[{"data":1,"prerenderedAt":253},["ShallowReactive",2],{"post-frp-grating-in-pulp-and-paper-mills":3},{"_path":4,"_dir":5,"_draft":6,"_partial":6,"_locale":7,"title":8,"description":9,"slug":10,"locale":11,"date":12,"author":13,"cover":14,"body":15,"_type":247,"_id":248,"_source":249,"_file":250,"_stem":251,"_extension":252},"\u002Fblog\u002Ffrp-grating-in-pulp-and-paper-mills.en","blog",false,"","Why Pulp and Paper Mills Specify FRP Grating for Wet and Chemical Service","Pulp and paper mills are consistently rated among the most aggressive\nchemical service environments in heavy industry. The kraft process\nalone circulates white liquor (NaOH + Na₂S at pH 13+), green liquor,\nand black liquor through every part of the recovery cycle. Bleaching\nplants add chlorine dioxide, peroxide, and ozone to that list. The\nwalking surfaces around this equipment have to survive continuous\nchemical splash, high humidity, and operating temperatures that\nregularly exceed 70 °C in the digester area.","frp-grating-in-pulp-and-paper-mills","en","2024-12-05","Endura FRP Team","\u002Fimages\u002Fblog\u002Ffrp-grating-in-pulp-and-paper-mills.svg",{"type":16,"children":17,"toc":238},"root",[18,25,30,37,42,47,53,58,63,68,74,130,136,153,158,168,174,227,233],{"type":19,"tag":20,"props":21,"children":22},"element","p",{},[23],{"type":24,"value":9},"text",{"type":19,"tag":20,"props":26,"children":27},{},[28],{"type":24,"value":29},"This is the environment FRP was designed for. It's also where FRP\ndelivers its most one-sided lifecycle cost advantage.",{"type":19,"tag":31,"props":32,"children":34},"h2",{"id":33},"the-stainless-steel-trap",[35],{"type":24,"value":36},"The stainless steel trap",{"type":19,"tag":20,"props":38,"children":39},{},[40],{"type":24,"value":41},"For decades the conservative spec was 316L stainless steel grating.\nIt works — until it doesn't. In bleach plant service, 316L shows\nmeasurable crevice attack and pitting within 5–8 years, particularly\naround the welded cross-bars that grating manufacturers use. In\ndigester and brown stock washer areas, chloride stress corrosion\ncracking is a documented failure mode at the bracket connections.",{"type":19,"tag":20,"props":43,"children":44},{},[45],{"type":24,"value":46},"Replacement is the expensive part. Stainless steel grating costs\n3–4× equivalent FRP, weighs roughly 3× as much, and the installation\nin an operating mill typically requires shutdown coordination.\nWhatever you saved by using the \"premium\" material you pay back when\nthe changeout happens.",{"type":19,"tag":31,"props":48,"children":50},{"id":49},"what-vinyl-ester-frp-actually-does-here",[51],{"type":24,"value":52},"What vinyl-ester FRP actually does here",{"type":19,"tag":20,"props":54,"children":55},{},[56],{"type":24,"value":57},"A properly manufactured vinyl-ester FRP grating panel — tested to\nASTM C581 in white liquor, black liquor, and ClO₂ at service\ntemperature — delivers a service life that exceeds 20 years in\npulp mill service with negligible maintenance.",{"type":19,"tag":20,"props":59,"children":60},{},[61],{"type":24,"value":62},"That number is not aspirational. It's been demonstrated across\nmultiple North American mills since the 1990s and is the basis for\nmost major mills' current walkway specs.",{"type":19,"tag":20,"props":64,"children":65},{},[66],{"type":24,"value":67},"The other advantage is installation. A 38 mm pultruded FRP panel at\nroughly 12 kg\u002Fm² is a one- or two-person lift. Equivalent galvanized\nsteel grating is a 35–40 kg\u002Fm² lift that needs two people and a\nplan to get it into position. Over a multi-thousand-square-meter\nwalkway, the labor delta is significant.",{"type":19,"tag":31,"props":69,"children":71},{"id":70},"where-it-goes-in-the-mill",[72],{"type":24,"value":73},"Where it goes in the mill",{"type":19,"tag":75,"props":76,"children":77},"ul",{},[78,90,100,110,120],{"type":19,"tag":79,"props":80,"children":81},"li",{},[82,88],{"type":19,"tag":83,"props":84,"children":85},"strong",{},[86],{"type":24,"value":87},"Digester building walkways",{"type":24,"value":89}," — high temperature, white liquor\nsplash",{"type":19,"tag":79,"props":91,"children":92},{},[93,98],{"type":19,"tag":83,"props":94,"children":95},{},[96],{"type":24,"value":97},"Brown stock washers",{"type":24,"value":99}," — wet, slippery, brown liquor splash",{"type":19,"tag":79,"props":101,"children":102},{},[103,108],{"type":19,"tag":83,"props":104,"children":105},{},[106],{"type":24,"value":107},"Bleach