Jushi Group Company, Ltd (a company registered in the People's Republic of China) v OCV Intellectual Capital, LLC (a company registered in the United States of America)

JurisdictionEngland & Wales
CourtIntellectual Property Enterprise Court
JudgeJudge Hacon
Judgment Date06 February 2017
Neutral Citation[2017] EWHC 171 (IPEC)
Date06 February 2017
Docket NumberCase No: IP-2015-000112

[2017] EWHC 171 (IPEC)




Royal Courts of Justice, Rolls Building

Fetter Lane, London, EC4A 1NL


His Honour Judge Hacon

Case No: IP-2015-000112

Jushi Group Co., Ltd (a company registered in the People's Republic of China)
OCV Intellectual Capital, LLC (a company registered in the United States of America)

Hugo Cuddigan QC (instructed by Beck Greener) for the Claimant

Tom Alkin (instructed by Mewburn Ellis LLP) for the Defendant

Hearing dates: 5–6 December 2016

Judge Hacon



The claimant ("Jushi") plans to import two different compositions of fibre glass products into the United Kingdom ("Product 1" and "Product 2"). It has brought this action for revocation of the UK designation of European Patent 1 831 118 B1 ("the Patent") in order to clear away potential objection to such importation. It also seeks declarations of non-infringement of the Patent. The Patent is owned by the defendant ("OCV") and is for an invention entitled 'Glass yarns for reinforcing organic and/or inorganic materials'. OCV has counterclaimed for threatened infringement.


Jushi has admitted that its threatened importation of Product 2 would infringe if the Patent is valid. OCV admitted in its pleadings that Product 1 fell outside the claims of the Patent. This was on the basis of Jushi's confirmation that the amount of CaO in Product 1 was always less than 11.5%. The trial was therefore concerned solely with the validity of the Patent. The priority date is 16 December 2004. The Patent is in French but there was no difficulty in working from a translation.


Hugo Cuddigan QC appeared for Jushi and Tom Alkin for OCV.

A short summary of the technical background


The invention concerns glass fibres of the sort used to reinforce other materials such as those used in the manufacture of glass fibre boats.


The mechanical properties of glass vary according to type and glass is categorised by reference to its properties. The categories with broadest recognition are those set out in the 'ASTM' standards, specified by ASTM (American Society for Testing Materials) International, a body based in Pennsylvania. For each category, the relevant standard specifies the ranges of constituents that go to make up that type of glass. In 2004 by far the most widely used category was 'E-glass'. 'E' is short for electrical grade. Fibres made from ASTM standard E-glass were at the centre of the present dispute. Two other ASTM categories were mentioned in evidence: R-glass (the R is for reinforcement) was of some significance and there was also S-glass (strength).


Two properties of any glass are its Young's modulus and its specific Young's modulus. The Young's modulus of a material is a measure of its stiffness, i.e. resistance to deformation. It is the force per unit area applied to the material divided by the amount of deformation caused by that force. This is sometimes called stress/strain. The specific Young's modulus is the Young's modulus divided by the mass density of the material, i.e. a measure of stiffness per unit mass.


The process for making glass fibres begins with constituents which are heated until they form a molten glass. The molten glass passes, by gravity, through a furnace or 'bushings' containing a pattern of holes like a sieve, to emerge as fibres which are subsequently cooled and treated further. For the passage through the bushings to work in a satisfactory manner, there are two prime considerations.


The first is to avoid the formation of solid crystals within the molten glass, a process known as 'devitrification'. The presence of crystals will adversely affect the strength of the glass. The 'liquidus' temperature of the glass is the lowest temperature at which the glass is wholly free of crystals.


The second consideration is that the glass should be of the correct viscosity when passing through the bushings – something like liquid honey. The temperature at which the glass will achieve the desired viscosity is known as the 'log 3 forming temperature' or the 'fibre forming temperature'.


One of the significant costs of glass production is that expended on heating. So using a process with a low fibre forming temperature offers an important cost advantage. On the other hand, to ensure that the production of fibres occurs without devitrification, the fibre forming temperature should be at least about 50°C above the liquidus temperature. The American prior art speaks of maintaining a temperature difference of 100°F, or 55.5°C, but the evidence at trial was that, as a rule of thumb, a differential of around 50°C will serve. This differential was referred to sometimes as the 'forming range', in the Patent as the 'fiberizing range', but mostly in evidence and argument as the 'Delta-T'.


