Viskase CORPORATION v Kureha Kagaku KKK
[2001] APO 16
•17 April 2001
OFFICIAL NOTICE
DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS
Application : No. 669926 in the name of VISKASE CORPORATION
Title: A HEAT SHRINKABLE NYLON FOOD CASING HAVING A FUNCTIONALIZED ETHYLENIC POLYMER CORE LAYER
Action: Opposition by KUREHA KAGAKU KKK
Decision: Issued .
Abstract
Opposition fails. Ground of manner of new manufacture not established.
The claimed invention was also found to be novel and inventive over the closest prior art document. EP467039 does not teach or suggest to the skilled worker a food casing with the particular combination of layers and shrinkage values that are essential features of the claimed invention.
PATENTS ACT 1990
DECISION OF A DELEGATE OF THE COMMISSIONER OF PATENTS
Re:Patent Application No. 669926 in the name of VISKASE CORPORATION, and opposition thereto by Kureha Kagaku KKK under section 59 of the Patent s Act 1990.
BACKGROUND
Patent application 669926 in the name of VISKASE CORPORATION (Viskase) was filed on 22 September 1993 with a priority date of 23 September 1992. The application was advertised as accepted on 27 June 1996.
Kureha Kagaku KKK filed a notice of opposition to the grant of this patent on 27 September 1996 and a statement of grounds and particulars served in time on 30 December 1996, following several public holidays. Each of the evidentiary stages was subject to a number of extensions while expert evidence was being obtained. Additionally evidence in answer was deferred until after the allowance of S.104 amendments. The evidentiary stages were finally completed on 13 March 2000. The applicant requested to have the hearing on 669926 to be held concurrently with the hearing on their related application 664308. The hearing on 669926 was set down to be held in Canberra on 20 June 2000. The opponent and the applicant were not represented on the day, but each provided written submissions through their attorneys.
STATEMENT OF GROUNDS AND PARTICULARS
The statement of grounds and particulars relies on all grounds of opposition allowed under Section 59:
Section 59(a) The nominated person is not entitled to a grant of a patent for the invention.
Section 59(b) The invention is not a patentable invention because it does not comply with paragraph 18(1)(a) or (b)
Section 59(c) The specification filed in respect of the complete application does not comply with SubSection 40(2) or (3).
GUIDE TO TECHNICAL TERMS AND ACRYNOYMS
I provide below an explanation of some technical terms and acronyms, as I understand them, appearing in this decision:
After-shrinking
"After-shrinking " is a process step where the cooked and cooled sausage (approximately 4oC) is heated to at least about 80oC or higher for a few seconds in a hot water bath or by hot air treatment. During this heat treatment, the casing film shrinks and lies more closely and wrinkle-free against the encased sausage meat, the volume of which had been previously reduced by cooling. This "after-shrinking" procedure is a step in the manufacture of many prior art plastic casings but was not required in the earlier manufacturing process for cellulose casings.
Orientation of multilayer films.
Orientation is a process where molecules are ordered by becoming aligned in the direction of an orienting force. Stretching after extrusion is a conventional technique to orient films. The stretching may be either in one direction resulting in a film that is uniaxially oriented, or the stretching may be in two directions, giving a product that is biaxially oriented.
Shirring
A method in which a flexible tubular container of either natural or artificial material, is gathered into pleats about a core or mandrel, prior to stuffing with meat or other ground foodstuff.
| EVA | Ethylene vinyl acetate copolymer |
| EMAA | Ethylene methacrylic acid copolymer |
| HDPE | High density polyethylene |
| LDPE | Low density polyethylene |
| LLDPE | Liner low density polyethylene |
THE SPECIFICATION
This Viskase application (as well as 664308) is directed at producing improved polyamide tubular films for use as sausage casings for processing and packaging cooked sausages including water cooked or steam cooked sausages such as liver sausage and fleischwurst or cheese sausage. A number of different tubular films or casings of this type exist in the prior art and it is known that such products must need to perform well for many criteria:
"It is generally known that selection of films for packaging food products such as meat and cheese sausages includes consideration of one or more criteria such as cost, abrasion resistance, meat adhesion, dimensional uniformity and stability, stiffness, strength, printability, durability, oxygen and water barrier properties, stretchability, machinability, optical properties such as haze, gloss and freedom from streaks and gels, and safety for contact with food."
