Different polymers and additives affect melting behavior and fusion quality. Inconsistent melting leads to uneven bonding, while excessive additives may interfere with layer fusion, compromising seal integrity.

Too low prevents proper melting; too high causes degradation. Optimal temperature varies by material and must balance complete fusion with structural preservation.

Insufficient pressure creates weak bonds with gaps, while excessive pressure thins the seal area. Balanced pressure ensures full contact without material displacement.

Short durations prevent complete fusion; prolonged exposure risks overheating and equipment sticking. Precise timing is crucial for thorough yet non-destructive bonding.

Contaminants (dust, oil) create bonding barriers, while physical defects (scratches, pinholes) cause inconsistent seal strength. Surface cleanliness and uniformity are essential.

Humidity affects heat transfer and moisture interference. Ambient temperature influences film's initial state and heat response, requiring process adjustments.