US DESIGNER and manufacturer of seals and sealing devices firm, Apple Rubber Products, offers two new silicone compounds with UL 50 and UL 50E certifications for use with and without environmental considerations.
UL 50 and UL 50E are the safety standards for seal use with enclosures for electrical equipment, and Apple Rubber has selected two silicone compounds, 14SL7ML and 35SL5ML, to provide to customers who require products with these certifications. These compounds provide an ultra-low compression set, even at elevated temperatures, and offer the quality and durability customers need for safe operations.
Included in the UL 50 and UL 50E listings are end uses for atmospheric ozone and generated ozone, therefore eliminating any environmental concerns due to ozone attacks. These compounds don’t contain any phthalate plasticisers, which would craze plastic-based enclosures, or require any anti-corrosion inhibitors for metal enclosures. They are also cured without sulfur or peroxide to allow very little residue that may outgas and corrode electrical components.
Apple Rubber has also tested 14SL7ML to ASTM E 595, which is the standard for outgas testing. The results fell well within the screening levels for spacecraft materials, which are less than 1% total mass loss (TML) and less than 0.1% collected volatile condensable materials (CVCM). The results for 35SL5ML were a TML of 0.33% and 0.05% CVCM.
The compounds provide one of the largest temperature ranges, says Apple Rubber, allowing for use in environments where temperatures are between -65°C and +200°C. Also, to provide even more flexibility for design engineers, these compounds have been approved for Type 12, 12K or 13 enclosures which require oil swell resistance.