Heat sealing is a common technique for sealing food packages. Unlike continuous films, the seal behaviours are less understood for packages involving both multilayer and non-woven (NW). This study investigated the effects of sealer parameters and seal contaminants on temperature profile and seal strength of multilayer and non-woven films used in coffee capsules. The interfacial temperature of seals with NW1 and NW2 was 5 and 11°C less, respectively when compared to seals without NW. The core and sheath contributed to the higher seal strength in seals with NW2. The coffee contaminants were visible under the thermal camera even when they were present under the opaque multilayer film. The temperature of the contaminated area was 30°C less in SC and MP and 38°C in SE sample than the clean area. Also, the seal strength decreased significantly in the presence of multiple particles when compared to the single-particle.