New Adhesive Shows How Much Has Been Applied

The dark blue (left) shows the application rate of PUR-FECT LOK 34-969A adhesive is too great. The lightest blue (right) shows the application rate is too little, which may lead to bond failure. The medium-blue color in the center shows the application rate is optimum for bond strength and cost effectiveness.
A new reactive polyurethane hot melt adhesive has been formulated that shows how much has been applied through the royal-blue color lightness or darkness. Designated PUR-FECT LOK 34-969A adhesive, the product is a 100%-solids, moisture-curing hot melt adhesive designed for immediate handling strength, fast setting speed and good deflection resistance. This adhesive provides full bond strength in hours and was designed for assembly bonding, panel bonding and vinyl laminating.

“A manufacturing-line operator can see if the application device is dispensing the optimum amount of adhesive by comparing the shade of blue with the ideal shade. It is based on the amount required to create the desired bond strength. A lighter shade would indicate that the bond strength might not be sufficient; a darker shade would represent the application of too much adhesive, showing that production cost is higher than necessary,” explains Dan Stauffer, marketing manager, Bondmaster Adhesives, National Starch and Chemical Co., Bridgewater, N.J.

Manufacturers can apply this product by roll coater or slot coater adapted for reactive hot melt adhesives at an adhesive temperature of 250 degrees F. Data on physical characteristics and precautions are available from the manufacturer.

For more information:

For more information on PUR-FECT LOK 34-969A adhesive, contact National Starch and Chemical Information Center, One Matrix Dr., Monroe, NJ 08831; phone 800-797-4992; fax 609-409-5699; or