Pleated bags are made of spun bond polyester filter media. They are one-piece structure completed with end caps and inner cores. They can be installed in existing baghouse dust collectors; replacing traditional needle felt bags and bag cages. The baghouse with pleated bags provide a significant update than traditional pulse jet needle felt baghouse collectors. The baghouse with pleated bags dramatically increase filter area and efficiency than needle felt bags while operate at much lower differential pressure. Compared with traditional needle felt bags, the pleated bags increase filter area by 100~300%, which allow for much smaller dust collector size.