Pre-existing casings are described in the Viskase application as meeting some of these requirements better than others. For example, commercialised cellulose casings are described as having excellent oxygen and moisture barrier properties and excellent dimensional uniformity and stability but are expensive to prepare. Plastic casings are said to be cheaper to prepare, but there have been difficulties in manufacturing a plastic casing that does not have serious deficiencies in its performance. In particular, prior art plastic sausage casings have tended to be deficient in one or more of the following areas:
(i) wrinkle free appearance in the encased sausage.
(ii) meat adhesion/preventing deposits of material collecting in pockets or spaces under the casing
(iii) dimensional stability of the casing
(iv) additional/difficult processing steps/equipment relative to that needed for cellulose casings.
The Viskase food casing comprises at least three layers:
"In the present invention it is a fundamental concept that the inner and outer layers comprise polyamide and the core layer comprises an ethylene polymer having at least one functional moiety selected from the group of esters, anhydrides, and carboxylic acids and the multilayer film be heat shrinkable having a heat shrinkage value at 90°C of at least 10% in at least one direction (preferably in both machine and transverse directions). By utilizing a multilayer film, the present invention overcomes disadvantages in monolayer polyamide casings of the prior art which sacrifice one or more desired functions such as moisture or gas impermeability, dimensional stability, or wrinkle resistance or meat adhesion for other functions including those listed above as well as processability or ease of manufacture."
The inner polyamide layer is said to provide good machinability and to facilitate passage of the casing over shirring mandrels or stuffing horns without the need for addition of antiblock additives, polymeric plasticizers, or slip agents to the anterior surface of the film. Selection of an appropriate type of polyamide allows this layer to adhere well to the meat without the need for other additives.
The core layer functions as a water vapor barrier, and provides the film with the suppleness and proper modulus for good shirrability and orientation and may also function to strongly adhere the outer layer to the inner layer.
The outer polyamide layer provides mechanical strength and acts as a gas barrier, particularly for oxygen. This outer layer is typically the thickest to provide support to the casing wall in order to withstand stuffing, cooking, and handling pressures and abrasion.
Another important feature of the casing is that it shrinks during the heat treatment phase.
"The films of the present invention are biaxially stretched and oriented films. An important feature of the invention is that the inventive films have sufficient shrinkage values and shrink forces to produce a smooth wrinkle resistant casing able to closely conform to encased foodstuffs during heat processing chilling, refrigeration and storage."
Generally the casings are described as requiring shrinkage values of at least 10% shrinkage in at least one direction, preferably in both the machine direction and the transverse direction and to have sufficient shrink force to ensure good conformation of the casing to enclosed foodstuffs.
Specific embodiments of the Viskase casing are also described which feature shrinkage values of over 20% at 90°C in both the transverse and machine directions. These embodiments also feature a core layer that consists essentially of a blend of EVA and EMAA.
CLAIMS
The claims on file are the result of amendments filed 19 May 1999 that were advertised as allowed on 20 January 2000. The opponent's evidence is directed against an earlier set of amended claims filed 13 February 1997 in which claim 31 was broader. I have reproduced below the two independent claims and highlighted changes made to claim 31 in the most recent amendments.
