Thermoplastic Lamination Techniques

Korad film is permanently bonded to plastic sheet substrates (ABS, PVC, HIPS, PMMA, PC ) by passing the film and hot plastic sheet through polishing or embossing rolls during the sheet extrusion process. Lamination is accomplished with the extrudate heat and roll pressure alone; no adhesive is required.

Optimum lamination conditions will vary with the substrate employed, sheet thickness, and equipment. Optimum adhesion to smooth sheet requires that higher polymer and polishing roll temperatures be employed than during the production of an embossed laminate.

For most substrates, Korad addition does not significantly change the physical properties of the sheet; however, Korad does improve surface properties and appearance. In addition, the sheet characteristics on exterior aging are improved over the unsurfaced sheet when a minimum of 0.0018" (1.8 mils) of Korad film remains after forming.

Lamination Techniques

• Correct tension of the Korad film is a key to successful lamination. Without sufficient tension the spreader roll will not operate correctly and the film will not lay flat on the extruded sheet.



• Film contact with the laminating roll should be minimum as illustrated in the figure below. We recommend as little contact as possible, certainly less than 45 degrees. The longer the Korad is in contact with the roll, shrinkage may occur creating wrinkles/ creases.



• The proper use of a bow-roll or spreader roll is important. This roll must be mounted in the correct direction and positioned to achieve the maximum effect. The roll manufacturers will provide instructions for optimum performance.



• The distance the film must travel unsupported should be minimal. This permits better control of the tension of the film and minimizes wrinkling.



• Good gauge control of the substrate material is also important. Poor sheet gauge can cause problems that appear to be wrinkles. Sheet should always be on gauge before the Korad film is introduced.