Elkem No Post-Curing Liquid Silicone Rubber: A Step Forward in Clean Molding

Direct from Our Lab: Purpose-Built for Modern Manufacturing

Many years of manufacturing have shown us the big difference even the smallest change in chemistry can bring. Our No Post-Curing Liquid Silicone Rubber (LSR) changes the game for factories looking to make reliable, safe parts right out of the mold. We know from experience that traditional rubber compounds often call for a long post-curing step after shaping. Skipping that stage saves more than just energy—every skip avoids extra cycles, extra labor, and the risk of overcuring or yellowing in the final piece. It also minimizes exposure to oven volatiles and helps managers tighten schedules with less downtime between batches.

No Guesswork: Cured Once, Ready for Use

Early experiments with “hot bake only” elastomers always showed problems—shrinkage, surface residue, or low tear resistance kept those products from matching real-world performance. Many factories end up relying on post-curing ovens just to reach safe extractable levels and to push out volatile residues, especially in clean-room and healthcare production. In each project, we saw costly fire risks, worker time spent monitoring bake-out, and energy meters spinning up higher bills. Our team found a smart way around this with the Elkem No Post-Curing LSR series. Using an advanced platinum cure system and strictly controlled compounding, we guarantee that the part is fully crosslinked and free of standard reaction residues as soon as molding is complete. Consistency in every batch comes from obsessive process analytics, so every drum meets the same benchmark. You don’t need to gamble on whether a batch will pass QC or whether it’s ready for sensitive applications.

How It Works in Practice

Over the years, we worked closely with processors and molders to understand the true pain points in silicone part production. With regular LSR, outgassing continues after demolding, filling test chambers with detectable siloxanes and requiring an extra curing stage inside hot air ovens. Running those ovens means waiting twelve or even twenty-four hours before the parts cool—sometimes more for thick walls or deep shapes. By contrast, our no post-curing material means parts drop out of the tool and, once cool, they meet both mechanical and extractives standards. A processor running three-shift production for baby bottle nipples or medical seals can move parts to packaging almost as soon as they are shaped, keeping up with orders that need to ship fast.

What really matters is the evidence coming back from real customers: lower scrap, nearly no rework, and much tighter turnaround. Avoiding post-curing cuts process times by a major margin. If the mold runs clean and dosing equipment stays within set tolerances, the finished part stays clear, odorless, and smooth to the touch without further steps.

Quality You Can Measure

Average extractables from our LSR lines have regularly landed below the detection limits used in FDA and EU food contact tests. Production teams in cleanroom environments have told us that their particle counts in packaging and assembly remain low, with very little surface blooming or condensation of volatiles. The compound reaches its full mechanical strength and tear resistance straight out of the press. Finished goods retain flexibility over a wide span of temperatures, and aging simulation shows no measurable yellowing after accelerated UV or oven exposure.

For medical, pharma, and baby care users, post-curing often remains a regulatory box to check. With our product, test data across hundreds of lots support both biocompatibility and extractives performance without that extra oven stage. The material has gone through the full battery of cytotoxicity, sensitization, and acute systemic toxicity tests. Chemists running validation trials for inhaler seals, infant soothers, or wound care patches have reported outstanding results for each batch. Some customers decide to keep the post-cure ovens as a backup, but after seeing actual performance, they move to single-step curing.

Models and Real-World Differences

As new tooling hits the floor, engineers want predictability in flow, reactivity, and end properties. The Elkem No Post-Curing LSR line includes several models tuned for popular applications: narrow durometer bands for softness or firmness, as well as options with different elongation and tear strength. Each one blends in the same basic platinum-catalyzed backbone, keeping extractive levels low. Instead of generic blends, we define properties based on what actually runs successfully in high-volume settings. A baby bottle manufacturer may choose the 30 Shore A grade for optimum softness and pull strength, while a medical device plant picks the 50 Shore A version for greater firmness and stability in moving parts. Transparency, optical clarity, and surface smoothness hold up batch after batch, even in precision molds with tight dimensions and fine details.

Producers often face challenges making thick-walled or oddly shaped goods, since curing through the wall can lead to uncured centers or defects at the mold face. Standard post-curing silicone often needs the oven just to bring the core up to spec. We have dialed in catalyst rates and filler loadings so our no post-curing grades gel and cure throughout—even for complex cross-sections. Production lines using vented molds and tight process control can trust the whole part, not just the surface, to match product standards. Just-in-time assembly lines can feed these parts straight from forming operations to final assembly or packaging without long cooling racks or overnight bakes.

Why Skip the Post-Curing Step?

Any factory running large volumes knows the cost of delayed shipments or red scrap bins. In the past, skipping post-curing with other silicones meant risking off-odors, tacky residue, or high levels of unreacted silane oils. In medical and baby care, those unreacted species mean failure at regulatory testing, delays in shipping, and loss of customer trust. We have invested hundreds of lab hours tracking every stage: the effect of mixing speed, pressure, and degassing on reaction completion; this is how we hit levels of unreacted residue below global safety limits without the oven. Customers have come back reporting major utility savings: a typical 1,000 kg/month operation using our material can avoid several thousand kilowatt-hours of oven energy. No open-door, high-temperature handling means less risk to staff and less airborne vapor during maintenance.

We have followed regulatory shifts across markets as authorities tighten limits on extractables and unreacted volatiles in food and medical packaging. With older post-cure-dependent materials, last-minute failures in extractives or volatiles mean waste, shipping holds, and sometimes full-scale recalls. Our product gives partners more confidence in passing global safety audits with no need for oven logs or energy-use documentation—cure once, test once, and ship.

