ELECTRET FIBER SHEET

摘要

PROBLEM TO BE SOLVED: To provide an electret fiber sheet which has high performance enabling the achievement of high dust-collecting characteristics that can not be achieved by electret fiber sheets prepared by conventional corona discharge methods. SOLUTION: This electret fiber sheet is characterized by electrically charging a fiber sheet so that both positive polarity and negative polarity exist together on the front and back sides of the fiber sheet and so that the total area of the charged portions is >=50% based on the whole area of each of both the front and back sides of the fiber sheet.