| 摘要 |
<p>A stationery form (1) comprising a single sheet of printable material has a self-seal contact adhesive (10) applied to edge regions (2, 3, 4, 5) arranged to contact each other when the form (1) is folded about a crease line (6). Contacting edge regions (2, 3, 4, 5) are releasably adhered when a first pressure is applied to seal temporarily the form (1) in a folded condition such that the form (1) can be opened and re-sealed. The contacting edge regions (2, 3, 4, 5) are non-releasably adhered when a second pressure higher than the first pressure is applied to seal permanently the form (1) in the folded condition. Low pressure sealing may be achieved manually, for example by finger pressure. High pressure sealing may be provided with a pressure sealing machine. A permanently sealed form (1) can be opened by tearing along lines of weakness (12) inboard of the adhesive (10) to remove the bonded regions (2, 3, 4, 5). Gaps (11) are provided in the adhesive to allow air to escape when the form (1) is folded and sealed. At least one window (7) is provided to allow printed material, for example an address, to be seen when the form (1) is folded and sealed.</p> |
