| 摘要 |
Food 11 is sandwiched between two webs 2, 10 which are ultrasonically sealed 114 to each other around the food. A greater area of one web than the other web is within the seal. The two webs may be two parts of a single film sheet with a fold between them, or separate sheets. The seals can be hermetic, withstand low external pressures and/or include patterns of discrete spots, parallel stripes or crosses. Ideally the films have coplanar at least 1x0.5cm tabs which are not sealed so that they can be pulled apart to open the container. The food could be chocolate. The pack should be made in a machine with space for the food between either two ultrasonic welders or between one ultrasonic welder and a web folding device. There can also be end sealers and the sealer can be rotary. |
