Meaning
Category of flexible and rigid containers made from polymers like polyethylene and polypropylene dominates the global market for consumer goods. Most polyolefin packaging is chosen for its low cost and excellent moisture barrier properties. These materials are chemically inert, making them suitable for direct contact with food and pharmaceuticals.
Barrier Performance
Resistance to water vapor prevents the spoilage of dry goods and maintains the freshness of produce. While they are excellent at blocking moisture, polyolefins often require additional layers or coatings to provide an effective barrier against oxygen or aromas. Multilayer structures combine different grades of resin to achieve the specific protection required for the contents.
The use of ethylene vinyl alcohol as a thin internal layer is common for high-barrier applications. Proper selection of the skin layers ensures that the package remains heat-sealable.
Mechanical Strength
Durability of the container depends on the balance between stiffness and impact resistance. High-density polyethylene is used for rigid bottles that must support the weight of a stack, while linear low-density polyethylene provides the puncture resistance needed for stretch wrap. The choice of resin grade affects the ability of the package to survive the stresses of shipping and handling.
Recycling Capability
Homogeneous construction from a single type of resin makes these packages easier to process in mechanical recycling streams. Flexible films made from pure polyethylene are increasingly preferred over multi-material laminates that are difficult to separate. Improving the design for recycling ensures that the material can be recovered and used to make new products.
