LSR injection molding
Liquid silicone rubber molding for detailed parts and insert assemblies — precise geometry, thin features and consistent dimensions across production batches.
What LSR is used for
When LSR fits
Detailed Molded Geometry
Suitable for products requiring fine details, narrow features or complex molded structures.
Soft-Touch & Flexible Components
Suitable where flexibility, soft feel and elastic recovery are part of the product function.
Thin or Controlled Wall Sections
Suitable for product areas requiring thinner or more controlled molded sections where the design allows.
Insert / Overmolded Structures
Suitable for LSR molded around compatible inserts or rigid components where the structure is designed for it.
Skin-Contact Consumer Applications
Suitable for selected consumer applications where soft-touch, cleanliness and material requirements are important.
Repeat Production Programs
Suitable for projects that require consistent molded geometry and repeat OEM/ODM production after approval.
Project inputs
The available project information is reviewed before tooling to confirm geometry, material, molding method, interface and production feasibility.
2D Drawing
Sketches or 2D drawings with key dimensions and sections.
3D / CAD File
CAD files for precise geometry and flow review.
Physical Sample
An existing part used as the reference for geometry and feel.
Existing Product
The product the LSR component must fit or enhance.
Product Dimensions
Key measurements used to scope the molding approach.
Target Hardness
Hardness expectation reviewed against the product function.
Material Requirement
Material expectations reviewed for the application.
Insert / Substrate Information
Insert material and geometry reviewed for overmolding.
Functional Requirement
Function defined per use: sealing, grip, protection or contact.
Target Market
Market context reviewed for material and finish requirements.
Material & hardness
Material selection depends on product function, geometry, target market, contact conditions and applicable compliance requirements.
LSR Grade
Grade reviewed for the product function and environment.
Shore Hardness
Hardness selected and confirmed on samples.
Elasticity
Elastic recovery reviewed for the intended use.
Tear Resistance
Tear behavior reviewed for thin or loaded sections.
Color Requirement
Color matched to confirmed references.
Surface Feel
Surface feel tuned for grip, contact and appearance.
Target Environment
Temperature, exposure and use environment reviewed.
Applicable Compliance Requirement
Reviewed for applicable products and markets.
LSR design
LSR projects should be reviewed before tooling to reduce avoidable filling, demolding, flash and fit issues.
Part Geometry
Geometry reviewed for LSR flow and demolding.
Wall Thickness
Wall sections planned for filling and cured strength.
Parting Line
Parting line placement agreed before tooling.
Flash Control
LSR flash behavior and trimming reviewed per surface.
Vent / Flow Considerations
Air entrapment and flow paths reviewed in the mold design.
Undercuts
Undercuts reviewed for release or side-action needs.
Insert / Substrate Interface
Insert geometry and positioning reviewed for bonding and retention.
Dimensional Tolerance
Tolerances agreed before mold making.
Insert & overmolding
LSR may be molded around compatible plastic, metal or engineered inserts where the product structure requires an integrated soft-touch, sealing or protective feature.
Plastic + LSR
LSR overmolded onto compatible plastic structures.
Metal + LSR
LSR molded around metal inserts and hardware.
Rigid Insert + Flexible Interface
Rigid carriers combined with flexible LSR contact areas.
Soft-Touch Grip Areas
Grip zones integrated into rigid structures.
Sealing Interfaces
Sealing features molded into the part geometry.
Protective Overmolded Features
Protective LSR features over fragile or exposed components.
Tooling & sampling
Each step is confirmed per project. Dedicated tooling and sampling support is described on the Tooling & Sampling capability page.
Drawing / Product Review
The drawing, sample or requirements are reviewed for LSR suitability.
Mold Structure Review
Mold structure, parting and flow are reviewed.
Tooling Development
LSR tooling is built around the confirmed design.
First Sample
First samples are molded from the new tool.
Dimension / Function Check
Samples are checked for dimensions and function.
Material / Hardness Confirmation
Material and hardness are confirmed on samples.
Color / Surface Confirmation
Color and surface finish are confirmed on samples.
Customer Approval
The approved sample becomes the production reference.
Production
Production follows the approved sample and confirmed project specifications.
Material Preparation
LSR material is prepared and colored per the confirmed specification.
Injection Molding
Parts are injection molded per the agreed parameters.
Curing
Parts are cured to the confirmed state before handling.
Demolding
Parts are removed and handled per the agreed method.
Trimming / Finishing
Flash is trimmed and surfaces finished per the agreed criteria.
Inspection
Parts are checked against the approved sample.
Assembly if Required
Multi-part products assembled per project scope.
Packaging
Parts packed per the agreed specification.
Quality focus
Checks are aligned with the approved sample and agreed criteria — see the Quality Control capability.
Dimensions
Dimensions checked against the approved drawing.
Hardness
Hardness matches the approved specification.
Color Consistency
Color matches the approved reference across runs.
Surface Finish
Surface quality consistent across batches.
Flash
Flash kept within the agreed allowance.
Parting Line
Parting line finished per agreed surfaces.
Detail Definition
Fine molded details reproduced consistently.
Insert Position
Inserts positioned and retained as designed.
Assembly Fit
Parts assemble into the product as intended.
Repeat Production Consistency
Repeat orders produced against the approved sample.
Application directions
Typical directions where LSR is applied.
Wearable & Device Components
Soft, flexible components for wearables and devices.
Beauty & Personal-Care Components
LSR parts and tools for beauty and personal-care products.
Soft-Touch Consumer Products
Soft-touch LSR products for consumer use.
Sealing & Interface Components
LSR sealing and interface components.
Protective Flexible Parts
Flexible protective LSR parts.
LSR + Plastic / Metal Components
LSR combined with plastic or metal components.
Engineering notes from production programmes
- Tactile-stability programmes: waterproof LSR buttons are validated across extended press-cycle testing, with snap ratio and contact-area geometry controlled.
- Optical and translucent grades: clarity retention under elevated service temperatures is reviewed during material selection.
Frequently asked questions
What is LSR injection molding best suited for?
LSR is suited for detailed, flexible and repeatable parts — soft-touch components, thin or controlled sections, overmolded structures and repeat production programs where the design allows.
How is LSR different from solid silicone molding?
LSR is a liquid material injected into a closed mold, which suits detailed geometry and consistent repeat production; solid silicone is typically compression or transfer molded. The suitable route depends on the part and program.
Can you develop an LSR part from a drawing or sample?
Yes. Projects can start from 2D drawings, 3D / CAD files or physical samples; geometry, flow and moldability are reviewed before tooling.
Can LSR hardness and color be customized?
Yes. Hardness and color are selected per the application and confirmed on samples.
Can LSR be overmolded onto plastic or metal?
Yes. LSR can be molded around compatible plastic or metal inserts; the interface is reviewed at the design stage.
Can LSR be used for thin or detailed molded structures?
Yes, where the design allows. Wall sections, flow and venting are reviewed during the tooling review.
How do you confirm tooling and samples before production?
Tooling follows a mold structure review; first samples are checked for dimensions, material, hardness, color and surface before customer approval.
What information is needed for quotation?
Drawings, CAD files or samples, application and fit requirements, hardness and material expectations, quantities and packaging expectations.
Where to go next
Developing an LSR part?
Send your drawing, reference sample or product idea with the application and estimated quantity. We review the LSR route and reply with the next steps.