Sealing technology manual for the process industry

Washing-out test EPDM/Fluoroprene® XP 40 First rinse cycle EPDM assumed as 100% precleanedEPDM water+80°C(+176°F)EPDM precleanedXP40 water+80°C(+176°F)XP40 100 90 80 70 60 50 40 30 20 10 0 Ester 1 Ester 2 Ester 3 Ester 4 Ketone 1 Ketone 2 Ketone 3 Flavor carry-over Flavor transfer or flavor carry-over is a well-known problem in beverage bottling. The seals absorb the ingredients of the flavoring mixture during the bottling of a flavored drink and gradually release them again during the next bottling process for another product. This may well go unnoticed if the products bottled successively are both flavored and one of the products merely has a slightly stronger raspber- ry taste, for example. It is different when after a slightly flavored water (so-called near-water products), the thus far flavorless mineral water is bottled and the subsequent batch has unintentionally absorbed a peach or cherry fla- vor, for example. In order to find the most suitable mate- rial for this application, different materials were analyzed by Freudenberg with respect to their flavor absorption and release capacity. Studies by Freudenberg related to the flavor carry-over of different materials, such as EPDM, FKM and Fluoroprene® XP, have shown that EPDM materials absorb and release flavor the most. The remigration rate of an EPDM material is 100 times greater than the uptake and release capacity of Fluoroprene® XP. In addition, the fluorinated material does not absorb all the components of the flavor mixture in equal measure. After the investigation, it turned out that the esters present in the flavor mixture could not be de- tected, i.e. that they had been absorbed by Fluoroprene® XP at a small, undetectable rate. However, the ketones migrat- ed into the elastomer matrix and decreased by half after the cleaning step. In bottling establishments where mul- tiple products of different flavor intensity are bottled on the same bottling line, it must be ensured that the quality of the product made remains constant after each produc- tion cycle and is not contaminated by the flavoring agents from the batch that was bottled last. Due to the negligible absorption of flavoring substances, the Fluoroprene® XP materials portfolio qualifies as especially suitable for such applications. APPENDIX PRODUCT PORTFOLIO MATERIALS RESISTANCE & PURITY ENGINEERING PLASTICS ELASTOMERIC MATERIALS TECHNICAL FUNDAMENTALS INTRODUCTION 59

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