As the product stream flows from the outside of the cartridge to the inside, the FIWA special water absorbent medium retains water, and the pleats expand.

当产品蒸汽从外向内流进过滤筒时，FIWA吸附剂过滤筒的特殊吸水剂介质将水分吸收，褶皱打开。

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So many pleats: pin pleats, cartridge pleats and gathers so fine that they read as pleats.

WSJ: Joaqu��n Sorolla & the Glory of Spanish Dress | Between Heaven and Earth | By Laura Jacobs