| 摘要 |
A method of sealing a container and a lid by melt adhesion by laser, wherein
either the container or the lid comprises a thermoplastic resin that permits the laser beam to transmit through and the other one comprises a resin composition of the thermoplastic resin containing a heat-generating substance that generates heat upon absorbing the laser beam, the laser beam is capable of applying a rectangular beam having a uniform intensity distribution,
the upper-limit of temperature that is elevated by the application of laser beam lies in a range of not lower than a melting point of the thermoplastic resin but lower than a thermal decomposition start temperature thereof in the melt adhesion interface between the container and the lid, and
the temperature reaches the upper-limit in a heating time t (msec) represented by the following formula (1), t msec = L / S
wherein L is the length (mm) of the rectangular beam in the scanning direction, and S is the rate of laser scanning (mm/msec) of not higher than 1.65 mm/msec.
The sealing method makes it possible to reliably seal the container and the lid together in a short period of time without causing foaming in the resin that constitutes the container and the lid. |
