Needle Felt Welded Filter Bags Bottom seams are 100% welded,both strong and flexible, allows the filter bag to conform to the shape of the retainer basket creating support as differential pressure builds. Welded construction can completely eliminates unfiltered liquid bypass from occurring due to needle holes. Constituent polypropylene and polyester felts are manufa ctured using 100% virgin fibres, ensuring maximum purity and consistent performance. FDA, EC food contact, Rohs and Silicon free certificated. O Material: needle felt Polyester ( PE ) , needle felt polypropylene ( PO/PP) O Collar type: steel ring or plastic ring O welded method: welded added heat seem O Surface treatment: singed finish or glazed finish Available Welding Methods: