Flexible air duct is made of steel wire and aluminum pet foil which are single side Al+PET foil or double side AL-PET-AL foil tape. General level quanlity is made of 6AL+15PET,7AL+12PET. The high quality flexible air duct is made of 6AL+15PET+6AL or 7AL+12PET+7AL. Single side AL-PET of density low which can help the flexible duct factory save cost . But the duct made of double AL-PET-AL have longer life
Aluminum pet foil for flexible ducting
