One of the strengths of polycarbonate is its toughness, combined with transparency, and a high-temperature resistance. But despite that toughness, polycarbonate has taken a major hit when it comes to packaging demand.
Negative publicity has had a detrimental impact on the packaging sector worldwide, especially with the introduction of legislation banning the use of polycarbonate in containers intended for children, but also due to pre-emptive actions by producers and retailers, according to a recent IHS Chemical global market study.
"Even though polycarbonate hasn't officially been banned from food packaging, individual states have banned polycarbonate in baby bottles," said Adrian Beale, director of global engineering plastics at IHS Chemical. "While scientific evidence is not conclusive at the moment, due to general public perception, the packaging market began moving away from polycarbonate containers a few years ago."
BPA in focus
PlasticsToday and sister publication Packaging Digest have combined resources for a comprehensive report on bisphenol A (BPA), including its history and future, as it relates to packaging.
|BPA in packaging: A lucrative past, a controversial present, and a tentative future|
|BPA in packaging: Defying the pressure|
|History of BPA|
|Eastman Chemical files lawsuit over Tritan estrogenic activity claims|
He estimated packaging accounts to about 3 to 4% of global demand for polycarbonate.
One remaining growth application for polycarbonate in packaging, is the 5-gallon water bottle. While, most of those are still polycarbonate, Beale said there's still potential to move away from polycarbonate in that area when there other alternatives are coming to the market.
Still, despite the bad PR for polycarbonate in packaging, the global demand for the resin is expected to grow at an average annual rate of around 5% during the next five years, reaching around 4.5 million metric tons by the end of 2016.
The fastest growth will be in the automotive glazing sector, which according to Beale, has the potential to be a "game-changer" for the polycarbonate industry due to the sheer scale of the potential demand for car windshields, windows and sun and moon roofs, which are currently constructed mainly from glass.
"Following a drop in demand for polycarbonate during the recession, we are seeing demand growth that is largely being driven by automotive, appliance and electronics applications," Beale said.
Electrical and electronic applications are the largest end-use for polycarbonates, accounting for around one-fifth of global demand at roughly 720,000 metric tons in 2011, he said. The key driver for this market will be the increased use in consumer electronics, such as tablet devices, flat screen televisions, mobile phones and office equipment, including printers.
According to 2007 data from the American Chemistry Council, along with nine plants that manufacture BPA, polycarbonate plastic or epoxy resins, approximately 1400 downstream facilities in the U.S. process polycarbonate or epoxy into finished products, with an investment value of $6 billion.
Two primary players
Several companies produce polycarbonate globally, but two companies, Bayer of Germany, and Sabic of Saudi Arabia, produce the lion's share of world supply, owning around 28% and 25% of global capacity, respectively.
Sam Stewart, VP of sales, Bayer MaterialScience, told PlasticsToday that polycarbonate is the plastic of choice for Bayer due to its balance of properties, clarity and mechanical, impact, chemical and heat resistance, "which make it ideal for a wide range of applications in various industries, including food contact, medical, automotive, electronics and construction."
"Our customers know best," he said. "They know that the U.S. Food and Drug Administration and other government agencies around the globe have approved the use of polycarbonate for these types of applications."
He said customers who have tried substitutes for polycarbonate have learned that these substitutes do not meet their stringent performance criteria, and in some cases they have seen a "re-selection" of polycarbonate.
When it comes to public perception of BPA, Stewart said the company is "concerned that people are not making the right decisions because consumers are being led down a path that is based on emotion rather than sound science."
"Bayer is committed to consumer safety," he said. "Scientific assessments from the FDA, the European Food Safety Authority and other international regulatory organizations consistently reinforce BPA and polycarbonate plastics are safe at current levels of exposure and for their intended uses."
BPA is one of the most thoroughly tested chemicals in commerce today, and it is so widely used that it would be unwise to attempt to replace it with anything that is less tested, Stewart said.
Sabic, the former GE Plastics and maker of the Lexan brand PC, declined to be interviewed for this article.
At NPE2012, Timothy O'Brien, VP engineering resins-America/Europe did talk with PlasticsToday about numerous investments, including a new polycarbonate copolymer, among other developments.
In spite of negative publicity regarding BPA, its usage continues to grow in excess of GDP, according to O'Brien, particularly in the electrical/electronic and automotive markets. "One is about weight and one is about miniaturization," O'Brien explained of the auto and electronics concerns, respectively.
Alternatives to polycarbonate
One of the biggest criticisms of alternatives to polycarbonate is the lack of toughness and clarity. Eastman Chemical believes its Tritan copolyester resolves any of those concerns. The company touts its Tritan material as a drop-in replacement for polycarbonate in food-contact applications.
According to Eastman, Tritan retains crystal-clear clarity, even after repeated commercial dishwashing, so it won't craze or discolor over time.
