space 36 preferably the rubber seal 34 consists of a chloroprene foam strip continuously inserted into said groove 32 not only in the frame portion 2 but also in frame portion 4 the foam layer 9 may follow the profiled contour of the plastic layer 7 to contribute to a stiffening of the frame portions 2 4 further the second frame portion 4 of the closing part 5 may be reinforced by an aluminum profile 38 in order to ensure a dimensional stability of the lid type closing part 5 the aluminum profile 38 consists of a strip profile which seen in cross section is provided with an inwardly projecting nose 46 such an aluminum profile being light and ensuring a high resistance to deformation it being possible for profile 46 to find its support in the foam layer 9 after all the cross section of the plastic layer 7 of closing part 5 is of a u shaped profile within the range of the second frame portion 4 at both sides of groove 32 so that two circumjacent ribs 40 42 are formed which receive between them in the groove 32 of a substantially rectangular cross section the rib 30 of the container part 2 in the outer rib 42 of the closing part 5 the aluminum profile 38 is inserted whose lower straight section is enclosed by the.