1. Introduction
The two decades between 1960s and 1980s saw a dynamic growth of classic polymer materials from petrochemicals (In the eighties they were produced in amounts greater than steel). However, since the mid-nineties, there is a constant growth of new technologies/biotechnologies of producing the so-called bioplastics [1]. Recent developments of knowledge in the domain of environmental sciences revealed that the environmental impact of different products, including those from plastics, has to be considered from the point of view of full life cycle not just on the stage of waste generation. Due to this, the concept of sustainable development, design, production and usage is currently in high demand. In addition to this, in business and production practices we can now observe introduction of higher standards than required by the current law. Many companies, especially international and global conglomerates, use the standardised Life Cycle Assessment (LCA) methodology in order to analyse the environmental impacts of their product and hopefully lower it by means of technical and material solutions. In this way a company may declare that it is more concerned about the environment than the competitiveness and the results of assessment form new directions in product design, that include such issues as: use of bioplastics, especially those from renewable resources, limiting carbon footprint values etc.[2].
2. Bioplastics
The term bioplastics was introduced in order to distinguish classic oil-based polymer materials from materials based on new technologies and biotechnologies. It is interpreted differentially by scientists and practitioners. It seems justified for practical reasons to adopt the definition applied by European Bioplastics [3].
Bioplastics are not single kinds of polymers but rather a family of materials that can vary considerably from one another.
There are three groups in the bioplastics family, each with its own individual characteristics [4]:
n biobased or partially biobased non-biodegradable plastics such as biobased PE, PP, or PET (so-called drop-ins) and biobased technical performance polymers such as PTT;
n plastics that are both biobased and biodegradable, such as PLA and PHA or PBS;
n plastics based on fossil resources and are biodegradable, such as PBAT or PCL.
It is important to note, that the property of biodegradation does not depend on the resource basis of a material, but is linked to its chemical structure. Definition of bioplastics was introduced in fig. 1.
Global production capacity of bioplastics by material type in 2014 was illustrated in fig. 2.
According to European Bioplastics works, bioplastics production capacity in years 2013-2013 was estimated to be 1,4-1,6 ml of tonnage. 2018 is predicated as a year of growth as high as up to 6.7 ml of tonnage (fig. 3).
3. Bioplastics for packaging
Bioplastics can be processed into a vast array of products using conventional plastics processing technologies. The process parameters of the processing equipment simply have to be adjusted to the individual specification of each bioplastic type. The application of various bioplastics in particular packaging formation technologies is presented in table 1., describing bioplastics for packaging production.
A number of different types of biodegradable polymers are already available on the market, some of them are completely made from renewable resources: for instance polylactic acid PLA, blends made from starch and next generation of cellulose films. PLA can be used to produce flexible films, extrude and thermoform rigid sheets, form packaging by injection moulding, laminate paper by extrusion [7]. Extension of market offer and increasing production capabilities can also be observed in blends made from starch used for production of flexible films and rigid sheets, thermoformed trays and containers, foamed space-filling materials in transport packaging, rigid packaging formed by injection moulding and also for coating of paper and cardboard [8] as well as compostable films – next generation cellulose films [9].
Rigid bioplastics applications are available, e. g. for cosmetics packaging of compact powders, creams and lipsticks as well as beverage bottles. Materials such as PLA, bio-PE or bio-PET are used in this section. Several well-known brands such as Coca-Cola, Vittel, Volvic or Heinz use bio-PET for bottles of all sizes containing sparkling drinks and other, non-gaseous, fluids. Procter & Gamble and Johnson & Johnson count on bio-PE to package different kinds of cosmetic products. The high percentage of biobased material in these products and the ability to combine them with recyclates from conventional PE and PET has resulted in a decisive increase in resource efficiency and a reduction of CO2 emissions. As a potentially mechanically recyclable material, PLA is also gaining pace in the rigid packaging market. With growing volumes, a separate recycling stream will become economically feasible, and the beneficial environmental potential of PLA will be further increased. Many different bioplastics are used for flexible packaging solutions. Biodegradability is a feature often sought when it comes to food packaging products for perishables. Biodegradable food packaging certified as industrially compostable was the first successfully commercialised bioplastic product. Films and trays are particularly suitable for fresh produce such as fruit and vegetables as they enable longer shelf life. In addition, confectionaries, such as chocolate and biscuits or dry food such as tea or muesli, are now being packaged with bioplastics. Food service packaging is another large growth segment. Whether it is cups, plates, cutlery or carrier bags – the entire product spectrum can be made from bioplastics. These products are used at sporting events, street festivals, on planes or in trains. They can be made of biobased non-biodegradable plastics or of biobased biodegradable plastics, depending on the end-of-life solution envisaged for the individual product. The biodegradability of certain types of bioplastics enables the joint recovery with food residue via composting or anaerobic digestion, provided that conventional plastics do not contaminate this stream. Retailers across Europe such as Rossmann, Spar, Coop and Carrefour use single or multi-use carrier bags made from bioplastics – some with the add-on bonus of biodegradability [6].
