Exhibit 3.1

CERTIFICATE OF INCORPORATION

OF

POLYPORE INTERNATIONAL, INC.

ARTICLE ONE

The name of the Company is Polypore International, Inc. (the “Company”).

ARTICLE TWO

The address of the registered office of the Company in the State of Delaware is 1209 Orange Street, Wilmington, New Castle County, Delaware 19801. The name of the Company’s registered agent for service of process in the State of Delaware at such address is The Corporation Trust Company.

ARTICLE THREE

The purpose of the Company is to engage in any lawful act or activity for which a corporation may be organized under the General Corporation Law of the State of Delaware (the “Delaware General Corporation Law”).

ARTICLE FOUR

The total number of shares of stock which the Company is authorized to issue is 2,000 shares of stock, of which 1,000 shares shall be designated common stock (the “Common Stock”) and 1,000 shares shall be designated preferred stock (the “Preferred Stock”), all of which shares of Preferred Stock are presently undesignated to a series. The board of directors of the Company (the “Board of Directors”) is hereby authorized from time to time to provide by resolution for the issuance of shares of Preferred Stock in one or more series not exceeding the aggregate number of shares of Preferred Stock authorized by this Certificate of Incorporation (this “Certificate”), as amended from time to time, and to determine with respect to each such series the voting powers, if any (which voting powers if granted may be full or limited), designations, preferences and relative, participating, optional or other special rights, and the qualifications, limitations or restrictions relating thereto (including, without limiting the generality of the foregoing, (i) the voting rights relating to shares of Preferred Stock of any series, which may be one or more votes per share or a fraction of a vote per share, which may vary over time and which may be applicable generally or only upon the happening and continuance of stated events or conditions, (ii) the rate of dividend to which holders of Preferred Stock of any series may be entitled, which may be cumulative or noncumulative, (iii) the rights of holders of Preferred Stock of any series in the event of liquidation, dissolution or winding up of the affairs of the Company, (iv) the rights, if any, of holders of Preferred Stock of any series to convert or exchange such shares of Preferred Stock of such series for shares of any other class or series of capital stock or for any other securities, property or assets of the Company or any subsidiary of the Company (including the determination of the price or prices or the rate or rates applicable to such rights to convert or exchange and the adjustment thereof, the time or times during which the right to convert or

exchange shall be applicable and the time or times during which a particular price or rate shall be applicable), (v) whether or not the shares of that series shall be redeemable, and, if so, the terms and conditions of such redemption, including the date or dates upon or after which they shall be redeemable, and (vi) the amount per share payable in case of redemption, which amount may vary under different conditions and at different redemption dates, and whether any shares of that series shall be redeemed pursuant to a retirement or sinking fund or otherwise and the terms and conditions of such obligation).

Each share of Preferred Stock shall have a par value of $.01 and each share of Common Stock shall have a par value of $.01.

ARTICLE FIVE

The number of directors of the Company shall be such as from time to time fixed by, or in the manner provided in, the Bylaws of the Company (the “Bylaws”). Unless, and except to the extent that, the Bylaws so require, the election of directors need not be by written ballot.

ARTICLE SIX

The Board of Directors may at any time and from time to time adopt, amend or repeal the Bylaws without the assent or vote of the stockholders, subject to the power of the stockholders to adopt any Bylaws or to amend or repeal any Bylaws adopted, amended or repealed by the Board of Directors.

ARTICLE SEVEN

SECTION 1. The Company shall indemnify to the fullest extent authorized or permitted under and in accordance with the laws of the State of Delaware (as now or hereafter in effect) any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of the Company), by reason of the fact that he or she is or was a director, officer, employee or agent of the Company, or is or was serving at the request of the Company as a director, officer, trustee, employee or agent of or in any capacity with another corporation, partnership, joint venture, trust or other enterprise, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by him or her in connection with such action, suit or proceeding if he or she acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the Company, and, with respect to any criminal action or proceeding, had no reasonable cause to believe his or her conduct was unlawful. The termination of any action, suit or proceeding by judgment, order, settlement, conviction, or upon a plea of nolo contendere or its equivalent, shall not, of itself, create a presumption that the person did not act in good faith and in a manner which the person reasonably believed to be in or not opposed to the best interests of the Company, and, with respect to any criminal action or proceeding, had reasonable cause to believe that the person’s conduct was unlawful.

SECTION 2. Expenses incurred in defending a civil or criminal action, suit or proceeding shall (in the case of any action, suit or proceeding against a director of the Company) or may (in the case of any action, suit or proceeding against an officer, trustee, employee or

agent) be paid by the Company in advance of the final disposition of such action, suit or proceeding as authorized by the Board of Directors upon receipt of an undertaking by or on behalf of the indemnified person to repay such amount if it shall ultimately be determined that he or she is not entitled to be indemnified by the Company as authorized in this Article Seven.

