Say cheese! Consumers smile over easy-open pack

Dairy Crest is the largest dairy in the U.K., with leadership positions in all sectors of the dairy market. Serving both the retail grocery trade and major food manufacturers, the dairy has manufacturing and packaging sites throughout the U.K.

At Maelor, in North Wales, Dairy Crest operates one of the most advanced, large-scale cheese packaging plants in the U.K. It is here that the company cuts and packs a wide variety of Dairy Crest cheeses, including the Cathedral City brand.

In order to differentiate its product on the supermarket shelves, Dairy Crest recently introduced a new package style for Cathedral City. Extensive research showed that cheese packs prove to be an irritation to consumers, because they are difficult to open, and it's hard to store unused portions to keep them fresh. In order to develop a new pack that would be more convenient and reusable, Dairy Crest carried out consumer tests before selecting an option offered by Sigpack Systems AG (www.sigpacksystems.com).

The new Cathedral City package is hermetically sealed and offers an easy-to-open wrap that is reclosable. It is now being produced at the Maelor creamery on a semi-automated line that packages up to 150 200-g cheese wedges/min. The entire line, which can also package 400- and 500-g wedges, can be changed over from one size to another in only 10 min.

Matured cheese arrives at the Maelor plant in 20-kg vacuum-packed blocks. These are opened and passed through a cutting wire to form "logs." The logs then pass through another cutter, which calculates where to make further cuts to produce the 200-g cheese wedges that are ready to be packaged.

As the wedges pass down the first part of the Sigpack line, the first cuts are normally rejected, as they are not of sufficient weight, due to the nonuniform nature of the original cheese logs. The remaining wedges pass through an aligning belt, which repositions them. Every second wedge of cheese is then gently rotated 180 deg by a robotic turning arm, specially developed by Sigpack Systems for this application.

The wedges pass along a Model FBP noncontact, in-line feeder with a double-pull nose that provides infeed compensation to position the cheese at even intervals along the line. This accurate spacing is essential to position the cheese wedges for wrapping.

A Model HSF long-dwell wrapping machine wraps the cheese in a hermetically sealed, pillow-pack-style wrap, in a three-side-sealed pouch, with a zipper fastener and easy opening. As the cheese approaches the wrapper, a sensor automatically locates its position and speeds up or slows down the acceleration belt on which it is traveling. This accurately places the cheese wedges in the correct position on the inside of the wrapping film.

The film reels are located under the piece track, and product friction ensures that the cheese is kept in the correct position. As the film passes around the wedges, its top end is both sealed and fitted with a zipper. At this stage, the film is also wrapped around a gas lance, which flushes out any oxygen and fills the pack with a mixture of carbon dioxide and nitrogen. As the now half-formed wrapper slips off the gas lance, it is sealed on both its sides and separated from the next pack by a thin end sealer. The pack is now hermetically sealed and free of oxygen, which prevents the cheese from spoiling in the pack.

At the wrapper exit, the packs are discharged over an air-blast reject station to ensure that only good wraps proceed to downstream packaging, where they are put into cartons and cases for immediate distribution.

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