摘要 |
<p>The formation of a tubular web in a form-fill process is achieved by drawing the web along a tapering guide (6) and then along a former tube (20) the axis of which is at a small angle to the guide plate and intersects the guide. The web is drawn along the guide and tube by opposed drive rollers (24) at a station along the length of the former tube, the rollers gripping the edges of the web together, but the side edges are fully brought together only after they reach the former tube. The drive rollers (24) or sealing rollers (26) further along the former tube seal the edges together to form a closed tube. Infusion packages (Figure 8) may be formed, each having a heat-sealed seam in the form of a fin which is tack-sealed to the body of the package to capture the thread of a tag between the fin and the body.</p> |