Cleaner Processing, Lower Maintenance

Operators in the field spend hours dealing with build-up on mold faces, die lines, and venting from partial reactions in traditional materials. Frequent downtime for cleaning means lost productivity and higher tool wear. By shifting to a formula engineered for single-stage cure, we see less deposit formation, lower exhaust emissions, and less need to vent or purge exhaust stacks. This not only improves part quality but also extends the life of critical process equipment. Ordinary platinum-cure LSR usually leaves a fine film, requiring aggressive solvents or abrasive cleaning. Our customers report cleaning frequency drops from once per shift to once per day, allowing for tighter scheduling and higher productivity targets.

Waste fractions fall because of fewer bad starts at each press cycle. Reduced need for rework or cleaning chemicals brings immediate savings in both raw material costs and environmental burdens. Maintenance teams appreciate the reduction in time spent manually scraping build-up or chasing leaks in ventilation systems. The low-odor, low-emission character of the final part means production can run over weekends or nights without triggering alarm systems or requiring extra ventilation, which can matter in jurisdictions with tight air quality controls.

Performance in Specialized Applications

Designers for infant care products know that every detail—transparency, smell, surface feel—carries major consequences for brand trust. We make sure batches fall within the same narrow color window, avoiding the yellowing or haziness sometimes seen with prolonged baking. We developed the no post-curing system with input from pacifier, bottle, and teething ring manufacturers. Child safe testing—migration of volatile or semi-volatile siloxanes—comes in below detection on standardized tests run at certified external labs. Even at thin section walls under 1.5mm, the tear strength meets or exceeds specifications for safe, reliable use.

In medical device production, failure risk and contamination are not negotiable. Responding to the requests of pharmaceutical closure and inhaler valve makers, our team fine-tuned the platinum-cure balance to eliminate incomplete cure though every critical cross-section. In pilot runs of single-use closure seals, users have measured consistent compression set and no change in surface friction after water or alcohol sterilization. Large-volume, high-value medical assemblies can streamline their workflow: no more segregating “oven stage” batches from “ready” batches and tracing oven records in detail.

Industrial users—especially in electrical insulation and thin-wall seals—have run the LSR grade at scale to make gaskets, O-rings, and vibration dampers. The temperature resistance and dielectric performance never drop below the norms set by traditional platinum-cure rubber, but without the risk of post-cure failures. Parts exposed to heat cycling, splashing oils, or outdoor elements show the same life in accelerated aging. Because the compound reaches full cure at the press, finished goods keep their elasticity and avoid developing surface brittleness often seen after excess oven times.

How Our Manufacturing Approach Makes the Difference

We don’t just offer off-the-shelf formulas. Our in-house chemists have spent years tuning the actual fill system and catalyst dispersion. Every lot gets tracked with in-process NMR analysis, confirming complete cross-linking and ultra-low residual platinum. Samples run through our FTIR and surface energy measurements, confirming that each batch matches the very low extractives profile needed for strict customers.

Real-world manufacturing is never as smooth as the lab. Hot and humid days, raw material shifts, or minor changes in mixing speed all threaten line stability. With this in mind, we revised our internal controls to catch deviations early. Our technical sales team often helps customers dial in shot size, mix speed, and hold times for their own process. With each optimization, we learn new details and send that knowledge back into our next generation of compounds.

Delivering reliability, not just a spec sheet, sets us apart. By choosing to manufacture at scale, with rigorous raw input controls and final property testing, we build confidence for clients who have tight order books and high expectations. It’s not just about chemistry; it’s about long-term partnerships that face tomorrow’s production and regulatory surprises together.

Clear Differences from Conventional LSR

Many standard LSR grades look similar in catalog sheets. The real difference shows up in processing and compliance. While typical LSR needs either a long oven step or accepts much higher extractable content, our product consistently passes the most stringent limits without extra process stages. In side-by-side tests, standard grades often show higher scrap rates from incomplete cure, part discoloration, or failed odor or taste tests. With ours, the process becomes more straightforward: one mold, one shot, one check.

No need to schedule post-cure time or verify oven records. No wrinkles or “overbake hardening” in thin sections. Production yields jump since weak or sticky parts from missed oven cycles no longer creep into shipment. For those who manage safety, process uptime, or reputation risk, the extra security counts for more than a cost line—knowing that each batch will leave the line ready for customer use without rework eases every planning conversation.

Fewer Surprises, More Possibilities

At the end of a long week of production, what plant owners and technical leads care about is batch stability and shipment reliability. Delays from cleaning, scrap, or failed re-tests waste more than time—they erode customer trust and disrupt tight schedules. This LSR system helps eliminate those cycles, giving production leaders a direct route from press to package. Teams once tied down by long post-curing cycles find new room to adjust tooling, fine-tune injection conditions, and tackle more demanding part designs.

By focusing on single-step curing, our product lets line engineers run lighter schedules and focus on what matters: consistent flow, tight control over flash, and quick reaction to shifting production demands. Shorter overall cycle times open space for custom runs, new product trials, or even “lights out” unattended shifts. Maintenance budgets go farther, and regulatory surprise checks become routine instead of a crisis.

Pushing the Industry Forward, One Batch at a Time

As global expectations around clean, efficient, and reliable silicone parts grow, we choose to keep pace by investing in rigorous process controls and new chemistries. Elkem No Post-Curing Liquid Silicone Rubber marks a shift not just for niche uses but for all high-value, high-integrity molded goods. Every improvement in processing efficiency, product cleanliness, and batch reliability lets our partners win more business and solve more of the challenges facing modern manufacturing.

We welcome every challenge our partners send our way. Production lines aren’t just looking for parts—they want confidence, traceability, and a process that stands up to today’s pace of business. Every batch of our No Post-Curing LSR represents those values, built from the ground up by a manufacturing team that listens, learns, and builds for what’s next.