UL Listed Closed Cell Sponge Rubber with Adhesive

What is the significance of using UL 50E / UL JMLU2 listed gasket materials?

Under Underwriters Laboratories (UL) standards for electrical equipment enclosures (UL 50E), every component forming the perimeter environmental seal must undergo extensive testing for tensile strength, elongation, accelerated heat aging, oil immersion, and ozone degradation. Utilizing CGR Products’ certified CGR 8002 or CGR 5031 materials means the sponge elastomer and the acrylic adhesive system have already been tested, validated, and listed under UL Category JMLU2 (Gaskets and Seals). This pre-certification significantly shortens UL agency approval timelines and prevents costly recertification testing for enclosure OEMs.

What is the difference between CGR 8002 and CGR 5031?

The primary difference is the base elastomer chemistry and environmental oil resistance:

• CGR 8002: A closed-cell Neoprene / EPDM / SBR blend engineered for standard outdoor and indoor NEMA 4, 4X, 12, and 13 enclosures. The EPDM content delivers exceptional resistance to UV weathering, ozone cracking, and thermal extremes, making it the most cost-effective all-weather choice.
• CGR 5031: A 100% pure closed-cell Neoprene (chloroprene) sponge. It provides significantly higher resistance to oils, greases, synthetic lubricants, and industrial refrigerants. It is specified for NEMA 12/13 industrial control panels, factory automation enclosures, and machinery consoles where exposure to cutting oils or hydrocarbons is prevalent.

Why must the adhesive backing be included in the UL gasket listing?

UL standards require that the adhesive backing bond reliably to the enclosure substrate (painted steel, stainless steel, aluminum, or polycarbonate) across temperature cycling without delaminating, creeping, or sliding under gasket compression. A raw rubber sponge cannot simply be paired with an unlisted tape; the specific combination of sponge, carrier, and pressure-sensitive acrylic adhesive must be certified as a complete system under UL JMLU2. CGR 8002 and CGR 5031 are certified and supplied with pre-applied acrylic PSA tested for long-term adhesion retention.

What compression range is recommended to maintain a NEMA 4 or 4X seal?

To achieve a watertight, dust-tight seal compliant with NEMA 4/4X and IP65/IP66 enclosure ratings, closed-cell sponge gaskets should typically be compressed between 25% and 35% of their original nominal thickness. Compressing less than 20% may allow water intrusion along irregular enclosure door flanges, while over-compressing beyond 50% can rupture internal microcellular walls, leading to compression set fatigue and water path leaks over repeated open-close door cycles.

What fabricating formats are available for CGR 8002 and CGR 5031?

CGR Products fabricates UL-listed sponge materials into three primary presentations:

• Slit Stripping & Continuous Rolls: Slit to custom widths from 1/4″ wide upward with continuous acrylic PSA and extended peel liners for manual or automated channel laying.
• One-Piece Continuous Die-Cut Gaskets: Precision-stamped or waterjet-cut frame gaskets that eliminate spliced corner joints, preventing leak paths at corner radii.
• Kiss-Cut Parts on Continuous Liners: Pre-cut strips or corner pads supplied on continuous silicone rolls for rapid operator assembly on production lines.