SECTION 3. The indemnification and other rights set forth in this Article Seven shall not be exclusive of any provisions with respect thereto in the Bylaws or any other contract or agreement between the Company and any officer, director, employee or agent of the Company. The Company shall have the power to purchase and maintain insurance on behalf of any person who is or was a director, officer, employee or agent of the Company, or is or was serving at the request of the Company as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise against any liability asserted against such person and incurred by such person in any such capacity, or arising out of such person’s status as such, whether or not the Company would have the power to indemnify such person against liability under this Article Seven and applicable law, including the Delaware General Corporation Law.

SECTION 4. Neither the amendment nor repeal of this Article Seven, nor the adoption of any provision of this Certificate inconsistent with this Article Seven, shall eliminate or reduce the effect of this Article Seven, in respect of any matter occurring before such amendment, repeal or adoption of an inconsistent provision or in respect of any cause of action, suit or claim relating to any such matter which would have given rise to a right of indemnification or right to the reimbursement of expenses pursuant to this Article Seven, if such provision had not been so amended or repealed or if a provision inconsistent therewith had not been so adopted.

SECTION 5. No director shall be personally liable to the Company or any stockholder for monetary damages for breach of fiduciary duty as a director; provided, however, that the foregoing shall not eliminate or limit the liability of a director: (i) for any breach of the director’s duty of loyalty to the Company or its stockholders; (ii) for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law; (iii) under Section 174 of the Delaware General Corporation Law; or (iv) for any transaction from which the director derived an improper personal benefit. If the Delaware General Corporation Law is amended after the date of this Certificate to authorize corporate action further eliminating or limiting the personal liability of directors, then the liability of a director of the Company shall be eliminated or limited to the fullest extent permitted by the Delaware General Corporation Law, as so amended.

SECTION 6. For purposes of this Article Seven, references to “the Company” shall include, in addition to the resulting corporation, any constituent corporation (including any constituent of a constituent) absorbed in a consolidation or merger which, if its separate existence had continued, would have had power and authority to indemnify its directors, officers, employees or agents, so that any person who is or was a director, officer, employee or agent of such constituent corporation, or is or was serving at the request of such constituent corporation as a director, officer, trustee, employee or agent of or in any capacity with another corporation, partnership, joint venture, trust or other enterprise, shall stand in the same position under this Article Seven with respect to the resulting or surviving corporation as he or she would have with respect to such constituent corporation if its separate existence had continued.

ARTICLE EIGHT

The directors shall have powers without the assent or vote of the stockholders to fix and vary the amount to be reserved for any proper purpose; to authorize and cause to be executed mortgages and liens upon all or any part of the property of the Company; to determine the use and disposition of any surplus or net profits; and to fix the times for the declaration and payment of dividends.

ARTICLE NINE

The directors in their discretion may submit any contract or act for approval or ratification at any annual meeting of the stockholders or at any meeting of the stockholders called for the purpose of considering any such act or contract, and any contract or act that shall be approved or be ratified by the vote of the holders of a majority of the stock of the Company which is represented in person or by proxy at such meeting and entitled to vote thereat (provided that a lawful quorum of stockholders be there represented in person or by proxy) shall be as valid and as binding upon the Company and upon all the stockholders as though it had been approved or ratified by every stockholder of the Company, whether or not the contract or act would otherwise be open to legal attack because of directors’ interest or for any other reason.

ARTICLE TEN

In addition to the powers and authorities hereinbefore or by statute expressly conferred upon them, the directors are hereby empowered to exercise all such powers and do all such acts and things as may be exercised or done by the Company subject, nevertheless, to the provisions of the statutes of the State of Delaware, of this Certificate and of any Bylaws from time to time made by the stockholders; provided, however, that no Bylaws so made shall invalidate any prior act of the directors which would have been valid if such Bylaw had not been made.

ARTICLE ELEVEN

Section 203 of the Delaware General Corporation Law shall not apply to the Company.

ARTICLE TWELVE

Whenever a compromise or arrangement is proposed between this corporation and its creditors or any class of them and/or between this corporation and its stockholders or any class of them, any court of equitable jurisdiction within the State of Delaware may, on the application in a summary way of this corporation or of any creditor or stockholder thereof or on the application of any receiver or receivers appointed for this corporation under Section 291 of the Delaware General Corporation Law or on the application of trustees in dissolution or of any receiver or receivers appointed for this corporation under Section 279 of the Delaware General Corporation Law, order a meeting of the creditors or class of creditors, and/or of the stockholders or class of stockholders of this corporation, as the case may be, to be summoned in such manner as the said court directs. If a majority in number representing three fourths in value of the creditors or class

of creditors, and/or of the stockholders or class of stockholders of this corporation, as the case may be, agree to any compromise or arrangement and to any reorganization of this corporation as consequence of such compromise or arrangement, the said compromise or arrangement and the said reorganization shall, if sanctioned by the court to which the said application has been made, be binding on all the creditors or class of creditors, and/or on all the stockholders or class of stockholders, of this corporation, as the case may be, and also on this corporation.

ARTICLE THIRTEEN

The Company reserves the right to amend, alter, change or repeal any provision contained in this Certificate in the manner now or hereafter prescribed by law, and all rights and powers conferred herein on stockholders, directors and officers are subject to this reserved power.