Entrepreneurial joint venture Hardcore DuPont Composites LLC seems to be attacking myriad market niches simultaneously. George Tunis, president and chief executive officer, said the three hottest projects are driving composite piling, gearing up to make composite railroad cars and qualifying for California Transpor-tation Department bridge-column wrapping.
Those projects merely hint at the venture's momentum in using SCRIMP technology. Other efforts include composite bridge decks and superstructures and energy-absorbing ship fender systems. SCRIMP stands for Seemann Composites Resin Infusion Mold-ing Process, a low-cost way to make large, high-glass-content, composite parts.
Hardcore DuPont was formed in late 1994 as a joint venture between DuPont Co. and Hardcore Composites Ltd. after the two companies had worked together on projects.
Tunis, 33, worked for DuPont for four years and formed Hardcore Com-posites in 1989. Now, the company employs 26 engineers, 18 technicians and six office workers.
``We have no red tape,'' he said. ``We're fast-moving and entrepreneurial and geared more toward robotics than hand-layup.''
DuPont sees the venture combining ``a very fleet-of-foot, very bright young organization and a stable, financially secure global organization with a lot of good ingrained processes,'' said J. Michael Bowman, vice president of DuPont Advanced Material Systems.
DuPont ``will be part of the engine'' financing a second Hardcore plant now being considered, Bowman said.
``We think it will pay out quick enough that [Hardcore] can keep up their end of the deal.''
The venture's core team includes reinforced-fabric supplier Brunswick Technologies Inc. of Brunswick, Maine, and resin supplier Dow Chemical Co. of Mid-land, Mich.
BTI supplies a mix of standard and custom bi-, tri- and quad-axial knitted fabrics, and Dow provides a variety of resins, including 8084 rubber-toughened vinyl ester for column wrapping.
``Composite piling allows us to SCRIMP for any large tube of any length,'' Tunis said. ``We have been field-testing those tubes, and we have project proposals this year in Louisiana, Delaware and Hawaii.''
The piling process is a way to use SCRIMP for high-quality composites without any molds.
``We can change size, length, diameter,'' Tunis said. ``In a port, everybody wants something different.''
In March tests, Kuhn Construc-tion of Wilmington, Del., used a 23,000-pound diesel hammer to drive hollow composite piles into Delaware River basin sand and clay outside Hardcore DuPont's facility in New Castle, Del.
``One of the owners, Ricky Kuhn, did the driving and said he had never beat on pile like that and had it hold up,'' Tunis said.
Two people can pick up a 65-foot pile. Wall thickness can range from less than one-eighth inch to more than 1 inch.
``We're using hollow piles with a diameter of 141/2 inches, have made some of 3 and 4 feet and expect to be able to go up to a 10-foot diameter,'' Tunis said.
Hudson Engineering, based in Camden, N.J., monitored the tests.
``They calculated the bearing load at 65 tons for the hollow pipe alone, based on blows per foot,'' he said. ``Finally, the diesel hammer shattered the thin piling - we needed to break it to find out what it could take - but a 0.22-inch piling held up.''
Deflection tests closely matched theoretical calculations.
``The vibrations emptied our building, bringing everyone outside to see what was going on,'' Tunis said.
``We are looking forward to a guarantee of much more than 10 years. Once the composite is in the ground, it is permanent construction.''
Hardcore DuPont has ``settled on warp-oriented tri-axial material from BTI as the standard'' for the piling, Tunis said. A majority of the fibers run lengthwise with remaining fibers in the bias direction for other loads, according to Rob Fuller, BTI vice president of sales.
A port authority or transportation department can ``have piles unfilled or filled,'' Tunis said. Filler materials include a high-strength concrete or a 200-pound-per-square-inch flowable fill material made from concrete and fly ash and known as pudding. Adding concrete improves stiffness at least threefold.
On the railroad car front, Hardcore DuPont is going to full production.
``We've had two [insulated, 68-foot-long] cars out for eight months now, and they have performed well on tough lines,'' Tunis said.
``Burlington Northern [Santa Fe Corp.] was running the cars on the Union Pacific line, which has tough deceleration and acceleration points.''
The design can handle end loads of 213,000 pounds when a shift occurs.
``It held up movement of 218,000 cans of beer,'' Tunis said.
Production is targeted to begin in 1996's third quarter with expectation of several hundred cars in the first year.
BTI's Fuller said the quad-axial material gives isotropic strength in all directions, allowing fabrication of a heavyweight laminate that can compete with conventional railroad-car materials such as steel.
``We will be scaling up with additional tool sets and should be producing at a rate of 1,000 by year-end 1997,'' Tunis said.
``It is so well-insulated it is used to ship cold beer for days in hot weather without any refrigeration,'' Bowman told a March 27 meeting of the Society for the Advancement of Material and Process Engineering.
On the seismic retrofit and rehabilitation front, the company
is collaborating with Foster City, Calif.-based contractor William P. Young Inc. in seeking an application for Hardcore DuPont's wrapping system, which was patented recently.
Prefabricated shells are glued in place. Methods range from pressure jackets to more sophisticated systems that suck glue into a vacuum.
California has given conditional approval to two advanced-composite companies to bid on bridge-column-wrapping contracts, and Hardcore DuPont is positioned to receive a similar approval.
``Many East Coast structures are crumbling,'' Tunis noted. ``The previous approach has been to chip off bad concrete, reform the structure and repour the concrete. That leads to more crumbling and starting all over in a few years.''
The Hardshell system uses fiberglass or carbon fiber, building a shell around the structures and spraying on coatings.
``We offset away from the column and pull a vacuum on the entire structure for one or two days,'' Tunis said.
``Using vinyl ester resins for corrosion-resistance, we fill every nook, cranny and crack and, literally, glue the rubble back together.''
By filling in and eliminating structure, ``we have found that we can be cost-competitive with spot masonry repairs,'' he said. ``We can fix 100 percent of a structure all at once.''
The composite shell has an exterior waterproof coating.
``It has taken us two years trying to get a satisfactory vacuum in field use,'' Tunis said. ``Now, it's routine.''
In October, the Delaware River and Bay Authority awarded a $420,000 contract for Hardcore DuPont to retrofit an Interstate 295 bridge that carries traffic between Baltimore and New York.