Pall Corp. v. Micron Separations, Inc.

• Decision Date: 26 September 1995
• Docket Number: 91-1394 and 91-1409,Nos. 91-1393,s. 91-1393
• Citation: 36 USPQ2d 1225,66 F.3d 1211
• Parties: , 43 Fed. R. Evid. Serv. 97 PALL CORPORATION, Plaintiff/Cross-Appellant, v. MICRON SEPARATIONS, INC., Defendant-Appellant.
• Court: U.S. Court of Appeals — Federal Circuit

Page 1211

66 F.3d 1211

36 U.S.P.Q.2d 1225, 43 Fed. R. Evid. Serv. 97

PALL CORPORATION, Plaintiff/Cross-Appellant, v. MICRON SEPARATIONS, INC., Defendant-Appellant.

Nos. 91-1393, 91-1394 and 91-1409.

United States Court of Appeals, Federal Circuit.

Sept. 26, 1995.

Rehearing Denied Oct. 24, 1995.

H. Michael Hartmann, Leydig, Voit & Mayer, Chicago, IL, argued, for plaintiff/cross-appellant. With him on the brief were Mark E. Phelps, Paul J. Korniczky, Bruce M. Gagala and Jeffrey S. Ward. Also on the brief was George P. Field, Boston, MA.

Steven M. Bauer, Testa, Hurwitz & Thibeault, Boston, MA, argued, for defendant-appellant. With him on the brief were Mark Schonfeld and Loletta L. Darden. Also on the brief was Robert M. Ward, Allegretti & Witcoff, Boston, MA.

Roy E. Hofer, President, Federal Circuit Bar Association, Washington, DC, Anne E. Brookes, Honegman, Miller, Schwartz & Cohen, Houston, TX and Robert J. Carlson, Christensen, O'Connor, Johnson & Kindness, Seattle, WA, were on the brief, for amicus curiae, Federal Circuit Bar Association.

R. Carl Moy, Assistant Professor, William Mitchell College of Law, Saint Paul, MN, was on the brief, for amicus curiae, R. Carl Moy.

Donald Chisum, Morrison & Foerster, Seattle, WA, William Alsup, Morrison & Foerster, San Francisco, CA, Gregory A. Long and Kent R. Raygor, Sheppard, Mullin, Richter & Hampton, Los Angeles, CA, Charles Fried and Arthur Miller, Cambridge, MA, were on the brief, for amicus curiae, Acuson Corporation and Honeywell, Inc.

S. Leslie Misrock, Rory J. Radding and Steven I. Wallach, Pennie & Edmonds, New York City, were on the brief, for amicus curiae, Ad Hoc Committee to Promote Uniformity in the Patent System.

Roger W. Parkhurst, Parkhurst, Wendel & Rossi, Alexandria, VA, Harold C. Wegner, Wegner, Cantor, Mueller & Player, Washington, DC, Nancy J. Linck, Cushman, Darby & Cushman, Washington, DC, and Gary L. Newtson, President, American Intellectual Property Law Association, Arlington, VA, were on the brief, for amicus curiae, American Intellectual Property Law Association.

Before RICH, PAULINE NEWMAN, and MAYER, Circuit Judges.

PAULINE NEWMAN, Circuit Judge.

Both parties appeal aspects of the judgment of the United States District Court for the District of Massachusetts, ¹ wherein Micron Separations, Inc. ("MSI") was adjudged

to have infringed a patent owned by Pall Corporation ("Pall") relating to polyamide membranes that are used in microfiltration. We affirm the judgment of infringement, reverse as to willful infringement, modify the damages award, and remand for recalculation of damages.

Background

Microfiltration membranes have an extremely small pore size, and are used to remove unwanted microscopic substances such as bacteria from fluids, or to separate and retain desired microscopic substances such as antibodies. Microfiltration membranes are used, for example, by pharmaceutical companies in bacteria-free drug production, by electronics manufacturers to purify water for chip manufacture, by hospitals to filter contaminants from fluids that are administered to patients, in diagnostics to detect the presence of antibodies or antigens, and as transfer membranes for identification of genetic characteristics. A particularly useful pore size for microfiltration membranes is about 0.22 micron, for this pore size yields the highest flow rate consistent with retention of the 0.3 micron Pseudomonas diminutia bacteria; removal of these bacteria is the standard criterion for sterilization by microfiltration.

Microfiltration membranes are not new, although membranes of the prior art were generally subject to deficiencies such as brittleness, excessive shrinkage, poor solvent resistance, limited flow rate, excessive clogging, and limited sterilizing ability. Microfiltration membranes had previously been made from organic polymers, but those membranes generally required the use of wetting agents for filtration, for water does not flow well through microporous membranes that are not instantly wettable. The addition of wetting agents to facilitate flow is undesirable because it adds impurities to the system.