plant",{"type":24,"value":109}," — ClO₂, peroxide, acid stages; the most\naggressive chemical service",{"type":19,"tag":79,"props":111,"children":112},{},[113,118],{"type":19,"tag":83,"props":114,"children":115},{},[116],{"type":24,"value":117},"Recovery boiler area",{"type":24,"value":119}," — hot, humid, occasional smelt spills",{"type":19,"tag":79,"props":121,"children":122},{},[123,128],{"type":19,"tag":83,"props":124,"children":125},{},[126],{"type":24,"value":127},"Stock preparation",{"type":24,"value":129}," — generally milder but consistently wet",{"type":19,"tag":31,"props":131,"children":133},{"id":132},"resin-and-construction-details",[134],{"type":24,"value":135},"Resin and construction details",{"type":19,"tag":20,"props":137,"children":138},{},[139,144,146,151],{"type":19,"tag":83,"props":140,"children":141},{},[142],{"type":24,"value":143},"Vinyl ester",{"type":24,"value":145}," is the only correct resin choice for bleach plant and\ndigester areas. ",{"type":19,"tag":83,"props":147,"children":148},{},[149],{"type":24,"value":150},"Isophthalic polyester",{"type":24,"value":152}," is fine for stock\npreparation and paper machine areas where chemical exposure is more\nmodest.",{"type":19,"tag":20,"props":154,"children":155},{},[156],{"type":24,"value":157},"For bleach plant specifically, look for resin systems tested in\nClO₂ at 5% concentration and 50 °C. That combination rules out most\npolyester systems and a meaningful number of \"vinyl ester\" formulations\nthat are actually vinyl-ester hybrids with too much polyester content\nto survive long-term bleach exposure.",{"type":19,"tag":20,"props":159,"children":160},{},[161,166],{"type":19,"tag":83,"props":162,"children":163},{},[164],{"type":24,"value":165},"Moulded grating",{"type":24,"value":167}," is the right construction for most pulp mill\nservice — it gives better bi-directional strength for the partial\npanels around equipment. Pultruded grating is reserved for long-span\napplications like clarifier launders or recovery boiler decks.",{"type":19,"tag":31,"props":169,"children":171},{"id":170},"standards-to-reference",[172],{"type":24,"value":173},"Standards to reference",{"type":19,"tag":75,"props":175,"children":176},{},[177,187,197,207,217],{"type":19,"tag":79,"props":178,"children":179},{},[180,185],{"type":19,"tag":83,"props":181,"children":182},{},[183],{"type":24,"value":184},"ASTM C581",{"type":24,"value":186}," — chemical resistance at service temperature",{"type":19,"tag":79,"props":188,"children":189},{},[190,195],{"type":19,"tag":83,"props":191,"children":192},{},[193],{"type":24,"value":194},"ASTM E84",{"type":24,"value":196}," — flame spread (typically Class 1 required)",{"type":19,"tag":79,"props":198,"children":199},{},[200,205],{"type":19,"tag":83,"props":201,"children":202},{},[203],{"type":24,"value":204},"ASTM D638 \u002F D790",{"type":24,"value":206}," — strength properties",{"type":19,"tag":79,"props":208,"children":209},{},[210,215],{"type":19,"tag":83,"props":211,"children":212},{},[213],{"type":24,"value":214},"ASTM F3055",{"type":24,"value":216}," — grating integrity and load rating",{"type":19,"tag":79,"props":218,"children":219},{},[220,225],{"type":19,"tag":83,"props":221,"children":222},{},[223],{"type":24,"value":224},"NSF\u002FANSI 61",{"type":24,"value":226}," — for any grating over process water or near\npotable water service",{"type":19,"tag":31,"props":228,"children":230},{"id":229},"bottom-line",[231],{"type":24,"value":232},"Bottom line",{"type":19,"tag":20,"props":234,"children":235},{},[236],{"type":24,"value":237},"Pulp and paper mills were the early proving ground for vinyl-ester\nFRP grating and remain the cleanest example of its lifecycle\nadvantage. The combination of chemical resistance, weight, and\ninstalled cost is hard to beat with any metallic alternative, and\nthe operational experience base is now deep enough that the spec\ndecision is essentially standard.",{"title":7,"searchDepth":239,"depth":239,"links":240},2,[241,242,243,244,245,246],{"id":33,"depth":239,"text":36},{"id":49,"depth":239,"text":52},{"id":70,"depth":239,"text":73},{"id":132,"depth":239,"text":135},{"id":170,"depth":239,"text":173},{"id":229,"depth":239,"text":232},"markdown","content:blog:frp-grating-in-pulp-and-paper-mills.en.md","content","blog\u002Ffrp-grating-in-pulp-and-paper-mills.en.md","blog\u002Ffrp-grating-in-pulp-and-paper-mills.en","md",1790155311224]