Abstract: A method for continuously and cost-effectively producing expanded thermoformable honeycomb materials comprising the steps of: providing raw thermoformable thermoplastic material (such as flakes or pellets) into an extruder; heating the material in the extruder; extruding the continuous sheet material to a suitable gauge and width; trimming the extruded material while it is still hot to desired widths; conveying this hot thermoformable, continuous sheet into a preheat/heating section comprised of either hot forming rolls or belts; heating the thermoformable continuous sheet on forming rolls or between continuous forming belts that have specific geometries machined on the surfaces; adhering the continuous sheet on the forming surfaces by hot tack adhesion; expanding the continuous sheet into expanded honeycomb by separating the forming surfaces so as to effect an expansion of the cross-section of the thermoformable continuous sheet material; transferring the expanded honeycomb through an array of cooling rolls