National Starch and Chemical Company has launched its new Aero-Lok system that is designed to optimise adhesive levels while producing high-quality low-cost laminations.

"It's a unique integration of specially engineered foaming equipment and innovative adhesive formulations that will enhance the consistency and productivity of your adhesive application process, while reducing overall costs," the company said.

"Adhesive aeration changes the adhesive's physical properties in two significant ways: It reduces adhesive density by air injection to improve adhesion between the laminate composites. It increases adhesive holdout on the substrates to improve the adhesive of the decorative overlays.

"We aerate to the optimal foam level by injecting air into the adhesive, creating micro bubbles that reduce adhesive density.

"By reducing the adhesive density, the volume of adhesive remains the same but the weight is reduced, extending your adhesive mileage."

The company said the Aero-Lok process generated several tangible benefits. The reduced moisture content produces improved adhesion with increased production. Lower coating weights yield improved adhesive mileage with lower energy costs. The increased holdout on highly porous substrates results in improved laminate quality. There are also reduced reject rates.

National's Aero-Lok system is composed of Glue-Mix-P equipment and unique formulations specifically designed for aerated adhesive processes.

"Our Glue-Mix-P unit is engineered to be simple to install and simple to use. It's easy to set up and can be directly plugged into existing delivery lines. Aeration per cent and supply rate to glue rollers are automatically controlled."

Meanwhile, a new hot melt adhesive manufactured by National Adhesives (a unit of National Starch and Chemical Company) and called Pur-Fect Lok 34-196A, has achieved UL723 approval from Underwriters Laboratories with a 0/0 rating for flame propagation and smoke generation.

In addition, this 100 per cent solids adhesive contains ultraviolet (UV) dye for improved visibility under a UV light source. The dye and UV light-sensing device enable manufacturers to ensure the adhesive is positioned where desired and that a sufficient amount is applied to achieve a specified bond strength.

Pur-Fect Lok 34-196A is a moisture-curing product that sets fast and provides immediate handling strength. Other benefits include good deflection resistance and the ability to run cleanly at only 250 degrees F. This adhesive has the appearance of a translucent solid.

Applications include vinyl laminating, assembly bonding and panel bonding. For vinyl laminating, National Adhesives recommends coating either the vinyl film or substrate at a rate of 1.5 to 2 wet mils of this adhesive. A handling bond develops immediately after nipping or pressing. Full cure occurs in three to seven days.

For assembly bonding, a handling bond is attained as soon as the adhesive cools. Manufacturers may apply this adhesive as a globule or in a bead 1/8 inch or more in diameter. Nip rolls, pneumatic clamps or a cold press apply sufficient pressure for the combining process.

Application of Pur-Fect-Lok 34-196A adhesive requires a roll coater or slot coater adapted for reactive hot melt adhesives. Open time ranges from three minutes to seven minutes, depending on the substrate's thermal conductivity.

National Adhesives is a unit of National Starch and Chemical Company, a worldwide manufacturer of adhesives, specialty polymers, electronic and engineering materials, natural polymers and advanced ingredients with headquarters in Bridgewater, NJ (US), and 2001 sales of $2.6 billion. The company is a member of the ICI Group.