Uncured Silicone Compound

ElastaPro supplies high-quality uncured silicone compounds (unvulcanized silicone rubber) catalyzed and ready for immediate fabrication. Sourced and processed in the USA, our materials are available rolled up off the mill or in sheet preforms (approximately .250″ thick) protected by a poly liner.

Whether your process requires compression molding, transfer molding, liquid injection, calendering, or extrusion, we provide custom-formulated masterbatches and specialized preforms to optimize your machine loading and processing efficiency.

Technical Specifications and Compliance Standards

Our specification-grade uncured silicone compounds meet rigid aerospace, defense, medical, and industrial standards.

• Elastomer Formulations: VMQ (Vinyl Methyl Silicone), FVMQ (Fluorosilicone), PVMQ (Phenyl Vinyl Methyl Silicone), and custom hybrid blends.

• Industry Callouts & Certifications: AS9100D, ISO 9001:2015, ITAR Registered, 3-A Sanitary, FDA/BgVV compliance, USP Class VI, ISO 10993, UL 94V-0, and FAR 25.853.

• Military Specifications: A-A-59588 (superseding MIL-R-5847), AMS-R-25988, AMS, ASTM D1056, ASTM E595, BMS, DMS, and PWA.

Platinum vs. Peroxide Cure Systems

The choice of catalyst system dictates both the processing constraints and the final mechanical properties of your cured components.

Platinum-Cured Systems (Addition Cure)

• Advantages: Odorless, tasteless, exceptional optical clarity, superior surface finish, and higher tear strength. Ideal for medical devices, food contact applications, and high-performance industrial sealing.

• Processing Note: Requires strict environment control to avoid catalyst inhibition from contact with sulfur, amines, or tin.

Peroxide-Cured Systems (Free Radical/Cure)

• Advantages: Excellent compression set resistance, longer material shelf life, and robust processing tolerance. Highly cost-effective for general industrial gaskets, automotive boots, and complex custom molded parts.

• Processing Note: Often requires a post-cure cycle to eliminate volatile byproducts and optimize physical properties.

5 Critical Factors for Fabricating Uncured Silicone

When sourcing raw, unvulcanized silicone rubber for custom fabrication, optimizing these parameters ensures part quality, processing safety, and minimized scrap rates:

1. Ingredient Dispersion and Consistency

Uncured silicone compound relies on a precise blend of raw polymer bases, fillers, heat stabilizers, flame retardants, and processing aids. Complete, homogeneous dispersion on the mill is vital. Poor dispersion creates localized weak points, uneven durometer readings, and aesthetic surface defects across your finished gaskets or profiles.

2. Catalyst Selection & Shelf-Life Boundaries

The choice of catalyst dictates storage conditions and processing windows. Typical shelf-life windows range from 90 to 180 days under standard ambient storage.

Pro Tip: Controlled refrigeration extends compound shelf life by an estimated 50%, delaying premature scorching (bin cure) without altering the compound’s chemical matrix.

3. Preform Configurations for Machine Loading

To maximize throughput and streamline material handling, ElastaPro supplies uncured compounds in specific preform formats tailored to your equipment:

• Wig-Wag / Continuous Strips: Optimized for continuous feed extrusion lines.

• Pigs / Logs: Sized for quick transfer and injection molding cylinder loading.

• Slabs & Slit Sheets: Pre-cut sheets (nominally .250” thick with protective poly liners) designed for quick die-cutting or direct compression molding cavity placement.

4. Cure Profile Optimization (Time vs. Temperature)

Thermoset vulcanization time is a direct variable of the specific catalyst chemistry, cross-linking temperatures, and cross-sectional part thickness. For high-precision parts, executing Rheological Studies (using a Moving Die Rheometer or MDR) establishes the exact scorch time, cure rate, and optimal time/temperature curve needed to prevent under-curing or thermal degradation.

5. Color Matching and Post-Cure Shifting

Custom colors are available to support unique brand aesthetics or component coding. However, color-matching evaluations must always happen after full vulcanization. Uncured silicone matrix compounds often undergo a distinct visual shift in hue, opacity, or intensity once subjected to high-temperature cross-linking.

Custom Compounding & RFQ Support

ElastaPro partners with custom molders, extruders, fabricators, and manufacturing engineers to deliver predictable, high-performance unvulcanized bases. From high-strength extreme low-temperature fluorosilicones to electrically conductive grades, we compound to your exact specifications.

Looking for a specific callout or custom preform? Contact us today to review your application parameters and request an engineered quote.