Extrusion International 3-2021

50 Extrusion International 3/2021 EXTRUSION BLOWMOLDING The blowmolding specialist W.MÜLLER has tested twomethods for the use of post-consumer recyclates (PCR) in packaging. In the fi rst examined variant, the PCR layer is surrounded by two layers of newmaterial, the second variant is shielded with an internal plasmacoating. Both variants had signi fi cantly lower migration values than hollow bodies made of pure PCR PCR in Cosmetic Packaging? It’s all a Question of Technology W. MÜLLER has many years of experi- ence with the use of PCR for the pro- duction of hollow articles in the blow molding process. With the in-house ReCo 3 called 3-layer-co-extrusion sys- tem, bottles can be produced consisting of a PCR layer that is surrounded inside and outside by a virgin layer. In this way, virgin material can be replaced by PCR in processing, and still unwantedmigra- tion from the PCR can be reduced. The company has tested how the mi- gration behavior of round bottles with a volume of 1l from 100% recyclate dif- fersfromthoseproducedwiththeReCo 3 process. Two certi fi ed PCR types were selected (one was Recylen BM 948-30, sponsored by OPG Holding, Teningen) and one bottle of the pure material and one with a virgin layer in the outer layer were produced. At the SGS INSTITUT FRESENIUS, Taunusstein/Germany, vari- ing. In a second series of experiments, FABES Forschungs-GmbH, Munich/Ger- many, investigated how a CHF layer (CHF stands for carbon – C, hydrogen – H and fl uorine – F) applied by the Bel- gian company Delta Engineering on the inside affects migration behavior. With the help of plasma, a barrier is created in the process. These bottles weremade fromSystalen70000na002HDPE,which was sponsored by “Der Grüne Punkt”. The tests showed that the coating dras- tically reduces migration. While 76 sub- stances were detected on the uncoated bottle, the CHF-coated bottle had only 5. Since fl uorine is used for theCHF coat- ing, additional tests have been carried out with the coated bottle to ensure that no residues have been formed. As a result, no substances can be detected. The bottles are therefore also compli- ant for direct contact with “Rinse-Off” products such as shower gel. The involved research institutes point out that users have to carry out their own risk assessment, as the results de- pend, for example, on the size of the bottle and the intended use, and the starting materials could change from batch to batch. Managing Director Christian Müller said: “We were able to show with the tests that the use of plastic recyclates for packaging of sensitive products is pos- sible. With the right technology, there is no demonstrable risk of migration from the recyclate to the fi lling material. The fi ndings con fi rm that our proven ReCo 3 process fully meets these requirements. With the plasma coating we have test- ed another possibility of shielding. The results have encouraged us to offer this technology as a supplement in the future if customers are interested. To- gether with our partner Delta Engineer- ing, we want to make it easier for our customers to use recyclates.” ous migration tests were carried out, such as global migration and screening for potentially migratable impurities, reaction and degradation products (NIAS). Global migration was tested in accordance with DIN EN 1186 2002-07 and the results were in all cases below the legal requirement of Regulation (EU) No 10/2011 of 10 mg/dm 2 . However, W. MÜLLERwas able to show on the basis of the tests that the ReCo 3 bottles show a lower global migration compared to the pure recyclate bottles. This is also con fi rmed by a signi fi cant reduction in the number and concentra- tions of migration-capable NIAS. In order to increase the recyclate con- tent in such three-layer systems, the sur- rounding layers must be as thin and yet stable as possible. In addition to plastic layers, plasma coatings are therefore also suitable for the purpose of shield- W. MÜLLER GmbH Am Senkelsgraben 20, 53842 Troisdorf-Spich, Deutschland www.w-mueller-gmbh.de For the test series, bottles were made of pure PCR (right), as well as bottles with a layer of virginmaterial inside and outside (All photos: W. MÜLLER) The two bottles for the second series of tests are made entirely of PCR. The bottle on the right was provided with a CHF coating from Delta Engineering In the cross-section of a bottle made with ReCo 3 , the two outer layers of virginmaterial as well as the inner PCR layer are visible