| 摘要 |
<p>A package-sealing apparatus includes a heat-sealing unit having a pair of opposed sealing heads relatively movable toward each other to join a region of overlap of a web of thermoplastic sheet material, and a cutting unit associated with one of the sealing heads for severing the web across the overlapping resion. Each of the sealing heads has a pair of spaced sealing lands and a channel defined between the sealing lands, the sealing lands being engageable with the web to fuse the overlapping region along two spaced portions extending respectively in registry with the sealing lands. The cutting unit includes a knife blade reciprocably movable through the channel of said one sealing head into the channel of the other sealing head for severing the web along a non-fused intermediate portion of the overlapping region. Preferably, the other sealing head is spring-loaded to accomodate a change in thickness of the web as well as to absorb a shock force applied thereto when the knife blade abuts against the other sealing head.</p> |