A seamless tubular, biaxially stretched, heat shrinkable, multilayer film, food casing having inner and outer surfaces, said casing comprising:
a) an inner layer comprising a polyamide;
(b) a water vapor barrier core layer comprising at least 50% by weight of at least one ethylene viny acetate copolymer having at least 70% by weight % ethylene units blended with at least 10% by weight of ethylene methacrylic acid copolymer; and
(c) an outer layer oxygen barrier layer comprising a polyamide;
wherein said casing comprises three polymeric layers (a), (b) and (c) wherein said core layer (b) is disposed between said inner layer (a) and said outer layer (c), and in direct adhering contact with said layers (a) and (c), with said inner layer (a) being continuous over said inner surface of said tubular casing, and said multilayer film has a shrinkage value of at least 10% in at least one direction at 90°C, said multilayer film having a thickness of between 25.4 to 76.2 microns.
A continuous process for making a seamless tubular, biaxially stretched, heat shrinkable, multilayer thermoplastic food casing comprising:
(a) coextruding a melt plastified multilayer thermoplastic tube having an exterior surface and an interior surface through an annular dye wherein said tube comprises an inner layer comprising a polyamide and an outer oxygen barrier layer comprising a polyamide, with a water vapor barrier core layer between said inner and outer layers of at least 50% by weight of at least one ethylene vinyl acetate copolymer having at least 70 weight % ethylene units blended with at least 10% by weight of at least one copolymer of ethylene having at least one functional moiety selected from the group of anhydrides and carboxylic acids;
(b) cooling said coextruded tube below the melting point of each layer by applying water to the exterior surface of said tube;
(c) transferring said cooled tube to an orientation zone wherein said tube is reheated to a temperature below the melting point of each layer followed by cooling while a fluid mass is admitted to the interior of said tube as said tube is passed between first and second means for blocking fluid flow along the anterior of said tube thereby causing said tube to stretch circumferentially about the entrapped fluid mass and simultaneous with said circumferential stretching said tube is stretched in a direction perpendicular thereto to produce a biaxially stretched tubular film; and
(d) annealing said biaxially stretched film at elevated temperature to dimensionally stabilize said film wherein said multilayer film has a shrinkage value of at least 10% in at least one direction at 90°C.
EVIDENCE
The evidence filed in support of the opposition consists of:
A statutory declaration by Dr John Kingsford Haken* dated 11 June 1998 together with Exhibits JKH-1 - JKH-8
A statutory declaration by John David O' Connor dated 11 June 1998 together with exhibits JDOC-1 to JDOC-40
A statutory declaration by Joachim R Buchner dated 12 February 1998 together with exhibits JRB-1, JRB-2 and JRB-3
A statutory declaration by Jill Newton dated 12 February 1998 together with exhibits JN-1 and JN-2.
The evidence filed in answer to the opposition consists of:
A statutory declaration by Stephen James Vicik* dated 1 June 1999 together with exhibits SJV-1, SJV-2, SVJ-3
A statutory declaration by David Henry Solomon* dated 25 May 1999 December together with exhibits DHS-1, DHS-2 and DHS-3
A declaration from Richard Hiram Baddeley dated 24 August 1998 together with Exhibits RHB-1 to RHB-3
The evidence filed in reply:
No evidence was filed in reply.
* Technical evidence on the Viskase application and/or the state of the art
SUBMISSIONS
Submissions by both parties will be referred to, where relevant, in the decision.
DECISION
Against the claims now on file, the sole ground on which the opponent is arguing the claims should be found invalid is manner of new manufacture.
The opponent's submissions on this ground are that there is a lack of inventiveness apparent from what the Viskase specification reveals about the prior art referring me generally to the evidence of Dr Haken. Dr Haken states relevantly:
"I am further at a loss to understand how the nature of the film and its method of manufacture which is claimed in the Viskase Application is any way inventive, particularly having read the subject matter under "Background of the invention" on pages 1-13 of the Viskase Application. Certainly none of the features of either the casing or the process claimed in the amended claims both separately and in combination were new as at the Priority Date."
