter.
Consumer Goods
Soft-touch components designed around product use and operating environment.
Consumer ElectronicsBaby Care
Pacifiers, bottle nipples, teething toys, and durable food-safe silicone rubber parts.
Food & Baby CareAutomotive
Connector seals, vibration components, grommets, and protective silicone rubber parts.
Mobility SolutionsElectronics
Waterproof seals, protective casings, keypad interfaces, and soft gaskets.
Electronics SolutionsFrequently Asked Questions
These answers cover the LSR injection molding questions teams usually ask before material selection, tooling, sampling, and production planning.
What materials can you mold?
We work with food-grade LSR, medical-grade LSR, optical-grade silicone, fluorosilicone, and custom compounds selected for each product requirement.
Can you support low-volume validation before mass production?
Yes. We can begin with DFM review, prototype tooling, and validation runs before moving into multi-cavity production tooling.
Do you provide secondary operations?
Yes. We can finish and assemble molded parts in-house. The required operations, such as post-curing or printing, are agreed during project review before final inspection and packaging.
Ready to build custom LSR injection molded parts?
Send drawings, CAD files, samples, target material, and volume. We will review the molding route and return practical production feedback.