A cycloolefin polymer (COP) bonding method wherein a first material that is COP and a second material that is COP or glass are bonded. The method includes: a step of exposing at least a bonding surface of the first material to H.sub.2O plasma; and a step of mating the bonding surface of the first material and a bonding surface of the second material. According to the method, the cycloolefin polymer (COP) can be bonded to a target material without applying high pressure or high temperature, and without affecting the optical properties.

An assembly method between a part made of metal material and a part made of organic matrix composite material, said method having a step of providing two parts, each including a surface to be welded, and the surface to be welded of said composite part is made up, at least partially, of an exposed portion of at least one metal insert which is partially embedded in said composite part; positioning said surfaces to be welded opposite and separated from each other; and projecting, at high speed, the surface to be welded of the metal part or the exposed portion of the metal insert, onto one another, to obtain high-speed clamping to one another and to obtain a weld between the exposed portion of the metal insert of the composite part and the complementary portion of the surface to be welded.

A cycloolefin polymer (COP) bonding method wherein a first material that is COP and a second material that is COP or glass are bonded. The method includes: a step of exposing at least a bonding surface of the first material to H.sub.2O plasma; and a step of mating the bonding surface of the first material and a bonding surface of the second material. According to the method, the cycloolefin polymer (COP) can be bonded to a target material without applying high pressure or high temperature, and without affecting the optical properties.

A packaging apparatus includes a packaging unit and two heater rollers. The packaging unit installs a stretch film on an article to be packaged and discharges the article to be packaged installed with the stretch film along a conveyance surface. The two heater rollers heat the stretch film positioned below the article to be packaged discharged from the packaging unit. The heater rollers have contact portions with the article to be packaged positioned higher than the conveyance surface. Among the two heater rollers, height of the contact portion of one heater roller on a upstream side in a discharge direction relative to the conveyance surface is lower than height of the contact portion of the other heater roller on a downstream side in the discharge direction relative to the conveyance surface.

An assembly method between a part made of metal material and a part made of organic matrix composite material, said method having a step of providing two parts, each including a surface to be welded, and the surface to be welded of said composite part is made up, at least partially, of an exposed portion of at least one metal insert which is partially embedded in said composite part; positioning said surfaces to be welded opposite and separated from each other; and projecting, at high speed, the surface to be welded of the metal part or the exposed portion of the metal insert, onto one another, to obtain high-speed clamping to one another and to obtain a weld between the exposed portion of the metal insert of the composite part and the complementary portion of the surface to be welded.