GB1405341A - Heat sealable enclosure - Google Patents

Abstract

1405341 Heat-sealable enclosure D BERNHARDT 16 July 1973 33695/73 Heading B8C A heat sealable enclosure comprises a tray member of rigid, heat-sealable plastics material the tray including a mouth portion surrounded by a continuous flange 13<SP>1</SP>-16<SP>1</SP> defining a frame, the uppermost surface of the frame being disposed in a common plane, an integral flap member 18 extending outwardly from a side portion of the frame, the flap member being hingedly connected to said frame member by a weakened line of connection 19, a transparent cover sheet 12 of a size adapted to register with the frame, said cover sheet 12 being connected to the upper surface of said flap along a narrow band, or line, 23, interposed between said line of connection 19 and the longitudinal marginal edge 22 of said flap. As shown, a heat-sealable cover sheet 12, preferably formed of transparent plastics material, is connected to the flap 18 by a narrow heat seal band, or line, of adhesive 23 which is disposed between the free longitudinal edge 22 of the flap 18 and the weakened line 19, which may be in the form of a perforation, or score, and which permits hinging as well as severing, a narrow margin of non-adhesive flap being left adjacent the longitudinal edge 22. The tray 11, is preferably of rectangular shape, and formed of foamed polystyrene. Alternatively, the tray may be formed of P.V.C. or, orientated polystyrene. The trays can be stacked as shown in Fig. 1, and, in use, a food article is deposited in a tray, and the flap 18, and its associated sheet 12, is folded over 180 degrees about the weakened line 19 so as to sandwich the adhesively connected portion of the sheet 12 between the flap 18 and the flange portion 16, Fig. 3. The sheet 12 is then secured, along a seal line, or area, L to the flange 15<SP>1</SP> and the flanges 13<SP>1</SP>, 14<SP>1</SP> up to the end edges 20, 21 of the flap which overlap the flanges 13<SP>1</SP>, 14<SP>1</SP>, the sealing being carried out by means of a heat seal forming element 24, Fig. 3, or, by a heater pencil, not shown. In order to open a sealed container the user can reach beneath the non- adhesive marginal edge 22 of the flap 18, sever the relatively light adhesive connection 23 between the sheet 12 and the flap 18 at the same time tearing off the flap 18 along the weakened line 19. Access between the cover sheet 12 and the flange 16 can then be obtained so that the cover 12 can be torn off. In a modification, Fig. 9 not shown, the tray has two separate compartments (25, 26).