The new ADDHERE ™ tie layer is designed specifically to bond an acrylic layer onto a substrate of thermoplastic polyolefin (TPO) for use in thermoforming applications. ADDHERE ™ has been introduced by Solvay Engineered Polymers Inc., and is the company's first adhesive tie-layer material for use in the production of extruded sheet. ADDHERE adhesive tie layer is a pelletized material that can be co- extruded with a TPO substrate, to which acrylic film rollstock can be laminated in-line. Or sheet producers can tri-extrude each of the three materials - acrylic, tie layer, and TPO - from the melt phase to produce a multi-layer sheet. Color can be introduced into an acrylic/TPO sheet in the opaque tie layer. With the acrylic layer free of pigment, it can provide optimum gloss, depth of image, and scratch resistance. At the same time, the absence of pigment from the TPO substrate means its performance properties can be easily and economically controlled.
The ability of the ADDHERE material to bond simultaneously to both an acrylic and an olefinic layer is a major breakthrough in the production of olefinic sheet stock. Acrylic films impart high gloss, depth of image, and surface durability in decorative applications. Engineered polyolefins are valued for their impact resistance, dimensional stability, and low- temperature ductility. But until now, there has been no way to effectively bond these two dissimilar materials in an efficient, in-line process.
Both major forms of scrap produced in the process of producing sheet for thermoforming can be recycled back into the TPO substrate - both the line-trim from the sheet extrusion, and the trim removed after the forming of the final shape. Solvay Engineered Polymers provides guidelines for recycling material containing the new ADDHERE(TM) tie layer, so that the properties of the TPO substrate are maintained.