The use of biodegradable plastics is heating up

Coop Italia, Italy’s most influential hypermarket chain, announced last month that the launch of a series of disposable tableware products using Cargill-Dow’s Nature Works biopolymer resin is a recent proof of the high-profile nature of plant-produced plastics.

However, one may ask the question whether disposable tableware can be considered environmentally attractive and attractive. According to Coop Italia's announcement, some retailers are focusing on the use of renewable resources and are increasingly becoming the focus of market interest. . With renewable resources year after year, polymers such as corn (eg Nature Works), cereals, wood, sugar cane, sugar beet, seem to be the ideal solution.

Accurately speaking, biopolymers are not really present at present. As early as the beginning of the 20th century, people have already used cellulose pulp to produce cellulose film or cellophane. However, although cellulose films are based on biological sources, they are non-composting. It is not composted at least when it is tested with the latest German DIN standards and US ASTM standards. Composting certification is a key requirement for biopolymers in today's environmentally-conscious markets, especially for critical requirements of biopolymers for packaging.
The film division of UCB, a Belgian specialty chemical company that was acquired by a privately-owned conglomerate in July last year, mentioned this when talking about the company's Nature Flex series of fully degraded cellulose films.

In terms of its natural state, this cellulosic film is highly transparent but does not have moisture barrier and heat seal properties. Paints and paints can overcome this drawback, but they also hinder the biodegradation of the film.
“Nature Flex is a product that can be coated with a polymer that can be completely composted,” said Andy Sweetman, marketing manager for special packaging films at UCB. “This is the only cellulose that we claim can be degraded.” Cellulose was once a pillar product of the plastic packaging film market. In recent years, however, it has severely lost its ground and has given way to traditional polymers, especially biaxially oriented polypropylene films. Sweetman said that the cellulose film is currently limited to use in some very special areas, and it is estimated that the global annual demand is slightly higher than 100,000 tons. In contrast, BOPP's annual demand is higher than 3 million tons.

In any case, the promotion of the biodegradable Nature Flex product enables the company to sell cellulose to new applications and replace traditional polymers.

Sweetman said: "At present, the most popular application is to replace cellophane tape with cellophane tape. However, its large number of applications still replace coextruded polypropylene film, coated polypropylene film and polyester film, that is, all mainstream transparent films.

Nature Flex can be obtained by a non-coating method or a three-layer coating method with moisture barrier, gas barrier, and good heat sealing properties.

Sweetman said that Nature Flex, like all biopolymer applications, is one of the important end-user markets for organic fruit and vegetable packaging. However, even in this market, there are still more technical problems than getting market profits.

He pointed out that “a typical problem is that although organic crops are a relatively easy market to enter, it seems that natural products use natural packaging. However, we found that only if you have both this market and technological advantages , you can succeed. Otherwise, the end user can only suffer some loss of performance."

“Although we must strike a proper balance between market and technology advantages, the fundamental issue is cost, because all plastics based on renewable resources are more expensive than traditional polymers,” he said.

“There is also a problem in food packaging, which is that bio-plastics have relatively low gas barrier and moisture resistance, and sometimes it affects the preservation and preservation of food.”

Increasing barrier performance is a technical issue, but Sweetman believes this is a major technical issue. Because if this moisture-blocking material also prevents the penetration of microorganisms, it will not degrade.

The introduction of a high-cost, low-tech packaging solution is always a very tough challenge for an important retailer. But if producers in the bioplastics industry can strengthen cooperation rather than compete, this will reduce this challenge. Sweetman now sees the dawn of this sign.

He said: "We are all beginning to realize the fact that if someone really wants to take a step, they will have to change the whole package."

His view is that the user may decide to use a starch-based material as an ideal material for the tray, but the wide range of heat-sealing or high transparency characteristics of cellulose may be the preferred packaging material. Considering MaterBi and Nature Works and Nature Flex as competitors, there is a trend that we have to strengthen cooperation in some areas. However, it is not. ”

Although manufacturers such as Cargill Dow and Novamont are pushing for the extrusion, casting or forming applications of cellulosic films, no significant progress has been made. In terms of scale and market development, Cargill Dow is considered to be the leader in the emerging industry of biopolymers. The polylactic acid polymer produced by the Cargill Dow Company in Nebraska, USA, has a designed production capacity of 140,000 tons per year. Kathleen Bader, CEO of the company, optimistically estimates that production capacity may be higher.

The production of polylactic acid polymers is not a complicated biochemical process. After the corn is harvested and ground, the starch is separated, the starch is refined into glucose, continuously fermented into lactic acid and condensed into lactide intermediate monomers, and finally it is polymerized in a solvent-free melting process. Bader said that the trick of Cargill Dow is to run the process at a cost that the market can afford.

“Our factory produces 140,000 tons per year, which is unique. Obviously, our output is gradually increasing. When you are a young company, you will expect such growth. Based on our competition with non-renewable polymer products This kind of fact, we are very willing to see the market can withstand accelerated growth." She said.

Bader believes that Nature Works and PS can compete on price, but this will only happen if the capacity is higher. In addition to Coop Italia, Cargill Dow has a long list of users, including Italian supermarket Iper packaging manufacturer, European packaging, and Belgian supermarket Bio-Planet. She acknowledged that she had to reshuffle the ranks of important big-name retailers.

"We need to look at people from the early days who can accept biopolymer products and move to big distributors who really control the value chain," Bader said. “They can really make an impact on the improvement of the environment. But there are very few companies that can take the initiative to continue with sincerity. Most of them still say that they have done less.”

Breakthroughs in biopolymer applications are most likely to occur in the packaging market, and most likely in food packaging. "Because our products are easy to replace PET, about 80% of our market is in packaging. The market has naturally created a pulling force." Bader said.

For products such as biopolymers, people's interest is not only in their biodegradability, they are also interested in other aspects, such as oil prices. We have recently seen that the price of oil has risen to the highest peak, and according to relevant forecasts we will face oil shortages of 20 years, 50 years or even 100 years. This is not a question of whether it will happen. It is just a matter of time.

Bader pointed out that over the past two or three decades, the price of oil and the price of the associated petroleum derivatives have undergone severe fluctuations, while the price of corn has remained almost unchanged. Many of Cargill Dow’s recent business contacts have taken into account such instability factors in controlling oil prices. Bader said: "The ability of users to predict the market cannot be underestimated."

Judging from the business of Cargill Dow, Italy is one of the markets in Europe with the greatest demand for biological materials. Perhaps worth mentioning is the great progress that Novamont has made. Nova-mont has a full range of biopolymers based on its MaterBi modified starch.

The company's starch-based products annually produce 20,000 tons. This summer, the company acquired Eastman's biopolymers business, thereby taking the biodegradable polyester product business into its pocket.

Catania Bastili, managing director of Novamont, believes that the introduction of Eastman's biotechnology and patents will be an important strategic development, which will further expand the company's product line.
Bastioli said: "The acquisition of the biopolymers business will enable us to further expand the scope of Novamont's proprietary products and accelerate the development of polyester based on renewable resources." She also said that opportunities for the development of bio-starch/polyester systems are also available. Also worth considering.

Biopolyesters are an important goal in the field of biopolymers. DuPont took a further step in creating a biopolyester. It formed a joint venture with Tate & Lyle to produce propylene glycol for Sorona polymer products.

DuPont Tate & Lyle BioPrroucts will use its own intellectual property fermentation and purification processes to produce propylene glycol from corn at a plant that will be built in Tennessee, USA. The new division is expected to be operational in 2006. In addition, DuPont's first corn-derived Sorona polymer production line at its North Carolina plant will also start production in the same year.

(Compiled by Wu Fangqun)
Source: Foreign Plastics