Cossma 7-8/2013

According to the latest estimates1,6 about 90 percent of all the plastics on the market today could be substituted by plastics based on renewable re- sources. A promising strategy consists of us- ing drop-in solutions since the produc- tion of polymers with well-known and established properties should then follow4 . Biopolymers as a packaging material for cosmetics? For those who wish to use biopoly- mers as packaging for natural cosmet- ics the questions to be asked are whether the biobased materials cur- rently available on the market are ef- fective in offering protection of the product, to what extent they are recy- clable or biodegradable, and from which resources they are produced. When looking at the sources of the raw materials used, subjects such as GMOs and possible competition with food producers for land will also have to be considered. Packaging for natural cosmetics A characteristic of natural cosmet- ics is that they are very complex prepa- rations of natural substances and that preservatives are not used or are sub- ject to strong restrictions. For this rea- son it is important to protect the prod- uct contents from changes caused by water vapour, UV light, oxygen and car- bon dioxide by using suitable packag- ing materials. At the present time this cannot al- ways be achieved using available bio- plastics, so that suitable barrier coat- ings such as aluminium are needed. In particular the figures for water vapour permeability are still unsatis- factory. Polylactic acid (PLA) and Poly- hydroxyalkanoates (PHA) have a cer- tain resistance to water vapour. In com- parison with PET and in particular PE or PP, PLA and PHA are still a weaker barrier to water vapour4 . Barrier per- formance can be optimised with some form of coating such as a plasma coat- ing or metallization. The material efficiency can also be improved by a combination of these ultra thin layers or coatings with biopolymers or recycled polymers. Coating does however still have the disadvantage that the coating itself is often subject to scratching or cracking. Polylactic acid (PLA) At the moment PLA is mostly made using genetically modified types of maize. It is estimated, in fact, that to- day 90 percent of PLA is based on ge- netically modified maize5 . Alternatively manioc, sugar cane or sugar beet can be used for the production of PLA. Under contract with companies such as Danone the PLA supplier, Na- tureWorks, is attempting to cultivate sustainably certified maize in accor- dance with the guidelines of the Inter- national Sustainability & Carbon Certi- fication (ISCC) and the Working Land- scapes Certificate (WLC) program. WLC insists on, among other things, that no genetically modified plants are used in the productionprocess. At the present time, however, the level of PLA production based on these certified harvests is still a very small percentage of the total PLA output5 . The need for agricultural land According to Prof. Dr. Hans-Josef Endres3 of the Hanover technical high school the likely demand for land to be used for bioplastics production in 2016 is less than 0.1 percent of global agri- cultural land. And if we switched all of the plastic used for packaging from pe- troleum-based plastics to bioplastics we would still need less than 2 percent of the agricultural land, and switching all petroleum-based plastics used in packaging, automobiles, and sport and leisure, to bioplastics, would still re- quire less than 5 percent of the world’s agricultural land. A more exact and detailed analysis is currently being prepared3 . Requirements for the future Apart from certain specific drop-in solutions or blends with perhaps high- er barrier performance at the present time there are, on the market, some biopolymers for production applica- tions which have a medium barrier per- formance against water vapour, oxy- gen, light etc. Depending on their field of application, especially where they are used in conjunction with sensitive formulations, an additional protective coating can be used, based on, for in- stance, aluminium. Biopolymers based on renewable resources are very much setting the trend and are currently being devel- oped, or are already available. For ex- ample the most commonly used con- ventional polymer types, such PE and PA, are also available as bio-PE and bio-PA. The assumption is that their material properties will vary very little from the equivalent polymers of fossil origin4,8 . However their availability, costs in comparison with conventional plastics, and the possibility of using them in blends with other (bio)poly- mers and/or additives, must be opti- mised. New types of biopolymers/bioplas- tics have new material properties and frequently cannot be processed under standard conditions. Hence detailed material data must, in future, be made available7 . The literature list can be found on the Internet (see Internet box) FOCUS: NATURAL COSMETICS PACKAGING 24 COSSMA 7-8I2013 Dr. Andrea Kühn head of quality control for pack- aging material at Wala Heilmittel Bad Boll/Eckwälden, Germany andrea.kuehn@wala.de www.wala.de Plastic packaging with biopolymers now includes lipstick tubes and cases for compact powder photos:Leoplast,SunCreativeCosmetics COS1307-8_22_Wala_GB_COS1105_10_Anti_Aging_GB 29.07.13 07:18 Seite 24

Cossma 7-8/2013

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