I particularly note at page 7, line 25 to page 9, line 2 of the Viskase Application, the reference to European Patent Document No 467,039, which I am informed is the Hoechst Application. While it is stated at page 7, line 25 of the Specification that there is no admission that European Patent document constitutes prior art, the discussion in relation to the Hoechst Application proceeds in my view to describe the multilayer casing described therein in terms of the invention."
The key part of the prior art discussion is that concerning European Patent Document No 467,039 (EP467039) by Hoechst AG. This document (and the equivalent United States patent) were filed as part of the evidence in support and have been specifically addressed by the applicant in their written submissions on the grounds of novelty, and inventive step.
I consider that the inventiveness issue raised by the opponent, is essentially whether the claims of the Viskase application are new or inventive over the disclosure of EP467039. I consider this inventiveness is more appropriately assessed based on the complete document rather than the partial disclosure of EP467039 provided in the Viskase application. For this reason I would prefer to consider whether the Viskase claims are novel and inventive over EP467039 before dealing with any remaining issues under manner of new manufacture.
EP467039 is in German, but a later published English language family equivalent, US 5185189 was also filed in evidence. In addition the opponent filed a declaration by German/English translator Joachim Buchner in which the two documents are compared. This comparison outlines the common disclosure and details the minor differences between these two patents. There is a translation by Mr Buchner of the claims of EP467039. In this matter it is relevant that both parties appear to have treated the disclosure in US5185189 as an equivalent to that of EP467039.
The situation is entirely analogous to that which arose my decision on related Viskase application 664308 and as all the same circumstances apply, I will take the same course of action, which is to treat the description of US 5185189 (excluding the claims) as essentially providing an English translation of the description of EP467039. Subject to the differences identified in the declaration of Mr Buchner, I will treat the US5185189 in this manner throughout this decision.
Novelty
EP 467039 discloses a multilayer, polyamide based food casing of low oxygen permeability suitable for use with liverwurst sausage meat. A comparison of the features of the casing of
claim 1 in the Viskase application and the features explicitly disclosed as present in the casing of EP467039 is provided below:
| FEATURE | Claim 1 | EP 467039 |
| A seamless tubular, biaxially stretched, heat shrinkable, multilayer film, food casing comprising: | Y | Y |
| An inner layer comprising a polyamide | Y | Y |
| A water vapor barrier core layer | Y | Y |
| Core layer comprising at least 50% by weight of at least one ethylene vinyl acetate (EVA) copolymer having at least 70% by weight ethylene units blended with at least 10% by weight of ethylene methacrylic acid copolymer. | Y | N |
| An outer layer comprising polyamide | Y | Y |
| Multilayer film has a shrinkage value of 10% in one direction at 90°C | Y | ? (Shrinkage values less than 20%) |
| Multilayer film has a thickness between 25.4 to 76.2 microns | Y | Y |
In Meyers Taylor Pty Ltd v Vicarr Industries Ltd (1977)137 CLR 228 at 235, Aicken J said:
“The basic test for anticipation of want of novelty is the same as that for infringement and generally one can properly ask oneself whether the alleged anticipation would, if the patent was valid, constitute an infringement.”
In Rodi & Weinenberger A.G v. Henry Showell Ltd [1969] 12 RPC 367 at 384, per Lord Hodson.
"for it is only where there are differences in inessentials, while the alleged infringement possesses all the essential features or integers of the claim, that there will be infringement."
No argument has been raised that any of the features are inessential and it is my assessment that all the features in the main independent claims (at least) are essential. Therefore the question before me is whether the citation discloses all the features of any of the claims. The features of claim 1 not explicitly disclosed in the citation, are the specific core layer composition and the required shrink or shrinkage values. This is true also of claim 31, but claim 31 also has process steps that are not explicitly disclosed in the citation.
