Nylons
Heat-stabilized nylon films are known for their resistance to punctures and chemicals, and their quick-release properties. This makes them very useful as bagging materials in vacuum-bag layup processes used to fabricate composites, particularly those used in the aircraft industry.
Compared to ordinary nylon films, biaxially oriented nylon (BON) films feature improved abilities to seal in flavor and aroma, better flex-crack properties, as well as superior gas barrier properties, abrasion and puncture resistance. As a result, BON films find wide applications in food packaging, and as protective coatings, release coatings and lamination layers. Metallized BON also possesses good UV resistance. As a food packaging film, BON is frequently coated with polyvinylidene chloride (PVdC), which gives the film added oxygen barrier characteristics, thus prolonging the shelf life of foods.
Tough and stretchable nylon films for vacuum bags used to fabricate laminated composites have service temperatures up to 176°C.
Figure 2: Tough and stretchable nylon films for vacuum bags used to fabricate laminated composites have service temperatures up to
176°C.
Source: Jamestown Distributors.
Nylon-6 also serves as the matrix for advanced nanocomposite films, in which microscopic plate-like clay particles are dispersed at low levels (less than 6% by weight) in a resin carrier. Because such composite films exhibit anywhere from three to six times the oxygen barrier and stiffness properties of the unfilled nylon, food processors can use the composites to down-gauge the thickness of their packaging. In the food industry, nanocomposite nylon 6 films are being used in boil-in bags, standup pouches and vacuum packs. Nanocomposite films for packaging are also made with polyester and PP base resins.