| 摘要 |
An apparatus and method is provided for forming a skin package particularly for food products, hardware and the like, in which said package is formed by a pressure differential applied to either an upper or lower member or both. This pressure is applied to the midportion of a film brought to a stretchable condition and held by its edges. When the film is thermoplastic this stretchable condition may be provided by holding its midportion against a heated platen until it is softened to a condition adapted for draping, sealing and forming. The product for packaging is placed on the lower covering member whose supporting face is adapted for sealing to the upper member by means of a pressure differential or air pressure and with this motion the film is stretched and brought to and is draped over the product. The air or atmosphere is used to form the package by pushing the film tightly around the product and into sealing condition with the other member. When both upper and lower members are thermoplastic film and are heated, either or both of the films after heating are urged toward each other. The chamber includes an upper and lower platen or clamping means and a mid-chamber form and may have provision for flushing the product or package with gas such as nitrogen, carbon dioxide and the like. A stretchable film may be used as one or both of the members and have an adhesive coated surface so that no heat is required but the stretchable film is pushed into sealing engagement with the other clamped member.
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