In one embodiment, the apparatus includes a decoder configured to determine a reference pixel group including a pixel to be filtered. The volume fraction of the silica gel to the volume fraction of the composite material amounts to at least 50%, especially at least 65%. The method also includes forming a polynomial model template representative of the plurality of sampling points. A trailing end of a thermoset polymer guide band abuts the third annular shoulder and a leading end abuts the first annular shoulder. Further disclosed are processes for making molded articles and tires, and for retreading tires.