In EP467039 the core layer can comprise a variety of polyolefins including polyethylene, blended with a adhesion promoting agent that prevents delamination. The types of compounds used as adhesion promoters are said to include copolymers containing units such as EVA or acrylic acid derivatives:
"Usually the adhesion-promoting agents are polyolefin resins modified with functional groups….Suitable adhesion promoters comprise in particular graft polymers, copolymers or terpolymers including ethylene or propylene units with at least one comonomer selected from the group including (meth)acrylic acid, (meth) acrylates (i.e., esters of n-alkanols having 1 to 6 carbon atoms, such as butylacrylate) ethylene vinyl acetate and maleic anhydride. The units carrying functional groups are usually present in an amount of 3-12% by weight, based on the total weight of the adhesion-promoting polymer. The modified polyolefin resins also include rubber-modified polyethylene."
The adhesion promoter is used in amounts up to about 50%. However EP467039 teaches that it should generally be kept as low as possible to avoid increasing permeability to water vapour.
The two examples disclose a multilayer casing with a core polyolefin made from 80% HDPE and 20% of an adhesion promoter based on LLDPE/methacrylic acid.
However several features of the core layer as claimed in the Viskase aplication are not taught by the earlier publication. EP467039 does not disclose the use of at least 50% by weight of EVA copolymer in the core layer. The citation also does not teach that the EVA copolymer should be blended with an ethylene methacrylic acid copolymer or (per claim 31) with a copolymer derivatized with anhydride or carboxylic acid groups.
The remaining feature of interest is the shrinkage values. In EP467039 shrinkage values are only discussed in terms of an optional heat setting treatment. Following biaxial stretching it is stated that “dimensional stability” can be improved by partially or completely heat setting the stretched casing. I do not have a precise definition of "dimensional stability", but the Viskase specification describes a lack of dimensional stability in the casing of prior patent US 4303711 as being associated with deformation and non uniform appearance. From the discussion in both the Viskase specification and EP467039, I would assume that taking steps to improve dimensional stability would be considered desirable in the art. Both examples in EP467039 use a heat setting treatment and this further persuades me to view the treatment as part of the preferred means of making the casings. The reference to heat shrinkage values in EP467039 is given below:
“To improve the dimensional stability, the stretched casings can be partially or completely heat-set. This thermal treatment is usually carried out at temperatures of between 120°C and 160°C. As a result of heat setting, the shrink of the film at temperatures up to about 90°C is relatively low, i.e. a shrink of less than 20%, in particular of less than 15%, is measured both in the longitudinal direction and in the transverse direction”
The heat set casing of EP467039 most preferably has shrinkage values less than 15%, and teaches that the heat set shrinkage values should be made relatively low. Does this mean that the skilled worker applying the directions in EP467039 would produce casings with shrinkage values above 10%? Dr Haken asserts that after heat setting the exemplified heat set casings of EP467039 would inevitably possess shrinkage values of at greater than 20%. Mr Vicik disagrees and asserts that the directions given there to carry out heat setting at a temperatures between 120°C and 160°C, are not sufficiently detailed to allow a determination of the resulting shrinkage value of the casing. Professor Solomon simply notes that Dr Haken's views appear contrary to the statement in EP467039 that the heat set casings have a shrink of less than 20%, in particular of less than 15%.
Dr Haken was Associate Professor in the Department of Polymer Science at the University of NSW for 16 years, but while he has extensive knowledge of the relevant literature, he concedes that he has had little practical experience with coextruded films. Mr Vicik, on the other hand, appears to have a great deal of practical expertise on the properties of multilayer casings. Of course, as the inventor Mr Vicik is an interested party. On balance, I find Mr Vicik's evidence on the shrinkage properties of the exemplified casings in EP467039 more persuasive because of his greater knowledge in this area. I therefore conclude that EP467039 does not teach a process that if followed would produce casings with shrinkage values above 20%. EP467039 teaches no more than to produce heat treated casings with shrinkage values reduced below 20% and most preferably below 15% in order that the casings will be dimensionally stable. There is insufficient evidence to allow a conclusion that the heat set casings will have shrinkage values greater than 10% and consequently I find that this feature also is not disclosed.
