barrier

[grigolga]

подскажите, пожалуйста, что означает barrier
PET bottle with barrier
Please give me your input about the PET preforms: shape, content 1L-2L, barrier or non-barrier

[tumanov]

Кажется, ответ можно найти вот тут:

http://www.ptonline.com/articles/200303fa2.html

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Many barrier choices

One of three fundamental ways to build CO2 and O2 barrier into PET bottles is to design a multi-layer structure sandwiching PET structural layers around a core layer or layers containing higher-priced barrier materials. This approach stands to benefit from promising new barrier materials such as nylon-based nanocomposites and “passive-active” barrier systems. The latter are dual-acting formulations of a passive barrier material and an active oxygen scavenger that blocks O2 entry and also absorbs O2 from the head space and contents.

Single-serve juices
Single-serve juices and juice drinks are the largest and fastest-growing sector inbarrier PET containers. (Photo: Amcor)

Surface-coating technologies apply a super-thin barrier to one surface of a monolayer PET bottle. Coating equipment is being tailored for specific barrier needs, throughput rates are soaring, and new machine designs are facilitating integration into existing high-speed filling lines.

The “ideal” route to a barrier PET bottle is a monolayer polyester structure. This approach would require blending a barrier resin or O2 scavenger—or both—with PET. Multi-layer or coating equipment would not be needed, and bottle design freedom would remain unfettered. Yet sources concede that few practical “monolayer solutions” are as yet on the horizon, mainly because suitable materials are high-priced.

About 70% of barrier PET bottles today are multi-layer structures, and the technology has proven itself for a decade in the PET ketchup bottle. “The multi-layer PET food bottle is the optimal solution in barrier performance, functionality, and cost,” asserts John Kermet, marketing and sales v.p. at Kortec Inc., a supplier of coinjection systems for multi-layer preform molding. The company is relocating to a larger production site to meet burgeoning global demand for multi-layer preform systems in beer, tea, juice, and other food markets.

Higher productivity currently favors multi-layer PET containers over coatings. Kortec has just introduced a 72-cavity preform coinjection system that works with the same 300-ton press previously used for 48 cavities (see story on p. 19). Without hurting cycle times, the outcome is 50% more output at 25% additional capital cost. The initial use is a 16-oz CSD bottle with double the CO2 shelf life typical for monolayer PET.

Multi-layer containers can be engineered to survive pasteurization, Kermet adds. Kortec technology is used in one pasteurizable PET beer bottle made by Zhong Fu in China. This is possible due to new bottle design features, processing techniques, and material modifications.
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[tumanov]

http://www.prlog.org/10275084-how-to-improve-barrier-performance-of-pet-bottle-preform.html

[tumanov]

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ET packaging represents 9% of this market characterized by very specific needs: to package beer at the lowest possible cost, with high annual production volumes, in bottle formats up to 2.5 liters, and for a shelf life of less than two weeks on average. For this type of packaging, neither glass nor plastic with barrier coating is necessary. A simple PET bottle is sufficient. The Combi for beer is fully suited to these production requirements.
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