
<PAGE>
 
                                                                   Exhibit 10.37

                              AMENDMENT NO. 1 TO
                               ROLL-IN AGREEMENT
                               -----------------

          This Amendment No. 1 to Roll-In Agreement (this "Amendment") is
entered into as of May 15, 1996 by and among ZB Holdings, Inc., a South Carolina
corporation ("ZBH"), The InterTech Group, Inc., a South Carolina corporation
("InterTech"), Polymer Group, Inc., a Delaware corporation ("PGI"), Polypore,
Inc., a Delaware corporation ("Polypore"), Chase Manhattan Investment Holdings,
Inc., a Delaware corporation ("CMIHI"), Jerry Zucker ("Zucker"), James Boyd
("Boyd"), and Golder, Thoma, Cressey Fund III Limited Partnership, an Illinois
limited partnership ("GTC").

          The parties hereto, together with FTG, Inc., a South Carolina
corporation ("FTG"), are parties to a Roll-In Agreement, dated as of November
18, 1994 ("Agreement").  InterTech has acquired all of the PGI capital stock
owned by FTG and, as a result, has succeeded to the rights and obligations of
FTG with respect to such stock under the Agreement.  The parties hereto desire
to amend the Agreement in the manner specified herein.  Capitalized terms used
herein and not otherwise defined shall have the respective meanings assigned to
such terms in the Agreement.

          NOW, THEREFORE, in consideration of the foregoing and other good and
valuable consideration, the receipt and sufficiency of which is hereby
acknowledged, the parties hereto hereby agree as follows:

          1.   Amendments.

          (A)  The second paragraph of the Agreement (i.e., the second recital)
     is hereby amended by deleting such paragraph and replacing it with the
     following:

          InterTech, GTC, Chase, Zucker and Boyd each own shares of PGI capital
          stock (in their capacity as holders of such capital stock, the "PGI
          Stockholders").  ZBH, GTC, Chase, Zucker and Boyd each own shares of
          Polypore capital stock (in their capacity as holders of such capital
          stock, the "Polypore Stockholders").  PGI and Polypore are
          collectively referred to herein as the "Companies."  The Polypore
          Stockholders desire to grant to the PGI Stockholders the option to
          cause the Polypore Stock (as defined below) to be exchanged for shares
          of PGI Stock (as defined below) on the terms and subject to the
          conditions set forth herein.

          (B)  A third paragraph (i.e., a third recital) is hereby added to the
     Agreement as follows:

          The parties hereto acknowledge that all outstanding shares of PGI
          capital stock are to be exchanged for shares of PGI's common stock,
          par value $.01 per share ("PGI Common Stock"), pursuant to a
          Recapitalization Agreement to be entered into by and among PGI and
<PAGE>
 
          its stockholders as of May 15, 1996 (the "Recapitalization
          Agreement"). A portion of the PGI Common Stock to be issued pursuant
          to the Recapitalization Agreement will be subject to this Agreement as
          set forth in paragraph 1(b) hereof.

          (C)  Paragraph 1 of the Agreement is hereby amended by deleting such
     paragraph and replacing it with the following:

          1.   Option to Require Exchange of Stock.

               (a) At any time, the persons who hold, as of May 15, 1996, a
          majority of the PGI Stock (as defined below) (the "PGI Majority
          Holders") will have one election, exercisable by written notice
          delivered to the Polypore Stockholders not less than 30 days prior to
          the closing date selected by the PGI Majority Holders, to cause the
          exchange (an "Exchange") by the Polypore Stockholders of the Polypore
          Stock  for the PGI Stock.  Each class of the Polypore Stock shall be
          allocated among the PGI Stockholders stock pro rata based upon their
          ownership of PGI Stock prior to the exchange.  The PGI Stock shall be
          allocated among the Polypore Stockholders pro rata based upon the
          relative values (determined under paragraph 2 below) of the Polypore
          Stock given up in the exchange by each Polypore Stockholder.

               (b) For purposes hereof, (i) the "PGI Stock" shall mean, for any
          PGI Stockholder, a number of shares of PGI Common Stock equal to 21.5%
          of the number of shares of PGI Common Stock into which the shares of
          PGI capital stock set forth opposite each PGI Stockholder's name on
          Schedule A attached hereto are converted pursuant to the
          Recapitalization Agreement (as such number is equitably adjusted for
          stock splits, stock dividends, combinations of shares,
          recapitalizations and similar transactions), or such lesser number of
          shares as may be owned by such PGI Stockholder at the time of an
          Exchange, it being understood that this Agreement shall apply to a
          certain number of shares of PGI Common Stock rather than any
          particular shares of PGI Common Stock; and (ii) the "Polypore Stock"
          shall mean, for any Polypore Stockholder, the number of shares of each
          class of Polypore capital stock set forth opposite each Polypore
          Stockholder's name on Schedule A attached hereto (as such numbers are
          equitably adjusted for stock splits, stock dividends, combinations of
          shares, recapitalizations and similar transactions); provided that
          immediately prior to any Exchange, all shares of convertible preferred
          stock of Polypore shall be converted to common stock.


