Custom LSR Molded Parts
Source finished components to your drawing and material specification. Define quantities, critical features, appearance, sample approval, and inspection requirements for initial and repeat production.
China Precision Tooling Company
Translation
» Liquid Silicone Rubber Molding
Custom silicone components & complete molds
Liquid Silicone Rubber Molding
Custom Silicone Components for Sealing, Flexibility & Functional Performance
GPT Precision provides custom liquid silicone rubber (LSR) molding services for components manufactured to customer drawings and specifications. We supply both finished LSR parts and complete LSR molds.
PHOTO TO FOLLOWCustom LSR seals, membranes & protective componentsApproved production photography pending
Functional review
Start with what the part needs to do.
Connect material properties, critical geometry, assembly fit, and operating conditions before committing to tooling.
SealingCompression and mating surfaces
FlexibilityMovement and elastic recovery
FitCritical geometry and assembly
ServiceTemperature, media, and repeated use
LSR Parts or a Complete Mold
Complete LSR Molds
Source a complete mold for your designated production facility. Provide the receiving machine and material-delivery interface requirements, together with trial, acceptance, handover, and documentation needs.
State whether your inquiry covers finished parts, a complete mold, or both. Tooling ownership, included trials, maintenance responsibilities, and any transfer requirements should be recorded in the agreed scope.
Custom LSR Molded Components
The part name is a starting point. Its function within the finished assembly determines the material and manufacturing requirements.
PHOTO TO FOLLOWRepresentative silicone component familiesApproved production photography pending
Seals & Gaskets
Molded seals and custom gaskets for mating surfaces. Review compression, groove geometry, compression set, service media, and leakage requirements.
Membranes & Diaphragms
Flexible components that deflect or respond to pressure. Define thickness, movement, pressure differential, repeated-use requirements, and tear-sensitive transitions.
Valves & Flow-Control Components
Flexible valve elements and sealing discs. Identify opening and closing behavior, seat geometry, pressure conditions, and fluid exposure.
Protective & Contact Components
Covers, boots, pads, buttons, and protective interfaces. Consider retention, tactile response, surface texture, environmental exposure, and appearance.
LSR Material Selection
Hardness alone does not define sealing performance, tear resistance, compression set, or durability. Specify the conditions in which the finished part will work.
| Property | Why it matters | Information to provide |
|---|---|---|
| Hardness | Flexibility, deformation, and contact response | Target Shore hardness, tolerance, or reference sample |
| Tensile & tear properties | Stretching, thin features, and demolding | Expected strain, feature geometry, and failure concerns |
| Compression set | Behavior under sustained compression | Compression, temperature, and service duration |
| Temperature & media | Suitability in the operating environment | Temperature range, exposure time, fluids, and cleaning agents |
| Color & appearance | Visible and contact surfaces | Color, transparency, texture, and appearance limits |
General-Purpose LSR
Select a grade that meets the required mechanical and environmental conditions.
Application-Specific Grades
Identify supporting documentation and material specifications for the intended use, including relevant medical or food-contact requirements.
Self-Bonding LSR
Review the compatible substrate, bonding method, curing conditions, and required retention performance.
Specialty Grades
Discuss optical properties, modified chemical resistance, or other specific performance requirements.
These categories describe material-selection possibilities, not a list of grades automatically available for every project. Provide the manufacturer and exact grade where known; otherwise, describe the required performance.
Design for LSR Molding
Low-viscosity flow and elastic behavior create distinct requirements for tooling, part release, and finished-part acceptance.
Define the functional surfaces.
Mark sealing regions, mating features, and cosmetic faces on the drawing. These priorities guide the tooling and inspection review.
Wall Thickness & Transitions
Review thin membranes, flexible lips, and thicker sections together. Filling, curing, deformation, and release depend on the selected material and geometry.
Parting Lines & Flash
LSR can flow into very small gaps. Identify flash-sensitive sealing lips and interfaces, and agree acceptable edge conditions before tooling.
Undercuts & Demolding
Elasticity permits some undercuts to release, but deep features or thin sections may stretch excessively or tear. Review draft, release direction, and surrounding geometry.
Shrinkage & Dimensions
Use material- and process-specific allowances. Identify critical dimensions, datums, measurement conditions, and any required fixtures.
Gates, Venting & Surfaces
Consider filling and air evacuation alongside functional areas. Identify where gate marks or surface interruptions are unacceptable.
LSR or Thermoplastic Elastomer?
| Decision factor | LSR | TPE |
|---|---|---|
| Processing | Thermoset material cured in a heated mold | Generally melt-processed and solidified through cooling |
| Service performance | Evaluate the grade for temperature, media, and compression set | Compare the chosen TPE family under equivalent conditions |
| Reprocessing | Cured material cannot be remelted | Some grades permit melt reprocessing, subject to restrictions |
| Application evidence | Documentation must match the grade and intended use | Documentation must match the grade and intended use |
Compare candidate grades against the same operating conditions. Neither material family is universally better.
From Drawing Review to Production
Review Requirements
Provide drawings, part function, material requirements, operating conditions, and quantities. Identify unresolved design decisions.
Define Material & Tooling
Review the grade, cavity arrangement, manufacturing approach, and approval requirements. For complete molds, include receiving-equipment compatibility.
Evaluate Initial Samples
Check dimensions, appearance, material requirements, and agreed functional performance. Identify any tooling, process, material, or design changes.
Approve the Supply
Confirm the approved revision and deliverables: production parts with agreed inspection, or a complete mold with agreed trial and handover records.
LSR is typically metered and mixed as a two-component material, injected into a heated mold, and cured. Unlike conventional thermoplastic molding, it sets through curing rather than melt cooling. Tooling investment, cavity arrangement, quantities, and inspection needs should be evaluated together.
Quality & Functional Verification
Link approval criteria to what the component must do. Dimensions alone may not establish the performance of a flexible part.
Dimensions & Appearance
Review critical dimensions, profile, surface condition, flash, and drawing-defined features. Agree measurement methods, fixtures, and support conditions where required.
Material Verification
Confirm the specified grade and required supporting records. Where hardness or other properties form part of acceptance, define the test method and limits.
Functional Evaluation
Project requirements may include leakage, compression recovery, movement, repeated actuation, assembly fit, or exposure testing. Availability, methods, limits, and reporting are agreed per order.
Records & Traceability
Specify material certificates, dimensional reports, first-article records, or batch traceability during quotation. Establish documentation scope before production.
PHOTO TO FOLLOWInspection of an LSR componentApproved production photography pending
Inspection methods and support conditions should avoid unintended deformation of flexible parts.
Common Engineering Questions
Prepare the initial review around your drawing, intended use, and acceptance requirements.
What hardness is suitable for my component?
Hardness depends on function, geometry, compression, and the operating environment. Provide a specified grade or Shore A value where known; otherwise, describe the required behavior and include reference samples if available.
Can you supply a complete LSR mold?
Yes. GPT Precision supplies both finished LSR components and complete LSR molds. For a mold intended for your facility, include receiving-equipment interfaces, trial requirements, acceptance criteria, and handover documentation.
Can LSR be molded with plastic or metal components?
Selected grades and substrates can support multi-material components. Review substrate compatibility, processing temperature, bonding or mechanical retention, geometry, and performance for the specific project.
Does LSR require post-curing?
Requirements depend on the material manufacturer’s guidance, processing conditions, and application. Where needed, define the treatment and acceptance criteria in the specification.
Can LSR meet medical or food-contact requirements?
Specific grades may have documentation for particular applications. Suitability must be established for the exact grade, intended use, processing conditions, and required evidence. The terms silicone, LSR, or platinum-cured alone do not establish compliance.
Discuss Your LSR Molding Project
Custom LSR components and complete molds, with the supply scope defined around your project.
Part Definition
Send the 2D drawing or 3D model, revision, critical dimensions, and sealing or mating surfaces. Include assembly information where it clarifies function.
Material & Performance
Specify the grade or hardness, color, operating temperature, service media, and compression or movement requirements.
Quality & Approval
Identify sample approval criteria, testing, inspection, documentation, and applicable material requirements.
Supply & Quantity
State parts, a complete mold, or both. Include quantities, repeat demand, milestones, and mold receiving-equipment details where applicable.
Share your drawings and project requirements to begin a manufacturing review. If the material or design is still open, identify the decisions that need further discussion.
Service
