Nylon film is prone to moisture absorption primarily because the molecular chains of nylon contain many hydrophilic groups, leading to a strong affinity for water. Nylon is a synthetic polymer with a molecular structure that includes amide chains with polar groups. These polar groups make nylon molecules hydrophilic, resulting in a tendency to adsorb water molecules.
The impact of nylon film's susceptibility to moisture absorption is evident in the following aspects:
Hygroscopicity: Nylon film exhibits strong hygroscopicity, particularly in high-humidity environments. After absorbing moisture, the physical properties of the nylon film may undergo changes, such as a decrease in tensile strength and tear resistance.
Dimensional changes: Moisture absorption can cause dimensional changes in nylon film, potentially affecting its stability during the packaging process. For example, moisture absorption may lead to the expansion of the nylon film.
Gas barrier properties: The hygroscopic nature of nylon film may also impact its barrier properties against gases. The presence of water molecules can increase the film's permeability to certain gases such as oxygen and carbon dioxide.