4. The leading packaging biopolymer producers
World markets are full of bioplastics listed in table 1, used also for rigid and flexible producing packaging. The leading producers of the above mentioned materials are:
n NatureWorks LLC, American brand manufacturing a group of polylactic acids obtained by the step-growth polymerization of lactic acid of corn starch using bacterial fermentation in a plant located in Blair (Nebraska, USA). NatureWorks PLA polymers are manufactured in vast variation used for the production of packaging films (biaxal oriented films, multi-layered films with a melt blown layer), extrude sheets and thermoforming, forming packaging by injection, and paper lamination by extrusion.
n Novamont Inc., Italian company manufacturing polymer-starch compositions with a trade name Mater-Bi. Terni based bio-refinery is manufacturing an entire group of Mater-Bi packaging oriented polymers, including those used for packaging films production (bags and wraps) and thermoformed sheets (trays and containers).
n Innovia Films, an English based brand manufacturing new generation of cellulose films with the trade name of Natureflex. The films are characterized with excellent optical properties, high oxygen and aromas barrier capacity, adjustable steam barrier capacity, heat-resistance, fat and chemicals resistance, and natural antistatic.
n BASF, a German brand producing biodegradable polymer Ecoflex and its polylactide composition named Ecovio. The material is used to manufacturing thermoformed trays as well as wrapping films, heat shrink films with the properties of polythene films possible to shrink in lower temperatures.
n Braskem, a Brazilian petrochemical brand producing a variety of bio-PE (HD-PE and LD-PE) for various packaging applications, including packaging films. Triunfo based installation is based on the technology of ethylene polymerization. The ethylene is based on ethanol produced through a fermentation from a renewable source (instead of fossil fuels) sugarcane.
Other example of biobased materials include PET bottles with biobased content. The technology is based on PET material production with some biomaterials inputs in production processes. The LCA of such application has proved that such material is sustainable as it limits the CO2 emission by 25% in comparison to a standard PET bottle. This innovative technology is going to be introduced by Coca-Cola Company in 2009. The production of this bottle (called PlantBottle) is illustrated on figure 5. PlantBottle has got 30% biobased content and after use it can be recycled similarly to standard PET. In 2015 during the Expo Milano, a food technology conference, Coca-Cola presented its first new PET bottle: 100 per cent plant-based [12].
5. Conclusions
Gradual depletion of global crude oil resources, used for production of conventional plastics, has influenced scientists to look for alternative material sources. One of the developed directions, concentrated on researching the technology of conventional plastic production from renewable resources. Second direction of research was focused on the development of biodegra
dable polymers (decomposed by enzymatic influence of bacteria and fungi), which could replace conventional plastic but would have similar characteristics at the same time. Particular interest of researchers was directed at biopolymers produced from natural renewable sources, which can be processed on conventional plastic processing machinery. Additional advantage of biodegradable plastics is the possibility of organic recycling – composting.
Bioplastics are more and more often employed for manufacturing packaging of various applications. The majority of aware consumers expects the producers of purchased products to apply green solutions.
According to the rule of sustainable development, the most significant role should be attributed to bioplastics from renewable resources (biomass), which can be divided between the following groups:
n classical plastics such as PE, PP and PET, which can be recycled;
n biodegradable materials which can be recycled organically – by composting.
Sources
[1] Żakowska H., Biopolimery – nowe materiały opakowaniowe, VI Międzynarodowa Konferencja Naukowa Rozkład i korozja mikrobiologiczna materiałów technicznych, Politechnika Łódzka, Wydział Biotechnologii i Nauk o Żywności, 24-26.09.2012, Łódź.
[2] Żakowska H., Ganczewski G., Bioplastics from renewable resources – next generation packaging materials, Opakowanie, English Edition, 40-44.
[3] Hasso von Pogrell, Market development of bioplastics and latest biopackaging trends, 4th Conference The future of biodegradable packaging, Warsaw, 27.09.2011.
[4] page [http://en.european-bioplastics.org/].
[5] Bio-based Building Blocks and Polymers in the World, nova-Institut GmbH, Version 2015-05.
[6] FACT SHEET. Bioplastics packaging-Combining performance with sustainability. Materials and market development in the packaging segment, European Bioplastics, January 2015.
[7] Widdecke H, Otten A., Bio-Plastics Processing Parameter and Technical Characteristic. A Worldwide Overview, IFR, 2006/2007.
[8] Hesler F., Mater-Bi – bioplastics, 3rd Conference The Future of Biodegradable Packaging, Warsaw, 28.09. 2010.
[9] Kornacki A., Kompostowalne folie celulozowe nowej generacji, IV Międzynarodowa Konferencja Naukowo-Techniczna Przyszłość opakowań biodegradowalnych, COBRO, Warsaw, 27.09.2011.
