A patented single-screw, single-barrel equipment package from Nordson Xaloy provides the cost-savings and versatility of two-component molding while requiring substantially less investment than more complex coinjection molding systems that use separate injection units, it was announced by the company.
Called Twinshot, the Nordson Xaloy system replaces a standard screw and barrel with counterparts designed to produce a two-component part in a single molding cycle with a single screw, single shot and single recovery. It is available as an option on new injection molding machines and as a retrofit that can be installed in one or two days. The Twinshot system is limited to simple “A-B-A” sandwich structures and cannot be used for hot-runner molding or on equipment with L/D ratios less than 20:1, but within these limitations it can process a wide range of resin and color combinations and can readily be switched back to single-material molding.
The advantages cited for Twinshot two-component molding include:
* confining high-cost specialty material to the skin layer with general-purpose material in the core
* using recycled or wide-spec material in the core
* combining a structural core with a cosmetic exterior
* adding new product value by, for example, combining a “soft-touch” TPE skin with a rigid core
* obtaining the benefits of a foam core (reduction in weight and molded-in stress and elimination of warpage and sink marks) while obtaining a cosmetic surface finish.
www.nordson.com