In accordance with United States Patent No. 4,340,479, invention of Dr. David B. Pall ("the Pall patent"), microfiltration membranes are made from organic polymers called polyamides. The particular polyamides of this invention are sometimes called "nylons," the generic term for linear aliphatic polyamides. The polyamide membranes at issue were made from the commercially available polymers nylon 66 and nylon 46. ² The method of making these membranes and the membranes themselves are described in the Pall patent and in the district court's opinion, and will be repeated only as necessary to explain our decision.

Membranes had been made of polyamides before Dr. Pall's invention, but the prior membranes were either soluble in alcohol or required the use of wetting agents for efficient filtration. The membranes of the prior art also had a surface skin of reduced porosity that retarded wettability of the membrane material and increased the flow time. The Pall patented membranes are naturally and instantaneously wettable and alcohol-insoluble, with uniform pore size throughout the membrane. They achieve efficient flow without the use of wetting agents. The Pall membranes, due to their improved properties and increased effectiveness in microfiltration, achieved not only commercial success but also scientific recognition. The trial court found:

Dr. Pall and his associates were pioneers both in the invention, development, and commercialization of functional nylon microfiltration membranes and in the theory of microfiltration.

The Pall microfiltration membranes were made of nylon 66, and were introduced into commerce in 1978. The Pall patent issued in 1982. In 1983 MSI introduced a microfiltration membrane made of nylon 66. Pall filed suit in 1986. In 1989 MSI converted most but not all of its nylon 66 membrane production to nylon 46. The case came to trial in 1991.

The district court held that the Pall patent was valid, that MSI's nylon 66 membranes MSI appeals the rulings of infringement and willful infringement. Pall cross-appeals aspects of the damage award.

literally infringed the patent's product claims, that MSI's nylon 46 membranes infringed the product claims under the doctrine of equivalents, and that MSI's process for producing the nylon membranes infringed the patent's process claims under the doctrine of equivalents. The court held that MSI's infringement was willful to the limited extent of MSI's continued manufacture of some nylon 66 membranes after it had shifted most of its production to nylon 46. Although MSI declared bankruptcy after the adverse district court judgment, ³ it remains operating under a stay of injunction granted by the district court as to MSI's nylon 46 membranes. ⁴

INFRINGEMENT

Nylon 66 Membranes

A representative product claim of the Pall patent is:

34. A hydrophilic skinless alcohol-insoluble polyamide resin membrane sheet of alcohol-insoluble hydrophobic polyamide resin selected from the group consisting of polyhexamethylene adipamide, polyhexamethylene sebacate, and poly-l-caprolactam, and capable when completely immersed in water of being wetted through within no more than one second, and reverting when heated to a temperature just below the softening temperature of the membrane to a hydrophobic material which is no longer wetted by water.

Nylon 66 is polyhexamethylene adipamide, named in claim 34. It was not disputed that all of the limitations of claim 34 were met by MSI's nylon 66 membranes, except for the term "skinless," the meaning of which received extensive attention at trial. MSI argued that the plain meaning of "skinless" eliminated the MSI products from infringement, because a photomicrograph showed a "skin" on the MSI membranes. Pall's position was that "skinless" as used in the specification and claims should be understood as a performance characteristic, for a skin is a nonporous layer that impedes filtration.

Claim interpretation is a question of law. Markman v. Westview Instruments, Inc., 52 F.3d 967, 34 USPQ2d 1321 (Fed.Cir.1995) (en banc ). We review the construction of the claims without deference to that of the district court. Id. at 979, 34 USPQ2d at 1329 ("Because claim construction is a matter of law, the construction given the claims is reviewed de novo on appeal.") In construing the claims we look to the language of the claims, the specification, and the prosecution history. Id. Extrinsic evidence may also be considered, if needed to assist in determining the meaning or scope of technical terms in the claims. Id. at 980, 34 USPQ2d at 1330.

At trial both sides presented support for their conflicting positions concerning the term "skinless." Pall presented data showing "bubble point," "flow time," and "KL curve" measurements of the membranes in suit. These measurements were described in the Pall patent specification as tests for determining the presence or absence of a skin on a membrane. The bubble point test measures the pressure applied to a membrane whose pores are filled with water in order to force the water through the pores; the larger the bubble point value, the smaller the pores in the membrane. Flow time is the time required for a certain amount of water to pass through a given area of membrane; the smaller the pores the longer the flow time. The KL curve depicts the flow of water through a membrane at constant pressure; skinless membranes characteristically show an initially level KL curve followed by a sharp rise in the curve as flow commences, whereas KL curves for skinned membranes show a gradual upward-sloping curve. These are generally accepted tests of whether a membrane is skinned or skinless, for a non-porous skin impedes the passage of water through the membrane, and is detected by all three tests. The district court defined "skinless" as a performance...