| 摘要 |
The invention relates to a multiple web business form stock comprising a base web formed with sprocket drive holes (23, 24) along one or both longitudinal edges (20, 22) and divided into a plurality of envelope lengths (26)by transverse lines of weakness(28), the base web having a longitudinal central fold line (30) dividing the web into upper outgoing envelope sheets (32) and lower outgoing envelope sheets (34), a longitudinal marginal line of heat sealable adhesive (45) along the marginal edge portion of each said upper envelope sheet inside the sprocket holes, upper and lower marginal lines of heat sealable adhesive (46, 48) adjacent and inside the upper and lower transverse lines of weakness (30) of each upper sheet of each envelope length such that when folded along the fold line (30) and subjected to heat each envelope length will provide a sealed outgoing envelope, marginal lines of perforation extending substantially around each envelope length inside the lines of adhesive so that when the lines of perforation are broken around such a sealed envelope the envelope forming base sheet can be unfolded along the fold line, characterised by a plurality of inner webs each being secured by adhesive along one edge, preferably adjacent the longitunal fold line, to the web beneath it with the lower of the inner webs being secured along one edge to the base web inside the sprocket holes, the inner webs having a transverse dimension less than half the transverse dimension of the base web, the inner webs being formed with transverse lines of weakening and perforation lines which are aligned with the transverse lines of weakening and perforation lines of the base web. |
