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Patent Review Board Must Re-Examine Leithem's Fluff Pulp Claim

By Robyn Hagan Cain on September 21, 2011 | Last updated on March 21, 2019

Fast and loose are two words that should never be associated with diapers, or with patent analysis.

The Federal Circuit Court of Appeals, however, ruled on Monday that a patent appeals board's "fast and loose" decision rejecting an applicant's diaper patent disregarded procedural safeguards to the applicant.

Phyllis Leithem's patent application disclosed an improved diaper. Traditional diapers are constructed using an absorbent core of dry shredded wood fiber pulp, known as fluff pulp, interposed between a water barrier sheet and a permeable layer that allows liquid to pass through to the absorbent fluff pulp core.

For absorption intensive devices, such as baby diapers, the fluff pulp is often pretreated with a chemical cross-linking agent to maintain the diaper's form while enhancing absorbency. Leithem wanted to invent a diaper that would avoid the expense of using chemically cross-linked fluff pulp while still retaining the superior absorbency properties characteristic of a cross-linked fluff pulp, and contends that prior to its discovery, such a diaper was thought impossible.

Leithem defied diaper logic, and discovered that when wood pulp is extracted with a caustic substance at low temperature and is then dried and fluffed, the resulting fluff pulp is imbued with superior absorbency properties without the need for the extra step and expense of chemically cross-linking the fluff pulp.

When Leithem attempted to patent the process, the examiner rejected the claim as modifications of two existing patents, Pociluyko and Novak. Pociluyko disclosed a diaper satisfying every element of Leithem's claim, except that it was "silent as to the method of manufacturing the fluff pulp," and Novak disclosed cold caustic extraction of wood pulp and "a method of making fluff pulp."

Leithem appealed to the Board of Patent Appeals and Interferences (Board), which found that, while the Novak patent didn't mention a fluffed pulp, it could be fluffed for diaper use. Leithem petitioned for re-hearing, claiming that the board had used a new ground of rejection that the examiner had not relied upon. The petition was denied.

The Federal Circuit Court of Appeals vacated the Board's decision, finding that Leithem is entitled to rehearing because the Board relied upon a new ground of rejection. Citing In re Kronig, the court noted, "The ultimate criterion of whether a rejection is considered 'new' in a decision by the Board is whether [applicants] have had fair opportunity to react to the thrust of the rejection."

Here, the examiner cited Novak as teaching a fluff pulp. Leithem argued that Novak's pulp is not fluffed, that Novak does not teach fluffing, and that Novak only teaches wet-laid paper. The Board agreed with Leithem but instead affirmed the examiner's rejection by finding that Novak teaches a pulp "which may be fluffed." The Board thus found new facts concerning the scope and content of the prior art.

Do you agree, or is the Federal Circuit Court of Appeals full of fluff?

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