Laser Sealing Containers with Heat-Generating Resin

The patent replaces the conventional thermal heat-sealing system with a laser-based melting system. The laser beam directly melts the thermoplastic resin at the sealing interface, eliminating the need for extended heat conduction from external heat-seal bars. This substitution of the heating mechanism enables rapid sealing while maintaining process simplicity.

The patent utilizes the phase transition of thermoplastic resin from solid to liquid through laser heating. By controlling the laser energy to reach the melting point of the resin, the material transitions to a molten state that enables adhesion, then solidifies to form a sealed joint. This phase transition mechanism achieves rapid sealing without the extended cooling periods required by conventional heat-sealing.

The patent applies local quality by concentrating laser energy precisely at the sealing interface between the container and lid, rather than heating the entire container body. This localized heating approach allows thick containers to be sealed rapidly at the specific sealing location without requiring extended heat conduction through the entire thickness of the container wall.

The patent replaces the external heat-seal bar system with direct laser irradiation at the sealing interface. This substitution eliminates the heat conduction limitation that plagues thick container sealing in conventional systems, enabling rapid sealing even through thick walls by directly melting the resin at the sealing location.

The patent applies parameter changes by precisely controlling the laser output power and scanning speed to maintain the resin temperature between the melting point and thermal decomposition point. By optimizing these parameters, the system achieves rapid sealing through high laser output while preventing thermal decomposition and foaming that would occur with excessive heating.

The patent employs feedback control mechanisms to monitor and adjust laser parameters in real-time during the sealing process. This feedback system ensures that the laser output remains within the optimal range to melt the resin without causing thermal decomposition, thereby maintaining both high productivity and sealing reliability.

The patent applies preliminary action by performing the sealing operation before the container is filled with hot or pressurized contents. The sealing is completed while the container is in a cooled, depressurized state, ensuring that no gas expansion occurs during the sealing process. This timing approach prevents sealing failure while maintaining versatility for various container types.

The patent prevents sealing failure by avoiding the harmful effect of gas expansion through preliminary sealing before pressurization. By completing the sealing operation in advance when the container is not under pressure, the system counteracts the potential harmful action of expanding gas that would otherwise cause sealing failure.