Opinion ID: 770809
Heading Depth: 4
Heading Rank: 4

Heading: Sustained Smoulder

Text: 43 B&W asserts that even if there were a motivation to reduce the circumference of the More cigarette, there would have been an expectation that a 19 mm cigarette would not be capable of sustained smoulder. The district court specifically addressed this concern. It found that the prior art, including the three references and the market successes of the More and other slim cigarettes, would teach one of ordinary skill that a commercially acceptable cigarette capable of sustained smoulder could be manufactured with a circumference of 19 mm. See B&W Opinion, slip op. at 24-25, 30. 44 We agree with the district court's finding regarding sustained smoulder. The inventor of the More cigarette, Cundiff, testified that he had concerns with smoulder, as well as a variety of other interrelated characteristics such as draw and pressure drop. As the district court noted, however, the success of the More revealed that Cundiff had successfully dealt with these concerns for a cigarette with a circumference of 20.8 mm. See B&W Opinion, slip op. at 30. It is not clearly erroneous to expect, as the district court did, that a person of ordinary skill would have been able to address these concerns adequately while reducing the circumference another 8.7% down to 19 mm. Further, B&W admits that the static burn rate at which conventional commercial cigarettes self-extinguish is in the range of 25-40 mg/min. The static burn rate of the More cigarette was found to be 39-42 mg/min. Given an 8.7% reduction in circumference, the Rice formula, which was described earlier and which was found to be extendible to 19 mm by Muramatsu's teaching, yields an expected static burn rate of 35.6-38.3 mg/min. (91.3% of the range of 39-42 mg/min.) for a 19 mm cigarette. This is well above B&W's stated lower limit of 25 mg/min. for conventional cigarettes. 45