IsoMelt HMPUR 5 Clear OB

IsoMelt™ HMPUR 5 Clear OB is a long assembly time, moisture-curing, hot-melt polyurethane adhesive that contains optical brightener. The adhesive is solid at ambient temperatures. The adhesive is applied in the molten form and cures in the presence of moisture to form a tough, durable bond. The IsoMelt™ HMPUR 5 bonds to a wide variety of substrates, but at least one substrate must be gas permeable. Typical substrates include wood and wood products, most foams, primed metals, FRP, and other plastics with Dyne levels greater than 38 dynes. At 3-mil thickness, the adhesive transfers to the opposing substrate at least through five minutes of assembly time, prior to nipping.



  • General sealing and bonding
  • Laminating
  • RV & Trailer Manufacturing


  • 100% Solids
  • Adhesion to various substrates
  • Excellent green strength
  • Five-minute assembly time
  • Roll coater stable
Product Types

Adhesive & Reactive Hot Melt


Product Testing

Test PerformedTest Results
% Solids100 % 
10 minute Green Strength23 psi 
15 minute Green Strength56 psi 
3 mil open time - Internal method - wood to wood5 Minutes 
5 minute Green Strength8 psi 
Color - ISOblue, pale yellow  
Elongation - ASTM D412360 % 
Hardness - ASTM D2240 - Shore D42 Shore D 
Lap Shear ABS - ASTM D1002450 psi 
Lap Shear Acrylic - ASTM D1002900 psi 
Lap Shear Aluminum - ASTM D1002300 psi 
Lap Shear Maple - ASTM D1002300 psi 
Lap Shear PVC - ASTM D10021000 psi 
Lap Shear SMC - ASTM D1002400 psi 
Open Time - 1/8 inch Normal9 Minutes 
Open Time - ASTM D4497 - 4 Mil7 Minutes 
Set Time - Wooden Block - Normal22 Minutes 
Specific Gravity - ISO1.1  
Tear Strength - ASTM D624, Die C300 pli 
Tensile Modulus - ASTM D41220 ksi 
Tensile Strength - ASTM D412900 psi