4:00 PM - 4:30 PM

Metal Replacement in Infrastructure – BMC/SMC Manhole Covers Provide Composite Solution



Replacing metal applications with plastics and composites has long been the goal of raw material suppliers, blenders, and plastics molders.  From observing GE Plastics metal conversions to Lexan in the 70’s through my experience with BMCI’s material conversion mission in the 90’s, converting metal to plastic – “organic growth” – was always considered the holy grail as compared to a “share-shift,” which was basically taking existing business from a direct competitor using a lower price or better service.  However, the composite material value proposition was not always quite bulletproof enough to push the paradigm away from the safe, apathetic, and incurious position of “it’s always been made with metal, it will always be metal.”  And if composite materials did check all the benefit boxes without major detracting ones, the applications themselves were rarely, if ever, a volume that would rival the circuit breaker, headlamp, or valve cover material consumptions.  We always quixotically hunted for that next substantial organic conversion chasing many windmills along the way.

We started seeing composite materials used in infrastructure applications primarily in non-US countries for a variety of reasons: corrosion resistance, low weight, and as a theft repellant.  Beijing, for instance, suffered in 2004 from the theft of 240,000 manhole covers for their metal scrap content.  Within three years several Chinese companies started making composite manhole covers which eliminated the root cause offering no scrap material value.  While China’s experience represents the first major volume surge using the composite manhole cover, a UK company reportedly started making access covers with a Resin Transfer Molding (RTM) technology in 1980.  Around 2002, the first American company to manufacture and market RTM manhole covers was GMI in Michigan and was owned by Bob Brady until a major iron manhole cover company acquired GMI in 2014.

In addition to manhole covers, metals and other materials have been replaced by plastic and composites throughout water and wastewater infrastructure.  Some major examples include Cured-In-Place-Piping (CIPP) for “trenchless” or no-dig pipe rehabilitation and fiber wound septic tanks, manhole tubes, grade rings, lift stations, and grease traps.  Beyond just water and wastewater infrastructure, composites have replaced many materials in electrical (underground) transmission & distribution, service stations, parks & recreation, steam, and other underground access points.

This presentation will focus on the conversion of iron manhole covers to composite manhole covers for primarily water and wastewater applications.  After initially investigating the benefit and market in 2011, and then starting a company devoted entirely to molding composite manhole covers in 2014, a great deal has evolved and been learned about not only the value proposition but also challenges to enter municipal supply arena.  My company, Composite Access Products or CAP, represents the first devoted effort in the USA to manufacture and market traffic-rated, DOT approved, compression-molded BMC/SMC manhole covers and frames.  Bringing much deeper and broader formula and application knowledge as compared to current composite manhole cover producers has allowed CAP – with the help of A. Schulman here in the US and Almasrya of Egypt – to enter and quickly disrupt a very mature cast iron market.  CAP’s product adds affordability, new end user benefits, and solves the problems of cast iron covers.  Furthermore, CAP’s technical depth delivers answers to key concerns that the municipal civil engineers and utility directors have previously lacked to specify composites for municipalities with confidence. 

We at CAP feel that the composite manhole cover has such a strong value proposition with a large enough potential material consumption – with some technical and market-entry challenges –that this application could be the next headlamp or circuit breaker for BMC/SMC materials.


Chad Nunnery grew up in the Berkshires of Massachusetts and started working in his father’s BMC production company, BMCI, during high school and college summer vacations. In his Junior year of college, he presented a paper at the SPI Retec conference called “Flow Behavior of Thermoset Polyesters and Their Effect on Process and Design.” Chad graduated in 1994 from Dartmouth College in Hanover, NH with Engineering and Chemistry degrees.   Chad has spent most of his career in Latin American countries starting foreign operations for BMCI in Mexico City, Ciudad Juarez and Brazil.  After 6 years residing in Mexico City with his family, Chad witnessed BMC being molded into manhole covers internationally for theft prevention. Chad could not convince his American molding customers to pursue this market, so he entered into an exclusive agreement with A. Schulman in North America.  After 22 years mixing and molding thermosets, Chad formed Composite Access Products, or CAP, in McAllen, TX, where Chad now resides, to mold thermoset composite manhole covers and related products.  CAP is the first US compression molder of traffic-rated composite manhole covers and has the first and only state DOT approval letter for any US composite manhole cover for “within the roadway” use.



CONTACT:  wcnunnery@compositeap.com


W. Chad Nunnery, President & Founder / Composite Access Products