All claims of the invention are novel over EP467039.
Inventive Step
In order to assess the claims of the Viskase application for inventive step, under the 1990 Patents Act I need to determine:
the relevant art
the person skilled in that art
whether the claimed invention is obvious at the priority date of the claims to the worker skilled in the art on the basis of common general knowledge alone or in combination with a single disclosure.
The claimed invention is defined generally as a polymeric food casing, but the specification is concerned entirely with polymeric casings for sausages. The relevant art relates to polymeric films for encasing food.
In my view (which, in this instance, accords with the applicant's submissions) the skilled worker in the art would be an individual or group having expertise in the development of plastic multilayer products and knowledge of requirements for food casings.
It is not required that I outlay the entire body of common general knowledge possessed by these skilled workers. From the evidence before me, I consider that the common general knowledge associated with this skilled worker at the relevant date would include knowledge of a number of synthetic food casings, the general processes of manufacturing them, and the polymers used in the Viskase specification. While not a critical issue in this decision, I consider that the disclosure of EP467039 has not been shown to be common general knowledge in Australia at the priority date of the Viskase application. Relevant to this conclusion, is the fact that none of the Australian based experts (Dr Haken or Professor Solomon) indicated that they had been aware of the document prior to being involved in the opposition proceedings.
The Viskase application provides a concise summary of the inventor's view of the state of the art at the priority date:
"Prior art fiber reinforced cellulose casings coated with moisture barrier coatings perform well in processing water/steam cooked sausages such as fleischwurst and liver sausage. However the high cost of manufacture of such casings has led casing manufacturers to search for less expensive alternatives. Thermoplastic films of various compositions have been suggested and some have found varying degrees of success in various segments of the market. Thermoplastic sheet film has been made into a tube by seaming, but this is a difficult process which produces a casing having a seamed area which may undesirably differ in appearance and performance relative to an unseamed casing.
Seamless tubular thermoplastic casings have been made which overcome the objections to seamed casings. Various materials have been employed, but materials containing chlorinated polymers have been objected to for environmental reasons among others. Seamless polyamide casings have been made of blown film, however these casings tend to have poor performance with respect to wrinkling, uniformity of diameter, and dimensional stability. Seamless biaxially oriented multilayer films have been also made, however, such films have been difficult to produce requiring special blend formulations and structures or complicated equipment and procedures."
The problem faced by the skilled worker is to discover a less expensive process for producing a multilayer thermoplastic casing that can still meet the needs for sausages including fleischwurst or liver sausage. A suitable casing of the invention should feature good moisture barrier properties, low oxygen permeability, a tight fitting casing having few or no wrinkles, and good dimensional uniformity and stability, as well as meet other conventional requirements of sausage casings. An aspect of this or an additional problem was the need to devise an improved method of manufacturing biaxially stretched multilayer casings.
There is no evidence on hand that suggests to me that the skilled worker in Australia at the relevant date would have developed a casing within the scope of the claims of the Viskase application on the basis of common general knowledge alone.
Where an assertion of a lack of inventive step relies upon information in a document not shown to be common general knowledge, then S.7(3) of the 1990 Patents Act requires that information to be such that the skilled person could, before the priority date of the relevant claim, be reasonably expected to have ascertained, understood and regarded as relevant to work in the relevant art in the patent area. Professor Solomon has argued that it can not be assumed that EP467039 would be found by the skilled worker seeking to solve the Viskase problem.
EP467039 is concerned with producing a multilayer, polyamide based food casing of low oxygen permeability, which does not wrinkle and is suitable for use with liverwurst sausage meat. Relevant to the issue of reducing costs, the document teaches the manufacture of thermoplastic casings rather than the expensive cellulose casings and the avoidance of what is described as an expensive cooling step. As EP467039 is concerned with a very similar product and provides a solution to many aspects of the Viskase problem, I would expect this document to be found and considered relevant by a person searching for a solution to the problem addressed by the Viskase application.
