## Facts

- Union Carbide owned two patents claiming methods and articles for packaging and dispensing stacks of plastic meat-packing bags.
- The claimed systems used a stack of bags with aligned holes and an elongate flexible binding passing through the holes to form a loop.
- The loop was secured to the bottom of the stack to serve as a handle and, when severed, continued to retain the stack while allowing bags to be removed one at a time.
- Before the claimed inventions, meat-packing bags were provided in other forms, including loose stacks, perforated rolls, shingled stacks, or dispenser boxes.
- Prior-art references considered by the district court included patents describing the retention/binding of stacked sheets using loops or similar bindings, including some references not cited during PTO examination.
- Union Carbide sued American Can for patent infringement in the Northern District of Illinois.
- The district court granted summary judgment to American Can, holding both patents invalid for obviousness under 35 U.S.C. § 103.
- Union Carbide appealed, arguing the inventions were nonobvious and that factual disputes existed about the scope/content of the prior art, particularly uncited patents.

## Issues

1. Whether the district court properly granted summary judgment that the asserted claims were obvious under 35 U.S.C. § 103 in view of the prior art.
2. Whether reliance on prior-art patents not cited by the PTO examiner created a genuine dispute of material fact as to the scope and content of the prior art, precluding summary judgment.

## Decision

- The Federal Circuit affirmed the summary judgment.
- The court held Union Carbide failed to raise a genuine issue of material fact regarding the scope and content of the prior art.
- The court held that, considering the references, the claimed inventions would have been obvious to a person having ordinary skill in the art at the time of invention.
- The court accepted consideration of prior-art references not cited during prosecution and rejected the argument that references focused on retaining paper sheets were categorically irrelevant to bag packaging.

## Legal Principles

- Summary judgment on obviousness is proper when there is no genuine dispute of material fact concerning the scope and content of the prior art and the obviousness determination can be made on the undisputed record.
- Prior art not cited or considered during PTO examination may be relied upon in litigation to prove invalidity; examiner silence does not bar consideration of additional references.
- A reference may qualify as analogous art even if it relates to a different material or product type, so long as it addresses the same or a closely related functional problem (e.g., binding, carrying, and controlled removal of stacked items).
- Differences framed as “dispensing” versus “retaining” do not defeat obviousness where the claimed invention addresses binding and handling functions taught by the prior art.

## Conclusion

The Federal Circuit upheld invalidation of Union Carbide’s bag-packaging patents as obvious, concluding that undisputed prior art teaching loop-based binding of stacked articles rendered the claims obvious and that uncited but analogous references could be used to sustain summary judgment under § 103.


Union Carbide Corp. v. Am. Can Co., 724 F.2d 1567 (Fed. Cir. 1984)