PETpla.net Insider 09 / 2018

INSPECTION 39 PET planet Insider Vol. 19 No. 09/18 www.petpla.net INSPECTION 39 the scavenger being consumed. After 20 days it has been completely con- sumed and the ingress slope is identi- cal to that of the non-coated reference bottle in Figure 8. A combination barrier system involves addition of Amosorb DFC oxygen scavenger to the PET layer of LC2-coated PET bottles. Locating the scavenger in the inner PET layer protects it from ambient oxygen. This inner-layer scavenger reacts with oxygen that has permeated through the outside coating and is available to diminish the headspace and dis- solved oxygen integrated by the filling process. Adding 1% scavenger to a coated PET bottle results in an ingress rate significantly below 1,000 ppb over a period of six months (C). Even after 180 days the scavenger is still active and total oxygen ingress is below 1,000 ppb. Reducing scavenger content from 1% to 0.5% (D) results in increased oxygen ingress but it is still well below 1 ppm. Bottle type 3: Inorganic coatings can be applied to the inside of the bottle after blowing. Sidel Actis coating technology produces a thin layer of amorphous carbon, typically 100 to 200 nm thick, on the inner surface. Fig. 10 Comparison of oxygen ingress into an Actis coated bottle and the respective non-coated reference bottle The inner coating provides an efficient barrier and prevents oxygen desorption from the PET bottle wall into the product during the first few days of storage. A BIF factor of 9.9 was determined by comparing the slopes of oxygen ingress of coated and non-coated bottles. For both bottle types, sampling rate was adjusted to 30 s; mean value was taken from seven bottles. Fig. 11 Common multilayer structure Bottle type 4: Multilayer bottle containing oxygen scavenger Fig. 12 Oxygen ingress in multilayer bottles; (A) without active barrier, (B) multilayer bottles containing propri- etary scavengers in the PA inner- layer. The sampling rate was adjusted to 30 s. The combination of a multilayer structure, incorporating an active barrier within the middle layer, decreases oxygen ingress signifi- cantly. To sum up, the best perfor- mance is shown by those bottles which use an active barrier (scaven- ger) additional to the passive barrier which is also acting as a protec- tion layer to prevent the reaction of the scavenger with atmospheric oxygen. A shelf-life of more than 180 days can be reached even when the amount of scavenger has been reduced. www.presens.de www.bericap.com Unique range of light weight screw and sports closures for light weight PET neck standards for water • Closures for all common neck sizes 26/22, 28mm (PCO 1810, PCO 1881), 29/25, 30/25 • Light weight Hexalite range allowing light weight neck • Still water closures suitable for N 2 dosing • Sports closures fulfill BSDA requirements • Boreseal systems for excellent tightness • Consumer friendly opening forces BERI CAP Technology for still water