NatureWorks® PLA: technical overview

The technology to produce NatureWorks® PLA allows abundant, annually renewable resources like ordinary field maize to replace finite ones (petroleum) in everyday products, such as food packaging, bottles, disposable serviceware, labels and sheet.

• The technology to produce NatureWorks PLA essentially harvests the starch stored in natural plant sugars. The sugar is then fermented into lactic acid, which is used to create a clear plastic called polylactide (PLA) that can be shaped into a variety of bottles, containers, trays, film and other packaging.

• NatureWorks LLC operates a global-scale facility in Blair, Nebraska, USA, capable of producing more than 140,000 metric tons (300 million pounds) of NatureWorks PLA per year.

• From cradle to resin, the production of NatureWorks PLA uses 68 percent less fossil fuel resources than traditional plastics (PET) and it is the world’s first greenhouse-gas-neutral polymer. *

Applications

A combination of performance and environmental attributes make NatureWorks PLA ideal for use in a wide range of packaging applications, including:

• Rigid Thermoforms – In addition to outstanding gloss and clarity, the relative ease of processing that NatureWorks PLA exhibits in extrusion and thermoforming enables it to be used for both conventional and form-fill-seal applications.

o Its stiffness enables more efficient down gauging versus existing PET materials. The environmental attributes of NatureWorks PLA make it a preferred packaging alternative with positive consumer appeal.

• Films and Labels – With its excellent performance qualities and unique blend of physical properties, NatureWorks PLA is well suited for a wide range of applications in the film market including labels, heat-seal overlays, window films, flow wrap, twist wrap and formulations for carrier bags.

o NatureWorks PLA offers performance attributes to help upgrade the aesthetic and functional performance of cut-and-stack, shrink sleeve and pressure sensitive film labels.

o NatureWorks PLA is a clear alternative to traditional plastic films such as cellophane, cellulose acetate and glassine, as well as a low temperature heat seal layer and/or flavor and aroma barrier in co-extruded structures where its combination of properties allows layer simplification or replacement of specific layers.

o NatureWorks PLA can be formulated for flexible film applications such as carrier and trash bags to replace LDPE and HDPE bags when a compostable solution is desired.

• Bottles – The properties of NatureWorks PLA are well suited for the injection stretch blow molding (ISBM) process used to form bottles and jars.

o NatureWorks PLA is primarily suited for short-shelf-life applications that use cold-filling techniques such as still water, fresh juices, dairy beverages, edible oil and other related applications.

o NatureWorks PLA allows for varied and complex bottle shapes and sizes.

o It is successful as a bottle resin because of its transparency and its fit with all landfill diversion options.

o Sensory paneling of several foodstuffs stored in NatureWorks PLA bottles show the corn-based material offers comparable organoleptic properties to glass and PET – confirming the suitability of NatureWorks PLA for a wide variety of food and beverage bottling applications.

• Disposable Serviceware – NatureWorks PLA can be used in the manufacturing of disposable cold drink cups, bowls, plates, and cutlery.

o The advantage of serviceware made from NatureWorks PLA is its compostability. It can be collected with food waste and transported to an appropriate commercial composting facility. Cups also feature high gloss and clarity, strength and excellent printability.

• Specialty Cards – Gift, phone, key, credit and retail cards made from NatureWorks PLA provide retailers a more responsible option to traditional plastics, and often replace PVC for these applications.

o The rigid properties of NatureWorks PLA sheet allow it to be easily scored.

o NatureWorks PLA exhibits an optimum surface for printing and varnishing.

o Many existing specialty cards are currently made from PVC. The use of NatureWorks PLA as a replacement material allows for an improved environmental position for many brand owners.

o The nature-based cards can be used for credit, membership, hotel, gift, retail, and other applications.

o Other sheet applications include folding cartons and blister packs.

Performance Attributes

NatureWorks PLA exhibits several attributes that make it an attractive and versatile polymer to packaging manufacturers and brand owners:

• Surface adhesion – Readily accepts coatings, inks and adhesives

• Breathability – Moisture can pass through films and rigids minimizing condensation

• Clarity & Gloss – Exhibits less than 5 percent haze

• Flavor & Aroma Barrier – Comparable organoleptic properties to glass and PET

• Grease Resistant – Provides excellent resistance to most oils and fats used in food products

• Printability – Natural surface energy readily acceptable for many ink formulations

• Stiffness – Allows for down gauging versus materials like aPET without loss of part strength

• Heat Sealability – Initiation temperatures are as low as 180oF (80oC), with heat seal strengths of greater than 2 lb./inch. Lower temperature allows for faster sealing and increased output

• Dead-fold – 25 percent better than cellophane, which means products stay packed, and spoilage or waste from open packages is reduced

Easy “Drop-in” to Existing Operations

Whether making containers, or packaging food items, NatureWorks PLA can be seamlessly “dropped in” to many existing operations with minimal changes.

Disposal Advantages

NatureWorks PLA offers the most landfill waste diversion options of any current commercial plastic material. It can be physically recycled, industrial composted, incinerated, chemically converted or land filled. ** NatureWorks LLC is working with representatives of the plastics recycling industry to study the handling of post-consumer PLA in mixed plastic streams. This research shows NatureWorks PLA can exist in the present North American infrastructure with the current commercial systems for recycling PET and HDPE. In addition, NatureWorks is committed to responsibly ensuring the successful introduction of the material into existing waste management and recycling infrastructures.

• Sorting: NatureWorks PLA can be sorted today from PET and HDPE using the standard Near Infrared (NIR) equipment used to sort out non-PET and HDPE plastics.

• Recycled Flake Quality: At early market-adoption volumes, independent testing shows that PLA in the recycle stream can exist at a 0.1% level in post-consumer recycled PET or HDPE flake with no limitation on its use in new bottles.

• Large Volume Post-consumer “Buy Back”: NatureWorks LLC instituted a “buy-back” program related to bottle introductions. The program requires commercial Municipal Recycling Facilities (MRFs) in North America in select geographic areas to separate post-consumer PLA bottles into distinct NatureWorks PLA bales – all meeting a predefined specification, resulting in truckload quantities (40,000 lbs.). NatureWorks LLC will then buy these bales at an agreed-upon price and recycle them appropriately. This program allows a bridge to the development of a commercially viable post-consumer PLA market.

Reader enquiries

NatureWorks
Gooimeer 6-10
1411 DD Naarden
Netherlands

+31 35 699 1344

www.natureworkspla.com