Industry Market Trends

Disposable Products a Natural for Bioplastics, But Composting Infrastructure Is Needed

Dec 26, 2012

Compostable cup made from corn. Credit: rsuehle, CC BY-SA 2.0

Plant-based materials find one of their most important and obvious markets in disposable products -- things like flatware, bags, packaging, medical supplies and bottles. Their contribution to the waste stream is potentially zero, if they can be processed in an industrial composting system that decomposes them completely. Manufacturers are developing polymers that can be broken down by enzymes into shorter molecules that can in turn be digested by bacteria and returned to the soil.

In its study "Bridging the Divide between Demands and Bio-Based Materials," Lux Research Inc. says bioplastics should be able to find a place in small markets such as disposable liners (under $1 billion) and plastic flatware (nearly $.5 billion). Medical containers represent a market of something under $5 billion. Markets such as containers and packaging present larger opportunities. Pike Research projects that the worldwide packaging market will reach $530 billion by 2014 and that the market for sustainable packaging will grow from $88 billion in 2009 to $170 billion in 2014. Clint Wheelock, managing director at Pike, says that "More eco-friendly plastic packaging will have a huge impact, because it represents more than a third of the total global packaging industry, second only to paper packaging."

PLA: The Go-To Material for Disposables

Biodegradable trash bag made with Ecovio. Credit: BASF.

Polylactic acid (PLA) is emerging as the most important bioplastics material for disposable applications. European Bioplastics, a trade association, describes PLA as one of a class of "starch blends made of thermo-plastically modified starch and other biodegradable polymers as well as polyesters." PLA offers performance characteristics similar to polyethylene (PE) and polypropylene (PP) and is being used for flatware, cups, clamshell containers, and water and juice bottles.

Lux Research believes that, in the disposables category, "PLA can't be beat." PLA is penetrating well in the market for disposable bags, bottles and cups, says the firm. Its "excellent barrier properties" make it a good candidate for plastic bottle applications.

NatureWorks LLC, with headquarters in Minnetonka, Minn., manufactures its Ingeo PLA material at a plant in Blair, Nebraska. Ingeo is made from corn-based sugar, although it can be manufactured from any other plant-based sugar. NatureWorks literature says that "In the future, Ingeo will be made from cellulosic raw materials, agricultural wastes and non-food plants." According to chemical-industry research firm ICIS, NatureWorks' Nebraska plant is capable of making 140,000 tons per year of Ingeo.

Ingeo is compostable, but as with most PLA-based materials, you can't just landfill it or throw it on the ground and expect it to rot away. NatureWorks says its material "can be physically recycled, industrially composted, incinerated, chemically converted back to lactic acid through hydrolysis (feedstock recovery) or landfilled." Industrial composting, the preferred method for PLA disposal, brings the material to a level of temperature and humidity sufficient to break the polymer chains into smaller polymers and lactic acid, which can be metabolized by organisms. The company claims that using Ingeo to replace the polyethylene terephthalate (PET) in 100,000 plastic food containers will "save greenhouse gas emissions equal to driving a car 16,000 miles and non-renewable energy equal to 19 barrels of oil or 775 gallons of gasoline." Ingeo is used by various food, juice and bottled water companies for containers. Aside from disposables, NatureWorks sells its product for such applications as durable goods, cartons and packaging, fibers, plastic cards, apparel and textiles.

Bioplastic meat tray. Photo by Doug Beckers.

Food-industry manufacturer Purac produces lactic acid and lactides for PLA manufacturing. Purac's PLA is used in fruit and vegetable packaging and disposable cups and cutlery. The company makes a Puralact heat-resistant PLA. ICIS says that Purac's plant in Thailand is capable of producing 750,000 tons per year of lactide.

Novamont, an Italian bioplastics manufacturer, produces 100,000 tons per year of its Mater-Bi, a compostable plastic. Novamont manufactures Mater-Bi, a starch-based polymer, at its plant in Terni, producing it in granular form that can be processed into various materials. The company says that besides being biodegradable and compostable, its product "can be worked using the same processes used for traditional plastics and with similar output," can be printed on using conventional inks and printing methods, can be colored in bulk, is antistatic and can be sterilized with gamma rays.


BioBag dog waste bag. Credit: photologue_np, CC BY 2.0

BioBag, based in Palm Harbor, Florida, uses Novamont's Mater-Bi for its compostable trash bags, liners, sandwich bags, wraps and films. BioBag says its products "are designed to be composted and returned naturally back to the earth." Placed in an open landfill, "they will decompose at a rate similar to other biodegradable materials in the same setting," that is 10 to 40 days in a typical municipal composting facility. BioBag has manufacturing facilities in the U.S., Norway and Belgium.

BASF Aiding the Development of Composting Infrastructure

Chemical company BASF manufactures two biodegradable plastics, Ecoflex and Ecovio, which are primarily marketed in Europe and are used for manufacturing of plastic garbage bags. Ecoflex is actually a petroleum-based aliphatic-aromatic copolyester designed to be added to other polymers such as PLA to impart greater flexibility. Ecovio is a blend of PLA and Ecoflex. In a report from BASF, Andreas Künkel, head of research for biopolymers at the company, explains BASF's rationale for using a petroleum-based material in its formulation:

Both components of Ecovio -- Ecoflex and polylactic acid -- are biodegradable. For a material to be biodegradable, it is unimportant whether the feedstock is plant- or petroleum-based. What matters is the structure of the molecules. Because this synthetic polymer has been engineered for outstanding biodegradability, microorganisms can easily digest it.

A report from ICIS says BASF estimates demand for biodegradable and bio-based plastics to grow 20 to 30 percent during the next few years because of "rising consumer demand, new environmental regulations and the development of new technologies and applications." The company sees applications for its bioplastics in such products as paper cups, shrink films and shopping bags.

Microscopic view of a coating of Ecovio on a paper cup. Courtesy of BASF.

One market challenge, according to Robert Heger, vice president for specialty plastics at BASF, is putting in place the infrastructure for collecting and separating organic waste and composting the materials. Not all countries have such systems in place. Yet, "The separation of organic waste has the potential to save money and also reduce greenhouse gas emissions," Heger tells ICIS, so BASF has been working with municipalities in the region on infrastructure development to help them meet sustainability goals. Heger says BASF is also forecasting growth in the biodegradable plastics market in North America, Japan and Australia. BASF is selling Ecovio in the U.S. through bioplastics manufacturer Metabolix.

While emerging markets might not have the regulatory requirements that drive expansion in developed countries, Heger feels that local solutions could be workable. BASF participated in a pilot project in Thailand to introduce biodegradable bags and composting facilities. Heger says that "You don't necessarily need total regulations for a country, but you could invest in a mobile composting facility in a village and at the end of the process, you have a valuable product that could be put on the fields."

After composting, degraded bioplastics can be used as fertilizer. Credit: BASF.


EDITOR'S NOTE: This article is the third in a series on how bioplastics are being used throughout the manufacturing industry. You can read the rest of the series here: