In almost all cases, the UK court will issue a final injunction following a finding of patent validity and infringement. Normally such final injunctions are drafted in general terms, to restrain the infringing party from any further infringement of the patent in suit. Injunctions are not normally linked to a particular infringing act or product.

This case considered the extent to which courts can later vary the terms of such final injunctions. Sir Anthony Mann allowed Fiberweb's application to exclude a new design-around product (which was not considered at trial and is subject to separate non-infringement proceedings) from an injunction that restrained Fiberweb from infringing Geofabric's patent. He held that such an application was analogous to similar applications made at the end of a trial to exclude modified and allegedly non-infringing variations from the injunction (see Illumina and Unilever below), and noted that the relevant considerations are similar to those for interim injunctive relief. In light of Geofabrics' unwillingness to provide a cross-undertaking in damages to Fiberweb, he found that the status quo required a variation to the injunction.


In March 2020 Mr David Stone, sitting as a Deputy High Court Judge, found Geofabrics' Patent to be valid and infringed by Fiberweb's product, Hydrotex 2. The patent relates to trackbed liners for railways, which prevent erosion caused by the repeated and rapid application of pressure from the passage of trains causing water, clay, and silt particles to be squeezed out of the trackbed. Such liners work by being permeable to water, but not solid particles, under the pressure of a passing train. For the present purposes, the relevant integer of the patent was the requirement that the liner was impermeable to water under normal conditions (i.e. in the absence of a train). Hydrotex 2 was found to fulfil this condition and thus to infringe.

At the form of order hearing in April 2020, Mr Stone awarded Geofabrics a final injunction in the standard form, restraining Fiberweb from infringing Geofabrics' patent (the 2020 Injunction). The parties agreed to stay the 2020 injunction pending appeal.

On 3 April 2020, between judgment and Mr Stone's order granting the injunction, Fiberweb commenced proceedings for a declaration of non-infringement (DNI) in respect of a new product, Hydrotex 4, which Fiberweb contends has greater permeability than Hydrotex 2, such that it avoids falling within the scope of the claims. Other than a short reference to Hydrotex 4 in Fiberweb's original application for a stay of the injunction pending appeal, no reference was made to Hydrotex 4 or the DNI proceedings at the form of order hearing before Mr Stone.

The Court of Appeal upheld Mr Stone's judgment in June 2021 (a summary of this decision can be found here) and the 2020 Injunction took effect. The question in the present case was whether Fiberweb was entitled to a carve-out from the 2020 Injunction for Hydrotex 4.


Distinguishing considerations of finality

Mann considered the decision in Tibbles1, in which Rix LJ emphasised the importance of finality for claims and stated that in order to revisit an earlier High Court order, "the applicant must either show some material change of circumstances or that the judge who made the earlier order was misled in some way, whether innocently or otherwise, as to the correct factual position before him". Mann distinguished this decision on the basis that Tibbles related to attempt by litigants to revisit issues already addressed by the court. In the present case, Fiberweb were not challenging the finality of Mr Stone's judgment but questioning its applicability to another product.

Mann acknowledged that such a distinction may not have been available if the question of whether Hydrotex 4 was excluded from the injunction had been the subject of an earlier formal decision (or was necessarily and obviously a part of what ought to have been raised before Mr. Stone). On the latter point, Mann noted that the parties had acknowledged the existence of Hydrotex 4 and the DNI proceedings prior to the form of order hearing before Mr Stone, but likely concluded that the stay would be appropriate for the time being to benefit Hydrotex 4.

Granting carve-out

Mann held that the application in this case was similar to applications made at the end of trial regarding the scope of an injunction, as considered in Illumina [2019] EWHC 2405 (where Arnold J refused to grant a general injunction which would cover a new product made from a modified process which the defendant contended did not infringe) and Unilever [1994] RPC 567 (where Jacob J qualified an injunction to carve-out a new product whose infringing qualities needed to be determined).

Mann considered that the issues raised in the case presented strong parallels with the court's approach to applications for interim injunctions. He found that:

  1. There was a bona fide case that Hydrotex 4 does not infringe and therefore there was a serious question to be tried;
  2. Damages may well be an adequate remedy to Geofabrics (Geofabrics had agreed to the stay of the 2020 Injunction pending appeal on the basis that damages would be paid if validity and infringement by Hydrotex 2 were upheld by the Court of Appeal); and
  3. Geofabrics were unwilling to provide a cross-undertaking in damages to Fiberweb.

Mann expressed sympathy for Fiberweb's disinclination to risk being found to have exploited its Hydrotex 4 product in breach of a court order. He noted that in the absence of a cross-undertaking there was a risk of significant loss to Fiberweb if it could not continue to exploit Hydrotex 4. He held that the status quo required the exclusion of Hydrotex 4 from the injunction and ordered the variation of Mr Stone's injunction to carve out infringement by Hydrotex 4 until determination of the DNI action.  


At first glance it may appear surprising that the court was willing to amend a final order so long after the decision was handed down and the final order made. However, Mann's recognition of the principles in Tibbles and his acknowledgement that his conclusions may have been different if the issue had previously been the subject of a formal decision are both consistent with the principle of finality. Any attempts by litigants to use this decision to get a second bite of the cherry for issues already determined will undoubtedly be thwarted by the court.

This case illustrates that it is in principle possible to obtain a carve-out from a final injunction to allow a variant designed to avoid a previous finding of infringement to be launched without risk of contempt proceedings. However, parties contemplating "design-around" modifications to avoid a finding of infringement should raise the issue as soon as is they reasonably can – ideally, if possible, by way of an application for a DNI in the original proceedings. Mann did not find Fiberweb's delay in bringing proceedings for a DNI until after Mr Stone's judgment to be determinative in this case. However, there remains a real risk that the court may decline to grant a carve out from a final injunction if a party  fails to raise the issue of (non)infringement of its new product when it should have done so earlier in the proceedings.  


1. [2012] 1 WLR 2591

Originally published 19 July 2021

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