Stora Enso Oyj

Jari Hovikorpi

Risto Vesanto

Päivi Määttä

Petri Laakso

Nina Miikki

Panu Tanninen

Paivi Maeaettae

Pëtri Laakso

Raimo Penttilä

Paeivi Maeaettae

Raimo Penttilae

The invention relates to a method for sealing a fiber-based material () 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 () through the fiber layer () of the material to a radiation-absorbing pigment disposed in the sealing area (), with the absorption heat melting the polymer () 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. carbon black, may be admixed in the plastic coating of the board or paper or the plastic film formed on the counter-surface, or the pigment may be located on the surface of the material to be sealed or its fiber layer, or on the counter-surface to which the material is sealed, e.g. as a component of printing ink applied to the counter-surface.

Method for sealing a fiber-based material

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 and sealing is performed with a laser sealing means moving along the sealing line, a means for opening the seal point pressing the members apart to continue keeping the seal point open, a laser beam being directed to the open seal point for melting the coating plastic and a means 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, among other things.

Apparatus for sealing a polymer coated paper or board

A board tray, a method for manufacturing a board tray and a tray blank from which the board tray is manufactured, said board tray containing side walls and a bottom wall made of a board layer provided on at least one surface thereof with a plastic coating, wherein areas of reduced thickness are formed in the board layer whereby portions of the plastic layer which have been melted and are disposed adjacent to areas of reduced thickness are compressed into such areas forming double-folded linear plastic compressions which seal on themselves.

Method for manufacturing a board tray, a blank for the tray, and a tray obtained by the method

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Kotka, Finland

Jari Hovikorpi