                                      -2-
<PAGE>
 
               (c) If any PGI Stockholder owns less than the number of shares of
          PGI Stock into which the shares of PGI capital stock set forth
          opposite such PGI Stockholder's name on Schedule A attached hereto are
          converted pursuant to the Recapitalization Agreement, the amount of
          Polypore Stock to be exchanged by the Polypore Stockholders shall be
          proportionately reduced, and such Polypore Stock received by the PGI
          Stockholders shall be allocated pursuant to (a) above taking into
          account such lesser number of shares.

               (d) The costs and expenses of any Exchange will be paid 78.5% by
          the PGI Stockholders and 21.5% by the Polypore Stockholders.

          (D)  All references to the defined term "Roll-In" anywhere in the
     Agreement shall be amended by deleting such reference and replacing it with
     the defined term "Exchange."

          (E)  Paragraph 2 of the Agreement is hereby amended by deleting the
     parenthetical at the end of the last sentence thereof.

          (F)  Paragraph 3 of the Agreement is hereby amended by deleting the
     last three sentences thereof.

          (G)  Paragraph 4(b) of the Agreement is hereby amended by deleting
     such paragraph and replacing it with the following:

                    (b) Stockholders' Agreements; Regulation Y.

                    (i)  All stockholder agreements relating to the PGI Stock
          and/or the Polypore Stock in existence immediately prior to any
          Exchange shall remain in full force and effect immediately after such
          Exchange, and the PGI Stock or Polypore Stock (as the case may be)
          shall continue to be subject to the terms thereof; provided that PGI,
          Polypore, the PGI Stockholders and the Polypore Stockholders hereby
          waive any restrictions on transfer that may be contained in any such
          agreement (whether now in existence or subsequently entered into) with
          respect to any Exchange.

                    (ii)  Any holder of stock who is subject to Regulation Y
          promulgated by the Board of Governors of the Federal Reserve, or any
          successor regulation thereto, will not be required to accept any
          securities in an Exchange which it would not be required to accept
          under Section 8.2(h) of the Stockholders Agreement, dated as of
          November 18, 1994, among Polypore, the Polypore Stockholders and
          certain other parties, and the parties will comply with Section 3H of
          the Purchase Agreement, dated as of November 18, 1994, among Polypore,
          GTC, ZBH and Chase, with respect to any Exchange.


                                      -3-
<PAGE>
 
          (H)  Paragraph 5 of the Agreement is hereby amended by deleting all
     references therein to "PGI Stock".

          (I)  Paragraph 6 of the Agreement is hereby amended by deleting the
     first sentence thereof and replacing it with the following:

          Except as otherwise provided herein, no modification, amendment or
          waiver of any provision of this Agreement shall be effective against
          any party unless such modification, amendment or waiver is approved in
          writing by the holders of a majority of the PGI Stock and the holders
          of a majority of the Polypore Stock; provided that to the extent any
          amendment would materially and adversely affect any party hereto, such
          amendment will not be effective without such party's consent.

          (J)  Paragraph 14 of the Agreement is hereby amended by deleting such
     paragraph and replacing it with the following:

          This Agreement will terminate on the earlier of (i) the tenth
          anniversary of the date hereof and (ii) the occurrence of a Change in
          Control.  The rights of the PGI Majority Holders hereunder will
          terminate on the earlier of (i) the date the Exchange contemplated
          hereby is consummated and  (ii) the first date on which GTC does not
          own any PGI Common Stock.  For purposes of this Agreement, "Change in
          Control" means the acquisition by an independent third party of a
          majority of the voting securities of Polypore or the sale by Polypore
          to an independent third party of all or substantially all of its
          assets.

          2.   Conditions to Effectiveness.  This Amendment will be effective
only upon (i) the consummation of the initial public offering of PGI's common
stock, and (ii) the execution by Connecticut General Life Insurance Company and
CIGNA Mezzanine Partners III, L.P.  of the consent attached hereto as Exhibit I.

