包装印刷板块9月18日跌1.58%，龙利得领跌，主力资金净流出2.55亿元

Core Insights - The packaging and printing sector experienced a decline of 1.58% on September 18, with Longlide leading the drop [1] - The Shanghai Composite Index closed at 3831.66, down 1.15%, while the Shenzhen Component Index closed at 13075.66, down 1.06% [1] Market Performance - Notable gainers in the packaging and printing sector included: - Dashengda (603687) with a closing price of 9.37, up 6.00% and a trading volume of 383,200 shares [1] - Zhongrui Co. (002374) closed at 3.10, up 3.68% with a trading volume of 1,311,400 shares [1] - Yongji Co. (603058) closed at 69.6, up 3.64% with a trading volume of 481,300 shares [1] - Major decliners included: - Longlide (300883) closed at 6.78, down 5.83% with a trading volume of 241,800 shares [2] - Wangzi New Materials (002735) closed at 15.73, down 4.49% with a trading volume of 483,200 shares [2] Capital Flow - The packaging and printing sector saw a net outflow of 255 million yuan from institutional investors, while retail investors contributed a net inflow of 178 million yuan [2] - The capital flow for key stocks showed: - Zhongrui Co. had a net inflow of 58.76 million yuan from institutional investors [3] - Dashengda experienced a net inflow of 44.71 million yuan from institutional investors [3] - Yongji Co. had a net inflow of 24.66 million yuan from institutional investors [3]