BOPP film with twice the barrier, but none of the PVdC coating

Plastics processor Toray Plastics (America) Inc. has introduced two new films, both bi-oriented polypropylene, that it says beat other BOPP films on moisture vapor barrier performance. The improved performance does not come with a loss of transparency, so packaged goods' brand appeal is still strong.

The processor, based in North Kingstown, Rhode Island, is a subsidiary of Japan's Toray Industries Inc. New from the company are its Torayfan CBH and CBLH biaxially-oriented clear-barrier polypropylene films, with these designed for use as mono-webs and as alternatives to films coated with polyvidylene chloride (PVdC). PVdC is commonly applied as a water-based coating to plastics films such as BOPP film to increase its barrier properties.

According to Toray, the CBH and CBLH films are twice as effective in protecting against moisture-vapor transmission as standard BOPP films are. The MVTR of the films, at 80G thickness, is typically 0.2g/100sq inches/day versus values double that for standard OPP of the same thickness. Better hermetic seals and improved barrier protection help maintain product freshness and brand integrity. Applications for the new films include baked goods, crackers, cookies, and confectionery items.

The Torayfan CBH film has a low coefficient of friction (CoF) for fast converting on form/fill/seal lines. CBH film does not need an over-lacquer to maintain a low CoF, saving a step in manufacturing. Toray told PlasticsToday that the treated side of the film (non-sealable side) has a static friction of 0.3 and a dynamic friction of 0.2.  CBH film's low seal-initiation temperature (SIT) and broad heat-seal window further expedite processing and manufacturing. The Torayfan CBLH film has the same characteristics as CBH film but has an improved sealant layer for greater seal strength and a better hermetic seal.