| 摘要 |
Plastic pipes made of unsaturated polyester resins have low-molecular polyester units with free hydroxyl groups. These functional groups, which are present in the inner lining that is rich in resin, form the inner wall of the pipes and act as centers for chemical reactions involving various compounds such as water, inorganic and organic acids, and oxidation agents. When polyester tubes are used in drinking water lines, constituents released by the chemical reaction of the water and the free hydroxyl groups pertaining to the polyester resin can have a negative influence upon the quality of the drinking water. The aim of the invention is to provide a method for producing polyester resin pipes with enhanced water resistance. The inventive method is characterized in that at least the polyester coating forming the inner part of the pipe is treated with at least one medium containing isocyanate. This treatment results in the formation of a matrix with polyurethane groups making the plastic pipe sufficiently water resistant, while improving sturdiness and impact resistance. |