I have already noted that the Viskase casing is quite similar in composition to the casing of EP467039. There is also much similarity in the advantages that the two applications describe as distinguishing their casings from the prior art, as indicated in the following table:
| PROPERTY | VISKASE CASING | EP467039 CASING |
| No wrinkling on stuffing or storage | Y | Y |
| Requires an "after shrinking" step | N | N (not cited as an advantage) |
| Low oxygen transmission and suitable for storing liverwurst meats | Y | Y |
| Little or no moisture loss during cooking or storage | Y | Y |
| Layers do not separate on cutting | Y | Y |
| Dimensionally stable | Y | Y |
| Good adhesion to meat without the use of starch based additives or treatment of electron beam irradiation or corona discharge | Y | Y |
| Shirring without antiblocking agents | Y | Y |
This raises the issue of whether the Viskase casing can be viewed as the casing disclosed in EP467039 subject to routine variations or improvements. This issue was considered in Winner & Anor v Ammar Holdings Pty Ltd, (1993) AIPC 90-971 where at page 39, 248 it was said:
"Notwithstanding that the inventive step may lie in the choice and management of integers in a combination patent (Wellcome Foundation at 281), where one starts with a known article or thing and merely substitutes or adds a known device or means to facilitate the better use of the thing, there is a risk of want of inventive step "unless the combination is substantially a new thing" (May v. Higgins (1916) 21 CLR 119 at 121"
These seemingly shared advantages of the two casings suggest the possibility that the Viskase application may be the result of replacement of some integers of the earlier casing with others that have equivalent function in the context of the problem the two casings solve.
The different core layer components of the Viskase application and the examples of EP467039 do have some common functionality. The use of EMAA to prevent delamination appears to be highly analogous with the use in EP467039 of an adhesive agent, such as the LLDPE/methacrylic acid copolymer to prevent layer separation. In contrast differences exist in the use of EVA. Although EVA does function as a moisture barrier (analogous to the polyolefin HDPE in EP467039), it also has a role in providing other significant properties.
"[EVA] excels in providing a desirable combination of shrink, shrink force, modulus and moisture barrier properties."
Shrinkage values are used in the Viskase application to promote wrinkle resistance:
"An important feature of the present invention is that the inventive films have sufficient shrinkage values and shrink forces to produce smooth wrinkle resistant casings able to closely conform to encased food stuffs during heat processing, chilling refrigeration and storage"
Mr Vicik describes HDPE as less suitable for providing these properties:
"HDPEs are typically stiffer and more difficult to orient to make a film which is heat shrinkable at 90°C. These properties of HDPE make it more difficult to process and less likely to be suitable for use in making a casing which relies upon heat shrinkability and shrink force to provide wrinkle resistance. This is different from the Hoechst US patent which relies upon elastic properties to provide wrinkle resistance. An HDPE core is clearly to be contrasted with a core of an EVA copolymer blended with EMAA copolymer."
Dr Haken refers to EVA having being used at the priority date to make coextruded films that have the desirable properties of LDPE but are much tougher. This suggests that EVA would be seen by the skilled worker as being more like a low density polyethylene rather than a high density polyethylene.
Mr Vicik also indicates that nylon casings having low shrinkage properties use elastic properties rather than shrink properties to promote a wrinkle-free appearance. It is not apparent to me what role the shrinkage values have in minimising wrinkles in EP467039. From what is described in EP467039 it appears that the properties of the outer polyamide layer are important in causing the casing to shrink during cooling and storage to prevent creases:
"During scalding or boiling of sausages, the outer layer absorbs water. During the subsequent cooling and storing of the sausages, this water is set free. This freeing of water from the outer layer causes the outer layer to shrink during drying, and the casing surrounds the cooled down sausage more tightly and without creases."
