The vast majority of the issues related to silicone materials do not appear in the datasheet, but in the behavior of the part after weeks or months of actual use. There is no use in staring at a perfect-looking TDS days, until that material has been molded into a actually part until it has been tested under the exact conditions it will be subjected to and then run through a small production batch.
Using paper specifications and a few visual samples is one of the most widespread-as well as costly-mistakes in silicone product development. Validation is not a by-product when the tooling is cut. It is the last, and most important step of your silicone material selection process. Until it passes through testing, prototyping and at least one pilot run without exposing any unacceptable failures, a silicone material is not really chosen. Validation should also be considered a part of material selection, not the process that you undertake once you have already made a decision.
Why Validation Matters More Than Most Teams Realize
In actual projects I have observed, compression-set failure, odor variation or dimensional drift were often detected only after the original 10,000 pieces were already in the warehouse. At that point the cost of changing material or redesigning the mold can easily go into the six figures. An organized decision-making process (lab tests, functional prototypes, and pilot runs) transforms guesswork into a disciplined decision-making process and reduces to near zero the risk of redesigns, recalls, or customer complaints.
Where Validation Fits in the Silicone Material Selection Process
Validation falls in-between initial sample testing and mass production approval. Bridge is what transforms a shortlisted grade into an industrial grade. This is the sequence of steps followed by most successful projects:
| Stage | Main Question | What Happens with Silicone Material |
| Initial screening | Is this grade theoretically suitable? | Check TDS, certificates, basic fit |
| Sample evaluation | Does it look and feel right? | Small sample parts, basic checks |
| Validation testing | Does it survive realistic stress? | Lab tests and functional tests |
| Pilot run | Can we manufacture consistently? | Short production run under real conditions |
| Mass production | Can we run this reliably at volume? | Ongoing quality monitoring |
The difference between the projects that go live with ease and those that get stuck in the costly loop is the idea of validation as a defined stage (as opposed to an optional step). When you need a more in-depth overview of the entire process of selecting a particular silicone material, our silicone material selection guide walks through the entire process from concept to final approval.
Step 1 — Define What You Need to Prove Before You Test
Do not begin to test, before you have jotted down the actual dangers which your part will meet in the field. Testing everything wastes time and money, targeted testing saves both.
Start by listing all the failure modes that might actually occur: the seal loses its force, the wearable strap tears, the kitchen utensil discolors after being subjected to multiple dishwasher cycles, or the baby product develops an off-odor after being sterilized.
Turn those risks into convincing points of proof.
| Potential Risk | What You Need to Prove |
| Seal loses force over time | Compression set and elastic recovery |
| Part cracks or tears during use | Tensile strength, elongation, tear resistance |
| Part smells bad or picks up odors | Cure system, post-curing, odor testing |
| Discoloration or yellowing | UV/heat aging behavior |
| Safety in contact with food / skin | Relevant FDA/LFGB-type tests and certificates |
Take 30 minutes with your team and have them write these questions down. That individual document will be your validation plan.
Step 2 — Plan Focused Material Tests (Not Just “Test Everything”)
After identifying the risks, only the tests that are important should be selected. These are the most popular ones and the time when they do count.
| Test Type | What It Measures | When It Is Especially Important |
| Shore A hardness | Softness/stiffness of the silicone | Feel, fit, sealing force |
| Tensile strength | Strength before breaking | Parts under stretching or pulling |
| Elongation at break | Ability to stretch without tearing | Flexible parts, wearable components |
| Compression set | Permanent deformation after compression | Seals, gaskets, cushions, keypads |
| Aging / heat aging | Property change over time and temperature | High-temp, long-life products |
| Chemical resistance | Behavior in contact with oils/chemicals | Automotive, industrial, personal care products |
The trick here is to establish test conditions that are equal or higher than real-life applications. Assuming that your part will be operated in a car dashboard at 80 o C, test at 100 o C to determine the expected lifetime hours. The results of tests on silicone parts at room temperature are nearly useless as far as how to test silicone parts in the real world.
