Laminating adhesives are thin layers of adhesive set on release paper. Once the adhesive is applied the paper is stripped away, leaving the adhesive bonded to the component’s surface. Adhesives like laminating that are used in medical, pharmaceutical and food processing applications must also meet FDA and USDA standards.
Laminating adhesives are cured using heat or a combination of heat and pressure much like hot melt adhesives. They can offer strong bonding and good resistance to high temperatures, as well as protection from low-risk environmental factors. This adhesive is always clear, which is why it is used to laminate papers that require protection from wetness and ripping but must also be able to be read.
Laminating machines come in three basic styles: hot pouch, cold pouch and roll laminating machines. Laminating pouches are clear plastic sheets that have been immersed with laminating adhesive on the inside of the pouch, which then seals around paper products by way of heat and pressure or just pressure. Roll machines have sheets of laminating film and adhesive on a roll that is heated up before the paper product is sent through.
The first two are commonly found in offices and even private homes, while the roll laminating machines are employed by industrial and commercial companies who require greater sizes and greater speed.
Because of varying compositions laminating adhesives may be formulated specifically to bond to certain surfaces. Some products adhere to glass, masonry, metal and paper, while others may adhere to porous surfaces, textiles and wood. Laminating adhesives may also be used to bond two dissimilar components, such as metal to rubber. A laminating adhesive may contain solvents or be solvent-free.
Depending on the formulation, once the adhesive has been applied, it may be repositioned slightly for a short time. Other laminating adhesives quickly form a strong permanent bond. Laminating machines seal the laminating adhesive almost immediately, but a bottled laminating adhesive can take up to an hour to fully bond with its surface object.
They can be formulated to withstand temperatures up to 450° and be chemical, UV and humidity resistant. Laminating adhesives are used in many industries and applications including aerospace, automotive, marine, military, optical and tooling applications. They may also be designed for use with electrical products and high-voltage applications.