In the absence of evidence to the contrary, I will accept Mr Vicik's submissions that casings with low shrinkage values use elastic properties rather than shrinkage values to reduce wrinkles and that HDPE is less suitable than EVA for generating high shrinkage values. The preferred use of HDPE in the core layer of EP467039 and the teaching to reduce shrink values suggests that this casing is more likely to depend on elastic forces rather than shrink values to reduce wrinkles. The Viskase application describes as a comparative example, a casing produced in accordance with the invention except that is was heat treated to reduce shrinkage values below 10% at 90°C. The resulting cooked and chilled sausage was said to have a non-uniform knobby appearance and be slightly more wrinkled than a sausage encased with the inventive casing. For all of these reasons I conclude that the claimed Viskase casing is substantially a new combination.
There is no evidence before me that suggests that the skilled worker would find a problem with the casing of EP467039 that would lead to the solution claimed in the Viskase application.
I therefore find that all claims of the Viskase application possess an inventive step over EP467039.
Manner of New Manufacture
Lack of invention apparent on the face of the specification
The opponent argues that there is a lack of inventiveness apparent from what the Viskase specification itself reveals, in other words the opposed specification fails the threshold test for inventiveness described in NV Philips Gloeilampenfabrieken v Mirabella International Pty Ltd (1995) 183 CLR 655. This 'threshold test' for inventiveness was recently considered in Bristol-Myers Squibb Co v F H Faulding & Co Ltd [2000] FCA 316:
"In our view … Philips stands for the proposition (as a matter of construction of the 1990 Act) that if, on the basis of what was known, as revealed on the face of the specification, the invention claimed was obvious or did not involve an inventive step - that is, would be obvious to the hypothetical non-inventive and unimaginative skilled worker in the field (Minnesota at 260 per Barwick CJ) - then the threshold requirement of inventiveness is not met. "
Very little indication is provided by the opponent on why they consider the Viskase application fails the threshold test, other than Dr Haken's statement that the Viskase application is not inventive over the disclosure of EP467039 detailed in the Viskase application. Whether any reference in an opposed specification to prior art documents can be relied upon for assessing inventiveness, under manner of new manufacture, is somewhat doubtful, see for example the recent Patent Office decision; Centaur Nickel Pty Ltd v QNI LTD [2000] APO 65 (31 October 2000). But in this case I do not need to decide on that issue, as no relevant additional disclosure is detailed in the Viskase application. The Viskase application discusses EP467039, but adds no significant new information over the disclosure of the document itself, and there is no teaching in the discussion of other prior art that would direct the skilled worker to the claimed invention. I have determined that the claims of the Viskase application have an inventive step over EP467039, and I find the claims are inventive over what the Viskase specification reveals. No other issues under manner of new manufacture were raised by the opponent.
I find all claims in the Viskase application are for a manner of new manufacture.
Section 40
None of the Section 40 matters raised in the statement of grounds and particulars were pursued in the opponent's submissions and none of these matters appear likely to render the patent invalid and so I will not consider them further in this decision.
CONCLUSION
I have found that the opposition fails on the ground of manner of manufacture and that the application accords with Section 40 and is novel and inventive when compared with EP467039.
Accordingly I direct the application be sealed after 30 days from the date of this decision. If the Commissioner has been served with a notice of appeal before that time, I direct that sealing not occur until the appeal has been decided or discontinued.
COSTS
Costs normally follow the event. The opponent has argued that even if they do not succeed, they should be awarded costs in recognition of the amendments that have taken place since the opposition began. In this case it is not apparent to me that the amendments made during opposition were of such significance as to warrant awarding costs. I think that in these circumstances it is appropriate that I award costs against the opponent.
Ross Osborne
Delegate of the Commissioner of Patents
Patent attorneys for the applicant : Watermark Patent & trademark Attorneys
Patent attorneys for the opponent : Spruson & Ferguson
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