Abstract: The invention relates to a method for sealing a package (1) containing a product (4), wherein the lid portion (3) and the bottom portion (2) of the package are joined together by means of plastic material. The bottom portion (2) and the lid portion (3) are joined together by sealing by injection molding, by molding plastic material (5) on both sides of a joint (10) between the bottom portion and the lid portion in such a way that the plastic material (5) exteriorly covers the joint (10) on the outside and joins the bottom portion (2) and the lid portion (3) together.

Abstract: The invention relates to a method and an apparatus for jointing members made of plastic-coated paper or board. In accordance with the invention, the sealable members are retained in position with clamps (8) and sealing is performed with a laser sealing means (7) moving along the sealing line, a means (9) for opening the seal point pressing the members apart to continue keeping the seal point open, a laser beam (11) being directed to the open seal point for melting the coating plastic and a means (12) for closing the seal pressing finally the members against each other, the plastic jointing the members when solidified. The method is applicable to lateral sealing of bag or container packages formed of blanks (1), among other things.

Abstract: The invention relates to a method for sealing a fibre-based material (1, 4) to a counter-surface to be bonded to it by melting polymer present at the sealing point. In accordance with the invention, the sealing is performed by directing a laser beam (8) through the fibre layer (4) of the material to a radiation-absorbing pigment disposed in the sealing area (9), with the absorption heat melting the polymer (5) and generating the sealing. The method allows sealing of plastic-coated paper or board to itself, to another plastic counter-surface or also to paper or board without any plastic coating. It is also possible to seal uncoated paper or board to paper or board containing plastic, such as plastic-coated paper or board, or to a plastic film. The absorptive pigment, e.g.

Abstract: The invention relates to a ready-made food package, to a method for manufacturing it and to the use of polymer-coated board in the ready-made food package. The package is manufactured by placing the food (16) in a raw state in the tray (2) where the food is baked, and by closing the tray with a lid (4) after baking. In accordance with the invention, the lid (4) is formed from a blank cut from polymer-coated board, the blank being placed over the mouth of the tray (2), and then the edges (9) of the blank are bent under the rim flange (6) of the tray and heat-sealed to the lower surface (11) of the rim flange by means of the polymer coating (14) of the board. The lid can be additionally heat-sealed to the upper surface (10) of the rim flange, so that two sealing lines (15) will be formed inside each other in the package. Accordingly, the tray (2) can be formed of polymer-coated board or optionally of polymer or aluminium alone.