          3.   Miscellaneous.  This Amendment may be executed in two or more
counterparts each of which shall be an original and all of which taken together
shall constitute one and the same Amendment.  This Amendment shall be governed
by the internal law, and not the law of conflicts, of New York.

                               *   *   *   *   *


                                      -4-
<PAGE>
 
          IN WITNESS WHEREOF, the parties hereto have executed this Amendment
No. 1 to Roll-In Agreement on the day and year first above written.

                                      THE INTERTECH GROUP, INC.


                                      By:  /s/ Jerry Zucker
                                           -------------------------------------

                                      Its: Chairman, President & CEO
                                           -------------------------------------

                                      POLYMER GROUP, INC.


                                      By:  /s/ Jerry Zucker
                                           -------------------------------------

                                      Its: Chairman, President & CEO
                                           -------------------------------------


                                      POLYPORE, INC.
                

                                      By:  /s/ Jerry Zucker
                                           -------------------------------------

                                      Its: Chairman, President & CEO
                                           -------------------------------------


                                      CHASE MANHATTAN INVESTMENT HOLDINGS, INC.


                                      By:  /s/ Donna L. Carter
                                           -------------------------------------
                                      Its: Senior Vice President & Treasurer



                                      /s/ Jerry Zucker
                                      ------------------------------------------
                                      JERRY ZUCKER


                                      /s/ James G. Boyd
                                      ------------------------------------------
                                      JAMES BOYD



<PAGE>
                      CONTINUATION OF SIGNATURE PAGES TO
                     AMENDMENT NO. 1 TO ROLL-IN AGREEMENT


 
                                      GOLDER, THOMA, CRESSEY FUND III LIMITED
                                      PARTNERSHIP

                                      By:   Golder, Thoma, Cressey, Rauner, L.P.
                                      Its:  General Partner


                                      By:  /s/ Bruce V. Rauner
                                           -------------------------------------
                                      Its: General Partner
                                           -------------------------------------

                                      ZB HOLDINGS, INC.


                                      By:  /s/ Jerry Zucker
                                           -------------------------------------
                                      Its: Chairman, President & CEO
                                           -------------------------------------


<PAGE>
 
                                  SCHEDULE A
                                  ----------


                               PGI Stockholders
                               ----------------
<TABLE>
<CAPTION>
 
Name                                 PGI Stock/1/
----                                 ------------

                    Class           Class           Class          Class
                     A-1             A-2             A-3             B
                   Common          Common          Common         Common
                   ------          ------          ------         ------ 
<S>                <C>             <C>            <C>            <C>
GTC               111,825                         115,000        185,902
                                                                
InterTech                                                        118,476
                                                           
Zucker                                                            21,802
                                                           
Boyd                                                               7,267
                                                           
CMIHI                              17,248                         14,136
                                                           
</TABLE>                                                        


                             Polypore Stockholders
                             ---------------------
<TABLE>
<CAPTION>
 
Name                           Polypore Stock/2/
----                           -----------------

                  Class A         Class B-1       Class B-2
                 Preferred       Preferred/3/    Preferred/3/   Common Stock
                 ---------       ------------    ------------   ------------ 
<S>              <C>             <C>             <C>            <C>
GTC                 2,565          18,314

ZBH                 5,861          41,872

Zucker                                                            27,876

Boyd                                                               9,289

CMIHI               2,565                          18,314

</TABLE>

---------------------

/1/    Amounts represent PGI capital stock outstanding as of the time of the
Polypore acquisition/formation, as adjusted for the recapitalization which
occurred on March 15, 1995 in connection with the Chicopee acquisition.  All
such shares will be converted into PGI Common Stock pursuant to the
Recapitalization Agreement.

/2/    Amounts are equal to 78.5% of each class of capital stock held by the
indicated stockholder.

/3/    All convertible preferred stock will be converted into common stock prior
to the Exchange.


<PAGE>

                                                                       Exhibit I
                                                                       ---------
 
                             Consent to Amendment


          The undersigned hereby consent to Amendment No. 1 to Roll-In Agreement
in the form attached hereto as Annex 1.



                                      CONNECTICUT GENERAL LIFE
                                             INSURANCE COMPANY

                                      By:   CIGNA Investments, Inc. (as Agent)


                                      By: 
                                          --------------------------------------
                                      Its: 
                                          --------------------------------------

                                      CIGNA MEZZANINE PARTNERS III, L.P.

                                      By:   CIGNA Investments, Inc. (as Agent)


                                      By: 
                                          --------------------------------------
                                      Its: 
                                          --------------------------------------