(If you are still learning the fundamentals, start with what silicone rubber is and how its properties affect selection before diving deeper.)
Step 3 — Build Functional Prototypes That Use the Right Silicone
The material is indicated in flat test slabs. Real geometry informs you of the part.
Apply the same (or nearly the same) molding process you intend to use in production–compression molding, LSR injection, or overmolding–because the cure rate, wall thickness and flow behavior varies and alters the final performance.
| Prototype Type | What It’s Good At | Limitations |
| Simple lab samples (slabs, dumbbells) | Measuring basic material properties | Do not reflect geometry or actual molding |
| Visual mock-up parts | Checking look and basic feel | Not always made from the final silicone grade |
| Functional molded prototypes | Testing fit, function, and material behavior | Higher cost/lead time but closest to reality |
Functional prototypes are where you initially find out that a material that had passed lab tests still defied or stuck in the shape of the actual part.
Step 4 — Test Prototypes Under Realistic Use Conditions
Bench testing at 23 C tells you virtually nothing whether the product will be subjected to 80 C, -20 C, UV or daily exposure to soap and oils.
Write straightforward, but purposeful tests:
- Compression/release many times over, results in long-term sealing behavior and tactile sensation.
- Flex and pull cycles – resistance to cracking and permanent deformation.
- Absorb in applicable fluids (detergents, oils, cosmetics) → swelling, softening, surface variations.
- Cycles of exposure to heat/cold ⇒ hardness, color, elasticity with time changes.
Certain problems are not manifested until 7-14 days. Arrange your test timetable.
For deeper insight into long-term behavior, see how temperature cycling and aging affect silicone performance.
Step 5 — Run a Pilot Batch to Check Manufacturing Reality
A pilot run is the initial occasion on which you produce dozens or hundreds of parts under conditions which are nearly production. This is where the process stability comes into its true colors.
| Pilot Run Focus | What to Monitor |
| Process stability | Cycle time, cure consistency, scrap rate |
| Dimensional consistency | Tolerances, warpage, shrinkage |
| Material property variation | Hardness, compression behavior, visual defects |
| Surface and aesthetics | Bubbles, flow marks, color consistency |
Document everything. One ignored flow indication or minor hardness movement can be a quality nightmare when played in full volume.
Step 6 — Decide Whether Your Silicone Material Has Truly Passed
Validation is terminated with a decision and not a pile of reports.
| Outcome from Validation | Recommended Action |
| All tests and pilot runs acceptable | Approve material for mass production |
| Minor issues but controllable | Approve with notes and process controls |
| Repeated failures or safety concerns | Revisit material choice or design |
Call in time when you still have time to revise the grade or modify the design. When it comes to mass production tooling, once it is cut, the cost of correcting any problems increases.
Common Validation Mistakes Teams Make with Silicone Materials
These are the most frequently occurring mistakes that I have witnessed over the years as project watchers:
- Using a single sample to demonstrate that the material is fine under all circumstances.
- Bypassing compression-set or long-term aging tests to seal parts.
- Only testing at room temperature when the product will be exposed to heat, cold or chemicals.
- Ignoring the difference between prototype molding process and final production process.
- Conducting a pilot batch but not quantifying anything in a systematic manner.
- Granting approval to material prior to confirmation that it complies with food-contact or skin-contact standards when used in actual application.
- Hurrying validation to release on a particular launch date, then having to pay for it later with field failures.
Conclusion — Validation Turns a Guess into a Controlled Decision
Validation does not concern being perfect. It is the wise, low risk choice that you make before you invest in costly tooling and mass manufacture. By taking focused lab tests, functional silicone prototypes, and a well-run pilot batch, you greatly decrease the likelihood of unpleasant surprises once you launch.
The validation flow of structured silicone material testing, prototyping, and pilot running will give you the confidence that whatever you have on paper will work in real world. It is this belief that can make the difference between a successful product launch and an expensive recall.
Take the time to validate properly. Your future self (and your customers) will thank you.
