T 0333/07 28-10-2008

1. The appeal is admissible.

2. In the statement of grounds of appeal, the appellant contested the admissibility of the late ground of opposition under Article 100(b) EPC in view of the fact that lack of sufficiency had already been overcome during examination. This objection was no longer pursued during the oral proceedings before the Board.

2.1 As already explained in the communication of the Board accompanying the summons to oral proceedings, the Opposition Division has a discretionary power (Article 114(1) EPC) to consider a ground raised by the opponent after the expiry of the time limit laid down in Article 99(1) EPC (see G 9/91, point 6), irrespective of whether the corresponding objection has already been overcome during examination, because opposition is an independent procedure following the grant procedure (see e.g. T 198/88, point 2.1). Since in the Board's view the Opposition Division correctly exercised its discretion by introducing the late ground of opposition in view of its relevance (and indeed the patent was revoked on that basis), there is no reason to overrule the discretionary decision of the Opposition Division.

3. It is not disputed that the patent in suit is silent about any method for producing a topsheet for body fluids in accordance with claim 1. As regards the issue of sufficiency of disclosure (Articles 100(b) and 83 EPC) it has thus to be assessed whether the skilled person would be capable, using his common general knowledge to supplement the information contained in the application (see e.g. T 206/83), of reproducing the claimed topsheet without any inventive effort over and above his ordinary skills (see e.g. T 10/86).

4. Claim 1 of all requests requires that around each aperture the first and second fibrous layers be integrated together so that the topsheet has a density progressively increasing from the upper surface towards the lower surface and, at least in the proximity of the lower surface, has a density higher than in the second fibrous flayer. As acknowledged by the appellant during the oral proceedings, this feature requires that the progressive increase of the density takes place along the walls of the apertures (see also col. 3, lines 38 to 44, of the patent in suit).

5. The patent in suit discloses a single embodiment of the topsheet according to the invention. Fig. 2 shows a sectional view of this topsheet. The tapered shape of the apertures shown in Fig. 2 suggests that, upon producing the apertures, fibres have been displaced both vertically and laterally.

5.1 The appellant essentially submitted that the skilled person would recognize that such apertures were produced by means of a tapered needle or punch, heated to a temperature sufficient to soften, but not melt, the fibres, such that the aperture would retain its shape on retraction of the needle or punch.

5.2 The Board concurs with the appellant's view that hot needling and punching are well-known processes for producing apertures in fibrous sheets and that the skilled person knows that fibres can be either softened or melted by the application of heat. This is in fact confirmed by the documents cited by the appellant. However, even with this knowledge at hand, the recognition that apertures such as shown in Fig. 2 of the patent in suit, where the density progressively increases along the walls of the apertures, can only be produced by a specific tool having a specific temperature would require efforts beyond the ordinary skills in the art. There is in particular no indication, either in the patent documents or from common general knowledge, that the progressive increase of density along the walls of these apertures would require any heating of the fibres. In fact, looking at the tapered shape of the apertures in Fig. 2, the skilled person would consider that the progressive increase of density is due to a progressive increase of the degree of compression of the fibres around the apertures. Thus, he would concentrate essentially on finding a suitable perforating tool, and in particular on determining a suitable shape and suitable operating parameters thereof (e.g. a cylindrical rather than conical tool, a punch or a needle or an embossed roll, a suitable retraction speed, etc.), allowing a progressive increase of the degree of compression to be obtained. He would however not immediately consider applying heat, as heat is normally applied for fusing, rather than compressing, fibres.

5.3 Moreover, the prior art documents cited by the appellant do not disclose apertures in which the density increases along their walls. These documents however confirm the above assertion that heat is normally used for fusing fibres.

D2, see Fig. 2, discloses tapered pores obtained by hot needling, whereby thermally fused areas (4) on the inside surface of the pores are produced by the heat of the needle (see page 5 of the English translation, first full paragraph). The presence of thermally fused areas speaks against a progressive increase of the density on the inside surface of the pores. In fact, by the appellant's own admission, thermally fused areas should be avoided when producing the topsheet according to the invention, by means of a careful selection of the temperature of the needle or punch.

D5 relates to a method of perforating a fibrous web by means of heated pins (see claim 18). The pins may have a tapered point (see Figs. 6-10); however, it is the diameter of the shaft which determines the diameter of the aperture formed (page 16, last paragraph). The pin penetrates the web and enters a matching hole of larger diameter (see Fig. 12), thereby producing an aperture of generally cylindrical shape and apparently uniform density along its wall.

D11 relates to perforating a fibrous web by hot roll calendering or hot needling (see the paragraph bridging pages 13 and 14). D11 discloses that apertures formed by hot needling have walls generally much less fused than those of apertures made by hot roll calendering (see page 14, lines 1,2). However, D11 positively teaches that the walls should be fused also in case of hot needling, whereby a progressive increase of density is not obtained. The microscope photograph of Fig. 5, referred to by the appellant, does not give any indication about the density along the walls of the apertures as it is a top view.

D14 discloses a method of making a laminated product using hot pins (see claim 1), wherein the hot pin melts at least a film of material provided in face-to-face contact with a fibrous layer (see col. 3, l. 25-30 and l. 23, 24; 61, 62). A progressive increase of the density along the apertures in D14 is thereby excluded.

D15 mentions known processes for making apertures (col. 1, line 19 ff.) but is wholly silent about the density along the walls of apertures.

6. Furthermore, the Board agrees with the respondent that a premise for reproducing the invention is that the skilled person is capable of ascertaining the progressive increase of density along the walls of the aperture.

6.1 In the decision under appeal (see the paragraph bridging pages 3 and 4), the opposition Division stated that "since claim 1 relates to relative density, there is no need for a specific method" for measuring the density. This is in principle correct. However, the claim does not merely relate to a difference of density between two discrete zones but requires a progressive increase of density, i.e. the density must be seen to increase progressively along the walls of the apertures.

6.2 During the oral proceedings the appellant submitted a microscope photograph of an aperture in a topsheet said to be in accordance with the invention. In the photograph, the single fibres are clearly visible. They extend mainly horizontally but also vertically (up and down) to form a confused mass of interlaced fibres. Although an upper layer (first fibrous layer) less dense than the lower layer (second fibrous layer) can be vaguely discerned, the thickness of the two layers is not for example of an order of magnitude greater than the thickness of the fibres such as to allow it to be clearly determined whether or not there is a progressive increase of density in each of the layers. Moreover, it is not apparent how it can be determined whether, for the shown topsheet, the requirement of claim 1 that the topsheet has, at least in proximity of the lower surface thereof, a density higher than in the second fibrous layer (lower layer), is met.

6.3 Therefore, the Board takes the view that, in the absence of any instructions in the patent in suit about how to determine whether the density progressively increases from the upper surface towards the lower surface around each aperture, the skilled person is not capable of ascertaining whether a given topsheet meets the requirements of claim 1. Accordingly, even if the skilled person would consider finding a suitable process for reproducing the claimed topsheet by trial and error, with the aim of arriving at success through the evaluation of initial failures, he would not be capable of making any evaluation and thus would not be capable of arriving at a suitable process. Therefore for this reason also he would not be capable of reproducing a topsheet according to claim 1.

7. In view of the above the Board comes to the conclusion that the skilled person is not capable of reproducing the invention. As the proprietor acknowledged, this finding applies to all requests, since the feature concerning a progressive increase of the density is present in the independent claim of each request.

8. Therefore, the decision of the Opposition Division to revoke the patent for lack of sufficient disclosure (Article 100(b) EPC) was well-founded, and is hereby confirmed.