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LSR Academy

A liquid silicone curriculum in engineering order: from material science through design and tooling to processing and validation. Conclusion first, mechanism second, verifiable criteria last.

CURRICULUM

Six-part curriculum

Customers don't search for product names — they search for problems. We answer those problems in order: materials → design → tooling → processing → validation. 25 articles planned, one new piece every two weeks, in both Chinese and English.

I1 of 6 live · updating

Materials ScienceMATERIAL SCIENCE

The molecular nature and property boundaries of LSR — the basis for every process judgement that follows.

01 Chemical nature (live — read now) 02 Platinum cure · in writing 03 Reading datasheets · in writing 04 Heat & aging · in writing 05 Food & medical compliance · in writing 06 LSR / HCR / RTV · in writing
IIPlanned

Part DesignPART DESIGN

Translating use requirements into manufacturable geometry — walls, shrinkage, draft and overmold interfaces.

01 Design rules　02 Shrinkage & tolerance　03 Overmold structure　04 Common design mistakes
IIIPlanned

Mold EngineeringMOLD ENGINEERING

What separates an LSR mold from a plastics mold is not precision — it is the cold runner, venting and the thermal field.

01 vs plastics molds　02 Cold runner systems　03 Venting & vacuum　04 Ejection & demolding　05 Steel & surface treatment
IVPlanned

Mold MakingMOLD MAKING

From manufacturability review to trial-shot correction — how a mold actually gets built.

01 DFM review　02 Mold design & layout　03 CNC / EDM / polishing　04 Trials & corrections
VPlanned

ProcessingPROCESSING

Dosing, mixing, injection, cure — how to build the process window and how to debug defects.

01 Metering & mixing　02 Injection & cure curve　03 Building the window　04 Defect atlas & fixes
VIPlanned

Quality & ValidationQUALITY & VALIDATION

Proving this batch matches the last one — and still will in three years.

01 Inspection & sampling　02 Aging & cycling　03 FAI & batch consistency
All Materials Process Selection Applications
Process analysis · Long read
PP overmolding: the hard part
isn't the trial shot. It's part 100,000.
9 min read · U-WECAN process team
PROCESS

Why PP + silicone overmolding is hard: interface, heat and the 70-boil cycle

Low surface energy is only the first gate: PP's heat limit sits under LSR's cure temperature, and the primer has to resist hydrolysis. How delamination and warpage happen — plus the full 18-month, dozens-of-combinations route to a fixed recipe.

Read the article →
Materials · 01

What is LSR? From the Si–O backbone to injection molding

Why LSR survives -50 to 230°C, why it can be as soft as Shore A 0, why the body accepts it — three capabilities, three different origins in the chemistry. Includes a datasheet-reading guide and an LSR / HCR / RTV selection table.

10 min read
Selection

LSR vs. solid silicone: how to choose

Liquid is not automatically better. Decide on volume, geometry complexity, tolerance and cost — with a comparison table.

In preparation · call us in the meantime
Selection

Medical-grade LSR: hardness, certification and sterilization

How to specify Shore hardness, what ISO 10993 and ISO 13485 each cover, and how EtO and gamma sterilization affect the compound.

In preparation · call us in the meantime
Process

Cold runner, venting and parting line: how tooling decides yield

Same part geometry, a slightly different mold design, a materially different yield. Three tooling details that get overlooked.

In preparation · call us in the meantime
Applications

Silicone-over-PPSU bottles: bond structure and leak-tight design

PPSU takes high temperatures but has an inert surface. How to design the overmold so it neither delaminates nor leaks, and still survives repeated sterilization.

In preparation · call us in the meantime
Applications

Silicone parts in assisted reproduction devices: low volume, high demands

This niche does not consume large volumes, but its requirements on material purity, batch consistency and traceability often exceed those of standard medical parts.

In preparation · call us in the meantime
QUICK ANSWERS

The three questions we hear most

Short answers here; the long form is in the articles.

LSR or solid silicone — how do I choose?
Liquid silicone rubber is a two-component platinum-catalyzed system with low viscosity, injection molded — suited to thin walls, tight tolerances, high cavitation and overmolded structures, curing fast with no by-products. Solid silicone (HCR) needs compounding, cutting and compression molding or extrusion, and suits large, thick or low-volume parts. The decision order: can the geometry be ejected cleanly → what tolerance is required → what volume and unit cost.
Why can't most plants run PP overmolding at volume?
PP is a low-surface-energy, non-polar semi-crystalline plastic with almost no chemical affinity for silicone; it also crystallizes fast and carries high internal stress, so adhesive failure, blistering and delamination tend to appear only once volume ramps. Holding it requires substrate-specific surface treatment, a dedicated process window, and continuous adhesion and aging validation — all three take time, which is why samples are common and sustained volume is not.
What certification do medical silicone parts need?
At system level, ISO 13485 medical device quality management is normally required. At material level, ISO 10993 biocompatibility testing applies, with the specific tests set by the type and duration of body contact. Production normally requires a cleanroom and batch traceability. We hold both ISO 13485:2016 and ISO 9001:2015.

Is a specific project stuck on material or process?

Faster than reading: describe the geometry. Send the drawing, the service environment and the validation requirements, and we will give you a judgement for your case.

Talk to an engineer