Nucrel® for Packaging

A High-Performance Foil Adhesive and Heat Sealant

DuPont™ Nucrel® provides excellent adhesion to metal with low-temperature seal-through-contamination properties ideal for packaging products from condiments to juices and aseptic milk to pharmaceuticals and personal care products.

DuPont™ Nucrel® ethylene acid copolymer resin provides an outstanding, chemically-resistant metal bond, making it a reliable, cost-effective foil adhesive for a range of applications. Nucrel® bonds to the oxide layer on the aluminum and provides strong bonds that are resistant to attack by mild to moderate acids and bases.

Versatile Performance Properties

Besides foil, Nucrel® can adhere to paper in extrusion coating, nylon in coextrusion, and can be extruded or injection molded at slightly lower processing temperatures than polyethylene (PE).

Nucrel® is also an excellent heat sealant, with hot tack strength and seal through contamination properties that allow for reliable heat seals at high packaging machine speeds. Other performance properties include toughness, light weight and durability in aggressive chemical (e.g., acetic acid) environments.

Proven in a Variety of Applications

As a foil adhesive layer, Nucrel® is used in:

  • Juice and aseptic milk packaging, where it resists mild acids in the liquids for a shelf life of up to one year
  • Condiment sachets, where it protects both sides of the foil from aggressive acids like vinegar found in ketchup and other condiments
  • Snack structures such as biscuit can liners
  • Toothpaste tubes
  • Typical Grades include: Nucrel® 3990, 30907, 0411HS, 0910HS

As a heat sealant or heat sealant backing layer, Nucrel® is used in:

  • Spice oil sachets, where it provides fast, low-temperature, seal through oil contamination, and resistance to swelling
  • Tea bags, where it provides moderate hot-tack to make hermetically sealed, individually wrapped bags
  • Sachets for alcohol swabs and towelettes
  • Condom pouches
  • Typical Grades include Nucrel® 3990, 30907, 0903HC, 0910HS, 1202HC

Nucrel® is also used as a coextrusion interlayer between DuPont Surlyn® ionomer resin and PE or other materials for processed meat packaging.

The Chemistry of Nucrel®

Nucrel® resins are branched copolymers of ethylene and methacrylic or acrylic acids. Acid side chain branches bring unique functionality to these highly polar resins, while long chain branches make these resins easy to use in producing blown and cast films, as well as extrusion coatings and laminations. 

Specialized Grades

Nucrel® HS (High Stability/High Speed) grades for extrusion coating allow for high-speed processing due to improved thermal stability, are capable of running at thin coating thickness, and support better processes and enhanced performance by reducing crosslinking issues.

Nucrel® HC (High Clarity) film grades provide very low haze and high gloss for applications which require see-through packaging.

The Benefits of Nucrel®

For converters with extrusion capabilities, Nucrel® is a cost-effective foil adhesive solution. It allows for high-speed extrusion coating and lamination, resulting in fewer package failures, which helps reduce waste. And unlike chemical primers and adhesives, Nucrel® resins provide adhesion without the inconvenience and rate limitation of applying and drying an adhesive solution.