| 摘要 |
<p>769,888. Packaging. HERMORION, Ltd. June 23, 1955 [June 29, 1954], No. 18174/55. Class 94(1). A method of producing liquid-filled, tetrahedron-shaped packages comprises successively compressing and sealing a thermoplastic tube along narrow zones transverse to the axis of the tube and alternately in two mutually perpendicular directions while supplying liquid to the tube at such a rate that its level is always above the zone being sealed and applying external pressure to the walls of the packages during the compressing and sealing operations to force them to enclose a somewhat smaller volume than that which would automatically be obtained without such pressure due to the pressure of the packaged liquid and the elasticity of the tube. The walls of each package extending from one sealing zone are thus caused to assume a plane or concave instead of a convex contour, and when the package is opened by cutting-off or piercing one corner they expand to cause lowering of the level of liquid in the package and prevent leakage or overflow. The package may be marked with a line to indicate where it may be cut without danger of leakage. As shown, the packages are produced by a modification of the machine described in Specification 711,855 in which transverse seals 5 and 6 are formed by pairs of co-operating jaws 1 and 2 provided with inclined flanges 7 and carried by endless conveyers, the flanges being formed with projections 9 which cause the walls of the packages to assume a concave contour 10 instead of a convex contour 8 during the sealing operations.</p> |
