Melamine crystal has been used as a flame-retardant additive in flexible polyurethane foam for close to a decade. But most U.S. foamers using melamine are infringing on a number of patents owned by Hickory Springs Manufacturing Co., according to Hickory Springs Vice President Bobby Bush.
The Hickory, N.C.-based firm announced Nov. 14 that it is initiating a national licensing program for the use of melamine in flexible PU foams.
Hickory Springs sent letters and copies of proposed contracts to the three U.S. melamine producers—Melamine Chemicals Inc., DSM Melamine America Inc. and Cytec Industries. The latter two operate the Amel melamine plant in the Fortier district, near Westwego, La., as a joint venture.
``Our goal is to license the three melamine producers in the U.S. and get them to sublicense to their foaming customers,'' Bush said, adding Hickory Springs hopes to get the program ``up and running by April 1.''
Hickory Springs did not disclose the terms of the proposed licensing program.
Melamine producers may not be too eager to adopt Hickory's proposal.
``We have not at this time agreed to become involved'' in Hickory Springs' licensing program, Mac Crews, director of research for Melamine Chemicals said in a Nov. 20 telephone interview from the firm's Donaldsonville, La., headquarters.
Crews acknowledged that Hickory holds patents on the production of foams with melamine, but did not think the raw material suppliers need to have a role in Hickory Springs' patent claims.
``We simply sell a commodity,'' Crews said. ``[Hickory Springs] ought to talk to the people who manufacture the foam.''
Officials from competing companies that might be affected by any licensing program could not be reached for comment by press time.
The Polyurethane Foam Association, a Wayne, N.J., trade group representing the flexible foam industry, is not taking sides on the issue.
``We're going to stay out of it,'' Lou Peters, executive director of the PFA, said Nov. 20. ``There are a number of ways to resolve disputes in the industry. A licensing agreement may be one of them.''
Hickory Springs holds four patents covering the use of melamine as a fire retardant in flexible PU foams: 5,656,678, 5,569,682, 5,536,757 and 5,506,278 — all issued in either 1996 or 1997, according to the U.S. Patent and Trademark Office's World Wide Web database.
``Where melamine is used in the production of flexible polyurethane foams, we are the originators,'' Bush said, adding the four patents cover methods to combine melamine with a variety of polyols.
``We pretty much cover the whole spectrum'' of the technically feasible methods of using melamine in foam, he said.
Melamine has been added to flexible PU foams since the late 1980s to help furniture cushions meet strict flammability regulations in Britain, Boston and California, Crews said.
``It's been a reasonable market for us for the last eight years or so,'' Crews said. ``Fire legislation in England forced manufacturers to begin using melamine in the late 1980s. Acceptance has been much slower here [in the United States]. Legislation is the only way to really grow that market.''
Melamine's flame-retardant properties come from its molecular makeup, which is 66 percent nitrogen. When exposed to heat, melamine releases nitrogen, diluting the oxygen that otherwise would combust. Melamine also is an endothermic material, meaning it essentially sucks the heat out of a fire instead of adding to it.