Liquid Silicone Rubber Molding Design Guide
Specify hardness, sealing geometry, and service temperature so the silicone grade and tooling can be evaluated together.
Get the Guide With Your QuoteLiquid Silicone Rubber (LSR) Molding Services
BoValley supports liquid silicone rubber (LSR) molding projects for selected flexible, resilient, and precision-molded components. LSR can be suitable for parts requiring elastic recovery, sealing performance, and resistance to demanding environmental conditions, depending on the selected silicone grade and application.
Project Review
- Sealing Geometry Review
- Compound Requirements
- Flash Criteria
- Inspection Planning
- Part Geometry
- Flexible seals & profiles
- Tooling Schedule
- Confirmed with the quote
- Material Type
- Liquid silicone rubber
Overview
What is Liquid Silicone Rubber Molding?
Liquid Silicone Rubber (LSR) molding uses a two-component liquid silicone system that is metered, mixed, and injected into a heated mold, where it cures into an elastomeric part. The process is used for selected components requiring flexibility, resilience, sealing, and stable performance across defined service conditions.
LSR is different from conventional thermoplastic injection molding. Silicone components are formed through a curing reaction rather than by cooling a molten thermoplastic. Mold design, material handling, curing conditions, and part removal all influence the final result.
Material grade and compliance requirements should be selected according to the actual application. Food-contact, medical, electrical, or other regulated uses require the appropriate material documentation and validation.
Liquid Silicone Rubber Molding Capabilities
Assess thin sections, sealing lips, intricate profiles, and other design features against tooling and process requirements.
Flexible Sealing Components
- Suitable LSR grades can support custom seals, gaskets, and flexible interfaces.
- Select material grades based on the required flexibility, compression behavior, and recovery characteristics.
- Assess thin sections, sealing lips, intricate profiles, and other design features against tooling and process requirements.
- Select hardness and flash criteria for the intended seal.
Elasticity & Resilience
- Suitable LSR grades can support custom seals, gaskets, and flexible interfaces.
- Select material grades based on the required flexibility, compression behavior, and recovery characteristics.
- Assess thin sections, sealing lips, intricate profiles, and other design features against tooling and process requirements.
- Select hardness and flash criteria for the intended seal.
Complex Silicone Geometries
- Suitable LSR grades can support custom seals, gaskets, and flexible interfaces.
- Select material grades based on the required flexibility, compression behavior, and recovery characteristics.
- Assess thin sections, sealing lips, intricate profiles, and other design features against tooling and process requirements.
- Select hardness and flash criteria for the intended seal.
Tooling and Flash
- Suitable LSR grades can support custom seals, gaskets, and flexible interfaces.
- Select material grades based on the required flexibility, compression behavior, and recovery characteristics.
- Assess thin sections, sealing lips, intricate profiles, and other design features against tooling and process requirements.
- Select hardness and flash criteria for the intended seal.
Hardness and Color
- Suitable LSR grades can support custom seals, gaskets, and flexible interfaces.
- Select material grades based on the required flexibility, compression behavior, and recovery characteristics.
- Assess thin sections, sealing lips, intricate profiles, and other design features against tooling and process requirements.
- Select hardness and flash criteria for the intended seal.
Quality Checks
- Suitable LSR grades can support custom seals, gaskets, and flexible interfaces.
- Select material grades based on the required flexibility, compression behavior, and recovery characteristics.
- Assess thin sections, sealing lips, intricate profiles, and other design features against tooling and process requirements.
- Select hardness and flash criteria for the intended seal.
MaterialsMaterials
Liquid Silicone Rubber Molding Materials
LSR grades are selected according to hardness, flexibility, temperature exposure, sealing requirements, color, and application-specific compliance. The following are material categories to discuss with the supplier.
- General-Purpose LSR
- Soft LSR Grades
- Heat-Resistant LSR
- Colored LSR
- Sealing-Grade LSR
- Specialty LSR Grades
- Shore A hardness
- Compression behavior
- Tear resistance
- Color and translucency
- Operating temperature
- Compression set
- Elastic recovery
- Sealing pressure
- Flash criteria
- Cure conditions
- Deflashing method
- Part wall thickness
- Mold shutoff
- Parting line position
- Surface texture
- Chemical exposure
- Dimensional checks
- Hardness test method
Surface Finish Options
LSR Technical Specifications and Design Considerations
| Parameter | Typical Options / Considerations |
|---|---|
| Material Characteristics | Elastomer, typically flexible |
| Material Type | Two-component liquid silicone system |
| Hardness | Selected Shore A grades, subject to material availability |
| Part Geometry | Seals, gaskets, membranes, flexible buttons, and selected thin-wall parts |
| Color | Natural translucent and selected colored grades, subject to availability |
| Curing | Heated mold and controlled curing cycle |
| Post-Processing | Deflashing, cleaning, and other agreed finishing or inspection |
| Quality Checks | Dimensions, flash, surface condition, and application-specific functional tests |
| Production Volume | Prototype or production tooling, subject to process and project feasibility |
The Process
Liquid Silicone Rubber Molding Parts?
Depending on the application, quality checks may focus on dimensions, flash, surface appearance, hardness, sealing features, and other functional requirements agreed for the project.
The advantages
- Elasticity and Recovery:• Suitable for selected parts that need to deform and recover their shape.
- Complex Sealing Features:• Supports detailed molded profiles for selected sealing and interface designs.
- Temperature Performance:• Suitable grades can perform across defined temperature ranges; confirm the selected compound's limits.
The challenges
- Flexible Component Design• Useful for selected membranes, buttons, gaskets, and compliant interfaces.
- Material and Color Options:• Selected grades and colors can be specified according to the product design.
QualityApplications for Liquid Silicone Rubber Molding
LSR is commonly considered for parts that need elasticity, repeatable shape recovery, and application-specific environmental performance.
Seals & Gaskets
Sealing interfaces and custom gasket components.
Flexible Boots & Covers
Protective covers and flexible molded shapes.
Buttons & Keypads
Flexible interfaces and tactile components.
Membranes & Diaphragms
Application-specific flexible parts.
Packaging
Especially beverage, food, cosmetic, and pharmaceutical packaging.
Appliances
Housings and components for smaller appliances.
| Types of Parts | Function |
|---|---|
| Sealing gaskets | Create a flexible contact interface between mating components. |
| Protective boots | Cover moving or exposed features while allowing deflection. |
| Keypads and diaphragms | Provide repeatable movement or tactile response in a molded part. |
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