Edgetherm® JS-780 polyisobutylene primary sealant

Edgetherm® JS-780 is a preferred choice as the primary seal on insulating glass units while providing the main moisture vapor seal between glass and metal spacers. It is a 100% solids sealant based on polyisobutylene polymer formulated to impart reinforcement, resist degradation from ultraviolet light and provide low moisture permeability. Edgetherm JS-780 must be used with a secondary seal designed to provide structural strength.

Edgetherm® JS-780 Sealant features:
  • Retains flexibility through a wide temperature range to compensate for thermal movement of the insulating glass unit
  • Available in black
  • JS-780 is available in pre-extruded strands for applying to spacer bars and in bulk (slug form) for application by various type extruders
  • Pre-extruded Strands: 1/8”, 3/32”, 1/16” diameter
  • Slugs: 7.5”D x 9.5” H (15 lb/7 kg)
  • 4.5”D x 7”H (4 lb/2 kg)
  • 9.5”D x 10.5”H (27 lb/12kg)
  • Drums: Steel 55 gallon
Edgetherm JS-780 offers the following benefits:
  • Excellent adhesion to glass and metal through a wide temperature range
  • Features an extremely low moisture vapor transmission rate
  • Extremely low argon permeance
  • Non-fogging (100% solids)
  • Consistent quality
  • Resists degradation from ultraviolet light and oxidation
The following information is published as general information only. The listed properties and performance characteristics are approximate values and are not part of the product specification.
Moisture Vapor Transmission Rate 0.13/m²/d, 0.060” fi lm, 100° F, 100% RHNorm ASTM F 1249
Volatile FoggingPassesASTM E 2189 CAN/CGSB 12.8
Low Temperature Flexibility Passes - 40° F, 1/2” mandrelASTM D 3111
Weight per Gallon (Specific Gravity) Black: 8.75 lb/U.S. gal (1.05 g/cc)
Tensile Adhesion Strength 40-50 psiTST 680B
Argon Permeance & Permeability 3 cc/100 in.²/d, 0.31” film 120 cc mil/100 in.²/dASTM D 1434
Edgetherm® JS-780 polyisobutylene primary sealant

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