"Tritan was created due to a growing need in the market for a product with good clarification that could withstand higher temperatures," said Tim Dell, VP of Innovation at Eastman. "Although the FDA hasn't banned BPA, the market is clearly asking for a choice. The Tritan copolyester is very tough, and in many cases, the strength of Tritan can exceeds that of polycarbonate."
Since its introduction in 2007, Tritan has been used in more than 600 food-contact products ranging from serving and storing items to reusable sports bottles, baby bottles and small appliances. Independent third party testing demonstrated that Tritan is free of estrogenic and androgenic activity, according to Eastman. BPA is not an ingredient or by-product of the production of Tritan.
Recently, Rubbermaid Commercial Products (RCP) partnered with Eastman to create BPA-free foodservice products using the Tritan copolyester.
"Even though there isn't a study that absolutely proves BPA is harmful, there are studies that do say it's possibly harmful," said Mark Jackmore, VP of marketing for RCP. "We don't want to be in the business of having products that could be potentially harmful."
RCP choose Eastman to produce its four product lines previously made from polycarbonate. Tritan has an inherent toughness that can help increase product life as well as reduce waste, allowing food-service industry professionals to work more easily toward sustainability goals and initiatives, according to the companies.
"It's a daunting task," Dell said. "It sounds like you just make a simple material change but because different polymers have distinctive characteristics, it take a certain amount of investment, capital, and time."
Eastman helped RCP mold Tritan copolyester to meet quality standards for the end products. The products then underwent performance testing, centering on real-world application scenarios, such as drop testing and repeated dishwashing. After field-testing with select large chain accounts, RCP received positive feedback about the switch to Tritan, making it feel confident in the product launch.
"There is a tremendous amount of noise around BPA, and consumers are concerned," Jackmore said. "For us, it's about offering consumers alternatives."
Corn-based isosorbide could serve as BPA replacement
Back in 2010, Michael Jaffe, a research professor of biomedical engineering at NJIT, received a patent for a chemical derived from sugar. This new material was a derivative of isosorbide and may be able to replace BPA in a number of consumer products.
Jaffe said that instead of polycarbonates, PET with isosorbide can be used for making a plastic and that a form of isosorbide can replace epoxy resins in lining metal containers.
Isosorbide is a sustainable chemical that can be synthesized from cornstarch. Both components of the epoxy, the resin and the hardener, are from water-soluble, plant-derived chemistries. The epoxy is cured by baking at an elevated temperature.
"We are viewing sugars as a chemical feedstock to produce new monomers, polymers and additives for a broad range of biomedical industrial applications," Jaffe said. "Sugar-based chemicals are attractive because they are generally regarded as safe, and are a renewable resource that can be made readily available at competitive pricing. Isosorbide offers molecular geometry and chemical functionality compatible with many existing commercial chemistries."
Archer Daniels Midland and isosorbide
Agricultural processing giant Archer Daniels Midland (ADM) markets isosorbide as part of its Evolution Chemicals product range.
"ADM recognized isosorbide as a unique molecule that showed promise in a number of important end applications including epoxy resins, performance polymers and solvents," a company spokesperson said. "ADM developed patented process technology and launched this product to provide our customers with additional viable alternatives to petroleum-based chemicals."
Isosorbide itself is a diol and can be used as a monomer in polycarbonates and other condensation polymers. The spokesperson said its customers are interested in isosorbide for numerous applications including packaging.
ADM doesn't consider this offering a PC replacement as the company focuses on producing the isosorbide intermediate chemicals, not the final polycarbonate.
"ADM is focused on producing drop-in intermediate chemicals and new molecules that serve vital needs," the spokesperson said.
Borealis promotes clarified PP as a replacement for PC
Plastics and chemicals supplier Borealis has launched a more transparent extrusion blowmolding grade of polypropylene (PP) specifically designed for cosmetics and baby bottles, with an eye on capturing market share forsaken by polycarbonate.
"Borclear RC737MO is the clear advance in transparency that the safety-conscious, aesthetically-driven cosmetics and baby sectors have been looking for when selecting PP for their product or packaging," stated Rainer Höfling, Borealis VP business unit molding.
The company said its Borclear RC737MO offers a "leap forward" in aesthetics by influencing the gloss, haze and clarity of bottles. The new PP bottles can be processed by applying the usual processing settings for random PP grades, with barrel temperatures in the range of 190-220°C. Its higher melt strength enables converters to more easily regulate wall thickness.
"Compared to PC, this PP grade shows better machine running cost efficiency and lower pressure needed to blowmold, improved safety and cost reduction," a Borealis spokesperson said.
Doesn't just stop at BPA
BPA-free products may bring comfort to some, but not Stuart Yaniger. He argues that a greater emphasis must be placed on chemicals and materials that exhibit estrogenic activity (EA), and said some BPA-free materials are not EA-free.
