Paper vertical form-fill-seal system aims for higher speeds

A new paper-only vertical form-fill-seal (VFFS) technology for dry goods, able to produce both gable-top and ‘brick’-type sachets with dust-tight seals, is likely to expand further into windowed options and higher-speed machine versions.

Bosch Packaging Technology has worked with Swedish-based paper supplier BillerudKorsnäs to develop the Sealed Paper Packaging system. This combines reel-fed Axello ZAP paper with a specific hotmelt adhesive and an adapted VFFS machine.

Currently, the system is producing 1kg gable-top bags of sugar at speeds of 40 packs per minute (ppm).

Categories that could benefit include sugar and flour, which already use paper packaging.

But Patrik Bosander, business development director for packaging paper at Billerud, has said that products such as pasta, which typically use film VFFS even though they do not require the barrier, could switch to all-paper.

‘System incorporating windows’

“A lot of pasta brands want the transparency of plastic film,” said Bosander. “Brand-owners have asked about a version of the system incorporating windows, and both Bosch and Billerud are looking at this.”

The first machine was installed in March this year at German sugar producer Pfeifer & Langen.

Product manager Karine Förmer said: “Advantages of the new pack concept are a controlled-tear bag that makes it easy to open, a good surface feel (smooth and matt) and a modern image that appeals to younger target groups.” The pack looks firm and stable on-shelf, she added.

A further module can be added to machines to produce ‘brick’-style bags at similar speeds.

Formability of the paper

Bosander emphasised that the formability of the paper in the machine and the specific surface chemistry that allows the adhesive to do its job were both of critical importance.

Once applied, the hotmelt adhesive is allowed to partially dry before being reactivated for optimum seal strength.

Today’s sugar and flour bagging lines tend to operate a very different system, typically filling three bags at a time and achieving speeds of up to 120ppm this way.

One logical step would be for Bosch to develop a mandrel-style version of the modular system, capable of hitting these higher speeds and so potentially winning new customers in high-volume sugar and flour markets.