Foil lamination consists of combining a sheet of aluminum foil with one or more other materials, such as paper and plastic films, using an adhesive, pressure, and heat for controlling adhesive viscosity, drying, and thermo-setting the bonding agent. The resulting product is a sandwich of three or more layers (solidified foil, adhesive, and paper or plastic).
The laminating process requires the rolls of foil and other material be unwound and a controlled application of adhesive be applied to one or the other, or occasionally to both of these webs. This combination of foil, adhesive, and other material is then brought together when it passes through the nip of the combining rolls, usually one steel as well as one rubber roll. This process applies enough pressure to join the materials into a single web.
There are roughly four main methods of laminating aluminum foil:
- Wet-bonding – combining is done before adhesive (water-based or solvent) is dry, usually with combining rolls.
- Dry-pressure or Thermoplastic Bonding – combining is performed after the adhesive is dry; the steel roll is usually heated to help reactivate the adhesive.
- Extrusion bonding – combining is done simultaneously with the application of a hot adhesive. In this case, the hot plastic is deposited from an extrusion die located at the combining roll nip, formed by a rubber and a steel roll. The steel roll is then chilled to affect the bond by quickly setting or solidifying the plastic.
- Hot-melt bonding – combining is done shortly after the adhesive (waxes and other thermoplastic compounds) is applied. Both the reservoir pan and application rolls can be heated. Combining rolls are sometimes used, but the adhesive bond is achieved by chill-setting the hot adhesive, either with a chill roll, air blast, or by other means.
If ingesting all of this information is overwhelming, fear not, as companies such as Jessup Manufacturing are available to help you fully understand the process and benefits to using foil lamination services. Jessup will help you decide if foil lamination is truly what you need for your particular need, and if so, Jessup can provide the work needed to complete this process.