Abstract: The lid according to the invention is for closing, by thermosealing, a container having a thermoplastic material sealing zone (3) defined by an internal closed line and an external closed line, of the type comprising a closure material (5), a varnish (7) applied to one of the faces of the closure material and an added thermoplastic material layer (6) fixed separably to the closure material and covering at least a part of the varnish which is intended to face the sealing zone of the container to be closed, said lid being characterized in that the added layer (6) has a thickness of the order of 100 to 1000.mu. (10.sup.-4 to 10.sup.-3 m), its thickness being chosen so that the thermoplastic material forming it may, by locally melting during closure of the container by thermosealing, encapsulate the traces of product finding its way on to the sealing zone during filling of the container.

Abstract: The method and machine according to the invention allow the closing of containers, particularly pots and small trays for food products. The method consists successively in separably fixing a strip of closure material (1) on a support strip (2), the closure material strip comprising pre-cutouts (4) defining lids (5) for closing the containers (6), separating from the support strip (2) the portion (10) of the closure material strip (1) which is situated externally of the lids (5), fixing a lid (5) on each of the containers (6) and separating the support strip (2) from each of the lids (5) fixed on the containers (6). The machine according to the invention comprises a supply station (7) for delivering a complex formed by a closure material strip (1) fixed separably to a support strip (2), a separation station (9) for separating from the support strip (2) the portion (10) of the strip (1), and a recovery station (12 ) for receiving the support strip (2).

Abstract: A lid for closing, by thermosealing, a container having a thermoplastic material sealing zone (3) defined by an internal closed line and an external closed line, of the type comprising a closure material (5), a varnish (7) applied to one of the faces of the closure material and an added thermoplastic material layer (6) fixed separably to the closure material and covering at least a part of the varnish which is intended to face the sealing zone of the container to be closed, said lid being characterized in that the added layer (6) has a thickness of the order of 100 to 1000.mu. (10.sup.-4 to 10.sup.-3 m), its thickness being chosen so that the thermoplastic material forming it may, by locally melting during closure of the container by thermosealing, encapsulate the traces of product finding its way on to the sealing zone during filling of the container.