The standard fold number of the high efficiency filter is determined by the height of the separator paper and the tightness of the separator paper and filter paper assembly. For example: the standard frame of the filter (610 * 610 * 120) mm is: first remove the thickness of the two sides of the board, then 610- (20 * 2) = 570mm, the interval of 570 ÷ 4 ÷ 2 = 71.25 fold, the result is about 70 to 72 fold.
