±0.02 mm
Critical-dimension tolerance held on the finished diaphragm seal.
Medical LSR Diaphragm Seal — From Drawing to Mass Production
CYES SILICONE developed a medical liquid-silicone-rubber (LSR) diaphragm seal end to end — drawing review, DFM, cold-runner tooling, mold trials and dimension verification — with measured process capability Cpk 1.24 on the critical inner-diameter dimension (study LSR-MED-007), reported honestly against the common 1.33 target.
Results at a Glance
Measured, Not Claimed
This case is backed by a real internal capability study, not a marketing description. Every number below is a measured result from the LSR-MED-007 study.
Cpk 1.24
Verified capability on the critical inner-diameter dimension (study LSR-MED-007), reported below the 1.33 target.
ISO Class 7
Molded and packed in an ISO 14644-1:2015 Class 7 cleanroom (cert. CR-2026-0714).
Full Lot
Every batch linked from raw material to mold, machine, operator and shipment.
The Seven Fields
Requirement to Result, Documented
We use this seven-field structure for every project we document — requirement, challenge, material, process, quality control, measured result and application — so you can compare like-for-like.
| Project field | This case |
|---|---|
| 1 · Customer Requirement | A medical diaphragm seal with a tight sealing-lip geometry, produced to ±0.02 mm on critical dimensions |
| 2 · Engineering Challenge | Thin-wall LSR flow, gate placement and demolding of a soft sealing lip without distortion |
| 3 · Material Selection | Medical-grade platinum-cured LSR, USP Class VI / ISO 10993 compliant |
| 4 · Manufacturing Process | Cold-runner LSR injection molding in an ISO Class 7 cleanroom with robotic handling |
| 5 · Quality Control | Optical measurement, first-article inspection, OQC and full lot traceability |
| 6 · Measured Results | Cpk 1.24 on the critical inner-diameter dimension (study LSR-MED-007), reported honestly against the 1.33 target |
| 7 · Final Application | Medical device fluid-path sealing component |
Engineering Stages
Six Stages, From Drawing to Production
| Stage | What was done | Key deliverable |
|---|---|---|
| 1 · Drawing Review | 2D/3D engineering review of geometry, draft, parting line and critical dimensions | Approved spec with tolerance plan and material confirmation |
| 2 · DFM | Gate layout, wall-thickness balance and demolding-risk mitigation | DFM report with design changes agreed before tooling |
| 3 · Precision Tooling | S136 mold steel, CNC + EDM machining, cold-runner system | Cavity to ±0.005 mm on critical shut-off / gate features (general cavities ±0.008 mm) |
| 4 · Mold Trial | T0 / T1 / Tn iterations tuning fill, cure and ejection | First-article samples at target dimensions |
| 5 · Dimension Verification | Optical measurement, OQC and batch linkage on critical dimensions | First-article inspection report and Cpk study (1.24) |
| 6 · Mass Production | ISO Class 7 cleanroom molding, robotic handling, OQ validation | Repeatable production lots with full traceability |
Material: medical-grade platinum-cured LSR · Tooling: S136 steel with cold-runner · Finished tolerance: ±0.02 mm critical dimensions. Full DFM, FAI and Cpk reports are available on request under NDA for qualified projects.
Honest Scope Note
What This Case Shows — and Does Not
What it demonstrates
A documented, end-to-end development of a medical LSR seal — from drawing review through cold-runner tooling to a measured Cpk 1.24 on the critical dimension — with full lot traceability and ISO Class 7 production.
What it does not claim
The measured Cpk 1.24 sits below the common 1.33 target, and we report that honestly rather than rounding up. The definitive verification for a given part is the complete re-validation report with full multi-batch trend and sample sizes, provided under NDA.