Advantages of Solvent Based polyurethane adhesive:
• well known history of performance
• types available for all types of food packaging laminations
• can be one-part for simplicity of handling
• two-part has enhanced heat, chemical and, in some cases, bond performance
• excellent clarity
• adhesion to wide range of substrates
Disadvantages of Solvent Based polyurethane glue:
• contain volatile organic compounds (VOC), though many Hazardous Air Pollutant (HAP) free
• can be economical to costly on dried applied basis
• health and safety concerns
• fire hazard
• water of alcohol contamination will compromise cure
• rate of drying often limiting step
• takes time for cure to develop
• two-part requires proper mixing and ratio, especially in higher performance applications – chance for error
Advantages of 100 % Solids polyurethane adhesive: (sometimes called solventless, solvent free)
• little or no VOC and no HAP
• high application speeds
• very competitive on applied cost
• often lower applied weight
• adhesion to wide range of substrates
• types available for low to high demand packaging
• excellent clarity
• reduced waste of adhesive
Disadvantages of solventless polyurethane adhesive:
• need dedicated laminator to apply
• need transfer pumps for one-part
• need meter-mix-dispense pump for two-part – chance for error
• little initial bond, no shear resistance initially
• some need pre-heat to pump and apply
• takes time for bond and final cure
