Lanzhou petrochemical shut down its big ethylene craker and its downstream polymer units due to an accident on 9 September, Sources said on Tuesday. The craker was not restarted yet, the source added. Total PE capacity of 500,000tonne/year and 300,000tonne PP unit was forced to shut down due to the craker accident, leading a sharp decrease in polymer production. However, the market still saw a downward trend in the week of 9 September on weak demand. Traders was worried about the outlook of polymer market in next couple weeks due to the high inventories of prodcuers and weak demand from downstream converters.