The impact of splicing seams on fire spread of PE sandwich panels under adjacent floor compartment spilled fires

Polyethylene (PE) sandwich panels are used as insulation on building exteriors, but the fire hazards of different splicing methods are often overlooked. This study examines the impact of splicing seams on fire spread of PE sandwich panels under adjacent floor compartment spilled fires through scaled experiments and theoretical analysis. The results reveal that spilled flames spread along the seams, intensifying combustion. Under the conditions of this experiment, a noticeable flame fusion phenomenon occurs when the fire power in the upper compartment reaches 3 kW. The peak temperature and temperature growth index within the sandwich panel are directly proportional to the fire power and the number of splicing seams, and the flame burns more violently when the seams are vertical rather than horizontal. Correspondingly, the building fire hazard is the highest at this time. Furthermore, a relationship between average mass loss rate and heat flux is established. The average flame height is influenced by both the fire source power and the splicing methods, showing a strong power-exponential relationship with the mass loss rate. These findings provide a crucial theoretical foundation for guiding the design and installation of external insulation panels, which is of great significance for ensuring the fire safety of building structures.