| 摘要 |
<p>1252-3A A web of flattened, tubular, heat-sealable bag material travels above and at the speed of a moving belt. Above the belt is a seal shaft which rotates a heated seal bar. The working edge of the seal bar may be adjusted inward and outward relative to its shaft. The edge causes a transverse seal to be made on the web at intervals. A rotary perforating knife is driven at the same speed as the seal shaft and, at a subsequent station; perforates the web proximate the seal. The linear speed of the edge of the seal bar is at the speed of the belt at the time of sealing contact (about 65.degree.). The speed of the seal shaft for the remaining 295.degree. is adjustable and thereby the distance between seals and perforations is adjustable.</p> |