The Delta-T can of course be higher than 50°C and if it is, this provides for a greater margin of error in production. In any event, the lower the liquidus temperature, the lower the fibre forming temperature can safely be while still accommodating an adequate Delta-T, and this will mean lower production costs.

The claimed invention


The invention claimed is a glass strand comprising 12 listed constituents, each being present in prescribed percentages by weight, with the further feature that three of those constituents taken in combination must constitute at least 23% of the total by weight. Claim 1 reads:

"1. A glass reinforcement strand whose composition comprises the following constituents in the limits defined below, expressed as percentages by weight:

SiO 2


Al 2O 3







< 2, preferably >1.3

Li 2O

0.1–0.8%, preferably < 0.6%

BaO + SrO


B 2O 3


TiO 2


Na 2O + K 2O

< 2%

F 2


Fe 2O 3

< 1%

wherein the composition has an Al 2O 3 + MgO + Li 2O content equal to 23% or higher."


The specification identifies the advantage of glass having a composition within the claimed range:

"The object of the present invention is to provide such glass reinforcement strands that combine the mechanical properties of R-glass, in particular its specific Young's modulus, with improved melting and fiberizing properties, approaching those of E-glass."


The Patent gives a number of examples within this range, set out in Table 1 with corresponding figures for the fibre forming temperature, the liquidus temperature, the difference between them, i.e. the Delta-T, and the figure for the Specific Young's modulus. Although examples 1 to 5 in Table 1 are of the invention claimed, the table shows that in only one instance, example 1, were the fibre forming temperature, the liquidus temperature and the Specific Young's modulus experimentally measured. The figures for examples 2 to 5 were all calculated. The table also contains four comparative examples: one with measured figures for a glass containing no lithium oxide (example 6) and one reproducing figures from the prior art (example 7). Figures are also given for E-glass and R-glass, by way of two further comparative examples.


Thus, the invention claimed in the Patent is supported by only one experimental example. This was a matter regarded as significant by Jushi and I will return to it below.


Aside from claim 1, three dependent claims were in issue. Claims 4 and 5 are each characterised by a specified weight ratio for Al 2O 3 / (Al 2O 3 + CaO + MgO). Claim 6 is in similar form to claim 1 but with most of the ranges for the constituents being narrower. (I will use the term 'constituent' loosely to include combined constituents, such as BaO + SrO, or a stated ratio of constituents, in particular CaO/MgO).

The issues in summary


The alleged grounds of invalidity were that the claims lacked novelty and inventive step. By the time of the trial only one item of prior art was relied on, namely US Patent No. 4,199,364 ("Neely").

The prior art


Neely disclosed a boron-free and fluorine-free glass composition for producing glass fibres. The specification notes that the cost of sources of boron oxide had risen significantly and that use of both boron and fluorine compounds in the manufacture of glass pose a threat to the environment. Compounds containing fluorine also contribute to the corrosion of furnace refractories. According to Neely there was thus a need for glass compositions which excluded those two elements and which retained favourable fiberizing properties. These are the properties that allow the glass composition to be melted and refined into fibres at high rates and relatively low temperatures.


The glass composition disclosed in Neely provided fibres with the mechanical properties of both E-glass and '621' glass, a type of glass from an alternative categorisation with properties similar to E-glass.


The general composition of Neely's glass is set out in Table IV of the specification:






SiO 2


Al 2O 3






Na 2O


Li 2O





Neely goes on to say this (at col.4, lines 7–14):

"In the glass composition of Table IV other substituents may also be present in small amounts typically below 1 percent each. In general, Fe 2O 3 is present in quantities of 0.1 to 0.5 percent, TiO 2 between 0.2 to 0.8 percent, K 2O between 0.1 and 0.5 percent and also if the glass composition desired is only a boron-free composition, then a small amount of fluorine up to 1 weight percent can be used in the composition."


The 12 constituents in claim 1 of the Patent are either listed in Table IV of Neely or in the passage quoted above. Alternatively their % content as disclosed...

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