Vernacare Limited v Moulded Fibre Products Limited

Patent infringement is assessed first by the normal, purposive construction of the claims and then, where necessary, by equivalence. A feature which is merely a common-general-knowledge strengthening rib will not ordinarily fall within a claim directed to a different inventive configuration, nor will the doctrine of equivalents extend a valid claim to an obvious variant. For obviousness, the skilled person is defined by the relevant art and its real-world common general knowledge. Specialist knowledge cannot be imported merely because specialist advice might be obtained. The Windsurfing/Pozzoli analysis must be undertaken without hindsight, having regard to motivation and the available research avenues. A known substance used in a new context may involve an inventive step where the prior art gives no reason to make that move.

Vernacare alleged that Moulded Fibre Products’ disposable moulded-paper-pulp washbowl infringed claims of two patents. The 793 Patent concerned the configuration of the bowl, including recesses forming grip means. The 947 Patent concerned a pulp composition using a fluorocarbon and a biocide to provide detergent resistance.

MFP denied infringement of the 793 Patent and relied on an invalidity squeeze. It accepted that its bowl fell within claims 1, 3, 9 and 12 of the 947 Patent, but contended that those claims were obvious over the Japanese applications Shimooka and Sugimoto. The issues were the proper construction of the claims, infringement, and inventive step.

1. 793 Patent. The court followed the two-stage infringement approach in Icescape v Ice World: normal construction followed, if necessary, by equivalence. On normal construction, “recesses” required recessed sections bounded by sides. A continuous sinusoidal ridge was not a pair of such recesses. The court agreed with the construction adopted in the earlier EPP Proceedings, although that decision was not binding.

2. The ridge would nevertheless have constituted grip means facilitating lifting if it had been a recess. The claim contained no requirement of intention. The infringement claim therefore failed because the necessary recesses were absent.

3. The invalidity squeeze reinforced that conclusion. The claim could not properly be construed to cover any common-general-knowledge strengthening rib. On equivalence, the court accepted the Formstein approach explained by Birss LJ in Facebook v Voxer: a valid claim should not be extended to an equivalent which is obvious over the prior art or common general knowledge. Alternatively, the third Improver question would have been answered for MFP.

4. 947 Patent. The expression “detergent resistant binding agent” was read as referring broadly to the relevant property of the pulp composition, whether technically achieved by binding or sizing. The inventive concept was a detergent-resistant moulded-paper-pulp washbowl made using a fluorocarbon in the pulp composition.

5. Applying the Windsurfing/Pozzoli approach, the relevant skilled person was the practitioner in the moulded-paper-pulp sector, not a specialist paper chemist. Fluorocarbons were not part of that person’s common general knowledge for detergent resistance. Neither Shimooka nor Sugimoto supplied a reason to move from oil and water resistance in food containers to detergent resistance in a washbowl. That step was inventive. The claims were therefore valid. Claims 3, 9 and 12 were also not shown to be obvious on the pleaded prior art.

6. Secondary evidence of long felt want and commercial success did not materially assist, although the product had achieved commercial success.

The 793 Patent was valid but not infringed. The relevant claims of the 947 Patent were valid and infringed.