Technology development of PE speciality resin for tubing

This paper developed a technology for producing polyethylene (PE) speciality resin for tubing which featured bimodal relative molecular mass distribution. The speciality resin was prepared with slurry polymerization process adopting two polymerizers in series. In order to endow the PE speciality resin with desired micro-structure and performance, the first polymerizer was used to prepare the portion of the resin having low relative molecular mass with homo-polymerization process while the second one was used to produce the portion of the resin having high relative molecular mass with co-polymerization process. The optimum conditions suitable for producing high-level speciality resin were selected through the analyses of the process parameters such as polymerization temperature, pressure, monomer dosage and ratio of hydrogen to ethylene. The resin product possessed a minimum necessary strength of over 8 MPa in the hydrostatic strength experiment and attained PE 80 grade of the speciality resin for tubing.