Clear plastics include strong, very tough materials like polysulfone (PS), polyphinelydene sulfide (PPS) and polycarbonate (PC, Lexan) - think food blenders, medical equipment and skylights - should a paper machine manufacturer want to achieve the gloss/cleanability of stainless steel tile at roughly 1/7 and 1/3 the density, respectively.  

Speaking of tile, that fine Roman invention, white water chests, pits and silos around the paper machine can be lined with 'anchored' polyethylene and polypropylene (PP) sheet that comes with 'pins' welded to the back to permanently lock the sheet in place by pouring concrete or grout behind it.   A standard, 1-1/4 inch thick tile lining weighs 20 lb/sq ft, compared to 1.5 lb/sq ft for 1/4-inch thick PP anchored sheet lining. 

Better still, constructing a tank or chest from solid duplex stainless steel or with welded sheet plastic in a stainless steel frame, with the only concrete being the building floor,  eliminates 150 lbs for every square foot of concrete wall and roof 12-inch thick, which most of them are.  

Steel dryers, SS chests and silos with PS and PPS windows, CPVC or HDPE pipe and high strength space frames for press rolls and dryers and the weight of the paper machine potentially is one tenth of the traditional machine.  It's nice to dream of progress, I wonder what it would be like to witness it?  That's probably what makes your work in Guatemala so rewarding.  

Dave Bennett,

LGMI Fellow

---