"In general, people are unaware how many different chemicals are in plastic products," said Yaniger, VP product development and research at PlastiPure. "The idea that you take one chemical away and somehow it's all okay now, it's a ridiculous thought. You have to fix the entire problem, and in some cases, the estrogenic activity hasn't been addressed."
Almost all existing plastics today, as well as many cosmetics, silicones, and paper products, release chemicals with EA, according to PlastiPure. Chemicals with EA have been associated with serious health problems, especially with infants, small children, and pregnant women.
PlastiPure works with companies throughout the entire plastics supply chain to develop EA-Free materials, compounds, colorants, processing aids, and PlastiPure-Safe certified EA-Free products. PlastiPure has also worked with resin manufacturers and compounders to create lines of EA-Free raw materials.
Environmental Health Perspectives (EHP), a peer-reviewed journal published by the National Institute of Environmental Health Sciences, published a scientific article from researchers at PlastiPure, CertiChem, and Georgetown University, which focused on quantifying and addressing the potential health issue of EA in plastic products.
The results of this study indicate that almost all the plastic products leached chemicals had detectable EA, including those advertised as BPA-free. Leaching increases when products are subjected to common-use stresses such as dishwashing, microwaving and sunlight.
"In some cases they (BPA-free producers) are making polymers that are just as estrogenic," he said. "This is a huge issue, and we haven't fixed the problem. In one sense BPA-free is viewed as marketing, not a health issue."
Yaniger said PlastiPure gets a variety of reaction from the industry on their work. Some companies are interested in working with them to help ensure its products are EA-free, while others are unwilling to make a market change yet.
"Listen, plastics is one of the best packaging materials out there," Yaniger said. "As long as it doesn't cause huge disruptions to our systems, plastics should and will continue to be used widely. They just need to be made safer."
Apparently, the entire industry isn't happy with their work. Yaniger said that "one big company" is suing PlastiPure.
"The big company" suing PlastiPure?
Eastman Chemical files lawsuit over Tritan estrogenic activity claims
Eastman Chemical has filed a civil action lawsuit against PlastiPure and CertiChem claiming the companies made false or misleading statements regarding estrogenic activity (EA) coming from Eastman's Tritan line of resins and products using these materials.
According to PlastiPure, the lawsuit stems from the company's findings that are in conflict with Eastman's claims that its Tritan resin line is EA-free.
Eastman contends that PlastiPure relies on the results from a screening test (called the MCF-7 test), "which is known in the scientific community to be a non-definitive, non-final test for making determinations of EA and from results of other unreliable testing protocols," according to an Eastman spokesperson.
Court documents titled "Eastman Chemical Co. v. PlastiPure" verify the nature of the suit is "Intellectual Property - Trademark." The file date was Wednesday, January 18, 2012 at the Texas Western District Court.
A PlastiPure spokesperson said the trial is "ongoing."
Scientists at CertiChem, PlastiPure, Georgetown University, and the University of Texas published a paper on EA in plastic materials and commercial products in 2011. In these tests, PlastiPure has disclosed information on which materials and products had EA before and after exposure to common-use stresses, including Eastman's Tritan.
CertiChem tested Tritan with various bioassays using different cell lines and repeatedly measured the effects of chemicals with EA leaching out of Eastman Chemical's Tritan materials following exposure to common-use stresses, according to PlastiPure.
During its testing, CertiChem simulates real-world use of products (e.g. dishwashing, sunlight exposure, leaving bottles in a hot car, etc.) and testing with an array of extract solutions to simulate a variety of drinks and foods.
Eastman claims that PlastiPure has contacted Eastman's customers and "has shared this false or misleading information to cause unnecessary confusion about Tritan."
"Contrary to PlastiPure's statements, testing by independent third-party laboratories using well-recognized methods have confirmed that Tritan does not exhibit EA," the Eastman spokesperson said. "Eastman intends to aggressively pursue its legal rights to enforce and protect its Tritan product and business from any false or misleading representations."
The PlastiPure spokesperson said the company believes Eastman is using this lawsuit as a means to censor test results performed on Tritan resins and products manufactured from them.
"Eastman Chemical does not state if their testing exposed the materials to common-use stressors (such as sunlight) or if their tests have the appropriate sensitivity to properly evaluate food and beverage packaging for potential chemical hazards," PlastiPure stated.
The company said Eastman continues to market Tritan as EA-free coinciding with the suit, which PlastiPure stated, "leaves consumers exposed to numerous potential health risks, while being assured by a multibillion-dollar chemical company that their products are perfectly safe."
"Eastman Chemical appears to be following a 'greenwashing' strategy where they wish to make new claims on an unimproved product to exploit the increasing market awareness of EA," PlastiPure stated.