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                                                                    EXHIBIT 3.15
                            ARTICLES OF INCORPORATION

                                       OF

                                   P P C, INC.

                                      ****

      THE UNDERSIGNED, desiring to form a corporation, for profit, under
Sections 1701.01 et seq. of the Revised Code of Ohio, do hereby certify:

      FIRST: The name of said corporation shall be

                                   P P C, INC.

      SECOND: The place in the State of Ohio where its principal office is to be
located is Cleveland, in Cuyahoga County.

      THIRD: The purposes for which it is formed are:

      to engage in any lawful act or activity for which corporations may be
formed under Sections 1701.01 to 1701.98 inclusive of the Revised Code of Ohio.

      To purchase or otherwise acquire, lease as lessee, invest in, hold, use,
lease as lessor, encumber, sell, exchange, transfer, and dispose of property of
any description or any interest therein.

      To acquire, hold, use, sell, assign, lease, grant licenses in respect of,
mortgage or otherwise dispose of letters patent of the United States or any
foreign country, patent rights, licenses and privileges, inventions,
improvements and processes, copyrights, trademarks and tradenames, relating to
or useful in connection with any business of this corporation.

      To acquire by purchase, subscription or otherwise, and to receive, hold,
own, guarantee, sell, assign, exchange, transfer, mortgage, pledge, or otherwise
dispose of or deal in and with any of the shares of the capital stock, or any
voting trust certificates in respect of the shares of capital stock, scrip,
warrants, rights, bonds, debentures, notes, trust receipts, and other
securities, obligations, choses in action and evidences of indebtedness or
interest issued or
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created by any corporations, joint stock companies, syndicates, associations,
firms, trusts or persons, public or private, or by the government of the United
States of America or by any foreign government, or by any state, territory,
province, municipality or other political subdivision or by any governmental
agency, and as owner thereof to possess and exercise all the rights, powers and
privileges of ownership, including the right to execute consents and vote
thereon, and to do any and all acts and things necessary or advisable for the
preservation, protection, improvement and enhancement in value thereof.

      To enter into, make and perform contracts of every kind and description
with any person, firm, association, corporation, municipality, county, state,
body politic or government or colony or dependency thereof.

      To purchase or otherwise acquire all or any part of the business, good
will, rights, property and assets, and to assume all or any part of the
liabilities of any corporation, association, partnership or individual engaged
in any business in which any corporation organized under sections 1701.01 et
seq. of the Revised Code of Ohio is entitled to engage.

      To borrow money, and issue, sell, and pledge its notes, bonds, and other
evidences of indebtedness, and secure any of its obligations by mortgage,
pledge, or deed of trust of all or any of its property, and guarantee or secure
obligations of any person.

      To purchase, hold, sell and transfer the shares of its own capital stock
to the extent permitted by law but no such purchase may be made when there is
reasonable ground for believing that the corporation is unable, or, by such
purchase, may be rendered unable to satisfy its obligations and liabilities.

      To conduct its business, and to have and maintain one or more offices,
within and without the State of Ohio and in all other states and territories, in
the District of Columbia, in all dependencies, colonies, or possessions of the
United States of America and in foreign countries; and to purchase, or otherwise
acquire, hold, own, equip, improve, manage operate, promote, finance, sell,
convey, mortgage or otherwise dispose of real and personal property in all such
states and places, to the extent that the same may be permissible under the laws
thereof.

      To carry on any other lawful business and to do any and every thing
necessary, suitable, convenient or proper for
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the accomplishment of any of the purposes or the attainment of any one or all of
the objects hereinbefore enumerated or incidental to the powers herein named or
for the enhancement of the value of the properties of the corporation or which
shall at any time appear conducive thereto or expedient, either as holder of, or
as interested in, any property or otherwise; to have all the rights, powers, and
privileges now or hereafter conferred by the laws of the State of Ohio upon
corporations organized under sections 1701.01 et seq. of the Revised Code of
Ohio or under any act amendatory thereof, supplemental thereto or substituted
therefor.

      The objects and purposes specified in the foregoing clauses shall, except
where otherwise expressed, be in nowise limited or restricted by reference to,
or inference from, the terms of any other clause in these articles of
incorporation, but the objects and purposes specified in each of the foregoing
clauses of this article shall be regarded as independent objects and purposes.

      FOURTH: The authorized number of shares of the corporation is Five Hundred
(500) which shall be classified as follows:



      CLASS             NO. OF SHARES           PAR VALUE
                                            
      Common                500                  $1.00


      FIFTH: The amount of stated capital with which the corporation will begin
business is Five Hundred Dollars ($500.00).

      SIXTH: The following provisions are hereby agreed to for the purpose of
defining, limiting and regulating the exercise of the authority of the
corporation, or of the directors, or of all of the shareholders:

      The board of directors is expressly authorized to set apart out of any of
the funds of the corporation available for dividends a reserve or reserves for
any proper purpose or
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to abolish any such reserve in the manner in which it was created, and to
purchase on behalf of the corporation any shares issued by it to the extent of
the surplus of the aggregate of its assets over the aggregate of its liabilities
plus stated capital.

      The corporation may in its regulations confer powers upon its board of
directors in addition to the powers and authorities conferred upon it expressly
by Sections 1701.01 et seq. of the Revised Code of Ohio.

      Any meeting of the shareholders or the board of directors may be held at
any place within or without the State of Ohio in the manner provided for in the
regulations of the corporation.

      Any amendments to the articles of incorporation may be made from time to
time, and any proposal or proposition requiring the action of shareholders may
be authorized from time to time by the affirmative vote of the holders of shares
entitling them to exercise a majority of the voting power of the corporation.

      SEVENTH: The corporation reserves the right to amend, alter, change or
repeal any provision contained in its articles of incorporation, in the manner
now or hereafter prescribed by Sections 1701.01 et seq. of the Revised Code of
Ohio, and all rights conferred upon shareholders herein are granted subject to
this reservation.
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      IN WITNESS WHEREOF, We have hereunto subscribed our names this 22nd day of
September, 1972.


                                       /s/ Robert D. Pischer
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                                       Robert D. Pischer


                                       /s/ Robert K. Bennett
                                       -------------------------------
                                       Robert K. Bennett


                                       /s/ Martin C. Roach
                                       -------------------------------
                                       Martin C. Roach