Polyvinylidene chloride Films
Polyvinylidene chloride or PVDC is a clear and flexible synthetic thermoplastic produced by the polymerization of vinylindene chloride. It is optically clear with a high degree of gloss and has outstanding oxygen and moisture barrier properties comparable to aluminum foil. This makes PVDC ideal for household wrap and food / medicine packaging to extend shelf life. It also is highly resistant to many chemicals including grease and oil.
PVDC can be easily extruded and laminated. It is also microwavable and printable using common ink systems.
The most common type is biaxial oriented PVDC film.1 It has low stretch and provides excellent bond strength and low water absorption.
Vinylidene chloride is sometimes copolymerized with other monomers. A common copolymer consists of about 85 percent vinylidene chloride and 15 percent vinyl chloride. This polymer film is known under the trade name SaranTM.
Because of its higher cost, PVDC is often combined with other cheaper plastics like polypropylene. It is usually applied as a thin coating or laminate to improve the barrier properties of the cheaper base film.
Due to the low odor, high chemical resistance and inertness, PVDC is suitable for packaging applications.2
Although PVDC is recyclable, most PVDC film is not recycled, mainly because PVDC is often used as a very thin coating which cannot be easily extracted.
Polyvinylidene chloride film is an attractive see-through packaging film. PVDC (coated) film is mainly used in packaging of food, drugs, cosmetics, and other perishable or delicate products to extend shelf life. In comparison with many common films, PVDC coated films have superior gas and moisture barrier properties, and excellent heat sealability. PVDC coated films often compete with acrylic, and PVOH coated films.
1”Biaxially oriented" means that the PET film is stretched in two different directions to increase strength and modulus (lower elongation and higher stiffness).
2Dow Saran PVDC Resins & Films brochure