LOCTITE LIOFOL LA 7992

Target Application

An aliphatic, non-yellowing adhesive system for use in medium and high performance packaging applications. It may be used in general laminating of film/film (including high slip films) laminations. NOTE: For food retort applications the mix ratio must be changed to 1:1 by weight as indicated below.

Other Applications

This adhesive may also be used for general-purpose food packaging laminations, health care, pharmaceutical and cosmetic applications.

Adhesive Selection

The selection of the adhesive system, substrates, and process conditions are critical to the success of the final structure. Thorough qualification on your equipment and substrates is recommended before commercial production begins.

Adhesive Mixing

This adhesive system requires the use of Meter/Mix/Dispense (MMD) equipment that will automatically measure and mix the correct amounts of adhesive and deliver them to the laminator. Verification that the unit is providing the correct amounts of adhesive and coreactant is recommended prior to startup. If the MMD unit is capable of phasing issues (one material enters the static mixer before the other) verification that each side is being dispensed at precisely the same time is required. The adhesive is sensitive to moisture. Tanks or large containers such as drums will require nitrogen purging or the attachment of a desiccant dryer. A DRIERITE desiccant unit is supplied (upon request) with the first drum to ensure that dry air enters the drum as adhesive is withdrawn.

Application Method

The recommended method of application for this product is with a series of rubber and steel, smooth surface transfer rollers on a specially designed solventless adhesive laminator. The adhesive is mixed by the MMD unit, deposited onto the first two rollers, and metered by the remaining rollers in the application station (typically 3 to 5 rollers). To improve the flow characteristics of the adhesive, heat the first two rollers to 90 - 105°F (35 - 40°C). The final application roller should be heated to 110 - 140°F (43 - 60°F). Modification of these temperatures may be required depending on line speed, substrates, and roller size.

Coating Weight

The coating weight will be dependent upon the film or foil combination, the end use of the lamination, and the thickness of the printing inks. Typically, 0.8 – 1.5 lb/ream (1.3 – 2.4 gm/m2 ) is suggested.

Combining Nip

Nip temperatures of 120 - 175°F (49 - 79°C) are generally recommended. Higher nip temperatures may be required depending on the line speeds, thickness, and substrates being bonded.

Initial Tack

There will be little or no initial tack with most solventless adhesive systems. Proper tension control during processing and winding will produce a good lamination.

Appearance Off-line

Very small bubbles (1/2 mm) between the layers of the lamination are typical off line. With proper winding parameters, the adhesive will flow and the bubbles will dissipate by the following day. To obtain maximum optical properties, a rewind temperature of 85 - 105°F (29-40°C) may be used.

Curing

Aliphatic adhesive systems cure slower than standard aromatic urethane adhesive systems. Storing the laminate in a hot room (110-120°F/43-49°C) will accelerate cure. If stored at room temperature (77°F/25°C), the laminate normally can be rewound and slit after several days. Bond development should be monitored. To achieve maximum chemical and thermal resistance, allow 14 - 21 days of storage at room temperature. Cure rate may depend on film combination. If rolls are subjected to low temperatures, a substantially longer cure time may result.

Clean Up

Clean up is accomplished with solvents such as ethyl acetate, methyl ethyl ketone or acetone. Care should be taken to insure the solvent used would not damage the rubber rollers in the application station. Protective gloves should be worn, and proper ventilation is recommended. Refer to the SDS regarding the recommended PPE.

• 1.0 part by weight 
• 0.95 parts by volume