| 摘要 |
1,175,434. Vacuum packaging. C. PLATELL 26 July, 1967 [27 July, 1966], No. 34362/67. Heading B8C. [Also in Division E2] Bags are formed and filled successively to provide a chain of joined packages divided from each other by transverse welds but intercommunicating along the chain and open to atmosphere at one end of the chain whereby they may be vacuumized through that end and if desired, have inert gas admitted. Vacuumizing is carried out by coiling the chain under tension with an interleaving strip and placing the coil in a vacuum chamber. The chain may be formed from one doubled or two superposed webs and the transverse welds may each have a gap providing the air withdrawal passage. Alternatively, an intermittent longitudinal weld 13 spaced from one edge may provide communication with a common passage 12 between the weld and edge, the passage being retained open by a permeable cord &c. filling 11. The end of such a passage or the gap in the transverse weld at the end of the chain is closed off before the packages are exposed to atmosphere, after which the incomplete welds are rendered continuous to seal off individual packages. The packages may remain in the chain with lines of perforations between them to assist separation, or may be severed from each other. The packages are vacuumized by winding them on a drum with the interleaving strip of steel, reinforced plastics &c. The coil is then strapped and placed in the vacuum chamber which may also be an autoclave for sterilization purposes. The strip may apply pressure and may have markings to impress a pattern &c. on packages filled with granular material. It may be a hollow sealed tube enclosing sufficient air to cause it to swell under vacuum between the package coils Figs. 7,8 (not shown), and thus have a shaping function. Alternatively, pairs of pins projecting from one side of the strip may bridge the spaces between the strip coils on either side of the packages and thus relieve the latter of pressure Figs. 5, 6 (not shown). Known sealing means may be provided on the vacuuming chamber to seal the air exit from the chain, or a one way valve, e.g. a spring clip may be fitted on the end package. Several chains of packages arranged side by side may be coiled or chains as in Fig. 2, may be joined by pairs of hinged clips, Figs. 9-12 (not shown, but see Division E2) and coiled, flexible pipe connections ensuring continuity of the channel. The end of the channel may be connected within the chamber to a three way valve which is switched over to an inert gas source after vacuumizing, Fig. 14 (not shown). The final sealing and severing may be controlled by photo-electric means. The side plates of the coiling drum may be adjustable for various package widths. |
