By Liz White, UT staffMidland, Michigan-Dow Chemical Co. said 20 March 2006 that it intends to permanently close at its Train I production line for TDI (toluene diisocyanate) at Freeport, Texas. The decision has been taken because margins in the TDI business have not returned to levels which would reward investment, Dow indicated. Dow added that the 60-kilotonnes-per-annum line will be permanently shut down immediately. "Weak demand and abundant market supply for TDI at the time," led to Dow idling the line, the company's 20 March announcement said. It is one of two production trains at the Freeport site. Dow said it plans to keep the other line operating. To return production levels to pre-idling levels would require significant investment, which is not economically viable long-term," said Steven English, business director for Dow's isocyanates business, in the statement. Despite some improvements and recovery in raw material and energy costs since third quarter of 2005, feedstock prices remain volatile," the Dow isocyanates boss continued. And, he added, "we don't anticipate these costs to ease up in 2006." "Pricing is still not where it needs to be and margins have not yet reached the levels necessary to justify reinvestment," English said.Dow said it is the world's largest producer of polyether polyols, a leading producer of aromatic isocyanates-MDI (methylene diphenyldiisocyanate) and TDI-and a major supplier of propylene oxide, an essential component of polyether polyols. These polyurethane raw materials are used in rigid foams, flexible foams, adhesives, sealants, coatings, elastomers, and in many other applications. "