Focused On Soft Silicone O Ring For 20 Years

Ultra-Soft Silicone O-Rings: 10A to 40A Shore A

The ultimate sealing solution for delicate assemblies. Stop cracking fragile plastics and fighting stiff rubber on the assembly line. Engineered for micro-clamping forces, our ultra-soft silicone perfectly conforms to rough surfaces, eliminates manual installation fatigue, and stays resilient in deep-freeze environments.

When 70 Durometer is Just Too Hard

For precision instrument designers and high-volume assembly lines, a standard 70A O-ring is a liability, not a solution. Traditional hard rubber demands excessive physical force, leading to broken parts, leaking micro-scratches, and exhausted workers.

RiseUp manufactures custom soft silicone o rings (ranging from ultra-soft 10A to 40A) specifically engineered to solve the 4 biggest physical balancing acts in precision sealing:

• Zero Housing Deformation (Low Closure Force): Stop breaking your designs. If you are sealing thin-walled plastics, delicate glass, or lightweight stamped metals, our soft rings require only a fraction of the compressive force. You achieve a perfect, leak-tight seal with a “light touch” that never cracks or warps your precision housing.
• Micro-Surface Conformity: Is your mating surface unpolished or slightly scratched? Hard O-rings bridge across these microscopic valleys, causing leaks. Our 20A-30A silicone acts like an elastomeric sponge, flowing deeply into machining imperfections to guarantee an absolute seal on less-than-perfect surfaces.
• Assembly Ergonomics (Eliminate Finger Fatigue): Installing thousands of stiff O-rings manually destroys assembly line efficiency and causes severe finger fatigue. Our ultra-soft compounds feature massive elongation and low tensile resistance. Workers can stretch and snap them into tiny grooves effortlessly, drastically speeding up production.
• Low-Temp Stiffening Defense: Most elastomers rapidly harden and lose their rebound when the temperature drops. If your device operates in cold storage or high altitudes, starting with a 30A soft silicone ensures that even when the cold sets in, the seal remains highly flexible, maintaining critical compression against the housing.

Conquering High Surface Energy: Micro-Friction for Automated Assembly

The inherent physical flaw of a 20A or 30A soft silicone o ring is its exceptionally high surface energy. The low cross-link density allows low-molecular-weight siloxanes to create strong Van der Waals forces, making the surface aggressively tacky (Dynamic Coefficient of Friction, COF > 1.5). This causes O-rings to clump in vibratory bowl feeders, jam automated pick-and-place nozzles, and roll out of the gland during male/female insertion.

RiseUp neutralizes this surface energy without compromising the ultra-soft core elasticity. We offer engineered surface modification protocols:

Sub-Micron Parylene C Deposition: For critical medical and optical devices, we apply a vapor-deposited Parylene C conformal coating. At just 2 to 5 microns thick, it completely seals the silicone surface, dropping the dynamic COF to <0.2 while strictly maintaining your micro-level CS (Cross-Section) tolerances.
Plasma Surface Fluorination: For high-volume consumer electronics, our proprietary plasma gas treatment permanently alters the chemical structure of the outermost molecular layer, creating a dry, slick, “Teflon-like” feel with zero risk of flaking or outgassing.

Hyperelastic Load Distribution & Gap Extrusion Defense

Sealing a thin-walled plastic sensor or a 0.5mm glass lens requires a precise understanding of non-linear hyperelasticity. A generic 70A O-ring requires roughly 40-50 lbs/linear inch to achieve a 20% static squeeze—a load that will instantly crack a fragile housing.

Our 20A Durometer compound shifts the stress-strain curve dramatically, achieving the exact same 20% volumetric gland fill at just 8 to 12 lbs/linear inch. However, designing with ultra-soft silicone requires strict engineering discipline regarding two critical factors:

Extrusion Gap (Clearance) Control: Soft silicone (under 40A) flows easily under pressure. If your hardware clearance (extrusion gap) exceeds 0.05mm, the soft ring will nibble and extrude into the gap. Our engineers will review your CAD drawings to calculate the exact maximum diametral clearance allowed for your operating pressure.
Defeating Compression Set: Traditional soft gums take a terrible “set” (permanently flattening out) because they lack structural density. We utilize a high-consistency, platinum-catalyzed matrix combined with a rigorous step-cured post-baking algorithm. This ensures our 20A rings maintain an industry-leading Compression Set resistance (<15%), bouncing back instantly even after years of continuous micro-compression.

Overcoming the Molding Barrier: LSR Precision for Ultra-Soft Rings

Specifying a 20A soft compound is only half the battle; manufacturing it is where generic suppliers fail. Traditional High Consistency Rubber (HCR) compression molding is ill-suited for ultra-low durometer materials. When a 20A ring is forcefully ejected from a heated compression mold, its low tear strength causes it to stretch, deform, or tear completely. Furthermore, the massive parting lines (flash/burrs) left behind become immediate leak paths in micro-groove applications.

RiseUp utilizes state-of-the-art [Liquid Silicone Rubber (LSR) Injection Molding] to bypass the physical limitations of traditional molding, delivering flawless precision even at 10A Shore A.

The LSR Advantage for Micro-Sealing:

Flash-Free Parting Lines: LSR is a closed-loop, high-pressure injection process. The liquid polymer fills microscopic mold cavities with absolute uniformity, producing zero-flash (burr-free) O-rings. This guarantees that your optical lens or medical pump seals perfectly without jagged parting lines interfering with the mating surface.
Micro-Tolerance Capabilities: Wearable devices and smartwatches often require miniature rings with Cross-Sections (CS) as small as 0.5mm. LSR injection allows us to maintain extremely tight ISO 3302-1 Class M1 tolerances, ensuring your micro-rings sit perfectly in their miniature glands without bunching.
[Platinum-Cured Purity (USP Class VI)]: Our ultra-soft LSR matrix is exclusively platinum-catalyzed. It cures completely without any peroxide byproducts, resulting in an odorless, non-leaching, and biologically inert seal that passes the strictest FDA and USP Class VI biocompatibility tests for medical wearables and fluid transfer.

Stop Guessing. Validate Your Closure Force with Our Engineering Sample Kit.

Do not risk cracking your expensive prototypes or jamming your automated assembly lines with generic, tacky rubber. Designing for fragile plastics, optical lenses, or medical wearables requires physical validation. You need to feel the micro-clamping force and test the insertion friction on your actual hardware.

Partner with RiseUp’s elastomer engineers. Instead of blindly guessing the correct durometer, let us send you a comprehensive Soft Silicone Matrix Kit. Test the exact compressive load, verify our anti-tack surface treatments in your bowl feeders, and experience true LSR micro-precision in your own lab.

• ✔️ Durometer Matrix Testing Kit (10A, 20A, 30A, 40A Shore A)
• ✔️ Anti-Tack & Parylene Coated Samples for Automation Testing
• ✔️ Flash-Free LSR Micro-Rings for Wearables & Optics
• ✔️ Free CAD Review & Extrusion Gap (Clearance) Calculations